Wallace W, Johnson C B
Department of Physiology and Environmental Studies, School of Agriculture, University of Nottingham, Sutton Bonington, Loughborough, LE12 5RD England.
Plant Physiol. 1978 May;61(5):748-52. doi: 10.1104/pp.61.5.748.
The 4S cytochrome c (Cyt c) reductase activity of several plant species was markedly stimulated by cyanide and ferrocyanide but those of the 8S nitrate reductase component and other particulate components of the maize (Zea mays L.) scutellum by comparison, were increased only slightly. The effect of cyanide and ferrocyanide was not due to elimination of cytochrome oxidase interference but resulted from the stimulation of NADH-dependent reduction of Cyt c. A 4S Cyt c reductase component which could be isolated by ammonium sulfate fractionation and diethyl-aminoethyl-cellulose chromatography was found to be stimulated markedly by cyanide and ferrocyanide. The remaining 4S Cyt c reductase, which was insensitive to cyanide and ferrocyanide, was also fractionated with ammonium sulfate into two components. One of these, like the 8S Cyt c reductase, was sensitive to a protease from the maize roots which is relatively specific for nitrate reductase. This 4S Cyt c reductase species could be a subunit of nitrate reductase.
几种植物的4S细胞色素c（Cyt c）还原酶活性受到氰化物和亚铁氰化物的显著刺激，但相比之下，玉米（Zea mays L.）盾片中8S硝酸还原酶组分和其他颗粒组分的活性仅略有增加。氰化物和亚铁氰化物的作用并非由于消除了细胞色素氧化酶的干扰，而是由于刺激了依赖NADH的Cyt c还原。通过硫酸铵分级分离和二乙氨基乙基纤维素色谱法可分离出的一种4S Cyt c还原酶组分，被氰化物和亚铁氰化物显著刺激。其余对氰化物和亚铁氰化物不敏感的4S Cyt c还原酶，也通过硫酸铵分为两个组分。其中之一，与8S Cyt c还原酶一样，对来自玉米根的一种蛋白酶敏感，该蛋白酶对硝酸还原酶具有相对特异性。这种4S Cyt c还原酶可能是硝酸还原酶的一个亚基。
