Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, India.
J Bioenerg Biomembr. 2010 Aug;42(4):293-300. doi: 10.1007/s10863-010-9296-5. Epub 2010 May 20.
In Part 1 of this invited article, we consider the fundamental aspects of energy coupling in oxidative phosphorylation. The central concepts of the chemiosmotic theory are re-examined and the major problems with its experimental verification are analyzed and reassessed from first principles. Several of its assumptions and interpretations (with regard, for instance, to consideration of the membrane as an inert barrier, the occurrence of energy transduction at thermodynamic equilibrium, the completely delocalized nature of the protonmotive force, and the notion of indirect coupling) are shown to be questionable. Important biological implications of this analysis for molecular mechanisms of biological energy transduction are enumerated. A fresh molecular mechanism of the uncoupling of oxidative phosphorylation by classical weak acid anion uncouplers and an adequate explanation for the existence of uncoupler-resistant mutants (which until now has remained a mystery) has been proposed based on novel insights arising from a new torsional mechanism of energy transduction and ATP synthesis.
在这篇特邀文章的第一部分,我们考虑了氧化磷酸化中能量偶联的基本方面。重新审视了化学渗透理论的核心概念,并从第一性原理出发,对其实验验证的主要问题进行了分析和重新评估。该理论的一些假设和解释(例如,将膜视为惰性屏障、能量转导发生在热力学平衡时、质子动力完全非局域化,以及间接偶联的概念)被证明是有问题的。对生物能量转导的分子机制的这种分析列举了重要的生物学意义。基于能量转导和 ATP 合成的新扭转机制所产生的新见解,提出了一种解释经典弱酸阴离子解偶联剂解偶联氧化磷酸化的新分子机制,并对解偶联剂抗性突变体(迄今为止一直是个谜)的存在提出了合理的解释。