Intramolecular electron transfer in yeast flavocytochrome b2 upon one-electron photooxidation of the fully reduced enzyme: evidence for redox state control of heme-flavin communication.
Intramolecular electron transfer in yeast flavocytochrome b2 upon one-electron photooxidation of the fully reduced enzyme: evidence for redox state control of heme-flavin communication.
复制标题
完全还原酶的单电子光氧化作用下酵母黄细胞色素 b2 的分子内电子转移：血红素-黄素通讯氧化还原状态控制的证据。
DOI：
10.1021/bi00249a033
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发表时间：
1994
期刊：
影响因子：
2.9
通讯作者：
Tollin,G
中科院分区：
文献类型：
--
作者：
Hazzard,JT;McDonough,CA;Tollin,G
Revised Manuscript Received June 28, 1994® abstract: Flavocytochrome¿ 2, which has been fully reduced using L-lactate, can be rapidly oxidized by 1 equiv using the laser-generated triplet state of 5-deazariboflavin. Parallel photoinduced oxidation occurs at the reduced heme and at the fully reduced FMN (FMNH2) prosthetic groups of different enzyme monomers, producing the anion semiquinone of FMN and a ferric heme. Following the initial oxidation reaction, rapid intramolecular reduction of the ferric heme occurs with concomitant oxidation of FMNH2, generating the neutral FMN semiquinone. The observed rate constant for this intramolecular electron transfer is 2200 s-1, which is 1 order of magnitude larger than the turnover number under these conditions. A slower reduction of the hemeprosthetic group also occurs with an observed rate constant of approximately 10 s-1, perhaps due to intersubunit electron transfer from reduced FMN to heme. The rapid intramolecular electron transfer between the FMNH2 and ferric heme is eliminated upon addition of excess pyruvate (Áj
