Heme-Cu complexes as oxygen-activating functional models for the active site of cytochrome c oxidase.
Heme-Cu complexes as oxygen-activating functional models for the active site of cytochrome c oxidase.
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DOI：
10.1016/s0162-0134(00)00170-7
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发表时间：
2001-02
影响因子：
3.9
通讯作者：
Y. Naruta;T. Sasaki;F. Tani;Y. Tachi;N. Kawato;N. Nakamura
中科院分区：
文献类型：
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作者：
Y. Naruta;T. Sasaki;F. Tani;Y. Tachi;N. Kawato;N. Nakamura
合成了三（2-吡啶甲基）胺铜配合物连接的铁meso-四苯基卟啉衍生物，用于模拟细胞色素c氧化酶的活性中心。尽管存在三个配位位点，两个在血红素上，一个在Cu上，但暴露于氧气将络合物的还原形式转化为相应的稳定的μ-过氧物种。用光谱法表征氧合形式。还原形式的氧化反应的动力学分析表明，优先O2结合发生在铜网站的血红素。这一机制也支持检查的两种金属离子的氧化还原电位。由于过氧复合物的模型表现出类似的结构，以前报道的完全氧化的形式，模型化学的酶反应的相关性进行了讨论。
Tri(2-pyridylmethyl)amineCu complex-linked iron meso-tetraphenylporphyine derivatives were prepared to model the active site of cytochrome c oxidase. Exposure to oxygen converted the reduced forms of the complexes to the corresponding stable μ-peroxo species in spite of the presence of three coordination sites, two on the heme and one on the Cu. The oxy forms were characterized spectroscopically. Kinetic analyses of the oxygenation reactions of the reduced forms suggests that preferential O2binding occurs at the Cu site over the heme. This mechanism is also supported by examination of the redox potentials of the two metal ions. Since the peroxy complexes of the models exhibit a structure similar to that of the previously reported fully-oxidized form, the relevance of the model chemistry to the enzyme reaction is discussed.