Abdullah K M, Udoh E A, Shewen P E, Mellors A
Guelph-Waterloo Centre for Graduate Work in Chemistry, University of Guelph, Ontario, Canada.
Infect Immun. 1992 Jan;60(1):56-62. doi: 10.1128/iai.60.1.56-62.1992.
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.
已从溶血巴斯德氏菌A1的培养上清液中分离出一种对O-唾液酸糖蛋白具有显著特异性的中性金属蛋白酶。这种35 kDa的酶可切割O-糖基化的人红细胞血型糖蛋白A,但不切割N-糖基化蛋白或非糖基化蛋白。当血型糖蛋白A存在于红细胞血影质膜原位或游离于溶液中时,均可被切割。该糖蛋白酶不会水解经神经氨酸酶处理去除了唾液酸残基的血型糖蛋白A。固定化的该酶制剂可在多个位置切割血型糖蛋白A,主要切割位点为Arg-31-Asp-32。该糖蛋白酶受到EDTA、柠檬酸盐和抗坏血酸盐的抑制,但这种抑制似乎是由于金属离子激活剂被掩盖,而非被去除。该酶不受其他细菌中性金属蛋白酶抑制剂磷酰胺素的抑制。