| Project/Area Number |
14340208
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic chemistry
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| Research Institution | Kyoto University (2004)
Kyushu University (2002-2003) |
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Principal Investigator |
OHBA Masaaki (2004) Kyoto University, Faculty of Engineering, Associate Professor, 工学研究科, 助教授 (00284480)
大川 尚士 (2002-2003) 九州大学, 大学院・理学研究院, 教授 (00037219)
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| Co-Investigator(Kenkyū-buntansha) |
OKAWA Hisashi Kyushu University, Faculty of Science, Professor, 理学研究院, 名誉教授 (00037219)
KODERA Masahito Doshisha University, Faculty of Engineering, Professor, 工学部, 教授 (00183806)
大場 正昭 京都大学, 大学院・工学研究院, 助教授 (00284480)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥14,300,000 (Direct Cost: ¥14,300,000)
Fiscal Year 2004: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2003: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2002: ¥8,800,000 (Direct Cost: ¥8,800,000)
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| Keywords | Phosphotriesterase / Phosphodiesterase / Hydrolysis / Dinuclear complex / Function model / コンパートメント配位子 / 非対称型二核化配位子 / ESI質量分析 / ウレアーゼモデル / ヘテロ二核錯体 / 尿素の化学変換 / 大環状二核化配位子 / 異常原子価二核錯体 / 配位位置異性 / μ-ペルオキソ錯体 |
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| Research Abstract |
(1)Phosphotriesterase-like hydrolytic function
Bis(μ-carboxylato)-μ-phenolatocomplexes, [M_2(L)(AcO)_2]^+(M=Mn,Co,Ni,Zn), based on ‘end-off' type dinucleating compartment ligand have been prepared as phosphotriesterase-model compounds which catalyze the hydrolysis of tris(p-nitrophenyl)phosphate (TNP)→bis(p-nitrophenyl)phosphate (BNP^-). The hydrolysis was traced by means of UV-vis and ESI mass spectra. The ability of hydrolysis depends on the metal combination of dinuclear core and decreased in the order, MnMn〜ZnZn>CoCo>>NiNi. This tendency is well explained by the order of nucleophilicity of water molecules binding to the metal centers. Actual phosphotriesterase has not MnMn but ZnZn dinuclear core as active sites, because natural abundance of Zn in the sea is more than that of Mn.
(2)Phosphodiesterase-like hydrolytic function
Hydrolysis of bis(p-nitrophenyl) phosphate (BNP^-) has been studied by using of dinuclear complexes, [M_2(L)(AcO)_2]^+ (M=Mn,Co,Ni,Zn). It was revealed that the hydrolysis progresses via [M_2(L)(AcO)(BNP)]^+ which was generated from an equilibrium [M_2(L)(AcO)_2]^++BNP^-= [M_2(L)(AcO)(BNP)]^++AcO^- and the ability of hydrolysis decreased in the order, MnMn〜CoCo>>NiNi>>ZnZn. The hydrolysis ability of ZnZn compound, [Zn_2(L)(AcO)_2]^+, is very low, because it forms ‘rigid' μ-acetato-μ-BNP core structure with BNP-, which is inconvenient to take water molecules on ZnZn core. In natural, phosphodiesterase has not CoCo but MnMn core as active sites, because natural abundance of Co in the sea is much less than that of Mn. Furthermore, the first function-model of purple acid phophatase which has FeZn core structure has been prepared successfully.
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