Electron Tranfer between Multi-copper Enzyme and Fe (CN) _6^<4->

多铜酶与Fe(CN)_6^<4->之间的电子转移

• 批准号: 06640737
• 负责人: HIROSE Junzo
• 金额: $ 1.02万
• 依托单位: Fukuyama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640737/
• 关键词: Multi-copper enzyme; Electron transfer reaction; Copper enzyme; 酸化還元電位; 配位残基

Bilirubin oxidase is the enzyme that catalyses the oxidation of bilirubin to biliverudin and a multi-copper enzyme containing type 1, type 2, and type 3 copper in the ratio of 1 : 1 : 2, respectively. Ferrocyanide ion (Fe (CN) _6^<4->) is a good substrate for bilirubin oxidase. Michaelis-Menten constant (K_m) and molar activity (K_<cat>) are 3.0*10^<-3>M and 300 sec^<-1>. Cr (CN) _6^<3-> that is structually similar to Fe (CN) _6^<4-> inhibits competitively the oxidation of Fe (CN) _6^<4->. The inhibition constant of Cr (CN) _6^<3-> is 3.0*10^<-3> M that is almost same value of K_m of Fe (CN) _6^<4->2. These results indicate that Cr (CN) _6^<3-> binds the binding site of Fe (CN) _6^<4-> in bilirubin oxidase. The gene of bilirubin oxidase was cloned and the nucleotide sequence of bilirubin oxidase has been determined. On the basis of the nucleotide sequence of bilirubin oxidase, the complete amino acid sequence of bilirubin oxidase has been determined. The amino acid residues that coordinate to cupric ions were decided and those that are around substrate binding site also are also guessed.

胆红素氧化酶是一种催化胆红素氧化为胆红素的酶，它是一种多铜酶，含有1型、2型和3型铜，其比例分别为1:1:2。亚铁氰化物离子（Fe (CN) _6^<4->）是胆红素氧化酶的良好底物。Michaelis-Menten常数（K_m）和摩尔活度（K_<cat>）分别为3.0*10^<-3>M和300 sec^<-1>。与Fe (CN) _6^<4->结构相似的Cr (CN) _6^<3->抑制Fe (CN) _6^<4->的竞争性氧化。Cr (CN) _6^<3->的抑制常数为3.0*10^<-3> M，与Fe (CN) _6^<4->2的K_m值基本一致。这些结果表明，Cr (CN) _6^<3->结合了Fe (CN) _6^<4->在胆红素氧化酶中的结合位点。克隆了胆红素氧化酶基因，测定了胆红素氧化酶的核苷酸序列。根据胆红素氧化酶的核苷酸序列，确定了胆红素氧化酶的完整氨基酸序列。确定了与铜离子配位的氨基酸残基，并猜测了底物结合位点周围的氨基酸残基。

项目成果

Hiroyuki Iwamoto: "Comparison of the Binding of β-Cyclodextrin and α-and γ-Cyclodextrins with pullulanase as Studied by Equilibrium." J.Biochem.116. 1264-1268 (1994)

Hiroyuki Iwamoto：“通过 Equilibrium 研究比较 β-环糊精、α-和 γ-环糊精与支链淀粉酶的结合。”116（1994）。

Junzo HIROSE et al: "Characterization of Ascorbate Oxidase from Acremonium sp. HI-25" J. Ionrg. Biochem.59. 718 (1995)

Junzo HIROSE 等人：“Acremium sp. HI-25 抗坏血酸氧化酶的表征”J. Ionrg。

Junzo Hirose et al.: "Characterization of Ascorbate Oxidase from Acremonium sp.Hl-25 and Bilirubin Oxidase from Trachyderma tunodae K-2539, Multi-Copper Enzyme" J.Inorg.Biochem.Vol.59. 718 (1995)

Junzo Hirose 等人：“Acremium sp.Hl-25 的抗坏血酸氧化酶和 Trachyderma tunodae K-2539 的胆红素氧化酶的表征，多铜酶”J.Inorg.Biochem.Vol.59。

Junzo Hirose et al.: "Charaterization of Ascorbate Oxidase from Acremonium sp HI-25" J. Inorg. Chem.59. 718 (1995)

Junzo Hirose 等人：“顶孢霉属 HI-25 抗坏血酸氧化酶的表征”J. Inorg。

Junzo Hirose: "Characterization of Ascorbate Oxidase from Acremonium sp.HI-25" J.Biochem.115. 811-813 (1994)

Junzo Hirose：“Acremium sp.HI-25 抗坏血酸氧化酶的表征”J.Biochem.115。