Purification of penicillin-binding protein 3 from Streptococcus pneumoniae.

Penicillin-binding protein 3 from wild-type Streptococcus pneumoniae has been purified to homogeneity by solubilization with Triton X-100 and successive column chromatography. The penicillin-binding activity during the fractionation procedure was monitored with a rapid filter binding assay using [3H]propionylampicillin and penicillin-binding protein 3 identified after fluorography of dodecyl sulfate gels. The purified protein showed penicillin-sensitive D,D-carboxypeptidase activity.