ATP synthase: activating versus catalytic proton transfer

FEBS Letters

Junge, Wolfgang¹  Groth, Georg¹ 

[1] Abt. Biophysik, Fachbereich Biologie/Chemie, Universität Osnabrück, D - 49069 Osnabrück, Germany

关键词: F-ATPase;    ATP synthase;    Phosphorylation;    Activation;    Protonmotive force;    Proton transfer;   

DOI  :  10.1016/0014-5793(94)01414-V

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

ATP synthase (F-ATPase) of chloroplasts, CF₀CF₁, is both activated and driven by transmembrane protonmotive force. We dichotomized between activating and driving proton transfer by specific inhibitors, tentoxin and venturicidin. Thylakoids membranes were submitted to voltage steps (by flashing light) superimposed to a steady pH-difference. Transient proton intake, transfer and release by CF₀CF₁ was monitored by spectroscopic probes. Both activities, activation and catalysis, required all three partial reactions of the proton, however, activating proton transfer rose first (monophasically, ) followed by another phase of equal magnitude with a time lag of about 15 ms. Both types of consecutive proton transfer reactions contribute free energy for ATP synthesis.

【 授权许可】

Unknown