Some characteristics of a new glycopeptidase acting on aspartylglycosylamine linkages.
A new type of glycopeptidase hydrolyzing beta-aspartylglycosylamine linkages was partially purified from almond emulsin by chromatography on Sephadex G-200 and DE 52. The enzyme degraded stem bromelain glycopeptide, Asn-Asn(Man3,Xyl1,Fuc1,GlcNAc2)-Glu-Ser-Ser, to yield equimolar amounts of intact oligosaccharide, peptide (Asn-Asp-Glu-Ser-Ser), and ammonia. The Km value for the stem bromelain glycopeptide was 4 mM, and the optimum pH was 5.2. The enzyme was markedly inhibited by 10 mM Cu2+, Fe3+, and Zn2+. Thiol inhibitors and actinomycete protease inhibitors had no effect. The glycopeptides used as substrates were prepared from stem bromelain, ovalbumin or ovotransferrin. The enzyme hydrolyzed glycopeptides with 3-11 amino acid residues, whereas it did not hydrolyze glycopeptides with 1-2 amino acid residues. Furthermore, Asn-oligosaccharide was not inhibitory to the enzyme.
D000117:Acetylglucosamine / Q000031:analogs & derivatives; D000581:Amidohydrolases / Q000378:metabolism*; D001224:Aspartic Acid / Q000031:analogs & derivatives; D006020:Glycopeptides; D007700:Kinetics; D010940:Plant Proteins; D013379:Substrate Specificity
D006020:Glycopeptides; D010940:Plant Proteins; D001224:Aspartic Acid; D000581:Amidohydrolases; D000117:Acetylglucosamine