VARIABLE STOICHIOMETRY IN RECONSTITUTED SHARK NA,K-ATPASE ENGAGED IN UNCOUPLED EFFLUX

被引：14

作者：

CORNELIUS, F

机构：

[1] Institute of Biophysics, University of Aarhus, Aarhus

来源：

BIOCHIMICA ET BIOPHYSICA ACTA | 1990年 / 1026卷 / 02期

关键词：

(Shark); ATPase; Electrogenicity; Na[!sup]+[!/sup]/K[!sup]+[!/sup]-; Reconstituted Na[!sup]+[!/sup]/K[!sup]+[!/sup]-ATPase; Sodium ion efflux; Sodium ion-proton exchange; Transport stoichiometry; Uncoupled Na[!sup]+[!/sup] efflux;

D O I：

10.1016/0005-2736(90)90057-U

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：

In liposomes with reconstituted shark Na,K-ATPase produced to contain no internal K+ or Na+ addition of external Na+ and ATP induce an uncoupled Na+ efflux on inside-out oriented pumps which is electrogenic and accompanied by hydrolysis of ATP (Cornelius, F. (1989) Biochem. Biophys. Res. Commun. 160, 801-807). At saturating cytoplasmic Na+ the net-charge translocated per ATP molecule split is compatible with coupling ratio of Nacyt transported per ATP split of 3:1 at pH ≥ 7.0. However, this ratio decreases to 1.5:1 below pH 7.0. At non-saturating cytoplasmic Na+ the 3:1 stoichiometry is attained at pH 7.0-7.5, whereas outside this range of pH the net-charge translocated per ATP molecule split decreases. © 1990.

引用

页码：147 / 152

页数：6

共 26 条

[1] OXONOL-VI AS AN OPTICAL INDICATOR FOR MEMBRANE-POTENTIALS IN LIPID VESICLES [J].