Bacterial display

Bacterial display (or bacteria display or bacterial surface display) is a protein engineering technique used for in vitro protein evolution. Libraries of polypeptides displayed on the surface of bacteria can be screened using flow cytometry or iterative selection procedures (biopanning). This protein engineering technique allows us to link the function of a protein with the gene that encodes it. Bacterial display can be used to find target proteins with desired properties and can be used to make affinity ligands which are cell-specific. This system can be used in many applications including the creation of novel vaccines, the identification of enzyme substrates and finding the affinity of a ligand for its target protein.
Bacterial display is often coupled with magnetic-activated cell sorting (MACS) or fluorescence-activated cell sorting (FACS) techniques. Competing methods for protein evolution "in vitro" are phage display, ribosome display, yeast display, and mRNA display. Bacteriophage display is the most common type of display system used although bacterial display is becoming increasingly popular as technical challenges are overcome. Bacterial display combined with FACS also has the advantage that it is a real-time technique.
History.
Cell display systems were first used in 1985, when peptides were genetically fused with proteins displayed on the M13 bacteriophage. Bacteriophage display is a commonly used cell display system, although it carries limitations in the size of proteins that can be displayed. Bacterial display was then introduced in 1986, allowing the surface display of larger proteins. Bacterial display systems were first introduced by Freudl et al. and Charbit et al. in 1986, when they used bacterial surface proteins OmpA and LamB to display peptides. Freudl et al. fused peptides with linkers with the "ompA" gene, causing the peptides to be expressed in the OmpA proteins. They showed that the proteins were now subject to cleavage by proteinase K. The non-OmpA peptides inserted were therefore a target of proteinase K. Insertion of the foreign peptides did not affect bacterial cell growth. Charbit et al. firstly defined the areas of the LamB protein that were "permissive" for foreign petide insertion ("ie" that did not lead to a complete loss of functionality of the protein). Then, they explored the versatility of the permissive sites (size limit, nature of the epitope...) that were all located in surface-exposed loops of the trimeric outer membrane porin, aiming at developing multivalent live bacterial vaccines (12-15). This was the first evidence of using bacterial surface display techniques to express proteins on the surface of cells, without altering the function of the cell.
Principle.
Peptides are very useful as therapeutic and diagnostic substances. Their use is getting more popular, and display systems offer a useful way to engineer peptides and optimise their binding capabilities. Cells express surface proteins which can be involved in a whole host of responses including recognition of other cells, interaction with other cells, and cell signalling. Many types of bacteria have cell surface proteins such as the enteropathogenic "E. coli" intimin protein which is involved in binding to host cells, or the OmpA protein of "E. coli" cells which is important in keeping the structure of the outer membrane. Many surface proteins are involved in bacterial cell attachment and invasion of the host cell. By using bacterial display, target proteins on the host cell can be identified. These surface proteins need to first be translocated across the bacterial cell membranes from the cytoplasm to the cell surface. Gram-negative bacteria have an additional periplasmic space, which Gram-positive bacteria lack, so they have a harder task of translocating proteins. The display of heterologous proteins on the bacterial cell surface normally requires the fusion of the protein with a surface protein, called a scaffold.
Scaffold.
Scaffolds are used to display the heterologous protein on the bacterial cell surface. There are various scaffolds which have been used such as outer membrane proteins, fimbriae/flagella proteins and CPX (circularly permuted OmpX). The CPX scaffold allows peptide fusion at both termini of the scaffold.
OMPs are common scaffolds for bacterial display. Proteins can also be displayed on the bacterial cell surface through the use of autotransporters. Autotransporters form part of the type V secretion system. They usually have three domains: leader sequence at the N-terminal; central passenger domain; autotransporter domain at the C-terminal. The heterologous protein is inserted at the passenger domain. Another method of heterologous protein fusion is fusion with fimbriae/flagella, which are filamentous protrusions on the cell surface. There are many fimbriae on mainly Gram-negative bacteria, so displaying proteins on fimbriae is advantageous over some other surface proteins which are less numerous. A disadvantage of using fimbriae is that there is a relatively small insert size limit of 10-30 amino acids.
Once the heterologous protein has been fused with the bacterial cell surface protein, it is exposed to either an enzyme, a cell (expressing a target protein) or an antibody (usually fluorescently tagged), depending on the application of the experiment. The sample is then passed through a beam of light during FACS, in a very narrow stream of fluid so that only one cell can pass at a time, and the fluorescence emitted is detected. Information on the size of the cell can be obtained by the scattering of light and if binding of the heterologous protein with the target protein/cell has occurred, there will be more fluorescence emitted.
Applications.
Bacterial surface display can be used for a variety of applications. These include affinity-based screening, antibody epitope mapping, the identification of peptide substrates, the identification of cell-binding peptides and vaccine generation.
Affinity-based Screening.
Screening is used to find the apparent affinities of heterologous proteins displayed on the bacterial cell surface for target proteins. This method is usually combined with FACS, and the addition of a non-fluorescent target protein competitor is beneficial to obtaining more accurate binding affinities. Adding a competitor reduces the chance of target proteins rebinding, which would render the binding affinity less accurate.
Antibody Epitope Mapping.
Antibody epitope mapping is used to find the specificity of an antibody. The epitope (antibody binding site of antigens) is expressed on the bacterial cell surface by expressing a region of the gene encoding the antigen. Flow cytometry with fluorescently-labelled antibodies is used to detect the amount of antibody binding to epitope.
Identification of Peptide Substrates.
This can be applied to find the best substrates for proteolytic enzymes. The substrate is displayed on the bacterial cell surface between an affinity ligand and the scaffold, and the kinetics of substrate proteolysis is measured using FACS.
Identification of Cell-binding Peptides.
Bacterial display can be used to find peptides which bind to specific cells e.g. breast cancer cells or stem cells. Displayed proteins are fluorescently tagged with GFP, so binding interactions between peptides and target cells can be seen by flow cytometry. Control samples are required in order to measure fluorescence levels in the absence of displayed peptides. Samples are also required which don’t contain displayed peptides, but contain mammalian cells and bacterial cells (including the scaffold).
Vaccine Delivery.
Vaccine delivery is a very common application of bacterial surface display. There are two types of live bacterial vaccines that can be made:
Using bacterial surface display of antigens is a valuable alternative to conventional vaccine design for various reasons, one of them being that the proteins expressed on the bacterial cell surface can act favourably as an adjuvant. Conventional vaccines require the addition of adjuvants. Another advantage of generating vaccines using bacterial display systems is that the whole bacterial cell can be incorporated in the live vaccine Unlike bacteriophage display systems which are generally used in vaccine development to find unknown epitopes, bacterial display systems are used to express known epitopes and the cells act as a vaccine delivery system.
Comparison with phage display.
Under similar conditions, selection of bacterial-displayed peptides to model protein streptavidin proved worse.
References.
12. Charbit A, Boulain JC, Ryter A, Hofnung M. Probing the topology of a bacterial membrane protein by genetic insertion of a foreign epitope; expression at the cell surface. EMBO J. 1986 Nov;5(11):3029-37.
13. Charbit A, Sobczak E, Michel ML, Molla A, Tiollais P, Hofnung M. Presentation of two epitopes of the preS2 region of hepatitis B virus on live recombinant bacteria. J Immunol. 1987 Sep 1;139(5):1658-64.
14. Charbit A, Molla A, Saurin W, Hofnung M.Versatility of a vector for expressing foreign polypeptides at the surface of gram-negative bacteria. Gene. 1988 Oct 15;70(1):181-9.
15. Newton SM, Klebba PE, Michel V, Hofnung M, Charbit A. Topology of the membrane protein LamB by epitope tagging and a comparison with the X-ray model. J Bacteriol. 1996 Jun;178(12):3447-56.


CPC Scientific

CPC Scientific is a biotechnology company that manufactures peptides. The company provides a number of products and services to academic researchers and pharmaceutical industries, including research- and GMP-grade custom peptides.
History.
Headquartered in Sunnyvale, California, CPC Scientific was founded in 2001 by Dr. Shawn Lee, Ph.D. Product lines initially included research-grade custom peptides, catalog peptides, and Fmoc-protected amino acids. In 2006, CPC Scientific opened a GMP (Good Manufacturing Practice) facility in Hangzhou, China and began producing GMP-grade peptides for use in clinical applications. By 2011, the GMP facility was inspected by the U.S. Food and Drug Administration (FDA) and the company began supplying pharmaceutical-grade peptides to companies in the United States. On March 17, 2016, CPC Scientific passed a 4th U.S. FDA inspection.
Manufacturing.
CPC Scientific manufactures most of their products by way of solid-phase peptide synthesis, a process originally described by Robert Bruce Merrifield in 1963. Solid-phase synthesis routes enable manufacturing of relatively long peptide sequences by avoiding isolation and purification of synthetic intermediates. This iterative process allows for the preparation of more complex peptides for use as active pharmaceutical ingredients (APIs), novel drug therapeutics, and general research applications. CPC Scientific has published some research articles that describe peptide synthesis methodologies, including a technique called hydrocarbon stapling. Stapled peptides contain a synthetic modification that involves olefin metathesis to stabilize alpha-helix and beta-sheet secondary structures. Products manufactured by CPC Scientific have also been cited in scientific journals.


Adenosylcobinamide-phosphate guanylyltransferase

In enzymology, an adenosylcobinamide-phosphate guanylyltransferase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are GTP and adenosylcobinamide phosphate; its two products are diphosphate and adenosylcobinamide-GDP.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is GTP:adenosylcobinamide-phosphate guanylyltransferase. Other names in common use include CobU, adenosylcobinamide kinase/adenosylcobinamide-phosphate, guanylyltransferase, and AdoCbi kinase/AdoCbi-phosphate guanylyltransferase. This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B12) in bacteria.


IsomiR

isomiRs (from "iso-" + miR) are miRNA sequences that have variations with respect to the reference sequence. The term was coined by Morin "et al" in 2008. It has been found that isomiR expression profiles can also exhibit race, population, and gender dependencies.
There are four main variation types:
Discovery.
miRBase is considered to be the gold-standard miRNA database—it stores miRNA sequences detected by thousand of experiments. In this database each miRNA is associated with a miRNA precursor and with one or two mature miRNA (-5p and -3p). In the past it had always been said that the same miRNA precursor generates the same miRNA sequences. However, the advent of deep sequencing has now allowed researchers to detect a huge variability in miRNA biogenesis, meaning that from the same miRNA precursor many different sequences can be generated potentially have different targets, or even lead to opposite changes in mRNA expression.
Biogenesis.
The advent of sequencing has permitted scientists to elucidate a huge landscape of new miRNAs, to increase our knowledge of the biogenesis involved and to discover putative post-transcriptional editing processes in miRNAs ignored until now. These processes mostly generate variations of the current miRNAs that are annotated in miRBase in the 3' and 5' terminus and in minor frequencies, nucleotide substitution along the miRNA length. The variations are mainly generated by a shift of Drosha and Dicer in the cleavage site, but also by nucleotide additions at the 3'-end, resulting new sequences different from the annotated miRNA. These were named "isomiRs" by Morin et al., 2008. IsomiRs have been well established along different species in metazoa and deeply described for the first time in human stem cells and human brain samples. Moreover, it has been proven that isomiRs are not caused by RNA degradation during sample preparation for next generation sequencing. Some studies have tried to explain the miRNA diversity by structural bases of precursors but without clear results. The functionality of adenylation or uridynilation at the 3'end (3'addition isomiRs) has been related to alterations in the miRNA-3'-UTR stability. Furthermore, isomiRs have been detected deregulated in D. melanogaster development and differential expressed during "Hippoglossus hippoglossus" L. early development, suggesting a biologically relevant function.


Anthony S. Weiss

Anthony Steven Weiss PhD AM FRSC FTSE FRSN FRACI, FTERM, FBSE is a university researcher, company founder and entrepreneur. He is the leading scientist in human tropoelastin research and synthetic human elastin. He holds the McCaughey Chair in Biochemistry, heads the Charles Perkins Centre Node in Tissue Engineering and Regenerative Medicine, and is Professor of Biochemistry and Molecular Biotechnology at the University of Sydney. His discoveries are on human elastic materials that accelerate the healing and repair of arteries, skin and 3D human tissue components. He is a Fellow of the Royal Society of Chemistry. Weiss is on the editorial boards of the American Chemical Society Biomaterials Science and Engineering, Applied Materials Today (Elsevier), Biomaterials, Biomedical Materials, BioNanoScience (Springer) and Tissue Engineering (Mary Ann Liebert, Inc.). He is a biotechnology company founder, promoter of national and international technology development, and has received national and international awards, including the Order of Australia.
His awards include the Eureka Prize for Innovation in Medical Research, Clunies Ross Award, NSW Premier's Prize for Science & Engineering Leadership in Innovation, Innovator of Influence, Applied Research Medal given by the Royal Australian Chemical Institute, Federation of Asian and Oceanian Biochemists & Molecular Biologists Entrepreneurship Award, Australasian Society for Biomaterials & Tissue Engineering Research Excellence Award, and Fulbright Scholar. He was President of the Matrix Biology Society of Australia and New Zealand, elected as Chair Asia-Pacific and the Governing Board of Tissue Engineering and Regenerative Medicine International Society and then elected as global President of the Tissue Engineering and Regenerative Medicine International Society.
Early life and education.
Anthony Weiss was born in Sydney, Australia and received his PhD from the University of Sydney. He was a Fulbright Scholar at Stanford University and NIH Fogarty International Fellow. He is a Fellow of the Royal Society of Chemistry, Fellow of the Australian Academy of Technology and Engineering, Fellow of the Royal Society of NSW, Fellow of the Royal Australian Chemical Institute and Chartered Chemist, Fellow of the American Institute for Medical and Biological Engineering, Fellow of the Australian Institute of Company Directors, Fellow of Tissue Engineering and Regenerative Medicine (FTERM) and Fellow of Biomaterials Science and Engineering.


Butylone

Butylone, also known as β-keto-"N"-methylbenzodioxolylbutanamine (βk-MBDB), is an entactogen, psychedelic, and stimulant psychoactive drug of the phenethylamine chemical class. It is the β-keto (substituted cathinone) analogue of MBDB and the substituted methylenedioxyphenethylamine analogue of buphedrone.
History.
Butylone was first synthesized by Koeppe, Ludwig and Zeile which is mentioned in their 1967 paper. It remained an obscure product of academia until 2005 when it was sold as a designer drug. Butylone shares the same relationship to MBDB as methylone does to MDMA ("Ecstasy"). Formal research on this chemical was first conducted in 2009, when it was shown to be metabolised in a similar manner to related drugs like methylone.
Synthesis.
Butylone can be synthesized in a laboratory via the following route:
3,4-methylenedioxybutyrophenone dissolved in dichloromethane to bromine gives 3′,4′-methylenedioxy-2-bromobutyrophenone. This product was then dissolved in dichloromethane and added to an aqueous solution of methylamine (40%). HCl was then added. The aqueous layer was removed and made alkaline by using sodium bicarbonate. For the extraction of the amine ether was used. To get butylone a drop of ether and HCl solution was added.
Metabolism.
There are three major metabolic pathways of bk-MBDB as shown in the figure. As result of demethylenation followed by O-methylation bk-MBDB metabolises into 4-OH-3-MeO and 3-OH-4-MeO metabolites in human urine. The second pathway is a β-ketone reduction into β-ketone reduced metabolites. The third pathway is a N-dealkylation into N-dealkyl metabolites. The first two pathways occur more than pathway three. The most common metabolite is the 4-OH-3-MeO metabolite. The metabolites containing a hydroxyl-group would be excreted as their conjugates in urine.
Mechanism of action.
Butylone acts in a similar way as MDMA and Methylone, it causes an increase in extracellular monoamine levels.
The following tables lists the half maximal inhibitory and half maximal effective concentrations for norepinephrine, dopamine and serotonin receptors, respectively.
Drug prohibition laws.
China.
As of October 2015 Butylone is a controlled substance in China.
Sweden.
"Sveriges riksdag" added butylone to schedule I ("substances, plant materials and fungi which normally do not have medical use") as narcotics in Sweden as of Feb 1, 2010, published by "Medical Products Agency" in their regulation LVFS 2010:1 listed as Butylon, 1-(1,3-bensodioxol-5-yl)-2-(metylamino)butan-1-on.
United States.
Butylone is also a Schedule I controlled substance under the Controlled Substances Act in the United States.


Mycena maculata

Mycena maculata, commonly known as the reddish-spotted Mycena, is a species of fungus in the family Mycenaceae. The fruit bodies, or mushrooms, have conic to bell-shaped to convex caps that are initially dark brown but fade to brownish-gray when young, reaching diameters of up to . They are typically wrinkled or somewhat grooved, and have reddish-brown spots in age, or after being cut or bruised. The whitish to pale gray gills also become spotted reddish-brown as they mature. The stem, up to long and covered with whitish hairs at its base, can also develop reddish stains. The mycelium of "M. maculata" has bioluminescent properties. The saprobic fungus is found in Europe and North America, where it grows in groups or clusters on the rotting wood of both hardwoods and conifers. The edibility of the fungus is unknown. Although the species is known for, and named after its propensity to stain reddish, occasionally these stains do not appear, making it virtually indistinguishable from "M. galericulata".
Taxonomy and naming.
The species was first described scientifically by the German mycologist Petter Karsten in 1890. The name "Mycena maculata" was also used by the Australian mycologist John Burton Cleland in 1934, but that usage was considered illegitimate, and the species he described has since been renamed to "Mycena austromaculata" by Cheryl Grgurinovic and Tom May in 1997.
The specific epithet "maculata" is derived from the Latin word "spotted". The mushroom is commonly known as the "reddish-spotted Mycena".
Description.
The cap of "M. maculata" varies in shape from broadly conic to convex initially, soon expanding to bell-shaped or broadly convex at maturity; when expanded the cap diameter is typically between . It usually has a distinct umbo, which can be abruptly convex in some individuals and very broad and low in others. The cap margin closely approaches the stem when young, but often flares or curves upward with age. The cap surface is smooth, slimy to the touch, often opaque when young but becomes partially translucent so that the outlines of the gills underneath the cap may be seen nearly to the center, before fading. It is often somewhat wrinkled or has the radial gill grooves deepening with age. It is initially dirty blackish-brown or nearly black, becoming paler dirty brown to brownish-gray with age, and usually with reddish-brown spots. The flesh is somewhat thick under the umbo, but becomes abruptly thinner over the area of the margin (about 0.15 mm). It is cartilaginous and firm, dark or pale watery gray, changing slowly to dirty reddish-brown when cut or bruised. It has no distinguishable odor, and a taste ranging from mild to slightly farinaceous (like flour).
The gills are bluntly adnate, later becoming toothed and somewhat sinuate. The gills are narrow, becoming moderately broad (4–5 mm), whitish to pale gray in color, soon staining with reddish spots. Sometimes the gills separate slightly from the cap, but remain attached to each other to form a collar. The gill spacing is close to subdistant, with about 17–24 gills reaching the stem; there are additionally about three tiers of lamellulae (short gills that do not extend fully from the cap margin to the stem). The stem is usually long and thick, occasionally much longer, often with a long pseudorhiza (a cordlike structure resembling a plant root) that can root into the substrate. The stem is densely covered with sharp, stiff white hairs on the lower portion, and smooth above. It is sometimes twisted, nearly equal in width throughout, hollow, and cartilaginous. The top portion of the stem is pallid, while the remainder is the same color or paler than the cap. The stem base becomes stained reddish-brown to purplish, or the entire lower portion turns a dirty wine red. The edibility of the mushroom is unknown.
Microscopic characteristics.
The spores are ellipsoid, amyloid (meaning they turn bluish-black to black when stained with Melzer's reagent), and measure 7–9 by 4–5 μm. The basidia (spore-bearing cells in the hymenium) are 30–35 by 7–8 μm, and four-spored. The cheilocystidia (cystidia on the gill edge) are embedded in the hymenium and inconspicuous, measuring 20–28 by 6–12 μm. They are irregular in form; some have short rodlike projections on the upper part, others have irregular branched finger-like protuberances, while others have wavy walls and an elongated contorted apex. There are no pleurocystidia (cystidia on the gill face) in "Mycena maculata". The gill tissue is hyaline or very faintly vinaceous-brown when stained in iodine. The cap tissue has a thin pellicle, and the region directly under it is made of hyphae with only slightly enlarged cells, while the remainder is filamentous, and stains yellowish to slightly vinaceous-brown in iodine. The mycelium of "M. maculata" is bioluminescent; this property has not been reported for the fruit bodies.
Similar species.
In the absence of the characteristic reddish staining (particularly in young specimens), "M. maculata" is indistinguishable in the field from "M. galericulata", which also tends to grow in groups or tufts on wood. Microscopically, the latter species has larger spores, ranging from 8–12 by 5.5–9 μm. Another "Mycena" that stains reddish is "M. inclinata"; it can be distinguished by its slightly larger spores, typically 7–9 by 5–6.5 μm, and the white flecks that develop on the lower part of the stem. It is common in eastern North America, and prefers to grows on decaying hardwood. "M. haematopus" also grows in clusters on wood, but can be differentiated by its scalloped cap margin, a stem which bleeds a reddish juice when cut or broken, and a preference for growing on hardwoods. "M. purpureofusca" has a purplish cap, gills with purple edges, and usually grows on pine cones. "M. atrochalybaea", a species known from Italy and Switzerland, has more gills that reach the stem (usually between 30 and 40), smooth hyphae in the cortical layer of the stem, and smooth, uninflated cystidia.
Distribution and habitat.
The fruit bodies of "M. maculata" grow in groups to clumps on the wood and debris of both coniferous and deciduous trees. The fungus is found in North America and Europe (Germany and Norway). The North American distribution ranges north from Quebec, Canada, south to Mexico. "Mycena" specialist Alexander H. Smith, in his 1947 monograph on the genus, called it "the most abundant "Mycena" on conifer wood in the Pacific Northwest." It has also been recorded as a new species in Turkey (Kahramanmaraş district) in 2006.


Cypridina-luciferin 2-monooxygenase

In enzymology, a Cypridina-luciferin 2-monooxygenase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are Cypridina luciferin and O2, whereas its 3 products are oxidized Cypridina luciferin, CO2, and light.
This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O2 as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O with incorporation of one atom of oxygen (internal monooxygenases o internal mixed-function oxidases). The systematic name of this enzyme class is Cypridina-luciferin:oxygen 2-oxidoreductase (decarboxylating). Other names in common use include Cypridina-type luciferase, luciferase (Cypridina luciferin), and Cypridina luciferase.
The primary sequence was determined by cloning the cDNA.


Attenuator (genetics)

In genetics, attenuation is a proposed mechanism of control in some bacterial operons which results in premature termination of transcription and is based on the fact that, in bacteria, transcription and translation proceed simultaneously. Attenuation involves a provisional stop signal (attenuator), located in the DNA segment that corresponds to the leader sequence of mRNA. During attenuation, the ribosome becomes stalled (delayed) in the attenuator region in the mRNA leader. Depending on the metabolic conditions, the attenuator either stops transcription at that point or allows read-through to the structural gene part of the mRNA and synthesis of the appropriate protein.
Attenuation is a regulatory feature found throughout Archaea and Bacteria causing premature termination of transcription. Attenuators are 5'-"cis" acting regulatory regions which fold into one of two alternative RNA structures which determine the success of transcription. The folding is modulated by a sensing mechanism producing either a Rho-independent terminator, resulting in interrupted transcription and a non-functional RNA product; or an anti-terminator structure, resulting in a functional RNA transcript. There are now many equivalent examples where the translation, not transcription, is terminated by sequestering the Shine-Dalgarno sequence (ribosomal binding site) in a hairpin-loop structure. While not meeting the previous definition of (transcriptional) attenuation, these are now considered to be variants of the same phenomena and are included in this article. Attenuation is an ancient regulatory system, prevalent in many bacterial species providing fast and sensitive regulation of gene operons and is commonly used to repress genes in the presence of their own product (or a downstream metabolite).
Classes of attenuators.
Attenuators may be classified according to the type of molecule which induces the change in RNA structure. It is likely that transcription-attenuation mechanisms developed early, perhaps prior to the archaea/bacteria separation and have since evolved to use a number of different sensing molecules (the tryptophan biosynthetic operon has been found to use three different mechanisms in different organisms.)
Small-molecule-mediated attenuation (riboswitches).
Riboswitch sequences (in the mRNA leader transcript) bind molecules such as amino acids, nucleotides, sugars, vitamins, metal ions and other small ligands which cause a conformational change in the mRNA. Most of these attenuators are inhibitory and are employed by genes for biosynthetic enzymes or transporters whose expression is inversely related to the concentration of their corresponding metabolites.
Example- Cobalamine biosynthesis, Cyclic AMP-GMP switch, lysin biosynthesis, glycine biosynthesis, fluroide switch etc.
T-boxes.
These elements are bound by specific uncharged tRNAs and modulate the expression of corresponding aminoacyl-tRNA synthetase operons. High levels of uncharged tRNA promote the anti-terminator sequence leading to increased concentrations of charged tRNA. These are considered by some to be a separate family of riboswitches but are significantly more complex than the previous class of attenuators.
Protein-mediated attenuation.
Protein-RNA interactions may prevent or stabilize the formation of an anti-terminator structure.
Ribosome-mediated attenuation.
In this situation RNA polymerase is dependent on (lagging) ribosome activity; if the ribosome pauses due to insufficient charged tRNA then the anti-terminator structure is favoured. The canonical attenuator example of the "trp" operon uses this mechanism in "E. coli".
RNA thermometers.
Temperature dependent loop formations introduce temperature-dependence in the expression of downstream operons. All such elements act in a translation-dependent manner by controlling the accessibility of the Shine-Dalgarno sequence, for example the expression of pathogenicity islands of some bacteria upon entry to a host. Recent data predict the existence of temperature-dependent alternative secondary structures (including Rho-independent terminators) upstream of cold shock proteins in "E. coli".
Discovery.
Attenuation was first observed by Charles Yanofsky in the trp operon of "E. coli". The first observation was linked to two separate scientific facts. Mutations which knocked out the trp R (repressor) gene still showed some regulation of the trp operon (these mutants were not fully induced/repressed by tryptophan). The total range of trp operon regulation is about 700 X (on/off). When the trp repressor was knocked out, one still got about 10 X regulation by the absence or presence of trp. When the sequence of the beginning of the trp operon was determined an unusual open reading frame (ORF) was seen immediately preceding the ORFs for the known structural genes for the tryptophan biosynthetic enzymes. The general structural information shown below was observed from the sequence of the trp operon.
First, Yanofsky observed that the ORF contained two tandem Trp codons and the protein had a Trp percent composition which was about 10X normal. Second, the mRNA in this region contained regions of dyad symmetry which would allow it to form two mutually exclusive secondary structures. One of the structures looked exactly like a rho-independent transcription termination signal. The other secondary structure, if formed, would prevent the formation of this secondary structure and thus the terminator. This other structure is called the "preemptor".
The "trp" operon.
An example is the "trp" gene in bacteria. When there is a high level of tryptophan in the region, it is inefficient for the bacterium to synthesize more. When the RNA polymerase binds and transcribes the "trp" gene, the ribosome will start translating. (This differs from eukaryotic cells, where RNA must exit the nucleus before translation starts.) The attenuator sequence, which is located between the mRNA leader sequence (5' UTR) and trp operon gene sequence, contains four domains, where domain 3 can pair with domain 2 or domain 4.
The attenuator sequence at domain 1 contains instruction for peptide synthesis that requires tryptophans. A high level of tryptophan will permit ribosomes to translate the attenuator sequence domains 1 and 2, allowing domains 3 and 4 to form a hairpin structure, which results in termination of transcription of the trp operon. Since the protein coding genes are not transcribed due to rho independent termination, no tryptophan is synthesised.
In contrast, a low level of tryptophan means that the ribosome will stall at domain 1, causing the domains 2 and 3 to form a different hairpin structure that does not signal termination of transcription. Therefore, the rest of the operon will be transcribed and translated, so that tryptophan can be produced. Thus, domain 4 is an attenuator. Without domain 4, translation can continue regardless of the level of tryptophan. The attenuator sequence has its codons translated into a leader peptide, but is not part of the trp operon gene sequence. The attenuator allows more time for the attenuator sequence domains to form loop structures, but does not produce a protein that is used in later tryptophan synthesis.
Attenuation is a second mechanism of negative feedback in the trp operon. While the TrpR repressor decreases transcription by a factor of 70, attenuation can further decrease it by a factor of 10, thus allowing accumulated repression of about 700-fold. Attenuation is made possible by the fact that in prokaryotes (which have no nucleus), the ribosomes begin translating the mRNA while RNA polymerase is still transcribing the DNA sequence. This allows the process of translation to directly affect transcription of the operon.
At the beginning of the transcribed genes of the trp operon is a sequence of 140 nucleotides termed the leader transcript (trpL). This transcript includes four short sequences designated 1-4. Sequence 1 is partially complementary to sequence 2, which is partially complementary to sequence 3, which is partially complementary to sequence 4. Thus, three distinct secondary structures (hairpins) can form: 1-2, 2-3 or 3-4. The hybridization of strands 1 and 2 to form the 1-2 structure prevents the formation of the 2-3 structure, while the formation of 2-3 prevents the formation of 3-4. The 3-4 structure is a transcription termination sequence, once it forms RNA polymerase will disassociate from the DNA and transcription of the structural genes of the operon will not occur.
Part of the leader transcript codes for a short polypeptide of 14 amino acids, termed the leader peptide. This peptide contains two adjacent tryptophan residues, which is unusual, since tryptophan is a fairly uncommon amino acid (about one in a hundred residues in a typical E. coli protein is tryptophan). If the ribosome attempts to translate this peptide while tryptophan levels in the cell are low, it will stall at either of the two trp codons. While it is stalled, the ribosome physically shields sequence 1 of the transcript, thus preventing it from forming the 1-2 secondary structure. Sequence 2 is then free to hybridize with sequence 3 to form the 2-3 structure, which then prevents the formation of the 3-4 termination hairpin. RNA polymerase is free to continue transcribing the entire operon. If tryptophan levels in the cell are high, the ribosome will translate the entire leader peptide without interruption and will only stall during translation termination at the stop codon. At this point the ribosome physically shields both sequences 1 and 2. Sequences 3 and 4 are thus free to form the 3-4 structure which terminates transcription. The end result is that the operon will be transcribed only when tryptophan is unavailable for the ribosome, while the trpL transcript is constitutively expressed.
To ensure that the ribosome binds and begins translation of the leader transcript immediately following its synthesis, a pause site exists in the trpL sequence. Upon reaching this site, RNA polymerase pauses transcription and apparently waits for translation to begin. This mechanism allows for synchronization of transcription and translation, a key element in attenuation.
A similar attenuation mechanism regulates the synthesis of histidine, phenylalanine and threonine.
Mechanism in the "trp" operon.
The proposed mechanism of how this mRNA secondary structure and the trp leader peptide could regulate transcription of the trp biosynthetic enzymes includes the following.
The location of ribosomes determines which alternate secondary structures form.
Other operons controlled by attenuation.
The discovery of this type of mechanism to control the expression of genes in a biosynthetic operon lead to its rediscovery in a wide variety of such operons for which repressors had never been discovered. For example:
Attenuation in eukaryotes.
Research conducted on microRNA processing showed an evidence of attenuation process in Eukaryotes. After co-transcriptional endonucleolitical cleavage by Drosha 5'->3' exonuclease XRN2 may terminate further transcription by torpedo mechanism.


FMN adenylyltransferase

In enzymology, a FMN adenylyltransferase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are ATP and FMN, whereas its two products are diphosphate and FAD.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is ATP:FMN adenylyltransferase. This enzyme participates in riboflavin metabolism.
Other names.
Other names in common use include


Guilty Gear Judgment

Guilty Gear Judgment is a 2006 fighting video game developed by Arc System Works and published by Majesco and Sega for the PlayStation Portable handheld game console as an entry in the "Guilty Gear" franchise.
Gameplay.
"Guilty Gear Judgment" consists of a port of "Guilty Gear X2 #Reload" and features a new side-scrolling single-player mode.
Development and release.
Majesco announced it for a spring 2006 release on January 30, 2006.
Reception.
"Guilty Gear Judgment" holds an average score of 74.36% on Game Rankings and 77 out of 100 on Metacritic.
It was nominated for Best of E3 2006 by IGN. GameZone gave it praise as potentially being one of the "hottest" PSP fighting games.


5,6-MDO-MiPT

5,6-MDO-MiPT, or 5,6-methylenedioxy-N-methyl-N-isopropyltryptamine, is a lesser-known psychedelic drug. It is the 5,6-methylenedioxy analog of MiPT. 5,6-MDO-MiPT was first synthesized by Alexander Shulgin. In his book "TiHKAL" ("Tryptamines I Have Known and Loved"), 5,6-MDO-MiPT produces slight paresthesia at low doses. Very little data exists about the pharmacological properties, metabolism, and toxicity of 5,6-MDO-MiPT.


Vladimir Pasechnik

Vladimir Artemovich Pasechnik (12 October 1937 Stalingrad, USSR – 21 November 2001, Wiltshire, England) was a senior Soviet biologist and bioweaponeer who defected to the United Kingdom in 1989, alerting Western intelligence to the vast scope of Moscow's clandestine biological warfare (BW) programme, known as Biopreparat. His revelations that the program was ten times larger than previously suspected were confirmed in 1992 with the defection to the United States of Colonel Kanatjan Alibekov, the No. 2 scientist for the program.
Biography.
A native of Leningrad, many members of Pasechnik's family, including his parents, perished in the Nazi siege of that city during World War II. Pasechnik studied at the Leningrad Polytechnical Institute, where he was one of the institute's brightest stars, graduating at the top of his class. Pasechnik initially specialised in the study of polymers for biological uses at the Institute of High Molecular Compounds in Leningrad. The intent was to develop new antibiotics and other treatments.
In 1974, at the age of 37, Pasechnik was invited by a general from the Soviet Ministry of Defence to start his own biotechnology institute in Leningrad and he was given "an unlimited budget" to buy equipment in the West and recruit the best staff available. The laboratory he created was in reality part of the countrywide Biopreparat program. Known as the Institute of Ultra Pure Biochemical Preparations, it was to work on the "Yersinia pestis" strain of the plague. The laboratory actually began operating in 1981, and over the next two years Pasechnik realised that, far from running a civilian research operation dedicated to vaccine development, as he had been promised, he had become part of a vast network of laboratories and factories involved in a massive BW program.
According to Pasechnik, the Institute, which had a staff of about 400, did research on modifying cruise missiles to spread the plague. The weapons system was to operate by flying low to avoid early-warning systems and use robot craft to spray clouds of aerosolised pathogens over unsuspecting enemies. The team succeeded in producing an aerosolised version of the plague microbe that could survive outside a lab. This version of the organism was genetically-engineered to be resistant to antibiotics.
In the mid-1980s, Pasechnik became increasingly dissatisfied. ("I couldn't sleep at night, thinking about what we were doing," he would tell his British handlers.) He began to plan a defection in 1988, but had never been permitted to travel abroad. His chance came in the summer of 1989, when in recognition of past performance he was allowed to travel to Toulouse to sign the contracts of a pending deal with a French maker of chemical laboratory equipment. Rather than signing, he reported to the British Embassy in Paris. Once revealed, the Soviet government insisted that Pasechnik's research had been intended to defend against acts of biological warfare by an enemy and that the program had been stopped.
In early 1993, the British government permitted Pasechnik to speak publicly. The next year, writer James Adams told Pasechnik's story in a book, "The New Spies". Pasechnik lived in Wiltshire and worked at the UK Department of Health's Centre for Applied Microbiology & Research (CAMR) at Porton Down, near Salisbury, before forming Regma Biotechnologies, which is involved in research into tuberculosis and other drug resistant infections.
Pasechnik died of a stroke in 2001 in Salisbury. He was survived by his wife, Natasha, a daughter and two sons. According to one of his sons, Nikita, he was always expecting the KGB (or the later FSB) to deal with him.


Guilty Gear X

, subtitled By Your Side in Japan, is a fighting game developed by Arc System Works and published by Sammy Studios. The second installment of the "Guilty Gear" series, "Guilty Gear X" was developed over a period of about two years after the first game's success. It was released in July 2000 for Japanese arcades, re-released on Dreamcast in December 2000, and later ported to PlayStation 2 in November 2001 and Game Boy Advance in January 2002.
"Guilty Gear X" continues its predecessor's timeline with new characters and gameplay features. A four-button game, its instant-kill techniques were weakened and a survival mode was added to the previous game's three modes. The Dreamcast and PS2 versions have sold over 100,000 copies in Japan; they have been praised for their graphics, controls and characters but criticized for their lack of replay value. The GBA version was the poorest-received, with the main complaints concerning ease and graphics.
Gameplay.
The fight system has a four-main-attack-button configuration: punch, kick, slash and heavy slash. Players may also launch taunt attacks, with their main objective to reduce the opponent's health to zero in a predetermined time. To win a fight a player must accumulate two points, with each round won earning a point. "Guilty Gear X" has features common in fighting games: combos, aerial attacks and counterattacks. A new feature is the Roman Cancel, which allows a player to cancel their move and its aftereffects to make other attacks.
The game has a tension gauge, increasing when a character causes damage or moves toward an adversary and decreasing when a character moves backwards or is stopped for a long time. When the gauge is half-charged a player can use specials called Overdrive Attacks, which cause more damage than regular moves. A full gauge allows a player to make an Instant Kill, defeating an opponent regardless of health; if an Instant Kill is unsuccessful, the tension gauge will not charge for the remainder of that round.
"Guilty Gear X" Dreamcast version includes four modes of play: Arcade, the game's primary narrative mode; Survival, in which the player fights through infinite levels until they are defeated; Training, which allows a player to practice moves with the help of an in-game move list and Versus, in which a player can fight another player. "Guilty Gear X Plus" also has art-gallery and story modes; according to the Sega website, the latter explains "misteries" which the Dreamcast version does not. The "Advance Edition" includes tag-team and three-on-three modes; each player chooses two or three characters, respectively, and can switch characters during a fight.
Synopsis.
Plot.
In the year of 2181 (22nd century), less than a year after the events of Guilty Gear, reports of a newly discovered commander Gear surfaced. Amid concern about a second war, another Holy Knights Tournament begins; whoever captures and kills Dizzy will receive 500,000 World Dollars. She is defeated, but her life is spared by Sol Badguy, as she proves to be inoffensive. Shortly after, she is found by Ky Kiske, the police chief of the United Nations and ex-chief of the Sacred Order of Holy Knights. He entrusts her care to Johnny and May, members of the Jellyfish Air Pirates, who welcome her as one of their own. Jam Kuradoberi, a bounty hunter and struggling chef, claims the credit for Dizzy's disappearance so she can collect the reward and finance her restaurant.
Characters.
"Guilty Gear X" has sixteen playable characters: Sol Badguy, Ky Kiske, May, Baiken, Faust, Potemkin, Chipp Zanuff, Millia Rage, Zato-1, Jam Kuradoberi, Johnny, Anji Mito, Venom, Axl Low, Testament and Dizzy. Fourteen are available from the outset, with Testament and Dizzy unlockable characters. "Guilty Gear X Plus" adds three unlockable characters: Justice and Kliff Undersn, who return from the first game, and Robo-Ky, an alternate version of Ky Kiske. The "Plus" edition allows a player to unlock gold versions of each character, who possesses a special advantage over the regular version.
Development and release.
After the success of the first "Guilty Gear" released on May 14, 1998 for PlayStation, Sammy Studios commissioned an arcade sequel in February 1999. Developed by Team Neo Blood, an Arc System Works production group led by Daisuke Ishiwatari, the sequel was about two years in development. Unveiled at the Amusement Expo in February 2000, "Guilty Gear X" was released to Japanese arcades on the Sega NAOMI system in July 2000. After the game's release, it was speculated that it would be ported to home consoles. Although the developers initially indicated that "Guilty Gear X" would debut for the PlayStation 2 (PS2), it was first released for Dreamcast on December 14, 2000 and re-released as part of a Dreamcast collection on May 23, 2003.
A PS2 version was announced by Sammy in June 2001 for release that fall, and "Guilty Gear X" was released in North America on October 2, 2001. Since it was released before the Japanese version, the North American edition did not have the additional features of the Japanese counterpart. Sammy released the PS2 version in Japan on November 29, 2001 and in Europe on March 1, 2002. In Japan, it was known as and was released in two versions: regular and deluxe, with the latter containing "Guilty Gear"-related special products. On February 13, 2003, the game was re-released in Japan as part of "PlayStation2 the Best".
CyberFront released a PC version for Windows on November 30, 2001 in Japan. Announced during an August 2001 convention at Space World, Game Boy Advance version was released on January 5, 2002. It was released in North America on August 13, 2002 and in Europe on September 27. "Guilty Gear X ver. 1.5", an Atomiswave arcade-system version, was released only outside of Japan in 2003 after its February 2003 introduction at the Amusement Expo. In 2020, a homebrew conversion of "Guilty Gear X ver. 1.5" was released for the Dreamcast.
Reception.
In June 2001, Sammy reported a profit of ¥284 million for "Guilty Gear X"s Japanese arcade version. In Japan, "Game Machine" listed the game on their September 1, 2000 issue as being the most-successful arcade game of the year. Its Dreamcast version was the 128th-bestselling title in Japan in 2000, with 97,934 copies sold from December 14 to December 31. In 2001 the game sold 33,822 more copies, for a total of 131,756. "Guilty Gear X Plus" sold over 128,000 copies in Japan.
Critical reception for "Guilty Gear X" on Dreamcast and PS2 was positive; they have average scores of 89.33 percent and 79.70 percent, respectively, on GameRankings and Metacritic gave the PS2 version 79 out of 100. Greg Orlando reviewed the Dreamcast version of the game for "Next Generation", rating it four stars out of five, and stated that "X marks the spot for brutality done beautifully." Anoop Gantayat of IGN called the Dreamcast edition "possibly the finest-looking 2D game ever, thanks to the high-res graphics, mega-ultra special effects and smooth animation." According to T.J. Deci of AllGame, the PS2 release is "notable for smooth, refined graphics, with richly detailed characters and backgrounds uncommon in 2D fighters." Although "Guilty Gear X"s overall graphics were praised, its sometimes-confusing backgrounds were heavily criticized.
The Dreamcast version's control responsiveness was praised by Gantayat. "Guilty Gear X"s PS2 version was also generally praised, with Greg Kasavin of GameSpot writing that it "controls smoothly and precisely". Major Mike of "GamePro" included the caveat that "some moves are difficult to execute and require patience to master fully." According to James Fudge for GameSpy, "The gameplay manages to be easy to pick up but isn't dumbed down enough to annoy expert fight fans." "Guilty Gear X"s limited replay value was heavily criticised; Jay Fitzloff of "Game Informer" said, "Since it's especially weak in the singles game, consider purchasing "Guilty Gear X" only if you and a friend want to go at it." The PlayStation 2 version was a runner-up for "GameSpot"s annual "Best Fighting Game" award among console games, losing to "".
The Game Boy Advance version was less well received, with aggregate scores of 64.97 percent and 67 out of 100 from GameRankings and Metacritic respectively. A common criticism was that the game's artificial intelligence was inefficient in combat, making it too easy. Although Chet of "Game Informer" said, "The new modes such as Tag Match and 3-on-3 add variety, but still cannot compensate for this fundamental problem", according to Michael Knutson of GameZone its balance "gives the game a better replay value." Its visual were very criticized; GamesRadar panned "Guilty Gear X"s "overblown aesthetics", giving it the game's worst score (three out of ten): "While it's not completely hellish, it definitely deserves purgatory." According to Star Dingo of "GamePro", "Most backgrounds seem like pale, watercolor imitations of the originals (you can count the colors on two hands)". Justin of "Game Informer" and Kaiser Hwang of IGN criticized the game's sprites, which they considered small compared with those of "".
Its characters were praised as "original" by Justin and "cool" by Kasavin. Gantayat wrote, "It's the characters that stand out the most", calling them "marvelously designed," "unmatched in terms of fine details" and "very distinct." According to Fudge, "There's a character of choice for just about everyone." The characters' balance was praised by Tom Bramwell and Knutson. "Guilty Gear X"s audio had a lukewarm response; according to Chet and Hwang it was "weak", and Dingo called it "atrocious". Mike and Kasavin found the fight announcer's voice "unintelligible", with Mike also criticizing the game's "oppressive" music. Knutson praised "Guilty Gear X"s sound effects and music, and Kasavin considered its music appropriate for "the game's fast-paced action, as well as its anime theme."
Other media.
Music.
"Guilty Gear X"s musical albums were published by First Smile Entertainment. Its arcade music was released on September 20, 2000 as , composed by Daisuke Ishiwatari and arranged by Kazuhito Tomizuka and Yasuharu Takanashi. The album received mixed reviews. Don Kotowski of Square Enix Music Online gave it an eight out of ten: "The improved sound quality is a plus, as are the addition of new character themes, but some people may be put off by the fact that some of the new themes aren't as good as some of the older ones." Another reviewer, GoldfishX, gave it a five, calling it "possibly the most ear-grating, hideous sound I have ever encountered in game music" but not giving it a worse score because "Ishiwatari deserves a ton of credit for putting together such brilliant compositions on such pathetic-sounding hardware."
A second album, "Guilty Gear X Heavy Rock Tracks: The Original Soundtrack of Dreamcast", composed by Ishiwatari and arranged by Koichi Seiyama, was released on January 17, 2001. It was well received by critics, with perfect scores from GoldfishX and Z-Freak of Square Enix Music Online. According to Goldfishx, "Even if you're skeptical about hard rock, this is something that everyone should experience in their lifetime. It's rare to have this type of heart-pounding sound without some form of vocals, but it's even rarer that the compositions reach this overall level of greatness." Z-Freak wrote, "Unless you totally hate hard rock, you have this CD" and David Smith of IGN said that its music would either be loved or hated.
Three albums by the rock band Lapis Lazuli were released on May 6, 2001. Known collectively as "Rising Force of Gear Image Vocal Tracks", the individual albums were entitled "Rock You!!", "Slash!!", and "Destroy!!"
Other.
Enterbrain published several "Guilty Gear X" tie-in books. An encyclopedic strategy guide was published on July 26, 2000, followed by "Drafting Artworks", which is about the game's universe, on December 13. Two novelizations, written by Norimitsu Kaihō and illustrated by Ishiwatari— and —, were published on January 20, 2001 and August 24, 2002.
A "Guilty Gear X" comic anthology was also published by Enterbrain on April 25, 2001. It inspired two "yonkoma" manga and an anthology, which were published by Ichijinsha on March 25, October 25, and September 25, 2001. A manga, with a collaboration by Ishiwatari, Norimitsu Kaihō and Akihito Sumii, appeared in Kodansha's "Monthly Magazine Z" on September 22, 2003. Based on "Guilty Gear X Plus", a two-part anthology was published on February 25 and April 25, 2002 by Enterbrain. Ichijinsha published a "yonkoma" manga and an anthology based on "Plus" on April 8 and 25, 2002.
"Battle for Saint", a compilation DVD with highlights of a "Guilty Gear X" arcade national championship, was released by Enterbrain on August 22, 2001. Two audio drama CDs with original storylines—"Guilty Gear X Vol. 1" and "Vol. 2"—were released by Scitron on October 24 and November 24, 2001. On October 25, 2002, Terranetz released a collectible card game series based on "Guilty Gear X".


Afrosoricida

The order Afrosoricida (a Latin-Greek compound name which means "looking like African shrews") contains the golden moles of Southern Africa, the otter shrews of equatorial Africa and the tenrecs of Madagascar. These three families of small mammals have traditionally been considered to be a part of the order Insectivora, and were later included in Lipotyphla after Insectivora was abandoned as a wastebasket taxon, before Lipotyphla was also found to be polyphyletic.
Naming.
Some biologists use Tenrecomorpha as the name for the tenrec-golden mole clade, but Gary Bronner and Paulina Jenkins argue that Afrosoricida is more appropriate, despite their misgivings about the similarity between the name "Afrosoricida" and the unrelated shrew subgenus "Afrosorex". However, "Afrosorex" Hutterer, 1986 is a synonym of "Crocidura" Wagler, 1832, eliminating any confusion.
Biology.
As a rule, tenrecs and otter shrews tend to be small animals varying from 4 cm to 39 cm in length. There is no pronounced body type since they have evolved to take over the insect-eating niche in Madagascar. However, based on the niche occupied, they look like shrews, hedgehogs or otters. Their coat can vary from smooth to spiny and the coloration of the fur is generally dirt brown. Most species are also nocturnal and have poor eyesight. However, their whiskers are rather sensitive and they can detect very minute vibrations in the ground to locate their prey.
Phylogeny.
Traditionally, these two families were grouped with the hedgehogs, shrews and moles in the Lipotyphla. However, there have always been minority opinions suggesting that Tenrecomorpha, or at least the golden moles, are not true lipotyphlans. These opinions are now supported by many genetic studies indicating an association between Tenrecomorpha and various other African mammals in the superorder Afrotheria. Afrosoricids are sometimes considered part of the Afroinsectiphilia, a clade within Afrotheria.


Athira Pharma

Athira Pharma is a clinical stage American therapeutics company developing regenerative therapies for neurological diseases such as Alzheimer's disease and Parkinson's disease. The company's main product is in very early human studies for Alzheimer's disease as of 2019.
The company was founded in 2011 and is headquartered in Seattle. Funding that supports the company is from both public and private investment groups including the Alzheimer's Drug Discovery Foundation, Dolby Family Ventures, the State of Washington's Life Sciences Discovery Fund, The W Fund, WRF Capital, and other private investors.
Leen Kawas currently serves as the company's President and CEO.
History.
The company has received financial support from venture capitalist groups and angel investors through four rounds of funding to date. Athira Pharma was known as M3 Biotechnology until it underwent a name change on April 11, 2019.
Core technology.
The company's lead asset, NDX-1017, is in very early human trials of Alzheimer's disease as of 2019. It aims to regenerate lost connections in the brain, protect brain cells from further damage, and prevent additional neuronal deterioration.


Mubtakkar

Mubtakkar is an Arabic word () with related meanings that translate into English as "invention", "initiative", or "inventive". The word was reportedly used by Al-Qaeda to describe a poison gas weapon developed and intended for use in an attack in the New York City Subway. According to author Ron Suskind, in his book "The One Percent Doctrine: Deep Inside America's Pursuit of Its Enemies Since 9/11", the plan for this attack was called off about forty-five days before execution by Al-Qaeda commander Ayman al-Zawahiri.
The mubtakkar is described as a small binary chemical device that would generate large amounts of hydrogen cyanide gas, which could potentially kill hundreds in an enclosed space. The components contained in two separate containers would not be lethal to humans if individually released, so these bombs can be assembled, stored, and transported without appreciable danger. However, when the device is put into operation it releases large quantities of a lethal gas.
For further information, see Ron Suskind's "The One Percent Doctrine", p. 192ff.


Merryn Tawhai

Merryn Tawhai is a New Zealand professor, director of MedTech CoRE and Deputy Director of the Auckland Bioengineering Institute, where she was a fellow from 2002. She is known for the development of mathematical models of the lungs that will help scientists understand differences between physiologically normal lungs and the pathological changes that might occur in a disease. She was inducted into the International Academy of Medical and Biological Engineering in June 2018. In November 2018, Tawhai was elected a Fellow of the Royal Society of New Zealand.
Early life.
When Merryn Tawhai was in high school her favorite subjects were mathematics and biology. In 2001 she graduated with a Ph.D. in engineering physics from the University of Auckland, and had two children at the same time.
In 2017, Tawhai was selected as one of the Royal Society Te Apārangi's "150 women in 150 words", celebrating women's contributions to knowledge in New Zealand.


Nell I. Mondy

Nell I. Mondy (October 27, 1921 – August 25, 2005) was an American biochemist known for her expertise regarding the potato. She spent the majority of her profession at Cornell University where in 1953 she earned a PhD in biochemistry and subsequently served as faculty there for nearly fifty years.
In 1997, she received the first Elizabeth Fleming Stier Award.
Biography.
Nell Mondy was born in Pocahontas, Arkansas to her father, Daly (sometimes recorded as Daley) who worked as the county tax assessor and mother, Ethel Caroll Mondy (born February 19, 1889). Her father died of tuberculosis in 1924 when Nell was not yet 3 years old. After his death her mother took up work as a journalist. Ethel Mondy continued to live with Nell throughout the many locations her work took her.
In 1943 she received her undergraduate degree summa cum laude in chemistry at Ouachita Baptist University followed by a master's degree from the University of Texas at Austin two years later. While in Austin she became a member of Iota Sigma Pi. In 1953 she received her Ph.D. in Biochemistry from Cornell University in New York State. She taught at Cornell for 48 years starting as an Associate Professor in Nutrition. Nell never married but always lived with her mother who moved with her to Ithaca where Ethel died in 1972.
In the winter of 1996 at the age of 75 Mondy was attacked by a teenager which left her partially deaf. Due to this incident she became active in victim's rights and elder safety that prompted bills in the New York Senate and Assembly. She championed changes to the support victims receive in terms of restitution, navigating bureaucracy, emotional support, and protection.
Professional Accomplishments.
Nell Mondy left a large body of writing and research behind her. Her work can be found in numerous publications describing a wide range of topics surrounding potatoes such as how the chemical content of potatoes is affected by amendments in soil or in how they are packaged. Her first book was Experimental Food Chemistry, published in 1980.
in 1960 Mondy was instrumental in setting up the first International Food Congress after receiving a NATO Award to go to Scotland and be a part of a seminar on the recent advances in Food Science. In the middle of that decade she worked as a consultant with the R.T. French company, (known today as French's). At Florida State University she worked as a professor of food and nutrition from 1960–1970. Under the US Government she worked for the USDA and from 1979 to 1980 she consulted for the Environmental Protection Agency.
In 2001 she published an autobiography, You Never Fail Until You Stop Trying: The Story of a Pioneer Women Chemist. The book focuses on Dr. Mondy's challenges being a woman in science and her work to improve worldwide food and nutrition, specifically in third world countries.


BOD (psychedelic)

BOD (4-methyl-2,5,β-trimethoxyphenethylamine) is a lesser-known psychedelic drug. It is the beta-methoxy analog of 2C-D. BOD was first synthesized by Alexander Shulgin. In his book "PiHKAL", the dosage range is listed as 15–25 mg, and the duration listed as 8–16 hours. BOD produces strongly distorted open-eye visuals, and some closed-eye visuals. It also has an entheogenic effect and produces humor. Very little data exists about the pharmacological properties, metabolism, and toxicity of BOD.
Legality.
United Kingdom.
This substance is a Class A drug in the Drugs controlled by the UK Misuse of Drugs Act.


BioTork

BioTork is a biotechnology company founded in 2008 that specializes in the optimization of industrial fermentation processes. BioTork provides robust microorganisms that are able to convert low-value, raw carbon sources such as agroindustrial by-products and waste into high-value chemical commodities (e.g.; biofuel and feed). These biochemical commodities such as omega-3 oil, lipids, fuels, enzymes, plastics and other compounds are derived from renewable feedstock using a continuous culture technology.
Technology.
BioTork has an exclusive license with Evolugate, a technology provider specializing in adaptive evolution technology that is a continuous culture apparatus which selects the fittest genetic variants from a certain population under controlled environmental conditions. After multiple stages of natural selection, the microorganisms acquire enhanced capabilities that were not present in the original strain. These new capabilities include a faster growth rate, the ability to grow at non-optimal temperatures, resistance to inhibitors or growth under nutrient limiting conditions
Non-GMO.
The microorganisms that are evolved with Evolugate's technology are done so through natural selection, and therefore are enhanced without genetically modifying their composition. This allows for the microorganism to exist without being labelled as a GMO, and therefore circumvents issues related to food and feed regulations.
Versatile Feedstock.
The technology that BioTork uses through Evolugate is able to convert unrefined, raw feedstock into several high quality resources, as mentioned before including omega-3 fatty acids and renewable chemicals. Raw carbon sources are generally renewable, often coming from biodiesel production or leftover agricultural waste. Therefore, the end-product that BioTork is left with is sustainable and inexpensive, in addition to non-GMO.
Hawaii Zero Waste Program.
BioTork is currently in collaboration with the US Department of Agriculture and Pacific Basin Agricultural Research Center (USDA-PBARC). This collaboration is related to recent legislation passed in Hawaii to promote upcycling of raw materials, or agricultural waste, as part of the Zero Waste initiative. The State of Hawaii has dedicated special purpose revenue bonds of up to $50,000,000 that will be used towards upcycling the unmarketable papayas from the state and convert them into omega-3 fatty acids that can then be refined into commercial fish feed.
Collaboration with BASF.
BASF, The Chemical Company, and BioTork currently have a bioplastics development deal to industrially produce biopolymers and green-based chemicals. The main objective of this collaboration is to improve biochemical production processes through strain development. The financial details of this collaboration and partnership have not been disclosed at this time.


4-HO-EPT

4-HO-EPT (4-hydroxy-"N"-ethyl-"N"-propyltryptamine) is a rarely encountered chemical compound of the tryptamine class, which makes it structurally related to psilocin (4-HO-DMT).


Jerome Hauer

Jerome M. Hauer is the chief executive officer of a consulting firm, The Hauer Group LLC. He has also held several governmental positions related to emergency management in the states of New York and Indiana. He has also worked as a member of the Hollis-Eden Pharmaceuticals board of directors.
Hauer served as Commissioner of Homeland Security and Emergency Services for the government of New York State from October, 2011 until December 2014.
Hauer was the acting assistant secretary for the Office of Public Health Emergency Preparedness (OPHP) within the US Department of Health and Human Services (DHHS). He was appointed by HHS Secretary Tommy G. Thompson on May 5, 2002 and served until replaced on April 28, 2004. In this role, Hauer was responsible for coordinating the country’s medical and public health preparedness and response to emergencies, including acts of biological, chemical and nuclear terrorism.
He was formerly the director of New York City's Office of Emergency Management under mayor Rudy Giuliani from 1996 to 2000. Additionally, he was previously an employee of Kroll Inc. which studied biological terrorism attacks.
Hauer was the director of the Indiana Department of Emergency Management from 1989 to 1993 during the gubernatorial administration of Evan Bayh. Hauer joined IBM in 1993 to manage programs for "Hazardous Materials Response" and "Crisis Management and Fire Safety". For his production of related training videos he received the "International Film and TV Critics of New York Bronze award" in 1996. In the early 1990s he received a master's degree in emergency medical services from the Johns Hopkins University School of Hygiene and Public Health (now known as the Johns Hopkins School of Public Health) and later became a member of the Johns Hopkins Working Group on Civilian Bio Defense. He wrote several articles on possible bio terrorist attacks. On April 10, 1998 Hauer attended a "roundtable on genetic engineering and biological weapons" under President Bill Clinton. Hauer holds a Ph.D. from the Defence Academy of the United Kingdom, Cranfield University.
Hauer was known for his pioneering work on autotransfusion in cardiac surgery and trauma. In 1978 Hauer developed the first unit to reinfuse blood lost following cardiac surgery, reducing the risk of hepatitis. That work reduced before morbitiy and mortality in these patients. He was issued a patent for his device. Before he became a Giuliani commissioner he had previously run emergency management programs for the State of Indiana and IBM.
On September 11, 2001, Jerome Hauer was a national security advisor with the Department of Health and Human Services, a managing director with Kroll Associates, and a guest on national television, because of his background in counter-terror and his specialized knowledge of biological warfare.
New York City Office of Emergency Management.
Jerome M. Hauer was the first director of Mayor Giuliani's Office of Emergency Management. He directed the agency since 1996, when Giuliani shifted responsibility for the city's emergency preparedness from the police department to the new agency – headed by Hauer.
Giuliani and Hauer began their relationship in January 1996 when Hauer was hired to lead the new Office of Emergency Management, created to coordinate the city’s response to crises.
Jerome Hauer is best known for being the director of the New York City Office of Emergency Management (NYC OEM) when he made the decision to build a $13 million crisis center on the 23rd floor at 7 World Trade Center. This crisis center was unveiled in June 1999, and became the subject of tension between the agency and the police department, whose own command center at 1 Police Plaza had until then been the focus of emergency preparedness operations.
As the first director of the new crisis center, "one of Hauer’s first tasks was to find a home for an emergency command center to replace the inadequate facilities at police headquarters," according to the Times. The site selected, was immediately controversial because it was part of the World Trade Center complex (although not in one of the Twin Towers), which had already been the location of a truck bomb attack in 1993. City officials, though, including Hauer, have long defended their decision, even after the command center had to be evacuated during the 2001 terror attack. The Emergency Operation Center was widely hailed as the finest such facility in the nation, receiving visitors from around the world and serving as a model for others. A memo revealed by Chris Wallace on Fox news showed that Hauer wanted to put the command center in Brooklyn but was forced by Guilliani to put the facility within walking distance of City Hall.
The center was destroyed when the 47-story tower collapsed at about 5:25 p.m. on 9-11.


APC internal ribosome entry site (IRES)

The APC internal ribosome entry site (IRES) is an RNA element which is located in the coding sequence of the APC gene. APC is a tumour suppressor gene which is associated with the inherited disease adenomatous polyposis coli (APC). It is thought that IRES-mediated translation of APC is important for an apoptotic cascade.


William Sharp (scientist)

William Sharp is a biotechnologist and entrepreneur, who holds a PhD in plant cell biology from Rutgers University. He is well known for his application of science into business, creating both start up companies and extensive technology transfer experience across the Americas and Asia in a broad sector of business ventures.
Papers.
Sharp has authored over seventy original research papers, abstracts and books in the field of plant cell biology including co-editing Plant Cell and Tissue Culture, The Ohio State University Press, Columbus, Ohio 1977 the five volume series entitled the Handbook of Plant Cell Culture, Volumes 1-5, MACMILLIAM Publishing Company, New York 1983-1986)and Reflections & Connections and Personal Journeys Through The Life Sciences, Volumes I & II, ScienceTechPublishers, LLC, Lewes, Delaware 2014.
Positions.
Sharp serves as a member of The Ohio State University College of Arts and Sciences Advisory Committee, the Ohio state University STEAM Factory, and the Ohio State University, Rutgers University, and University of São Paulo Tripartite Collaborative Program.
Sharp was the former Professor and Dean of Research at Cook College; Director of Research at New Jersey Agricultural Experiment Station at Rutgers University, Executive Vice-President of DNA Pharmaceuticals Inc., Executive Vice-President for Research at DNA Plant Technology Corp, Research Director at Pioneer Research, Campbell Institute for Research & Technology, the Campbell Soup Company a Full Professor at the Ohio State University, Visiting Professor, Center for Nuclear Energy in Agriculture, University of São Paulo, and Fellow of the Argonne National Laboratory.
Achievements.
Sharp was a Fulbright Grantee during 1971 and 1973. He received the distinctive honor of having the Rod Sharp Professor of Microbiology, Ohio State University and the William "Rod" Sharp Biotechnology Conference Room, University of São Paulo named for him, recipient of the University of São Paulo Eminent Professorship and the Luiz Queiroz Distinguished Service Medal award from the University of São Paulo.
Sharp was awarded The Board of Trustees Distinguished Service Award in recognition for his contributions to the Colleges of Arts and Sciences from The Ohio State University by President Gordon Gee at graduation commencement on December 9, 2007 and more recently the College of Arts and Sciences 2016 Alumni Distinguished service Award.
Sharp continues to mentor and advise his former students.
Sharp is the father of Integrated Media Executive and Film Producer, Jeff (Jeffrey) Sharp .President & CEO, Sharp Independent Films, Beverley Hills, CA.


MSCRAMM

MSCRAMM (acronym for "microbial surface components recognizing adhesive matrix molecules") adhesin proteins mediate the initial attachment of bacteria to host tissue, providing a critical step to establish infection.
Examples include protein A, clumping factor A (ClfA), fibronectin binding protein A (FnbpA) from "Staphylococcus aureus", SdrG from "Staphylococcus epidermidis", M protein from "Streptococcus pyogenes", and protein G in other "Streptococcus" species. All of these MSCRAMMs bind to fibrinogen except protein A, that binds IgG, but also other targets for MSCRAMMs are known, such as fibronectin. Protein M binds to the Fc region of certain antibodies.
The MSCRAMMs have mainly been studied in Gram positive pathogens and are promising drug targets.
The monoclonal antibody tefibazumab targets ClfA and has been tested in a phase II trial.
Staphylococcus aureus
An example for MSCRAMMs is "S. aureus". On its surface, protein A is expressed, which binds to the Fc region of IgG antibodies (the default antibody type, dealing with bacterial and viral infections). This has an antiphagocytic effect, i.e. macrophages cannot "see" these bacteria as easily as if they were correctly opsonised by antigen. Also, "S. aureus" expresses fibronectin-binding proteins, which promote binding to mucosal cells and tissue matrices. This protein is also referred to as clumping factor.


Physical mapping

Physical map is a technique used in molecular biology to find the order and physical distance between DNA base pairs by DNA markers. It is one of the gene mapping techniques which can determine the sequence of DNA base pairs with high accuracy. Genetic mapping, another approach of gene mapping, can provide markers needed for the physical mapping. However, as the former deduces the relative gene position by recombination frequencies, it is less accurate than the latter.
Physical mapping uses DNA fragments and DNA markers to assemble larger DNA pieces. With the overlapping regions of the fragments, researchers can deduce the positions of the DNA bases. There are different techniques to visualize the gene location, including somatic cell hybridization, radiation hybridization and "in situ" hybridization.
The different approaches to physical mapping are available for analyzing different sizes of genome and achieving different levels of accuracy. Low- and high-resolution mapping are two classes for various resolution of genome, particularly for the investigation of chromosomes. The three basic varieties of physical mapping are fluorescent "in situ" hybridization (FISH), restriction site mapping and sequencing by clones.
The goal of physical mapping, as a common mechanism under genomic analysis, is to obtain a complete genome sequence in order to deduce any association between the target DNA sequence and phenotypic traits. If the actual positions of genes which control certain phenotypes are known, it is possible to resolve genetic diseases by providing advice on prevention and developing new treatments.
Low-resolution mapping.
Low-resolution physical mapping is typically capable of resolving DNA ranging from one base pair to several mega bases. In this category, most mapping methods involve generating a somatic cell hybrid panel, which is able to map any human DNA sequences, the gene of interest, to specific chromosomes of animal cells, such as those of mice and hamsters. The hybrid cell panel is produced by collecting hybrid cell lines containing human chromosomes, identified by polymerase chain reaction (PCR) screening with primers specific to the human sequence of interest as the hybridization probe. The human chromosome would be presented in all of the cell lines.
There are different approaches to producing low-resolution physical mapping, including chromosome-mediated gene transfer and irradiation fusion gene transfer which generate the hybrid cell panel. Chromosome-mediated gene transfer is a process that coprecipitates human chromosome fragments with calcium phosphate onto the cell line, leading to a stable transformation of recipient chromosomes retaining human chromosomes ranging in size from 1 to 50 mega base pairs. Irradiation fusion gene transfer produces radiation hybrids which contain the human sequence of interest and a random set of other human chromosome fragments. Markers from fragments of human chromosome in radiation hybrids give cross-reactivity patterns, which are further analyzed to generate a radiation hybrid map by ordering the markers and breakpoints. This provides evidence on whether the markers are located on the same human chromosome fragment, and hence the order of gene sequence.
High-resolution mapping.
High-resolution physical mapping could resolve hundreds of kilobases to a single nucleotide of DNA. A major technique to map such large DNA regions is high resolution FISH mapping, which could be achieved by the hybridization of probes to extended interphase chromosomes or artificially extended chromatin. Since their hierarchic structure is less condensed comparing to prometaphase and metaphase chromosomes, the standard "in situ" hybridization target, a high resolution of physical mapping could be produced.
FISH mapping using interphase chromosome is a conventional "in situ" method to map DNA sequences from 50 to 500 kilobases, which are mainly syntenic DNA clones. However, naturally extended chromosomes might be folded back and produces alternative physical map orders. As a result, statistical analysis is necessary to generate the accurate map order of interphase chromosomes.
If artificially stretched chromatin is used instead, mapping resolutions could be over 700 kilobases. In order to produce extended chromosomes on a slide, direct visual hybridization (DIRVISH) is often carried out, that cells are lysed by detergent to allow DNA released into the solution to flow to the other end of the slide. An example of high resolution FISH mapping using stretched chromatin is extended chromatin fiber (ECF) FISH. The method suggests the order of desired regions on the DNA sequence by analyzing the partial overlaps and gaps between yeast artificial chromosomes (YACs). Eventually, the linear sequence of the interested DNA regions could be determined. One more to note is that if metaphase chromosome is used in FISH mapping, the resolution resulted will be very poor, which is to be classified to low-resolution mapping rather than a high-resolution mapping.
Restriction site mapping.
Restriction mapping is a top-down strategy that divides a chromosome target into finer regions. Restriction enzymes are used to digest a chromosome and produce an ordered set of DNA fragments. It involves genomic fragments of the target rather than cloned fragments in the library. They will be pinned to probes from the genomic library that are chosen randomly for detection purpose. The lengths of the fragments are measured by electrophoresis, which can be used to deduce their distance along the map according to the restriction site, the markers of a physical map. The progress involves combinatorial algorithms.
During the progress, a chromosome is obtained from a hybrid cell and cut at rare restriction site to produce large fragments. The fragments will be separated by size and undergo hybridization, forming the macrorestriction map and different contiguous blocks (i.e. contigs). To ensure the fragments are linked, linking clones with the same rare cutting sites at the large fragments can be used.
After producing the low-resolution map, the fragments can be cut into smaller sections by restriction nucleases for further analysis to produce a map with higher resolution. PFG fractionation can be used for separation and purification of the fragments generated for small genome.
Through different digestion approaches, different types of DNA fragments are produced. The variation in types of fragments might affect the calculation result.
Double digestion.
It uses two restriction enzymes and a combination of the two enzymes for digestion separately. It assumes that complete digestion occurs at each restriction site. The lengths of the DNA fragments are measured and used for ordering of fragments by computation. This approach is easier to handle for the experiment but more difficult to solve when dealing with the combinatorial problem required for mapping.
Partial digestion.
It uses one restriction enzyme to digest the desired DNA in separated experiments with different duration of exposure. The extent of digestion for the fragments is different. DNA methylation is a technique to that prevent the reaction at cutting sites to be completed. This method requires more care to the experiment. However, its mathematical problem can be solved by easy exponential algorithm.
Sequencing by clones.
Using clones to generate a physical map is a bottom-up approach with fairly high resolution. It uses the existing cloned fragments in genomic libraries to form contigs. Through cloning the partially digested fragments generated by bacterial transformation, the immortal clones with overlapping regions of the genome, which will be examined by fingerprinting methods and stored in the libraries, are produced. During sequencing process, the clones are randomly selected and placed on a set of microtitre plates randomly. They will be fingerprinted by different methods. To ensure there is a minimum set of clones that form one config for a genome (i.e. tiling path), the library used will have five to ten times redundancy. However, such techniques might produce unknown gaps in the map produced or result in saturation in clones eventually.
Application.
Physical mapping is a technique to complete the sequencing of a genome. Ongoing projects that determine DNA base pair sequences, namely the Human Genome Project, give knowledge on the order of nucleotide and allow further investigation to answer genetic questions, particularly the association between the target sequence and the development of traits. From the individual DNA sequence isolated and mapped in physical mapping, it could provide information on the transcription and translation process during development of organisms, hence identifying the specific function of the gene and associated traits produced. As a result of understanding the expression and regulation of the genes, potential new treatments can be developed to alter protein expression patterns in specific tissues. Moreover, if the location and sequence of disease genes are identified, medical advice can be given to potential patients who are the carrier the disease gene, with reference to the knowledge of the gene function and products.


Protein S (Myxococcus xanthus)

Protein S is a protein found in "Myxococcus xanthus". Its name derives from being the "S" band in an alphabetical ordering of proteins run from Myxococcus xanthus cell contents on a SDS-denaturing gel. Its study was initially prompted by the huge increase in Protein S production during sporulation of Myxococcus xanthus.
Function.
Though it has been purported as recently as 1994 that Protein S enables myxospores of Myxococcus xanthus higher resistance to endure heating, desiccation, UV radiation and sonication no such evidence exists. The work that cites claims no such evidence:
and there are other studies that also found that there is no increase in resistance when Protein S is eliminated.
Structure.
Overview.
Protein S is structured into two domains. The two domains are highly homologous and have a Greek key structure. The domains share high similarity with other crystallin proteins.
Binding Site.
Protein S binds two 2 mol of calcium per mol of protein with a binding dissociation constant of 27 and 76 μM according to dialysis experiments. In the same study mutagenesis experiments revealed arginine replacements to residue 40 or residue 129 can reduce the binding affinity. Since then, an NMR structure determine positions for the two binding sites at residues 10 and 71 and also at residues 99 and 159. However, these binding sites were based on a cluster analysis of side-chain oxygen atoms and on results from site-directed mutagenesis studies and not yet experimentally verified. More recently, an X-ray crystal structure on the truncated N-terminal domain revealed crystallographic evidence of two binding sites in the N-terminal domain. These binding sites are at residues 7,37,39 and 76 as well as at residues 36,77, and 79, which agree with the mutagenesis experiments. However, if the N-terminal domain can bind two Ca2+ then either only the N-terminal domain binds calcium, or, the full Protein S can bind more than two mol of calcium per mol of protein. Since both these claims have been experimentally shown to not be true then the exact binding site of Protein S cannot yet fully be described.


Psychrobacter okhotskensis

Psychrobacter okhotskensis is a Gram-negative, catalase- and oxidase-positive, aerobic, facultatively psychrophilic, nonmotile bacterium of the genus "Psychrobacter", which was isolated from seawater of the Monbetsu coast of the Okhotsk Sea in Hokkaido in Japan.


Carnobacterium pleistocenium

Carnobacterium pleistocenium is recently discovered bacterium from the arctic part of Alaska. It was found in permafrost, seemingly frozen there for 32,000 years. Melting the ice, however, brought these extremophiles back to life. This is the first case of an organism "coming back to life" from ancient ice. These bacterial cells were discovered in a tunnel dug by the Army Corps of Engineers in the 1960s to allow scientists to study the permafrost in preparation for the construction of the Trans-Alaska pipeline system.
The discovery of this bacterium is of particular interest for NASA, for it may be possible for such life to exist in the permafrost of Mars or on the surface of Europa. It is also of interest for scientists investigating the potential for cryogenically freezing life forms to reduce the transportation costs (in terms of life support systems) that would be associated with long-duration space travel.