Quantitative analysis of x-ray absorption near edge structure data by a full multiple scattering procedure: the Fe-CO geometry in photolyzed carbonmonoxy-myoglobin single crystal

Phys Rev Lett. 2001 Oct 8;87(15):155501. doi: 10.1103/PhysRevLett.87.155501. Epub 2001 Sep 19.

Abstract

We report the first quantitative analysis of the Fe K-edge polarized x-ray absorption near edge structure of the iron protein carbonmonoxy-myoglobin (MbCO) single crystal and of its cryogenic photoproduct Mb(*)CO. The CO-Fe-heme local structure has been determined using a novel fitting procedure based on the full multiple scattering approach. The extracted local structure of Mb(*)CO includes a Fe-CO distance of (3.08+/-0.07) A, with a tilting angle between the heme normal and the Fe-C vector of (37+/-7) degrees, and a bending angle between the Fe-C vector and the C-O bond of (31+/-5) degrees.

MeSH terms

  • Animals
  • Binding Sites
  • Carbon Monoxide / chemistry*
  • Crystallography, X-Ray
  • Heme / chemistry
  • Iron / chemistry*
  • Myoglobin / chemistry*
  • Photolysis
  • Protein Conformation
  • Scattering, Radiation
  • Spectrometry, X-Ray Emission
  • Whales

Substances

  • Myoglobin
  • carboxymyoglobin
  • Heme
  • Carbon Monoxide
  • Iron