Endoglycosidase - Citizendia

An Endoglycosidase is an enzyme that releases oligosaccharides from glycoproteins or glycolipids. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins An oligosaccharide is a Saccharide polymer containing a small number (typically three to ten of component sugars also known as Simple sugars. Not to be confused with Peptidoglycan. Glycoproteins are proteins that contain Oligosaccharide chains ( Glycans) covalently attached Glycolipids are Carbohydrate -attached Lipids. Their role is to provide Energy and also serve as markers for cellular recognition Or it merely cleaves polysacharride chains between residues that are not the terminal residue, although releasing oligosaccharides from conjugated protein and lipid molecules is more common.

It breaks the glycosidic bonds between two sugar monomer in the polymer. A monomer (from Greek mono "one" and meros "part" is a small Molecule that may become chemically bonded to other A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds It is different from exoglycosidase that it does not do so at the terminal residue. A exoglycosidase is a Glycoside hydrolase enzyme which breaks the glycosidic bonds at the terminal residue Hence, it is used to release long carbohydrates from conjugated molecules. If an exoglycosidase were used, every monomer in the polymer would have to be removed, one by one from the chain, taking a long time. An endoglycosidase cleaves, giving a polymeric product.

PROTEIN-x1-x2-x3-x4-x5-x6-x7-x8-x9-x10-x11-. . . -xn

A exoglycosidase would remove each carohydrate monomer (x) one by one from the end, starting at xn, whereas and endogylcosidae can cut at any glycosidic bond (-) and may cleave after a signature 'link oligosaccharide' that links certain carbohydrates to certain proteins.

For more information on linkages to proteins see O- and N- linked glycoproteins

See also