The phosphate potential maintained by mitochondria in State 4 is proportional to the proton‐motive force

FEBS Letters

Woelders, Henri¹  van der Zande, Wim J.¹  van Dam, Karel¹  Colen, Anne-Marie A.F.¹  Wanders, Ronald J.A.¹ 

[1] Laboratory of Biochemistry, BCP Jansen Institute, University of Amsterdam, PO Box 20151, 1000 HD Amsterdam, The Netherlands

关键词: Mitochondria;    Energy transduction;    Localised chemiosmotic coupling;    Proton-motive force Phosphate potential ATP synthase stoichiometry;    DNP;    2;    4-dinitrophenol;    FCCP;    carbonyl cyanide p-trifluoromethoxyphenylhydrazone;    S13;    5-chloro-3-tert-butyl-2'-chloro-4'-nitrosalicylanilide;    AP5A;    P1;    P5-di(adenosine-5'-)pentaphosphate;    ΔG ex p;    extramitochondrial phosphate potential;    Δμ̃H+;    the electrochemical potential difference for protons between two separate spaces;   

DOI  :  10.1016/0014-5793(85)80534-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Evidence is presented for a proportional relationship between the extramitochondrial phosphate potential (ΔG ^ex _p) and the proton-motive force (Δ_gmH+ ) across the mitochondrial membrane in rat-liver mitochondria oxidising succinate in State 4, when Δ_gmH+ is varied by addition of uncouplers or malonate. This relationship was found when precautions were taken to minimise interference with the determination of ΔG _p ^ex and Δ_gmH+ by intramitochondrial nucleotides, adenylate kinase activity, the quenching method, and Δ_gmH+ -dependent changes in matrix volume. A non-proportional ΔG _p ^ex/Δ_gmH+ relationship was obtained when these precautions were omitted. Our results do not support mosaic protonic coupling, but are not necessarily in conflict with other localised coupling schemes.

【 授权许可】

Unknown