Synthesis and Characterization of High Valnet Reaction Intermediate of Non-Heme Iron Enzymes

• Project/Area Number: 14340212
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Inorganic chemistry
• Research Institution: Okazaki National Research Institutes
• Principal Investigator: FUJII Hiroshi Okazaki National Research Institutes, Center for Integrative Bioscience, Associate Professor, 統合バイオサイエンスセンター, 助教授 (80228957)
• Co-Investigator(Kenkyū-buntansha): KURAHASHI Takuya Okazaki National Research Institutes, Institute for Molecular Science, Assistant Professor, 分子科学研究所, 助手 (90353432)
• Project Period (FY): 2002 – 2003
• Project Status: Completed (Fiscal Year 2003)
• Budget Amount: ¥15,000,000 (Direct Cost: ¥15,000,000); Fiscal Year 2003: ¥3,800,000 (Direct Cost: ¥3,800,000); Fiscal Year 2002: ¥11,200,000 (Direct Cost: ¥11,200,000)
• Keywords: Bioinorganic Chemistry / Oxygen Activation / Non-Heme Enzyme / High Valnet Iron / Oxidation / Reaction Intermediate / Saren Complex / 酵素活性化 / サレン

Research Abstract

High-valent iron-oxo species are proposed to be the key reactive intermediate in oxidation reactions catalyzed by both heme and non-heme iron enzymes. In the case of heme enzymes, porphyrin model complexes have been extensively investigated, and oxo-iron (IV) porphyrin π-cation radical have been characterized as the most probable candidate for the active species. However, it is still unclear whether such high-valent iron-oxo species are generated from mononuclear non-heme iron active sites, in which there is no electron pool that can replace the large π-conjugation of the porphyrin ring. It is thus worth challenging to prepare transient oxidizing species from a mononuclear non-heme iron model complex for a detailed study of the electronic structure in comparison with the heme case. To this end, we have prepared a salen iron complex having a mesityl substituent, as a model for mononuclear iron enzymes. We have also tried to make a transient intermediate generated from the sterically hindered salen iron complex and m-chloroperoxybenzoic acid (mCPBA).

Research Products

• [Publications] Hiroshi Fujii et al.: "Trigonal Bipyramidal Ferric Aqua Complex with Sterically Hindered Salen Ligand as a Model for Active Site of Protocatechuate 3,4-Dioxygenase"Angew.Chemie.Int.Ed.. 41. 3638-3641 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Masataka Ohashi et al.: "Preparation of Artificial Metalloenzymes by Insertion of Chromium(iii) Schiff Base Complexes into Apomyoglobin Mutants"Angew.Chemie.Int.Ed.. 42. 7418-7426 (2003)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Roman Davydov et al.: "Kinetic Isotope Effects on the Rate-Limiting Step of Heme Oxygenase Catalysis Indicate Concerted Proton Transfer/Heme Hydroxylation"J.Am.Chem.Soc.. 125. 16208-16209 (2003)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Roman Davydov et al.: "A Superoxo-Ferrous State in a Reduced Oxy-Ferrous Hemoprotein and Model Compounds"J.Am.Chem.Soc.. 125. 16340-16346 (2003)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Hiroshi Fujii et al.: "Essential Amino Acid Residues Controlling the Unique Regioselectivity of Heme Oxygenase in Psudomonas aeruginosa"J.Am.Chem.Soc.. 126. 4466-4467 (2004)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Hiroshi Fujii et al.: "Trigonal Bipyramidal Ferric Aqua Complex with Sterically Hindered Salen Ligand as a Model for Active Site of Protocatechuate 3,4-Dioxygenase"Angew.Chemie.Int.Ed.. 41. 3638-3641 (2002)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Masataka Ohashi et al.: "Preparation of Artificial Metalloenzymes by Insertion of Chromium(iii) Schiff Base Complexes into Apomyoglobin Mutants"Angew.Chemie.Int.Ed.. 42. 7418-7426 (2003)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Roman Davydov et al.: "Kinetic Isotope Effects on the Rate-Limiting Step of Heme Oxygenase Catalysis Indicate Concerted Proton Transfer/Heme Hydroxylation"J.Am.Chem.Soc.. 125. 16208-16209 (2003)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Roman Davydov et al.: "A Superoxo-Ferrous State in a Reduced Oxy-Ferrous Hemoprotein and Model Compounds"J.Am.Chem.Soc.. 125. 16340-16346 (2003)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Hiroshi Fujii et al.: "Essential Amino Acid Residues Controlling the Unique Regioselectivity of Heme Oxygenase in Psudomonas aeruginosa"J.Am.Chem.Soc.. 126. 4466-4467 (2004)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Masataka Ohashi et al.: "Preparation of Artificial Metalloenzymes by Insertion of Chromium(iii) Schiff Base Complexes into Apomyoglobin Mutants"Angew.Chemie.Int.Ed.. 42. 1005-1008 (2003)
• [Publications] Xuhong Zhang et al.: "Regiospecificity of Each of the Three Steps of Heme Oxygenase Reaction from Hemin to meso-Hydroxyhemin, from meso-Hydroxyhemin to Verdoheme, and from Verdoheme to Biliverdin"Biochemistry. 42. 7418-7426 (2003)
• [Publications] Roman Davydov et al.: "Kinetic Isotope Effects on the Rate-Limiting Step of Heme Oxygenase Catalysis Indicate Concerted Proton Transfer/Heme Hydroxylation"J.Am.Chem.Soc.. 125. 16208-16209 (2003)
• [Publications] Roman Davydov et al.: "A Superoxo-Ferrous State in a Reduced Oxy-Ferrous Hemoprotein and Model Compounds"J.Am.Chem.Soc.. 125. 16340-16346 (2003)
• [Publications] Hiroshi Fujii et al.: "Essential Amino Acid Residues Controlling the Unique Regioselectivity of Heme Oxygenase in Psudomonas aeruginosa"J.Am.Chem.Soc.. 126(印刷中). (2004)
• [Publications] Hiroshi Fujii, Yasuhiro Funahashi: "Trigonal Bipyramidal Ferric Aqua Complex with Sterically Hindered Salen Ligand as a Model for Active Site of Protocatechuate 3,4-Dioxygenase"Angew. Chemie. Int. Ed.. 41. 3638-3641 (2002)