Isolation by covalent affinity chromatography of the penicillin-binding components from membranes of Bacillus subtilis.

An affinity chromatography technique was developed to isolate the five penicillin-binding components present in Bacillus subtilis membranes. The proteins were solubilized by the detergent Nonidet P-40, bound covalently to penicillin-substituted Sepharose, and subsequently eluted from the matrix with neutral hydroxylamine, which cleaves the penicilloyl-enzyme bond. Penicillin binding-component V, the D-alanine carboxypeptidase, makes up 1% of the total membrane protein. A modification of the above procedure enabled this enzyme to be obtained from the membrane in pure form in a single step with 50% overall recovery of enzymatic activity.