漆酶与各种类型底物反应性能的微量热法研究

Studies on the character of the reaction between laccase and different substrates by microcalorimetry

在厌氧条件下．用LKB－2107Batch微量热系统研究了在298．15K,0．1mol／L磷酸盐缓冲溶液（pH7．4）中谈树漆酶与5种废物的反应．测定了各反应的反应焓变△rHm，米氏常数Km，酶底复合过程的吉布斯自由能上△Go,复合物中电子转移速率常数k_2，以及漆酶对各种废物的催化活性EA讨论了在相同的实验条件下，各种酶底复合物的稳定性，底物官能团及其位置对酶反应中的电子转移速率和非酶反应中自由基聚合形式及产物结构的影响．

Under anaerobic condition, the reactions between Rhus vernicifera laccase and 5 klnds of substrates have been studied by I,KB-2lO7 Batch microcalorimetry system at 298. 15 K in O. l mol/I, phosphates salt buffer (pH 7. 4 ).The molar reaction enthalpy (Q.H,,, ), the Michaelis constant (K,,, ), the rate constantof electron transfer process (k, ), the laccase activity (EA ) and the Gibbs bindlng en-ergy (dG', ) for each substrate have been determ1ned. The stability of laccase suh-strate complexes,the electron transfer rate of the enzymatlc reaction and the struc-ture of products of non-enzymatic reaction are discussed for each substrate underthe same experiment condition.