In another recent study, Blaum et al. examined the pentasaccharide glycan component of ganglioside GM1, a membrane-bound ligand for a range of proteins, including those of viruses and bacteria. In their work, they identified an alternative conformation of GM1, exhibited in its complex with a 155 kDa protein, Factor H. Subsequent long time scale MD simulations (10 s) of GM1 in explicit solvent identified this structure as a secondary low-lying minimum on the free energy surface. Interestingly, this alternative conformation of GM1, although consistent with NMR data from a prior combined NMR/modelling study, did not correspond to a good set of NOE restraints and thus had not been reported. The Lewis blood group oligosaccharides constitute key mediators of biomolecular recognition. This blood group mainly consists of six oligosaccharides (Figure ), all of which share a common trisaccharide core comprising galactose (Gal), N-acetylglucosamine (GlcNAc) and fucose (Fuc) residues. The six Lewis sugars are divided into two types, I and II, based on the linkage configuration of this core. For type I Lewises, the core trisaccharide is Gal13)(Fuc14))GlcNAc, denoted Le a (Figure ); this can be further sialylated (sLe a , Figure ) or fucosylated (Le b , Figure ). For type II sugars, the glycosidic linkage connectivity of the core trisaccharide is interchanged to give Gal14)(Fuc13))GlcNAc, known as Le x (Figure ); as for Type I Lewises, this can be further sialylated (sLe x , Figure ) or fucosylated (Le y , Figure ). While important contributors to normal physiological function, the Lewis oligosaccharides have also been associated with several disease states due to their role in the immune system, including pathogenic inflammatory response and carcinomas. Characterising their conformational behavior is therefore useful in further understanding their role in these disease states and potentially assisting in the development of novel therapeutics.