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Modes of action of uncouplers in thylakoids I. Proton conduction characteristics
Author(s) -
Schönfeld Mordechay,
Schickler Hedva
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)81144-x
Subject(s) - thylakoid , proton , photophosphorylation , chemistry , gramicidin , proton transport , biophysics , electrochemical gradient , chloroplast , membrane , biochemistry , biology , physics , quantum mechanics , gene
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 NH 4 Cl, matched simulated curves portraying increases of proton permeability. Effects of DCCD fitted those expected for blocking CF 0 ‐CF 1 channels. Unexpectedly, effects of gramicidin or FCCP on proton conduction indicated that interference with proton efflux via CF 0 ‐CF 1 , and not stimulation of proton leakage, was the direct cause for inhibition of photophosphorylation by these uncouplers.