title: Misfolding of glycoproteins is a prerequisite for peptide: N-glycanase mediated deglycosylation.
abstract: Peptide:N-glycanase (PNGase) is a deglycosylating enzyme that catalyzes the hydrolysis of the beta-aspartylglycosylamine bond of aspargine-linked glycopeptides and glycoproteins. Earlier studies from our laboratory indicated that PNGase catalyzed de-N-glycosylation was limited to glycopeptide substrates, but recent reports have demonstrated that it also acts upon full-length misfolded glycoproteins. In this study, we utilized two glycoprotein substrates, yeast carboxypeptidase and chicken egg albumin (ovalbumin), to study the deglycosylation activity of yeast PNGase and its mutants. Our results provide further evidence that PNGase acts upon full-length glycoprotein substrates and clearly establish that PNGase acts only on misfolded or denatured glycoproteins.
authors.affiliation: Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY 11794-5215, USA.
authors.forename: Shivanjali
authors.initials: S
authors.lastname: Joshi
authors.forename: Samiksha
authors.initials: S
authors.lastname: Katiyar
authors.forename: William J
authors.initials: WJ
authors.lastname: Lennarz
mesh_terms: D002384:Catalysis; D002942:Circular Dichroism; D006031:Glycosylation; D006868:Hydrolysis; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / Q000378:metabolism*; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary
chemical_list: D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase