A membrane enzyme from Staphylococcus aureus which catalyzes transpeptidase, carboxypeptidase, and penicillinase activities.
Staphylococcus aureus H membranes were found to contain four major binding components: Mr = 115,000; Mr = 100,000 doublet; and Mr = 46,000. The low molecular weight protein bound penicillin reversibly and was purified by prebinding membranes with penicillin prior to affinity chromatography. The purified protein catalyzed transpeptidase and carboxypeptidase reactions using di[14C]acetyl-L-lysyl-D-alanyl-D-alanine as the substrate and glycine and hydroxylamine as the acceptors. In addition, the enzyme catalyzed a penicillinase reaction. Kinetic analysis of these reactions revealed similar Vmax values suggesting that, if there is a single active site, the rate-determining steps (i.e. deacetylation) are similar. Rapid denaturation of the enzyme.substrate complex resulted in the detection of covalent penicilloyl- and diacetyl-L-lysyl-D-alanyl.enzyme complexes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
D000217:Acyltransferases / Q000378:metabolism*; D002268:Carboxypeptidases / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D007700:Kinetics; D008970:Molecular Weight; D010400:Penicillin G / Q000494:pharmacology; D010405:Penicillinase / Q000378:metabolism*; D010458:Peptidyl Transferases / Q000302:isolation & purification / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology*
D000217:Acyltransferases; D010458:Peptidyl Transferases; D002268:Carboxypeptidases; D010405:Penicillinase; D010400:Penicillin G