Time-resolved resonance Raman spectroscopy of transient species formed during the oxidation of cytochrome oxidase by dioxygen
Time-resolved resonance Raman spectroscopy of transient species formed during the oxidation of cytochrome oxidase by dioxygen
复制标题
细胞色素氧化酶被双氧氧化过程中形成的瞬时物质的时间分辨共振拉曼光谱
DOI：
10.1021/ja00338a056
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发表时间：
1984
影响因子：
15
通讯作者：
W. Woodruff
中科院分区：
文献类型：
--
作者：
G. Babcock;J. Jean;L. N. Johnston;G. Palmer;W. Woodruff
细胞色素氧化酶能快速有效地将氧气还原为水。在这个机械复杂的四电子/四质子反应中发生的一系列事件涉及细胞色素A3Fe2+-CuB1+位上的氧结合，随后这些金属和更远的细胞色素a Fe2+和CuA1+中心的电子转移。1由于O2结合(~108M~(-1)S‘1)和电子转移(~105M~(-1)S~(’1))反应的速度很快，所以很难获得关于这个过程的更详细的信息，特别是关于初始氧加合物和部分还原中间体的结构的信息。为了克服这个动力学障碍，我们将快速混合和闪光光解方法2与时间分辨共振拉曼技术相结合，以便我们可以使用这种特定结构的振动光谱来研究室温下的细胞色素氧化酶/氧反应。我们在这里证明了这种方法的可行性，并提供了关于02还原的早期事件的信息。
Cytochrome oxidase catalyzes the rapid and efficient reduction of dioxygen to water. The sequence of events that occurs in this mechanistically complex, four electron/four proton reaction in-volves oxygenbinding at the cytochrome a3 Fe2+-CuB1+ site followed by electron transfer from these metals and from the more remote cytochrome a Fe2+ and CuA1+ centers. 1 More detailed information on this process, particularly on the structures of the initial oxygen adduct and of the partially reduced intermediates, has been difficult to obtain owing to the rapid rates of 02 binding (~ 108 M" 1 s'1) and electrontransfer (~ 105 to 103 s'1) reactions. To overcome this kinetic obstacle, we have combined rapid mixing and flash photolysis methods2 with time-resolved resonance Raman techniques so that we can use this structure-specific vibrational spectroscopy to study the cytochrome oxidase/oxygen reaction at room temperature. We demonstrate here the feasibility of this approach and provide information on early events in the reduction of 02.