Velikiĭ N N, Sen'ko L N, Babicheva E I
Ukr Biokhim Zh (1978). 1988 Sep-Oct;60(5):35-40.
The submitochondrial particles (SMP, inverted inner membrane vesicles of mitochondria of the turned out vesicles in internal mitochondrial membranes) of the rat liver are characterized for their ability to incorporate [14C]citrate depending on the concentration of exogenic citrate, temperature and time of incubation. The rate of citrate incorporation into SMP does not depend on the addition of the oxidation substrate into the medium, however in the presence of malate and phosphate it is sharply activated. 1,2,3-benzene tricarboxylase (1,2,3-BTC) is an active inhibitor of the citrate transport into SMP. The citrate transport is determined by the protonation-deprotonation processes of the carrier protein on the outer and inner side of the membrane. A decrease in the pH of the medium favours protonation of the carrier protein on the outer side of the membrane and intensifies [14C]citrate incorporation into SMP, whereas the pH increase inhibits this process. The effect of pH changes is less pronounced in the presence of K+ ions. Valinomycin in the K+ medium activates incorporation of [14C]citrate increasing the carrier protein deprotonation rate on the inner side of the SMP membrane. Protonophore separators intensify conductivity for H+ ions and remove the stimulating influence of valinomycin on the rate of [14C]citrate incorporation into SMP.
大鼠肝脏的亚线粒体颗粒（SMP，线粒体内膜翻转形成的囊泡内的内膜囊泡）的特征在于其根据外源性柠檬酸盐的浓度、温度和孵育时间掺入[14C]柠檬酸盐的能力。柠檬酸盐掺入SMP的速率不取决于向培养基中添加氧化底物，然而在苹果酸和磷酸盐存在的情况下，其会被急剧激活。1,2,3-苯三羧酸酶（1,2,3-BTC）是柠檬酸盐转运到SMP中的活性抑制剂。柠檬酸盐转运由膜外侧和内侧载体蛋白的质子化-去质子化过程决定。培养基pH值的降低有利于膜外侧载体蛋白的质子化，并增强[14C]柠檬酸盐掺入SMP，而pH值升高则抑制该过程。在K+离子存在的情况下，pH变化的影响不太明显。缬氨霉素在K+培养基中通过提高SMP膜内侧载体蛋白的去质子化速率来激活[14C]柠檬酸盐的掺入。质子载体分隔物增强了H+离子的传导性，并消除了缬氨霉素对[14C]柠檬酸盐掺入SMP速率的刺激作用。
