Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lectin IV of Griffonia simplicifolia (Mr approximately 56,000), which has a strong affinity for both the Lewis b and Y blood-group determinants, is a dimeric protein of two subunits, alpha (29 kDa) and beta (27 kDa), separable by SDS/PAGE and containing covalently linked oligosaccharide. After digestion with N-glycanase, the protein migrates as a single band with a mobility identical with that of the beta-subunit. After cleavage with hydroxylamine of 3H-labelled, but otherwise intact, lectin, the radioactively labelled oligosaccharide was found to be associated with two blocked N-terminal peptides separable by h.p.l.c. and having identical amino acid compositions. One of these had three or four glucosamine residues per molecule, whereas the other had only one or two. Sequence analyses of these, as well as of a 21 kDa hydroxylamine-cleaved fragment and of the intact lectin pretreated with pyroglutamate aminopeptidase, have provided a unique sequence for residues 1-62 of the two subunits. Evidence is presented for two sites of N-linked oligosaccharide attachment at Asn-5 and Asn-18. Whereas the alpha-subunit has oligosaccharide linked to both sites, the beta-subunit has carbohydrate associated with only one (Asn-18). Sugar analyses of the whole lectin reveal a monosaccharide composition of (Xyl)3(Fuc)2(Man)10(GlcNAc)6, representing 6.4% of the mass of the molecule. Taken together with the susceptibility of the Asn-5 linkage (but not of Asn-18) to N-glycanase digestion, the observations indicate that the structures of the oligosaccharides at residues 5 and 18 are different.
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PMID:Molecular-mass heterogeneity of Griffonia simplicifolia lectin IV subunits. Differences in the oligosaccharide moieties in the N-terminal region. 226 64

Selective enrichment of glycopeptides from complex sample followed by cleavage of N-glycans by PNGase F to expose an easily detectable mark on the former glycosylation sites has become the popular protocol for comprehensive glycoproteome analysis. On account of the high enrichment specificity, hydrazide chemistry based solid-phase extraction of N-linked glycopeptides technique has sparked numerous interests. However, the enzymatic release of glycopeptides captured by hydrazide beads through direct incubation of the beads with PNGase F is not efficient due to the inherent steric hindrance effect. In this study, we developed a hydroxylamine assisted PNGase F deglycosylation (HAPD) method using the hydroxylamine to release glycopeptides captured on the hydrazide beads through the cleavage of hydrazone bonds by transamination followed with the PNGase F deglycosylation of the released glycopeptides in the free solution. Because of the homogeneous condition for the deglycosylation, the recovery of deglycosylated peptides (deglycopeptides) was improved significantly. It was found that 27% more N-glycosylation sites were identified by the HAPD strategy compared with the conventional method. Moreover, the ratio of identified N-terminal glycosylated peptides was improved over 5-fold.
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PMID:Highly Efficient Release of Glycopeptides from Hydrazide Beads by Hydroxylamine Assisted PNGase F Deglycosylation for N-Glycoproteome Analysis. 2639 94