NRVS Studies of the Peroxide Shunt Intermediate in a Rieske Dioxygenase and Its Relation to the Native FeII O2 Reaction

Kyle D. Sutherlin, Brent S. Rivard, Lars H. Böttger, Lei V. Liu, Melanie S. Rogers, Martin Srnec, Kiyoung Park, Yoshitaka Yoda, Shinji Kitao, Yasuhiro Kobayashi, Makina Saito, Makoto Seto, Michael Hu, Jiyong Zhao, John D. Lipscomb, Edward I. Solomon

研究成果: Article査読

19 被引用数 (Scopus)

抄録

The Rieske dioxygenases are a major subclass of mononuclear nonheme iron enzymes that play an important role in bioremediation. Recently, a high-spin FeIII-(hydro)peroxy intermediate (BZDOp) has been trapped in the peroxide shunt reaction of benzoate 1,2-dioxygenase. Defining the structure of this intermediate is essential to understanding the reactivity of these enzymes. Nuclear resonance vibrational spectroscopy (NRVS) is a recently developed synchrotron technique that is ideal for obtaining vibrational, and thus structural, information on Fe sites, as it gives complete information on all vibrational normal modes containing Fe displacement. In this study, we present NRVS data on BZDOp and assign its structure using these data coupled to experimentally calibrated density functional theory calculations. From this NRVS structure, we define the mechanism for the peroxide shunt reaction. The relevance of the peroxide shunt to the native FeII/O2 reaction is evaluated. For the native FeII/O2 reaction, an FeIII-superoxo intermediate is found to react directly with substrate. This process, while uphill thermodynamically, is found to be driven by the highly favorable thermodynamics of proton-coupled electron transfer with an electron provided by the Rieske [2Fe-2S] center at a later step in the reaction. These results offer important insight into the relative reactivities of FeIII-superoxo and FeIII-hydroperoxo species in nonheme Fe biochemistry.

本文言語English
ページ(範囲)5544-5559
ページ数16
ジャーナルJournal of the American Chemical Society
140
16
DOI
出版ステータスPublished - 2018 4月 25
外部発表はい

ASJC Scopus subject areas

  • 触媒
  • 化学 (全般)
  • 生化学
  • コロイド化学および表面化学

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