Purification of Streptococcus faecium penicillin binding protein 5, a multifunctional penicillin-binding protein.

Penicillin-binding protein 5 of Streptococcus faecium has been solubilized and partially separated from other membrane proteins by covalent affinity chromatography. PBP 5 was successively purified to homogeneity by resolution on SDS-polyacrylamide gel, elution and renaturation of penicillin-binding activity. The purification procedure does not alter the properties that the protein exhibits in the membranous environment.