Modes of action of uncouplers in thylakoids I. Proton conduction characteristics

FEBS Letters

Schönfeld, Mordechay¹  Schickler, Hedva¹ 

[1] The Hebrew University of Jerusalem, Department of Agricultural Botany, PO Box 12, Rehovot 71600, Israel

关键词: Chloroplast;    Thylakoid membrane;    Proton permeability;    Proton conduction;    Uncoupler;    CF0-CF1;    (Lettuce);    J H;    rate of proton efflux;    P H;    proton permeability of the thylakoid membrane;    [H+]i;    [H+]0;    internal and external proton concentrations;    respectively;    CF0-CF1;    the thylakoid H+-ATPase;   

DOI  :  10.1016/0014-5793(88)81144-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A formal description of proton efflux from chloroplasts as a function of proton concentrations inside and outside the thylakoids, was used to analyze effects of uncouplers and energy transfer inhibitors on proton conduction in thylakoids. Plots of proton efflux vs ΔpH, obtained with NH₄Cl, matched simulated curves portraying increases of proton permeability. Effects of DCCD fitted those expected for blocking CF₀-CF₁ channels. Unexpectedly, effects of gramicidin or FCCP on proton conduction indicated that interference with proton efflux via CF₀-CF₁, and not stimulation of proton leakage, was the direct cause for inhibition of photophosphorylation by these uncouplers.

【 授权许可】

Unknown