Chance B, Saronio C, Leigh J S, Ingledew W J, King T E
Biochem J. 1978 Jun 1;171(3):787-98. doi: 10.1042/bj1710787.
The reaction of solubilized cytochrome oxidase in the fully reduced state with O2 at low temperatures reveals components with characteristics similar to those observed with the membrane-bound oxidase, namely compounds A and B, which are proposed to be 'oxy' and 'peroxy' compounds respectively. Similar species are identified in both solubilized and membrane-bound oxidases; the reaction velocity constant for the reation with O2 and the dissociation constant are decreased 2-3-fold in the solubilied preparation as compared with the membrane-bound species, owing to decreased reactivity towards O2 in the former. The oxidase prepared in the mixed-valence state shows the distinctive absorption band characteristic of compound C, identified in the membrane-bound oxidase. The assignment of the alpha, beta, gamma and near-i.r. absorption bands to possible valence states of these compounds is made.
完全还原状态的可溶性细胞色素氧化酶在低温下与O₂的反应揭示了具有与膜结合氧化酶所观察到的特征相似的组分，即化合物A和B，分别被认为是“氧基”和“过氧基”化合物。在可溶性和膜结合氧化酶中都鉴定出了类似的物种；与膜结合物种相比，可溶性制剂中与O₂反应的反应速度常数和解离常数降低了2-3倍，这是由于前者对O₂的反应性降低所致。以混合价态制备的氧化酶显示出在膜结合氧化酶中鉴定出的化合物C的独特吸收带。对这些化合物可能的价态进行了α、β、γ和近红外吸收带的归属。
