漆酶对酚类化合物生物催化氧化动力学研究——以儿茶酚和表儿茶素为模式底物  

Study on Kinetic Behaviors of the Biocatalysis of Laccase on Oxidation of Phenolic Compounds——Using Catechol and Epicatechin as Model Substrates

作　　者：罗耀红[1] 左莹[1] 苏钰琦[1] 马惠玲[1] 

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100

出　　处：《林产化学与工业》2008年第3期13-17,共5页Chemistry and Industry of Forest Products

基　　金：西北农林科技大学博士专项基金(08080101)

摘　　要：以白腐菌漆酶为试材,儿茶酚和表儿茶素为模式底物进行了酶促氧化反应动力学参数的测定。结果表明,以儿茶酚和表儿茶素为底物,漆酶催化氧化的产物最大吸收波长分别为388和408nm,作用最适pH值分别为5.5和5.75;最适反应温度均为55℃。漆酶对2种底物的催化氧化反应均符合米氏方程规律。在25℃反应条件下测得儿茶酚和表儿茶素2种底物的Km值分别为0.279和0.145mol/L;Vmax分别为0.114和1.139A/(U.min)。漆酶对表儿茶素的催化活性大大高于对儿茶酚的,作用于其混合物时需以儿茶酚的酶用量为准,即底物浓度0.5mol/L时加酶0.04U/mL。Trametes versicolor laccase was employed to measure enzymatic kinetics parameters for oxidation of model substrates, namely catechol and epicatechin. The results showed that the maximum absorption wavelengths of laccase-catalyzed oxidation end- products from catechol and epicatechin were 388 and 408 nm, respectively; Optimum pH values were 5.5 and 5.75, respective- ly; Optimum reaction temperatures were both 55 ℃, and laccase-catalyzed oxidations for both substrates fitted the Michaelis- Menten equation. Under the reaction temperature of 25 ℃, Km values for catechol and epicatechin were 0. 279, 0. 145 mo[/L, respectively; Vmax values were 0.114, 0. 139 A/（U-min） , respectively. This indicates that the catalytic activity of laccase on oxidation of epicatechin is much more higher than that of catechol. For the bio-transformation of mixture from the 2 substrates, enzyme dosage for catechol should be adopted which is 0.04 U/mL for substrate concentration 0.5 mol/L.

关 键 词：漆酶 生物催化 儿茶酚 表儿茶素 动力学特性 

分 类 号：TQ941[化学工程]