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Structure and Function of Heme-regulated Proteins and Their Molecular Mechanisms

Research Project

Project/Area Number 15350101
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Chemistry related to living body
Research InstitutionHokkaido University (2005)
Kyoto University (2003-2004)

Principal Investigator

ISHIMORI Koichiro  Hokkaido University, Division of Chemistry, Faculty of Science., Professor, 大学院理学研究科, 教授 (20192487)

Co-Investigator(Kenkyū-buntansha) TAKAHASHI Satoshi  Osaka University, Institute for Protein, Associate Professor, 蛋白質研究所, 助教授 (30283641)
WAKASUGI Keisuke  The University of Tokyo, Department of Life Science, Graduate School of Art and Science, Associated Professor, 大学院総合文化研究科, 助教授 (20322167)
Project Period (FY) 2003 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 2005: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2004: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2003: ¥7,100,000 (Direct Cost: ¥7,100,000)
KeywordsHeme-regulated Protein / Iron Responsive Element / Irr / IRP2 / Replacement of Axial Ligands / Pulse Radiolysis / Resonance Raman / Heme Regulatory Motif / ヘム / 鉄代謝制御蛋白質 / ポルフィリン生合成 / 酸化的修飾 / 軸配位子交換 / 共鳴ラマンスペクル / 電子線照射 / ヘム生合成制御 / MCD / 制御因子 / 蛍光消光
Research Abstract

The major results we have obtained in this research project are as follows:
1. Ligation of Cys to Ferric Heme in Irr and IRP2. Based on the resonance Raman spectra, we successfully identified the Fe-Cys stretching modes in ferric heme-bound Irr and IRP2. These Fe-Cys stretching modes were downshifted, compared with that in conventional Cys-ligated hemoproteins such as P450cam. The downshifted Fe-Cys stretching modes correspond to the lower affinities of these proteins to ferric heme, which is also supported by fluorescence heme titration in Irr. Such weak affinities of these proteins to heme would be one of the characteristics of heme-regulated proteins having "Heme Regulatory Motif'
2. Redox-dependent Replacement of Axial Ligands. We confirmed the ligation of Cys to ferric heme in Irr and IRP2. By reduction of the heme iron, however, the absorption spectra of heme-bound Irr and IRP2 were drastically changed and the resultant spectra were quite different from ferrous P450cam, which were rather similar to bis-His ligated hemoproteins like cytochrome b_5. The spectral similarity to His-ligated hemoprotein was more evident in the CO adducts of heme-bound Irr and IRP2. The resonance Raman measurements. clearly showed the Fe-His stretching modes in ferrous heme bound lrr and IRP2 and the Fe-C and FeC-O stretching modes in the CO adducts, confirming that axial Cys is replaced with His by reduction of the heme iron. Considering that molecular oxygen can bind to ferrous heme, not ferric heme, the His ligated species in these proteins would be active species to generate reactive oxygen species, which leads to the oxidative modification of the peptide and protein degradation.

Report

(4 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • Research Products

    (9 results)

All 2007 2005 2004 Other

All Journal Article (8 results) Publications (1 results)

  • [Journal Article] Molecular Basis of Guanine Nucleotide Dissociation Inhibitor Activity of Human Neuroglobin by Chemical Cross-linking and Mass Spectroscopy2007

    • Author(s)
      Kitatsuji, C.
    • Journal Title

      J. Mol. Biol. (in press)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Two Heme Binding Sites Are Involved in the Regulated Degradation of the Bacterial Iron Response Regulator (Irr) Protein2005

    • Author(s)
      Yang, J.
    • Journal Title

      J. Biol. Chem. 280

      Pages: 7671-7676

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Involvement of Heme Regulatory Motif in Heme-Mediated Ubiquitination and Degradation of IRP22005

    • Author(s)
      Ishikawa, H
    • Journal Title

      Mol. Cell. 19

      Pages: 171-181

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Involvement of Heme Regulatory Motif in Heme- Mediated Ubiquitination and Degradation of IRP22005

    • Author(s)
      Ishikawa H.
    • Journal Title

      Mol. Cell. 19

      Pages: 171-181

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Two Heme Binding Sites Are Involved in the Regulated Degradation of the Bacterial Iron Response Regulator (Irr) Protein2005

    • Author(s)
      Yang, J.
    • Journal Title

      J.Biol.Chem. 280

      Pages: 7671-7676

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Involvement of Heme Regulatory Motif in Heme-Mediated Ubiquitination and Degradation of IRP22005

    • Author(s)
      Ishikawa, H.
    • Journal Title

      Mol.Cell 19

      Pages: 171-181

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Two Heme Binding Sites Are Involved in the Regulated Degradation of the Bacterial Iron Response Regulator (Irr) Protein2005

    • Author(s)
      Yang, J. et al.
    • Journal Title

      Journal of Biological Chemistry 280

      Pages: 7671-7676

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Identification of Crucial Histidines for Heme Binding in the N-terminal Domain of the Heme-regulated elF2α Kinase2004

    • Author(s)
      Inuzuka, T.
    • Journal Title

      J. Biol. Chem. 279

      Pages: 6778-6782

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Publications] Inuzuka, et al.: "Identification of Crucial Hhistidines for Heme Binding in the N-terminal Domain of the Heme-regulated eIF2α kinase"Journal of Biological Chemistry. 279. 6778-6782 (2004)

    • Related Report
      2003 Annual Research Report

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Published: 2003-04-01   Modified: 2016-04-21  

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