细胞色素c与细胞色素c氧化酶的电荷相互作用。

Charge interactions of cytochrome c with cytochrome c oxidase.

作者信息

Mitovska M I, Dancheva K I, Atanasov B P

出版信息

Int J Biochem. 1984;16(10):1059-64. doi: 10.1016/0020-711x(84)90088-0.

Abstract

The pyridoxal phosphate (PLP) modification of the lysine amino groups in cytochrome c causes decrease in the reaction rate with cytochrome c oxidase. The rate constants for (PLP)2-cyt. c, PLP(Lys 86)-cyt. c, PLP(Lys 79)-cyt. c and native cytochrome c (at pH 7.4, I = 0.02) are 3.6 X 10(-3) sec-1, 5.5 X 10(-3) sec-1, 5.2 X 10(-3) sec-1 and 9.8 X 10(-3) sec-1, respectively. In spite of the same positive charge of singly PLP-cytochromes c the reaction between PLP(Lys 86)-cyt. c and cyt. c oxidase exhibits the ionic strength dependence that differs from those of the PLP(Lys 79)-cyt. c. The rate constants at zero and infinite ionic strength for PLP(Lys 86)-cyt. c is 2-fold less than that for PLP(Lys 79)-cyt. c. The positively charged cytochrome c lysines 86 and 79 form two from four or five predicted complementary charge interactions with carboxyl groups on cytochrome c oxidase.

摘要

细胞色素c中赖氨酸氨基的磷酸吡哆醛（PLP）修饰导致其与细胞色素c氧化酶的反应速率降低。（PLP）2 - 细胞色素c、PLP（赖氨酸86） - 细胞色素c、PLP（赖氨酸79） - 细胞色素c和天然细胞色素c（在pH 7.4，离子强度I = 0.02条件下）的反应速率常数分别为3.6×10^(-3) s^(-1)、5.5×10^(-3) s^(-1)、5.2×10^(-3) s^(-1)和9.8×10^(-3) s^(-1)。尽管单PLP - 细胞色素c带有相同的正电荷，但PLP（赖氨酸86） - 细胞色素c与细胞色素c氧化酶之间的反应表现出与PLP（赖氨酸79） - 细胞色素c不同的离子强度依赖性。PLP（赖氨酸86） - 细胞色素c在零离子强度和无限离子强度下的反应速率常数比PLP（赖氨酸79） - 细胞色素c的低2倍。带正电荷的细胞色素c赖氨酸86和79与细胞色素c氧化酶上的羧基形成了四到五个预测的互补电荷相互作用中的两个。