Vesicle penicillinase of Bacillus licheniformis 749/C. Apparent identity with the plasma membrane enzyme.

A substantial fraction of the total membrane penicillinase of Bacillus licheniformis 749/C is attached to the vesicles released during conversion of the cells to protoplasts. This enzyme was purified since there was indirect evidence that it differed from the enzyme that remained with the protoplast. The purified vesicle penicillinase has the same molecular weight and general properties as the plasma membrane (protoplast) enzyme and, similarly, contains a covalently linked phosphatidylserine residue. Treatment of the two enzymes with trypsin produced phosphatidylserine-containing peptides which could not be distinguished by gel or paper electrophoresis. The two membrane penicillinases are very similar, if not identical.