丙酮酸对大肠杆菌丙酮酸脱氢酶复合体抑制作用的表征

Characterization of the inhibition of Escherichia coli pyruvate dehydrogenase complex by pyruvate.

作者信息

Datta A

机构信息

University of Wisconsin Biotechnology Center, Madison 53705.

出版信息

Biochem Biophys Res Commun. 1991 Apr 15;176(1):517-21. doi: 10.1016/0006-291x(91)90955-7.

DOI:10.1016/0006-291x(91)90955-7

PMID:2018539

Abstract

The E. coli pyruvate dehydrogenase complex was inhibited by pyruvate in absence of its cofactor, NAD+. The inhibition was found to increase with pH and phosphate concentration of the buffer and decrease with its ionic strength. The inhibition profile was different with MOPS buffer. No radioactivity was found in the enzyme, when the latter was incubated with 2-14C-pyruvate. The results suggest that covalent adduct formation is not necessary for the observed inhibition.

摘要

在缺乏辅因子NAD⁺的情况下，大肠杆菌丙酮酸脱氢酶复合体受到丙酮酸的抑制。研究发现，这种抑制作用会随着缓冲液的pH值和磷酸盐浓度的增加而增强，随着离子强度的增加而减弱。在MOPS缓冲液中，抑制曲线有所不同。当酶与2-¹⁴C-丙酮酸一起孵育时，未在酶中发现放射性。结果表明，观察到的抑制作用并不需要形成共价加合物。