Submitted Papers

Resonance Raman spectroscopy study of change of iron spin state in horseradish peroxidase C induced by removal of calcium

  1. Qing Huang1,
  2. Monique Laberge2,
  3. Krisztian Szigeti2,
  4. Judit Fidy2,
  5. Reinhard Schweitzer-Stenner1,*

Article first published online: 4 JUN 2003

DOI: 10.1002/bip.10417

Issue

Biopolymers

Biopolymers

Volume 72, Issue 4, pages 241–248, 2003

Additional Information

How to Cite

Huang, Q., Laberge, M., Szigeti, K., Fidy, J. and Schweitzer-Stenner, R. (2003), Resonance Raman spectroscopy study of change of iron spin state in horseradish peroxidase C induced by removal of calcium. Biopolymers, 72: 241–248. doi: 10.1002/bip.10417

Author Information

  1. 1

    Department of Chemistry, University of Puerto Rico, Río Piedras Campus, P.O. Box 23346, San Juan, Puerto Rico 00931

  2. 2

    Institute of Biophysics and Radiation Biology, Semmelweis University, Puskin u. 9, Budapest H-1088, Hungary

*Department of Chemistry, University of Puerto Rico, Río Piedras Campus, P.O. Box 23346, San Juan, Puerto Rico 00931

Publication History

  1. Issue published online: 23 JUN 2003
  2. Article first published online: 4 JUN 2003
  3. Manuscript Accepted: 21 FEB 2003
  4. Manuscript Revised: 19 FEB 2003
  5. Manuscript Received: 21 NOV 2002

Funded by

  • National Institutes of Health. Grant Number: COBRE P20 RR16439-01
  • Hungarian OTKA. Grant Number: T-032117
  • NATO Science Program

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article (HTML) Get PDF (235K)

Keywords:

  • resonance Raman spectroscopy;
  • heme proteins;
  • horseradish peroxidase;
  • Ca2+ binding protein;
  • protein stability

Abstract

Resonance Raman spectroscopy is used to probe the effect of calcium depletion on the heme group of horseradish peroxidase C at pH 8. Polarized Raman spectra are recorded with an argon ion laser at eight different wavelengths to provide a sound database for a reliable spectral decomposition. Upon calcium depletion, the spectrum is indicative of a predominantly pentacoordinated high spin state of the heme iron coexisting with small fractions of hexacoordinated high and low spin states. The dominant quantum mixed spin state of native ferric horseradish peroxidase, which is characteristic for class III peroxidases, is not detectable in the spectrum of the enzyme with partial distal Ca2+ depletion. The quenching of the quantum mixed spin state and the predominance of the pentacoordinated high spin state are likely to arise from distortions induced by distal calcium depletion, which translates into a weaker Fe-Nϵ(His) bond and a more tilted imidazole. A correlation is proposed between the lower enzyme activity and the elimination of the pentacoordinated quantum mixed state upon Ca2+ depletion. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003

View Full Article (HTML) Get PDF (235K)