Metal compound-mediated hydrolytic cleavage of oxidized insulin B chain: Regioselectivity and influence of peptide secondary structure

• 来源期刊: 中国化学(英文版)
• 年，卷（期）: 2000,（6）
• 所属期刊栏目: Articles
• 页码范围: 855-862
• 页数: 8页
• 语种: 英文

摘要

The interaction of oxidized insulin B chain (B) with cis-[Pd-(en) Cl2] (en= ethylendiamine), cis-[Pd-(dtco-3-OH)Cl2](dtc o-3-OH= dithiacyclooctan-3-ol) and CuCl2 was studied by electrospray mass spectrometry. It is discovered that the binding of Pd(Ⅱ) complexes and the sites of cleavage are highly dependent on the secondary structure and local e nvironment of B. The hydrolytic cleavage of denatured B by Pd (Ⅱ) complexes was monitored by HPLC. The reaction is regioselective and follows first order kinetics with half-life of 4.8 days at 40°C. Two a mide bonds, i.e. at Leu6-Cys7 and at Gly8-Ser9, which are close to the two potential Pd(Ⅱ) binding sites His5 and His10, are selectively cleaved. In the case of Cu(Ⅱ) ion as promoter, only one cleavage site was observed which is located at Gly8-Ser9 bond. These results provide improved understanding on the deign of artificial metallopeptidase.