Figure 7
Hydrolytic activity of CcEstA toward β-lactam-related compounds.
(A) Chemical structures of nitrocefin, 7-aminocephalosporanic acid (7-ACA), and cefotaxime (CTX). (B) A pH shift assay was conducted to verify the hydrolytic activity of CcEstA toward 7-ACA and CTX. PBS-2, a bacterial PBP homologue from Paenibacillus sp., was used as a positive control55. Note that CcEstA showed almost no hydrolytic activity toward 7-ACA and CTX, while nitrocefin can be hydrolyzed. (C) Competitive inhibition assay of CcEstA. 7-ACA and CTX were used as competitive inhibitors of nitrocefin. Note that both 7-ACA and CTX have almost no inhibitory effect on nitrocefin hydrolysis.
