flow out, and water from the surrounding tissue enters. The loss of important small molecules to the cell can disrupt protein synthesis and other crucial cellular reactions. The loss of ions, especially calcium, can cause cell signaling pathways to be spuriously activated or deactivated. The uncontrolled entry of water into a cell can cause the cell to swell up uncontrollably: this causes a process called blebbing, wherein large parts of the cell membrane are distorted and give way under the mounting internal pressure. In the end, this can cause the cell to burst. In particular, nuclear - free erythrocytes under the influence of alpha-staphylotoxin undergo hemolysis with the loss of a large protein hemoglobin. Binary toxins There are many different types of binary toxins. The term binary toxin simply implies a two part toxin where both components are necessary for toxic activity. Several β-PFTs form binary toxins. As discussed above, the majority of the Toxin_10 family proteins act as part of binary toxins with partner proteins that may belong to the Toxin_10 or other structural families. The interplay of the individual components has not been well studied to date. Other beta sheet toxins of commercial importance are also binary. These include the Cry23/Cry37 toxin from Bacillus thuringiensis. These toxins have some structural similarity to the Cry34/Cry35 binary toxin but neither component shows a match to established Pfam families and the features of the larger Cry23 protein have more in common with the Etx/Mtx2 family than the Toxin_10 family to which Cry35 belongs. Enzymatic binary toxins Some binary toxins are composed of an enzymatic component and a component that is involved in membrane interactions and entry of the enzymatic component into the cell. The membrane interacting component may have structural domains that are rich in beta sheets. Binary toxins, such as anthrax lethal and edema toxins (Main article: Anthrax toxin), C. perfringens iota toxin and C. difficile cyto-lethal toxins consist of two components (hence binary): an enzymatic component – A a membrane-altering component – B In these enzymatic binary toxins, the B component facilitates the entry of the enzymatic 'payload' (A subunit) into the target cell, by forming homooligomeric pores, as shown above for βPFTs. The A component then enters the cytosol and inhibits normal cell functions by one of the following means: ADP-ribosylation ADP-ribosylation is a common enzymatic method used by different bacterial toxins from various species. Toxins such as