A thiolate-ligated nonheme oxoiron(IV) complex relevant to cytochrome P450
A thiolate-ligated nonheme oxoiron(IV) complex relevant to cytochrome P450
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DOI：
10.1126/science.1119092
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发表时间：
2005-11-11
期刊：
影响因子：
56.9
通讯作者：
Que, L
中科院分区：
文献类型：
--
作者：
Bukowski, MR;Koehntop, KD;Que, L
巯基连接的氧合铁（IV）中心被假定为氧活化细胞色素P450和相关酶的催化循环中的关键氧化剂。尽管进行了大量的合成努力，化学家们还没有成功地制备出合适的模型复合物。本文报道了[Fe-IV（O）（TMCS）]（+）的合成和光谱表征，其中TMCS是一个五齿配体，提供了一个四方锥形N-4（SR）（顶端），其中SR是硫代配体，铁中心周围的配体环境，这与细胞色素P450的配体环境相似。配体框架的刚性使硫醇盐在氧化环境中稳定。反应性研究表明，硫醇配位有利于氢原子抽象化学氧原子转移途径的存在下，还原底物。
Thiolate-ligated oxoiron(IV) centers are postulated to be the key oxidants in the catalytic cycles of oxygen-activating cytochrome P450 and related enzymes. Despite considerable synthetic efforts, chemists have not succeeded in preparing an appropriate model complex. Here we report the synthesis and spectroscopic characterization of [Fe-IV(O)(TMCS)](+) where TMCS is a pentadentate ligand that provides a square pyramidal N-4(SR)(apical), where SR is thiotate, ligand environment about the iron center, which is similar to that of cytochrome P450. The rigidity of the ligand framework stabilizes the thiolate in an oxidizing environment. Reactivity studies suggest that thiolate coordination favors hydrogen-atom abstraction chemistry over oxygen-atom transfer pathways in the presence of reducing substrates.