Czyz A, Szewczyk A, Nałecz M J, Wojtczak L
Nencki Institute of Experimental Biology, Warsaw, Poland.
Biochem Biophys Res Commun. 1995 May 5;210(1):98-104. doi: 10.1006/bbrc.1995.1632.
The two components of the protonmotive force, the pH gradient (delta pH) and the transmembrane electric potential (delta psi), were measured in rat liver mitochondria as a function of K+ concentration in the suspending medium. It was found that both the rate of formation and the final level of delta pH upon energization of mitochondria with succinate increased with increasing [K+]. Concomitantly, delta psi decreased so that the level of the protonmotive force remained practically unchanged. Potassium channel opener RP66471 further potentiated both the formation rate and the level of delta pH. These results are interpreted as showing that the electrophoretic K+ influx enables the formation of delta pH by partly compensating charge transfer due to the proton pumping.
在大鼠肝线粒体中，测量了质子动力势的两个组成部分，即pH梯度（ΔpH）和跨膜电势（Δψ），作为悬浮介质中K⁺浓度的函数。结果发现，用琥珀酸使线粒体通电后，ΔpH的形成速率和最终水平均随[K⁺]的增加而增加。与此同时，Δψ降低，使得质子动力势的水平实际上保持不变。钾通道开放剂RP66471进一步增强了ΔpH的形成速率和水平。这些结果被解释为表明，K⁺的电泳流入通过部分补偿质子泵引起的电荷转移，从而使ΔpH得以形成。
