[Multiplicity of molecular forms of soluble carboxypeptidase-B-like enzymes in the cat brain]

Four forms of enzymes possessing carboxypeptidase-B-like activity have been detected in the soluble fraction of the cat encephalon. The first of these forms has molecular weight 50 kDa pH optimum is 5.0-5.6, it is four times activated by Co2+ ions and intensively inhibited by EDTA and reagents to sulphydryl groups. The other form has molecular weight 100 kDa, manifests maximum activity at pH 5.0-5.5 and is inhibited by HgCl2. EDTA, Co2+ ions and 2-mercaptoethanol take no effect on its activity. Molecular weight of the third form is not less than 280 kDa, optimum pH 5.5, is activated by Co2 ions and 2-mercaptoethanol, intensively inhibited by EDTA and reagents to sulfhydryl groups. The fourth form has molecular weight about 280 kDa, wide pH optimum with maximum at 5.5, is not activated by Co2+ ions and inhibited by EDTA, HgCl2, N-ethyl maleimide and 2-mercaptoethanol.