Kumar C, Naqui A, Powers L, Ching Y C, Chance B
Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia 19104.
J Biol Chem. 1988 May 25;263(15):7159-63.
The reaction of peroxide with cytochrome oxidase generates a peroxide compound having a Soret maximum at 428 nm. X-ray absorption spectroscopy analysis of the local structure of the active site iron shows marked similarity to that of the cytochrome c peroxidase intermediate Compound ES, which contains a short iron to proximal nitrogen distance compared to globins. Reductive titration of the 580 nm band of this compound indicates that the iron is one oxidizing equivalent above the resting oxidized form. These results support the presence of a ferryl iron (Fe(IV) = O) in the peroxide compound similar to that found for the peroxidases.
过氧化物与细胞色素氧化酶的反应生成一种在428nm处有最大索雷特吸收峰的过氧化物化合物。对活性位点铁的局部结构进行的X射线吸收光谱分析表明，它与细胞色素c过氧化物酶中间体化合物ES的结构有显著相似性，与珠蛋白相比，该中间体化合物中从铁到近端氮的距离较短。对该化合物580nm波段的还原滴定表明，铁比静止氧化态高出一个氧化当量。这些结果支持了在过氧化物化合物中存在类似于过氧化物酶中发现的铁酰铁（Fe(IV)=O）。
