Oligosaccharide Accessibility to peptide:N-glycosidase as Promoted by Protein-Unfolding Reagents

摘要: The ability of almond emulsion peptide:N-glycosidase to remove oligosaccharide chains from intact glycoproteins was studied. Protein conformation appeared be the main factor affecting carbohydrate removal. In native state oligosaccharides ribonuclease B and Fab mu fragment derived immunoglobulin M were completely resistant enzyme, indicating that polypeptide chain restricts access site hydrolysis. Heat denaturation in sodium dodecyl sulfate rendered these susceptible peptide:N-glycosidase, but perturbation with chaotropic salts provided a more gentle approach, which as effective detergent-unfolding compatible stability enzyme. Once exposed by unfolding reagents, complex released rapidly than high mannose B, consistent their preferential release small glycopeptides (Plummer, T. H., Jr., Tarentino, A. L. (1981) J. Biol. Chem. 256, 10243-10246).