Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Inorg Chem. 2010 Apr 19;49(8):3610-7. doi: 10.1021/ic902062d.
This Forum focuses on the nature of the elusive oxidizing intermediate in P450 catalysis. The identity of this species has reemerged as a topic of contentious debate. It was recently reported that laser flash photolysis (LFP) can be used to generate P450 compound I (P450-I) quantitatively. Kinetic analyses of the reaction of the LFP-generated intermediate with substrates have been suggested to indicate that compound I is not the active oxidant in P450 catalysis. We evaluate these claims via an analysis of the UV/visible spectrum of the LFP-generated intermediate. The techniques of singular value decomposition and target testing are used to obtain the spectrum of P450-I in a model-independent manner from stopped-flow data of the reaction of P450 with m-chloroperbenzoic acid. It is shown that the LFP-generated spectrum bears no similarity to the P450-I spectrum. One may conclude that the LFP-generated intermediate is not P450-I.
本论坛聚焦于 P450 催化中难以捉摸的氧化中间物的本质。这种物质的身份重新成为争议性辩论的话题。最近有报道称，激光闪光光解（LFP）可用于定量生成 P450 复合物 I（P450-I）。对 LFP 生成的中间物与底物反应的动力学分析表明，复合物 I 不是 P450 催化中的活性氧化剂。我们通过分析 LFP 生成的中间物的紫外/可见光谱来评估这些说法。奇异值分解和目标测试技术用于从 P450 与间氯过苯甲酸反应的停流数据中以无模型的方式获得 P450-I 的光谱。结果表明，LFP 生成的光谱与 P450-I 光谱没有相似之处。可以得出结论，LFP 生成的中间物不是 P450-I。
