1987 Fiscal Year Final Research Report Summary
Studies on the Molecular Engineering of Functional Regulations of Synthetic Pigment Substituted Hemoproteins
| Project/Area Number |
61470079
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業物理化学
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| Research Institution | Kyoto University |
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Principal Investigator |
MORISHIMA Isao Kyoto University, Faculty of Engineering, Associate Prof., 工学部, 助教授 (50026093)
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| Co-Investigator(Kenkyū-buntansha) |
YONEZAWA Teijiro Kyoto University , Faculty of Engineering, Professor, 工学部, 教授 (20025787)
SHIRO Yoshitsugu Postdoctoral Fellow of JSPS, 特別研究員
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| Project Period (FY) |
1986 – 1987
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| Keywords | Metal-substituted Hemoproteins / Molybdenum and Tungusten-substituted Hemoproteins / タングステン置換ヘムタンパク質 / ニッケル置換ミオグロビン / ルテンウム置換ヘモグロビン / グリーンヘムタンパク質 / クロクン含有ヘムタンパク質 |
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| Research Abstract |
We have studied the structures and functions of hemoprotein derivatives reconstituted with a variety of metal-substituted hemes and iron-chlorin derivatives. Molybdenum (Mo) and tungustem (W) substituted myoglobin (Mb) and horseradish peroxidase (HRP) (where the heme iron is replaced by Mo=0 or w=0) were prepared. It was found that Mb favors the reduced state (+4), while HRP stabilizes in the oxidized state (+5). Nickel(II)-substituted Mb, Hb and HRP were oxidized with iridate to examine whether porphyrin <pi>-cation radical is formed or not in these hemoproteins. It was found that Ni(II)-porphyrin <pi>-cation radical is formed in all of these hemoproteins, although it is less stable in Mb and Hb than in HRP. Tese results are discussed in relation to the different features of higher oxidation states of native Mb and HRP. Diruthenium-substituted Ru-Fe hybrid Hbs were synthesized by heme substitution from protoheme to Ru(II)CO-deuteroporphyrin in the <alpha> or <beta> subunits. The proton NMR spectra of the intersubunit hydrogen-bonded protons showed that the quaternary structures of the two complementary hybrids both remain in the "T-like-state" at low pH, suggesting that the T to R structural conversion is induced by ligation of the third ligand molecule. E have also studied hemoproteins containing iron-chlorin prosthetic groups and their model chlorin complexes.
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