Tuena de Gómez-Puyou M, Ayala G, Darszon A, Gómez-Puyou A
J Biol Chem. 1984 Aug 10;259(15):9472-8.
The effect of some organic solvents, in particular dimethyl sulfoxide, on oxidative phosphorylation, the Pi-ATP exchange reaction, and ATP hydrolysis has been studied in submitochondrial particles from bovine heart. The three reactions are inhibited by dimethyl sulfoxide, but with a different sensitivity. Oxidative phosphorylation takes place at considerable rates in the presence of concentrations of dimethyl sulfoxide that completely inhibit the Pi-ATP exchange reaction. The sensitivity of the Pi-ITP exchange reaction to dimethyl sulfoxide measured in the presence of electron transport is also higher than that of oxidative phosphorylation. Dimethyl sulfoxide inhibits an electrochemical H+ gradient-dependent stimulating effect of inorganic phosphate on ATP hydrolysis which is linked to the Pi-ATP exchange reaction. In the absence of phosphate or in the presence of phosphate plus uncoupler, dimethyl sulfoxide does not inhibit hydrolysis. These findings, together with the observation that electron transport increases the rate of the Pi-ITP exchange reaction, suggest that electrochemical H+ gradients modify the kinetic characteristics of particulate Fi-ATPase. Glycerol and methanol, but not dimethylformamide, induce effects similar to those of dimethyl sulfoxide on oxidative phosphorylation and the Pi-ATP exchange reaction. This suggests that the described effects of solvents could be due to alterations of water structure.
已在牛心亚线粒体颗粒中研究了某些有机溶剂，特别是二甲基亚砜对氧化磷酸化、磷酸-ATP交换反应和ATP水解的影响。这三种反应均受到二甲基亚砜的抑制，但敏感性不同。在完全抑制磷酸-ATP交换反应的二甲基亚砜浓度存在下，氧化磷酸化仍以相当高的速率进行。在电子传递存在的情况下测得的磷酸-ITP交换反应对二甲基亚砜的敏感性也高于氧化磷酸化。二甲基亚砜抑制了无机磷酸盐对ATP水解的电化学H+梯度依赖性刺激作用，该作用与磷酸-ATP交换反应相关。在没有磷酸盐或存在磷酸盐加解偶联剂的情况下，二甲基亚砜不抑制水解。这些发现，连同电子传递增加磷酸-ITP交换反应速率的观察结果，表明电化学H+梯度改变了颗粒F1-ATP酶的动力学特性。甘油和甲醇，但不是二甲基甲酰胺，对氧化磷酸化和磷酸-ATP交换反应产生与二甲基亚砜类似的影响。这表明所述溶剂的作用可能是由于水结构的改变。
