A Putative Fe2+-Bound Persulfenate Intermediate in Cysteine Dioxygenase

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• 作者：Chad R. Simmons ; Kalyanaraman Krishnamoorthy ; Spencer L. Granett ; David J. Schuller ; John E. Dominy ; ; Tadhg P. Begley ; Martha H. Stipanuk ; P. Andrew Karplus
• 刊名：Biochemistry
• 出版年：2008
• 出版时间：November 4, 2008
• 年：2008
• 卷：47
• 期：44
• 页码：11390-11392
• 全文大小：147K
• 年卷期：v.47,no.44(November 4, 2008)
• ISSN：1520-4995

文摘

The common reactions of dioxygen, superoxide, and hydroperoxides with thiolates are thought to proceed via persulfenate intermediates, yet these have never been visualized. Here we report a 1.4 Å resolution crystal structure of the Fe²⁺-dependent enzyme cysteine dioxygenase (CDO) containing this putative intermediate trapped in its active site pocket. The complex raises the possibility that, distinct from known dioxygenases and proposed CDO mechanisms, the Fe-proximal oxygen atom may be involved in the primary oxidation event yielding a unique three-membered Fe−S−O cyclic intermediate. A nonpolar environment of the distal oxygen would facilitate isomerization of the persulfenate to the sulfinate product.