Purification and properties of inducible penicillin beta-lactamase isolated from Alcaligenes faecalis.

An inducible penicillin beta-lactamase was purified from a strain of Alcaligenes faecalis resistant to beta-lactam antibiotics. The purified enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis, and its molecular weight was 29,000 based on sodium dodecyl sulfate-acrylamide gel electrophoresis. Its isoelectric point was 5.9. The enzyme more rapidly hydrolyzed penicillins, such as penicillin G, ampicillin, carbenicillin, piperacillin, and cloxacillin, than it hydrolyzed cephalosporins. For the hydrolysis of penicillin G, the optimal pH was 5.5, and the optimal temperature was 35 degrees C. The enzyme activity was inhibited by iodine, Cu2+, Hg2+, and EDTA but was not inhibited by clavulanic acid and sulbactam.