Evaluation and Modification of Chemical Functions of Dicopper Proteins

[1]蘑菇酪氨酸酶活性的测定：用电流法对蘑菇酪氨酸酶的过氧化氢酶和过氧化物酶活性进行了动力学研究。定量分析了一系列对取代苯酚对过氧化物酶活性的影响，表明该反应机理与酚酶反应机理相同，即以过氧二铜(II)为中间体的亲电性芳香取代机理。同样的过氧基中间体被认为是过氧化氢酶活性的中间体。此外，儿茶酚酶的活性也以同样的方式进行了研究，以证明过氧二铜(II)中间体对苯酚的氧化涉及类似的亲电紧张性机理。[2]为了研究酪氨酸酶fr…的催化功能和机理，分离和纯化了粗脉孢子菌酪氨酸酶：粗脉孢子菌酪氨酸酶。二铜氧配合物氧化苯酚的机理：首次系统研究了(μ-η^2：η^2-Peroxo)二铜(II)络合物和双(μ-氧代)二铜(III)络合物对中性酚的氧化作用。比较Cu2/O2络合物氧化苯酚的速率依赖关系与苯酚底物的单电子氧化电位的关系，为深入了解苯酚氧化的机理以及Cu2/O2络合物的电子转移氧化能力提供了深刻的见解。[4]比较了N，N-bis(6-methyl-2-pyridylmethyl)-2-phenylethylamine三齿配体负载的铜(I)络合物的结构、物理化学性质和双氧反应性。N-双[2-(2-吡啶基)乙基]-2-苯乙胺三齿配体和N，N-二(2-吡啶甲基)-2-苯乙胺三齿配体的铜(I)配合物3。与1一样，2在低温下氧化生成了一个侧向的过氧二铜(II)络合物，但其O-O键相对1的过氧络合物相对较弱。另一方面，3与氧反应非常迅速地生成了双(μ-氧代)二铜(III)络合物。这些结果可以通过考虑配体的电子给体能力的差异来解释。较少

[1] Evaluation of Enzymatic Activities of Mushroom Tyrosinase:Catalase and peroxygenase activity of mushroom tyrosinase have been investigated kinetically by using amperometric methods. Quantitative analysis on the substituent effects of a series of p-substituted phenols in the peroxygenase activity has demonstrated that the reaction mechanism is the same to that of the phenolase reaction, that is the electrophilic aromatic substitution mechanism by a side-on peroxo dicopper(II) intermediate. The same peroxo intermediate has been imprecated to be involved as an intermediate of catalase activity. Furthermore, catecholase activity has investigated in the same manner to demonstrate that the oxidation of phenols by the side-on peroxo dicopper(II) intermediate involves a similar electrophilic tonic mechanism.[2] Purification of Neurospora crassa Tyrosinase :Neurospora crassa tyrosinase has been isolated and purified in order to examine the catalytic functions and mechanisms of tyrosinase fr … More om different origins.[3] Oxidation Mechanism of Phenols by Dicopper-Dioxygen Complexes :The first systematic study on the oxidation of neutral phenols by the (μ-η^2:η^2-peroxo) dicopper (II) complex and the bis (μ-oxo) dicopper (III) complex. Comparison of the rate-dependences in the oxidation of phenols by the Cu_2/O_2 complexes on the one-electron oxidation potentials of the phenol substrates provides profound insights into the mechanistic basis of the phenol-oxidation as well as the electron-transfer oxidation ability of the Cu_2/O_2 complexes.[4] Ligand Effects on the Copper(I)-Dioxygen Reactivity :Structure, physicochemical properties, and dioxygen-reactivity of copper (I) complexes supported by N, N-bis(6-methyl-2-pyridylmethyl)-2-phenylethylamine tridentate ligands have been compared to those of copper (I) complex 1 of N, N-bis[2-(2-pyridyl)ethyl]-2-phenylethylamine tridentate ligand and copper (I) complex 3 of N, N-bis(2-pyridylmethyl)-2-phenylethylamine tridentate ligand. Oxygenation of 2 at a low temperature gave a side-on peroxo dicopper (II) complex as in the case of 1, but its O-O bond was relatively weakened as compared to that of the peroxo complex derived from 1. On the other hand, 3 reacted with dioxygen very rapidly to give a bis (μ-oxo) dicopper (III) complex. These results can be interpreted by taking account of the difference in electron donor ability of the ligands. Less