Vasil'ev V B, Neĭfakh S A, Rusakov D V, Iakovleva T Iu, Kholmogorov V E
Biokhimiia. 1988 Apr;53(4):620-5.
The absorbance and EPR spectra of type 1 and 2 copper-binding centres which are present in ceruloplasmin (Cp) molecule were shown to disappear upon the reduction of the enzyme by ascorbate under anaerobic conditions. The fluorescence band attributed to type 3 Cu was altered concomitantly. The electron-accepting nitroxyl radical added to reduced Cp restored the absorbance, EPR and fluorescence spectra of the oxidase. Only type 1 and 3 copper ions, as judged by spectral changes, can be reduced by ascorbate and then reoxidized by the nitroxyl radical in the azide-treated Cp. The spectral properties of Cp provided by copper ions of different types change simultaneously and concordantly upon oxidation/reduction. This seems to be caused by cooperative interaction of these ions involved in the electron transfer from the donating substrate to the accepting molecule of the nitroxyl radical (in model studies of oxidase reaction) or oxygen (under natural conditions). The copper ions in the active centre of Cp constitute an intramolecular electron transport chain, which may, at least in vitro, function without one of its links.
在厌氧条件下，用抗坏血酸还原铜蓝蛋白（Cp）分子中存在的1型和2型铜结合中心时，其吸光度和电子顺磁共振（EPR）光谱显示消失。归因于3型铜的荧光带也随之改变。添加到还原型Cp中的电子接受性硝酰自由基恢复了氧化酶的吸光度、EPR和荧光光谱。从光谱变化判断，在叠氮化物处理的Cp中，只有1型和3型铜离子能被抗坏血酸还原，然后被硝酰自由基再氧化。不同类型铜离子提供的Cp光谱特性在氧化/还原时同时且一致地变化。这似乎是由参与从供体底物到硝酰自由基（在氧化酶反应的模型研究中）或氧气（在自然条件下）的接受分子的电子转移的这些离子的协同相互作用引起的。Cp活性中心的铜离子构成了一个分子内电子传输链，至少在体外，该链可以在没有其一个环节的情况下发挥作用。
