在ToMOH中作为二氧化铁 (III) 物种的氧化中间体的表征
Leslie J Murray1, Sunil G Naik, Danilo O Ortillo
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|October 31, 2007
概括
研究人员在多烯/o-烯单氧基酶中确定了一个关键的二铁 (III) 中间体. 这种中间体起到活性氧化剂的作用,促进基质化,并揭示了对二氧化物激活机制的洞察力.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 金属蛋白的化学成分
背景情况:
- 多烯/o-烯单氧化酶 (TOXM) 对于芳香碳化合物的降解至关重要.
- 了解TOXM的机制,特别是其氧气激活,对于生物修复和生物催化是至关重要的.
- 之前的研究已经涉及铁中心在TOXM的催化循环.
研究的目的:
- 为了描述在减少TOXM与二氧化物反应过程中形成的二铁 (III) 中间体.
- 阐明这种二铁 (III) 中间体作为TOXM中的活性氧化剂的作用.
- 研究二氧化激活的可逆性和基质基化机制.
主要方法:
- 对二氧化铁 (III) 中介的光谱表征 (光学,Mössbauer)
- 介质衰变和基质基化的动力学研究.
- 准替代醇氧化过程的线性自由能量关系分析.
主要成果:
- 一种过渡性二铁 (III) 中间体被生成并进行了表征.
- 双铁 (III) 中间体的衰变速度是由,一个TOXM基板加速.
- 过氧化是在稳态循环过程中生成的,并由氧化氧酶分解,表明可逆的二氧化激活.
- 线性自由能量关系中的负rho值证实了氧化剂对芳香基质的电友性攻击.
结论:
- 双铁 (III) 中间体是TOXM系统中的活性氧化剂.
- 这种中间体是过时的过氧铁,尽管与其他已知的中心的光谱差异不同.
- 这些发现为这种中间体在TOXM的催化循环中的作用提供了令人信服的证据.
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