邻苯二酚与漆树酶反应的微量热法研究

STUDIES OF THE REACTION BETWEEN LACCASEAND O-DIHYDROXYBENZENE BY MICROCALORIMETRY

在０．１ｍｏｌ／Ｌ的磷酸盐缓冲溶液（ｐＨ７，４）中，用微量热法测定了２９８．１５Ｋ时，漆树漆酶与邻苯二酚反应的摩尔反应焓ΔｒＨｍ＝－２５７．７０±１．３７ｋＪ／ｍｏｌ，米氏常数Ｋｍ＝５．４９×１０－２ｍｏｌ／Ｌ和表观一极反应速率常数Ｋ１＝９．５８×１０－４Ｓ－１，及此条件下邻苯二酚作底物时的漆酶活性值ＥＡ＝０．０５９ＩＵ．

The total molar enthalpy and Michaelis constant and the observed velocity constant of first-order reation of the reaction between laccase and catechol in 0.1mol/L phosphate salt buffer(pH7.4) were determined by calorimetry to be ΔrH m=-257.70±1.37kJ/mol and K m =5.49×10 -2 mol/L and K 1=9.58×10 -4 S -1 ,respectively .The enzymatic activity of the laccase using o-dihydroxybenzene as the substrate was determined to be E A=0.059IU under this condition.