[Comparative characteristics of penicillin-binding proteins of representatives of the genus Streptomyces].

Penicillin-binding proteins (PBPs) in Strepomyces strains producing clavulanic acid and beta-lactamase and in Streptomyces strains not producing these compounds were studied comparatively. In S. clavuligerus, the organism producing clavulanic acid, there were detected 3 PBPs in the membrane fraction. S. griseus, the organism producing beta-lactamase, contained 6 PBP. In S. cacaoi and S. olivaceus, organisms producing neither beta-lactams nor beta-lactamase, there were detected 5 and 4 PBP, respectively. The set of the PBP in the organism producing clavulanic acid varied during fermentation. In a variant of S. clavuligerus isolated after protoplasting of the mycelial cells and their regeneration the content of the electrophoretically most mobile PBP lowered. The PBP of S. clavuligerus did no show any high affinity to other beta-lactams such as methicillin and ampicillin tested as competing agents of 14C-benzylpenicillin.