THE FUNCTION OF THE 4'-AMINOPYRIMIDINE COMPONENT IN THE MECHANISM OF THE CATALYSIS OF THIAMINE PYROPHOSPHATE ENZYMES FROM TODAYS VIEW

被引：27

作者：

SCHELLENBERGER, A

机构：

[1] Universität Halle‐Wittenberg, Halle, DDR‐4020

来源：

CHEMISCHE BERICHTE | 1990年 / 123卷 / 07期

关键词：

Substitutions; site‐directed; Thiamine pyrophosphate enzymes; Thiamine pyrophosphate mechanism;

D O I：

10.1002/cber.19901230709

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The Function of the 4′‐Aminopyrimidine Component in the Mechanism of the Catalysis of Thiamine Pyrophosphate Enzymes from Today's View Binding mechanism and coenzyme function of thiamine pyrophosphate (TPP) are described with the help of site‐directed substitutions at different positions of the coenzyme. In accordance to the earlier suggestions of Langenbeck (see this issue2) it is shown, that besides the thiazolium moiety (C2 atom) also the aminopyrimidine part plays an essential role in the catalytic mechanism of TPP enzymes such as pyruvate decarboxylase, pyruvate dehydrogenase, and transketolase, respectively. A two‐center mechanism of TPP is proposed explaining the function of the amino group as an internal proton relay in the catalytic mechanisms of TPP enzymes. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim

引用

页码：1489 / 1494

页数：6

共 25 条

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BERNHARDT R, 1976, THESIS U MOSKAU

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