Dioxygen activation at non-heme diiron centers:: Characterization of intermediates in a mutant form of toluene/o-xylene monooxygenase hydroxylase

被引：45

作者：

Murray, Leslie J. ^{[1
]}

Garcia-Serres, Ricardo

Naik, Sunil

Huynh, Boi Hanh

Lippard, Stephen J.

机构：

[1] Emory Univ, Dept Phys, Atlanta, GA 30322 USA

[2] MIT, Dept Chem, Cambridge, MA 02139 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2006年 / 128卷 / 23期

关键词：

D O I：

10.1021/ja062762l

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We report the generation and characterization of an intermediate in a mutant form of the toluene/o-xylene monooxygenase hydroxylase component from Pseudomonas stutzeri OX1. The reaction of chemically reduced I100W variant in the presence of the coupling protein, ToMOD, with dioxygen was monitored by stopped-flow UV/visible spectroscopy. Rapid-freeze quench (RFQ) samples were also generated for EPR and Mössbauer spectroscopy. A transient species is observed in the UV/visible spectrum with an absorption maximum at 500 nm. EPR and Mössbauer spectra of RFQ samples identified this species as a diiron(III,IV) cluster spin-coupled to a neutral W radical. A diamagnetic precursor to the mixed-valent diiron(III,IV) was also observed at an earlier time point, with Mössbauer parameters typical of high-spin FeIII. We have tentatively assigned this antiferromagnetically coupled diiron(III) intermediate as a peroxo-bridged cluster, and this complex has also been observed in preliminary studies of the wild-type hydroxylase. Copyright © 2006 American Chemical Society.

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页码：7458 / 7459

页数：2

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