論文

査読有り
2021年1月

Effect of the Electron Density of the Heme Fe Atom on the Nature of Fe-O Bonding in Oxy Myoglobin

Inorganic chemistry
  • Yamamoto, Yasuhiko
  • ,
  • Hasegawa, Kazuyasu
  • ,
  • Shibata, Tomokazu
  • ,
  • Momotake, Atsuya
  • ,
  • Ogura, Takashi
  • ,
  • Yanagisawa, Sachiko
  • ,
  • Neya, Saburo
  • ,
  • Suzuki, Akihiro
  • ,
  • Kobayashi, Yasuhiro
  • ,
  • Saito, Makina
  • ,
  • Seto, Makoto
  • ,
  • Ohta, Takehiro

60
2
開始ページ
1022
終了ページ
1028
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1021/acs.inorgchem.0c03123
出版者・発行元
AMER CHEMICAL SOC

Mössbauer spectroscopy has been used to characterize oxygenated myoglobins (oxy Mbs) reconstituted with native and chemically modified Fe-enriched heme cofactors with different electron densities of the heme Fe atom (ρ) and to elucidate the effect of a change in the ρ on the nature of the bond between heme Fe and oxygen (O), i.e., the Fe-O bond, in the protein. Quadrupole splitting () was found to decrease with decreasing ρ, and the observed ρ-dependent confirmed an increase in the contribution of the ferric-superoxide (Fe-O) form to the resonance hybrid of the Fe-O fragment with decreasing ρ. These observations explicitly accounted for the lowering of O affinity of the protein due to an increase in the O dissociation rate and a decrease in the autoxidation reaction rate of oxy Mb through decreasing H affinity of the bound ligand with decreasing ρ. Therefore, the present study demonstrated the mechanism underlying the electronic control of O affinity and the autoxidation of the protein through the heme electronic structure. Carbon monoxide (CO) adducts of reconstituted Mbs (CO-Mbs) were similarly characterized, and we found that the resonance between the two canonical forms

リンク情報
DOI
https://doi.org/10.1021/acs.inorgchem.0c03123
ID情報
  • DOI : 10.1021/acs.inorgchem.0c03123
  • ISSN : 1520-510X

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