Pulsed EPR studies of the exchangeable proton at the molybdenum center of dimethyl sulfoxide reductase.

Journal Article (Journal Article)

Electron spin echo envelope modulation (ESEEM) spectroscopy has been used to determine the hyperfine ( hfi) and quadrupole ( nqi) interactions of the exchangeable deuteron (proton) at the Mo(V) site of DMSO reductase. The data obtained have been translated into structure-related parameters. It was found that isotropic hfi constant of the proton is not unique, but is distributed within a range of 26-36 MHz. From this hfi distribution, a 30 degrees -wide distribution of the OH bond orientations due to a rotation around the Mo-O bond was estimated. The angle between the axes of the nqi and anisotropic hfi tensors was found to be anomalously small in comparison with that expected from the Mo-O-D bond geometry. This peculiarity was attributed to the effect of spin density on the hydroxyl oxygen atom. The orientation of the Mo-OH fragment with respect to the g-frame was determined from the experimental orientations of the nqi and hfi tensor axes and a theoretical evaluation of the anisotropic hfi axis direction.

Full Text

Duke Authors

Cited Authors

  • Raitsimring, AM; Astashkin, AV; Feng, C; Enemark, JH; Nelson, KJ; Rajagopalan, KV

Published Date

  • January 2003

Published In

Volume / Issue

  • 8 / 1-2

Start / End Page

  • 95 - 104

PubMed ID

  • 12459903

International Standard Serial Number (ISSN)

  • 0949-8257

Digital Object Identifier (DOI)

  • 10.1007/s00775-002-0393-8


  • eng

Conference Location

  • Germany