title: A neutral glycoprotease of Pasteurella haemolytica A1 specifically cleaves O-sialoglycoproteins.
abstract: A neutral metalloprotease with marked specificity for an O-sialoglycoprotein has been isolated from culture supernatants of Pasteurella haemolytica A1. The 35-kDa enzyme cleaves human erythrocyte glycophorin A, which is O glycosylated, but does not cleave N-glycosylated proteins or nonglycosylated proteins. Glycophorin A was cleaved when it was present in situ in erythrocyte ghost plasma membranes or when it was free in solution. The glycoprotease did not hydrolyze glycophorin A from which sialate residues had been removed by neuraminidase treatment. An immobilized preparation of the enzyme cleaved glycophorin A at several positions, with a major site of cleavage at Arg-31-Asp-32. The glycoprotease is inhibited by EDTA, citrate, and ascorbate, but inhibition appears to be due to the masking of metal ion activators rather than to their removal. The enzyme is not inhibited by phosphoramidon, an inhibitor of other bacterial neutral metalloproteases.
authors.affiliation: Guelph-Waterloo Centre for Graduate Work in Chemistry, University of Guelph, Ontario, Canada.
authors.forename: K M
authors.initials: KM
authors.lastname: Abdullah
authors.forename: E A
authors.initials: EA
authors.lastname: Udoh
authors.forename: P E
authors.initials: PE
authors.lastname: Shewen
authors.forename: A
authors.initials: A
authors.lastname: Mellors
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006020:Glycopeptides / Q000494:pharmacology; D006021:Glycophorins / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D066298:In Vitro Techniques; D016978:Mannheimia haemolytica / Q000201:enzymology*; D008666:Metalloendopeptidases / Q000302:isolation & purification / Q000502:physiology*; D009439:Neuraminidase / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D002951:Citrates; D006020:Glycopeptides; D006021:Glycophorins; D012795:Sialoglycoproteins; D019343:Citric Acid; D004492:Edetic Acid; D009439:Neuraminidase; D008666:Metalloendopeptidases; C070738:O-sialoglycoprotein endopeptidase; D001205:Ascorbic Acid; C008890:phosphoramidon