漆酶的结构与催化反应机理

漆酶是一种广泛分布的多酚氧化酶,主要由单一多肽、铜离子活性中心、糖配基组成。多肽链一般含有18种氨基酸,构成漆酶的结构主体;糖配基因漆酶的来源不同而异,是漆酶多样性的标志之一。漆酶活性中心的铜离子依据光学和磁学特性被分为3种类型:Ⅰ型或蓝型铜,Ⅱ型或通常型铜,Ⅲ型或偶联的双核型铜。漆酶的催化反应机理主要包括酶对底物的电子提取、电子的传递和氧分子对酶的还原三步,是一个通过电子转移发生氧化还原反应的过程。

Structure and Catalytic Mechanism of Laccase

Laccase is one kind of polyphenol-oxidase distributed widely. It is mainly composed of single peptide,copper ions active center and sugar genin. There are 18 kinds of amino acid in the peptide generally,making up the structure body; sugar genin,as one of the signs of diversity,differs in laccases. The copper ions in the acticve center are divided into 3 types based on optical and magnetic properties: type Ⅰor blue type copper,type Ⅱor usually type copper,typeⅢ or coupling double-core copper. The catalysis of laccase is redox reaction through electron transfer,generally including the electronic extraction of substrate, the transmission of electrons ,enzyme reduction by O 2 . Factors like temperature,pH,buffer system,acid, inhibitors,etc. all have an effect on the catalytic ability of laccase.