Mitovska M, Paneva R, Dancheva K
Eksp Med Morfol. 1993;31(1-2):16-22.
The effect of different buffer anions on the maximal velocity (Vmax) and Michaelis constant (Km) of the first reaction between horse cytochrome c and beef cytochrome c oxidase was studied. The Michaelis constant for the high affinity phase varies little as the buffer anions borate, phosphate, succinate and citrate were employed, but Vmax varies significantly. At the ionic strength I = 0.1 and pH 7.4 the Vmax increases in the order as following: borate < phosphate < succinate < > citrate. citrate. The differences in maximal activities in the presence of the anions may result from the changes in anion binding side on cytochrome c that affect its interaction with cytochrome c oxidase. The effect of the phosphate, succinate and citrate anions on the electron transfer reaction between cytochrome c and cytochrome c oxidase is important as a control of the respiration process in mitochondria at physiological conditions.
研究了不同缓冲阴离子对马细胞色素c与牛细胞色素c氧化酶之间第一步反应的最大反应速度（Vmax）和米氏常数（Km）的影响。当使用硼酸盐、磷酸盐、琥珀酸盐和柠檬酸盐等缓冲阴离子时，高亲和力阶段的米氏常数变化不大，但Vmax变化显著。在离子强度I = 0.1和pH 7.4条件下，Vmax按以下顺序增加：硼酸盐＜磷酸盐＜琥珀酸盐＜柠檬酸盐。阴离子存在时最大活性的差异可能是由于细胞色素c上阴离子结合位点的变化影响了其与细胞色素c氧化酶的相互作用。磷酸盐、琥珀酸盐和柠檬酸盐阴离子对细胞色素c与细胞色素c氧化酶之间电子转移反应的影响在生理条件下作为线粒体呼吸过程的一种控制是很重要的。
