Bliumenfel'd L A
Biofizika. 1976 Sep-Oct;21(5):946-57.
Physical principles underlying the chemiosmotic hypothesis of membrane phosphorylation are analysed. The utilization of free energy determined by dydrogen ions concentration difference across the membrane for ATP synthesis requires ATP-synthetase to be an entropy machine able to perform work on account of heat. The chemiosmotic hypothesis assumes the possibility of interchangeable utilization of both components of proton electrochemical potential-the membrane electrical difference and proton concentration gradient-for ATP synthesis. This assumption requires the fulfillment of practically unrealizable conditions. Energetic coupling of intracellular chemical reactions must be realized by means of a mechanism in which every act of energydonating reaction leads compulsory to one act of energyaccepting reaction. For such a mechanism both reactions ought to proceed essentially in one elementary act. For intracellular macromolecular and supramolecular systems it implies the necessity of excitation of specific mechanical slowly relaxing degrees of freedom.
分析了膜磷酸化化学渗透假说背后的物理原理。利用由跨膜氢离子浓度差所决定的自由能来合成ATP,这要求ATP合成酶成为一台能够因热而做功的熵机器。化学渗透假说假定,质子电化学势的两个组成部分——膜电位差和质子浓度梯度——可相互替换地用于ATP合成。这一假设需要满足实际无法实现的条件。细胞内化学反应的能量耦合必须通过一种机制来实现,即每一次能量供体反应行为都必然导致一次能量受体反应行为。对于这样一种机制,两种反应都应该基本上在一个基本行为中进行。对于细胞内的大分子和超分子系统,这意味着需要激发特定的机械性缓慢弛豫自由度。