CHARACTERIZATION OF THE MEMBRANE-BOUND INORGANIC PYROPHOSPHATASE IN RHODOSPIRILLUM-RUBRUM

被引：33

作者：

RANDAHL, H

机构：

[1] Avdelningen for Biokemi, Arrheniuslaboratoriet, Stockholm Universitet, Stockholm

来源：

EUROPEAN JOURNAL OF BIOCHEMISTRY | 1979年 / 102卷 / 01期

关键词：

D O I：

10.1111/j.1432-1033.1979.tb06287.x

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The membrane‐bound inorganic pyrophosphatase (EC 3.6.1.1) from Rhodospirillum rubrum has been investigated with the tools of enzyme kinetics, and with two amino acid reagents, N‐ethyl‐maleimide (MalNET) and 4‐chloro‐7‐nitrobenzofurazan (Nbf‐Cl). The concentration of the true substrate, MgPPi, was varied with constant concentrations of free Mg2+ or PPi. It was observed that Mg2+ acted as an activator. Heat inactivation of the enzyme at 62°C was slowed down in the presence of Mg2+. MalNET and Nbf‐Cl bind to the enzyme, and inhibit its activity. The effect of both reagents is dependent on the temperature. A model is proposed where the 1:1 complex of Mg2+: PPi acts as substrate and Mg2+ interacts directly with the enzyme as an activator. PPi can bind to the enzyme, but is not hydrolyzed in the uncomplexed form. Copyright © 1979, Wiley Blackwell. All rights reserved

引用

页码：251 / 256

页数：6

共 14 条

[1] BACTERIAL PHOTOPHOSPHORYLATION IN ABSENSE OF ADDED NUCLEOTIDE - A SECOND INTERMEDIATE STAGE OF ENERGY TRANSFER IN LIGHT-INDUCED FORMATION OF ATP [J].