Evaluation and Modification of Chemical Functions of Dicopper Proteins

蘑菇酪氨酸酶活性的评价：采用电流法对蘑菇酪氨酸酶的过氧化氢酶和过氧酶活性进行了动力学研究。对一系列对取代酚对过氧酶活性的取代效应进行了定量分析，表明反应机理与苯酚酶反应相同，即侧对过氧二铜（II）中间体的亲电芳香取代机理。同样的过氧化物中间体也被认为是过氧化氢酶活性的中间体。此外，儿茶酚酶活性也以同样的方式进行了研究，以证明侧对过氧二铜（II）中间体对苯酚的氧化涉及类似的亲电性张力机制粗草神经孢子虫酪氨酸酶的纯化：为了研究不同来源粗草神经孢子虫酪氨酸酶的催化功能和机制，对粗草神经孢子虫酪氨酸酶进行了分离纯化二铜-二氧配合物对苯酚的氧化机理：首次系统研究了（μ-η^2:η^2-过氧）二铜（II）配合物和双（μ-氧）二铜（III）配合物对中性苯酚的氧化作用。比较Cu_2/O_2配合物对苯酚的氧化速率对苯酚底物单电子氧化电位的依赖性，有助于深入了解苯酚氧化的机理基础以及Cu_2/O_2配合物的电子转移氧化能力配体对铜(I)-二氧反应性的影响：将N， N-二（6-甲基-2-吡啶基甲基）-2-苯基乙胺三叉配体负载的铜(I)配合物的结构、理化性质和二氧反应性与N， N-二[2-（2-吡啶基）乙基]-2-苯基乙胺三叉配体的铜(I)配合物1和N， N-二（2-吡啶基甲基）-2-苯基乙胺三叉配体的铜(I)配合物3进行了比较。2在低温下的氧化得到了与1类似的侧对过氧铜（II）配合物，但它的O-O键与由1衍生的过氧配合物相比相对减弱。另一方面，3与二氧迅速反应生成双（μ-氧）二铜（III）配合物。这些结果可以通过考虑配体电子给体能力的差异来解释。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