Carbohydrate-active Enzymes

An increasing number of structurally related families of enzymes that degrade, modify, or create glycosidic bonds are being identified and characterized. Davies, et al., estimated that carbo­hydrate-active enzymes represent 1-3% of all proteins encoded by the genomes of most organisms, and identification of 12,000+ open reading frames for glyco­side hydrolases and glycosyl­trans­ferases was projected for 2006.1 Since carbo­hydrate-active enzymes act on the most structurally diverse substrates in nature, the number of enzymes identified from gene sequences will continue to expand. The variety and specificity of carbohydrate-active enzymes reflects the large amount of information coded by the glycan moiety of glycosylated bio­mole­cules and the impact those com­pounds have in the life cycle of complex cells.


The Carbohydrate-Active Enzymes Database (CAZy, www.cazy.org), maintained by Université de Provence/ Université de la Méditerranée, Marseille, France contains information for over 200 families of glycoside hydrolases (glyco­sidases), glycosyltransferases, poly­saccha­ride lyases, and carbohydrate esterases.2


Glycosidases, including endoglycosidases and exoglycosidases, are primarily used in analytical applications and deglycosylation techniques, but innovative preparative applications are emerging. Polysaccharide lyases and carbohydrate esterases are used to degrade glycosaminoglycans and prepare polysaccharide components. Glycosyltransferases are being studied for use in engineering selective glycosylation to improve the therapeutic properties of proteins and antibodies.3-5
For more information on Glycobiology please browse our online Glycobiology Analysis Manual.
References:
1. Davies, G.J., et al., Recent structural insights into the expanding world of carbohydrate-active enzymes, Curr. Opin. Struct. Biol., 15, 637-645 (2005).
2. Coutinho, P.M., and Henrissat, B., Carbohydrate-active enzymes: an integrated database approach. Recent advances in Carbohydrate Bioengineering, Gilbert, H.J., Davies, G., Henrissat, B., and Svensson, B. (eds)., The Royal Society of Chemistry, Cambridge, UK, 3-12 (1999).
3. Shriver Z., et al., Glycomics: a pathway to a class of new and improved therapeutics. Nature Rev. Drug Discov., 3, 863-873 (2004).
4. Hodoniczky, J., et al., Control of recombinant monoclonal antibody effector functions by Fc N-glycan remodeling in vitro. Biotechnol. Prog., 21, 1644-52 (2005).
5. Fujiyama, K., et al., Production of mouse monoclonal antibody with galactose-extended sugar chain by suspension cultured tobacco BY2 cells expressing human β(1,4)-galactosyltransferase. Biochem. Biophys. Res. Commun., 358, 85-91 (2007).