Stoichiometry of K+/H+ antiport helps to explain extracellular pH 11 in a model epithelium

FEBS Letters

Wieczorek, Helmut¹  Harvey, William R.¹  Azuma, Masaaki¹ 

[1] Zoologisches Institüt der Universität, Postfach 202136, D-80021 München, Germany

关键词: K+/H+ antiport;    V-ATPase;    K+ transport;    Alkalinization;    Manduca sexta;    MOPS;    3-morpholinopropanesulfonic acid;    TMA;    tetramethylammonium;   

DOI  :  10.1016/0014-5793(95)00146-Z

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The stoichiometry of K⁺/H⁺ antiport was measured fluorometrically by the static head method in highly purified vesicles from goblet cell apical membranes of larval lepidopteran midgut. The measured stoichiometry of 1 K⁺/2 H⁺ explains how the antiport results in electrophoretic exchange of extracellular H⁺ for intracellular K⁺, driven by the voltage component of the proton-motive force of an H⁺ translocating V-ATPase that is located in the same membrane. In turn, the exchange of K⁺ for H⁺ helps to explain how the midgut contents are alkalinized to a pH of 11.

【 授权许可】

Unknown