血红蛋白氧化还原反应的动力学研究。I. 亚铁氰化物对耐热细胞色素c-552和马心细胞色素c的还原作用。

Kinetic studies on redox reactions of hemoproteins. I. Reduction of thermoresistant cytochrome c-552 and horse heart cytochrome c by ferrocyanide.

作者信息

Kihara H, Nakatani H, Hiromi K, Hon-Nami K

出版信息

Biochim Biophys Acta. 1977 Jun 9;460(3):480-9. doi: 10.1016/0005-2728(77)90086-x.

PMID:195599

Abstract

The oxidation-reduction reaction of horse heart cytochrome c and cytochrome c (552, Thermus thermophilus), which is highly thermoresistant, was studied by temperature-jump method. Ferrohexacyanide was used as reductant. (Formula: see text.) Thermodynamic and activation parameters of the reaction obtained for both cytochromes were compared with each other. The results of this showed that (1) the redox potential of cytochrome c-552, + 0.19 V, is markedly less than that of horse heart cytochrome c. (2) deltaHox of cytochrome c-552 is considerably lower than that of horse heart cytochrome c. (3) deltaSox and deltaSred of cytochrome c-552 are more negative than those of horse heart cytochrome c. (4) kred of cytochrome c-552 is much lower than that of horse heart cytochrome c at room temperature.

摘要

采用温度跃升法研究了马心细胞色素c与极具热稳定性的嗜热栖热菌细胞色素c（552）的氧化还原反应。用亚铁氰化物作为还原剂。（化学式：见正文）。比较了两种细胞色素反应的热力学和活化参数。结果表明：（1）细胞色素c-552的氧化还原电位为+0.19V，明显低于马心细胞色素c。（2）细胞色素c-552的氧化焓远低于马心细胞色素c。（3）细胞色素c-552的氧化熵和还原熵比马心细胞色素c的更负。（4）在室温下，细胞色素c-552的还原速率远低于马心细胞色素c。