Frieden E, Osaki S, Kobayashi H
J Gen Physiol. 1965 Sep;49(1):Suppl:213-52. doi: 10.1085/jgp.49.1.213.
A comprehensive survey of the interaction of the copper proteins and oxygen is presented including a correlation of structure, function, and other properties of the known copper oxidases and of hemocyanin. The origin of their blue color and the structure of copper complexes and copper proteins are related to the oxidation state of copper ion and relevant electronic transitions probably arising from the formation of charge transfer complexes. The oxygen reactions of hemocyanin, ceruloplasmin, and cytochrome oxidase show half-saturation values far below the other Cu enzymes. The formation of hydrogen peroxide as a reaction product is associated with the presence of one Cu atom per oxidase molecule or catalytic system. Water is the corresponding product of the other Cu oxidases with four or more Cu atoms per molecule, except for monoamine oxidase. Mechanisms for the oxidase action of the two and four electron transfer Cu oxidases and tyrosinase are proposed. These reactions account for the number, the oxidation-reduction potential, and the oxidation state of Cu in the resting enzyme, the cyclical change from Cu(II) to Cu(I), the diatomic nature of O(2), the sequence of the oxidation and reduction reactions, and other salient features. The catalytic reactions involved in the oxidation of ascorbic acid by plant ascorbate oxidase, ceruloplasmin, and Cu(II) are compared. Finally the substrate specificity, inhibitory control, and the detailed mechanism of the oxidase activity of ceruloplasmin are summarized.
本文全面综述了铜蛋白与氧的相互作用，包括已知铜氧化酶和血蓝蛋白的结构、功能及其他性质的相关性。它们蓝色的起源以及铜配合物和铜蛋白的结构与铜离子的氧化态以及可能由电荷转移配合物形成引起的相关电子跃迁有关。血蓝蛋白、铜蓝蛋白和细胞色素氧化酶的氧反应显示出远低于其他铜酶的半饱和值。作为反应产物的过氧化氢的形成与每个氧化酶分子或催化系统中存在一个铜原子有关。除单胺氧化酶外，水是其他每个分子含有四个或更多铜原子的铜氧化酶的相应产物。提出了双电子转移和四电子转移铜氧化酶及酪氨酸酶的氧化酶作用机制。这些反应解释了静息酶中铜的数量、氧化还原电位和氧化态、从Cu(II)到Cu(I)的循环变化、O₂的双原子性质、氧化和还原反应的顺序以及其他显著特征。比较了植物抗坏血酸氧化酶、铜蓝蛋白和Cu(II)催化抗坏血酸氧化的反应。最后总结了铜蓝蛋白的底物特异性、抑制控制和氧化酶活性的详细机制。
