Structural and electronic characterization of non-heme Fe(II)-nitrosyls as biomimetic models of the Fe(B) center of bacterial nitric oxide reductase

J Am Chem Soc. 2011 Oct 26;133(42):16714-7. doi: 10.1021/ja111693f. Epub 2011 Jun 23.

Abstract

The detoxification of nitric oxide (NO) by bacterial NO reductase (NorBC) has gained much attention as this reaction provides a paradigm as to how NO can be detoxified anaerobically in cells. However, a clear mechanistic picture of how the heme/non-heme active site of NorBC activates NO is lacking, mostly as a result of insufficient knowledge about the properties of the non-heme iron(II)-NO adduct. Here we report the first biomimetic model complexes for this species that closely resemble the coordination environment found in the protein, using the ligands BMPA-Pr and TPA. The systematic investigation of these compounds allowed us to gain key insight into the electronic structure and geometric properties of high-spin non-heme iron(II)-NO adducts. In particular, we show how small changes in the ligand environment of iron could be used by NorBC to greatly modulate the properties, and hence, the reactivity of this species.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacteria / metabolism
  • Crystallography, X-Ray
  • Electrons*
  • Ferrous Compounds / chemistry*
  • Models, Biological*
  • Nitric Oxide / chemistry*
  • Organometallic Compounds / chemistry*
  • Oxidoreductases / chemistry*

Substances

  • Ferrous Compounds
  • Organometallic Compounds
  • Nitric Oxide
  • Oxidoreductases
  • nitric-oxide reductase