邻氨基苯酚与漆树漆酶反应的微量热法研究

STUDIES OF THE REACTION BETWEEN LACCASE AND O AMINOPHENOL 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时漆树漆酶与邻氨基苯酚反应的摩尔反应焓ΔｒＨｍ＝２５２．２１±３．５９ｋＪ／ｍｏｌ，米氏常数Ｋｍ＝７．７７×１０－３ｍｏｌ／Ｌ和表观一级反应速率常数ｋ１＝７．２３×１０－３ｓ－１，及此条件下邻氨基苯酚作底物时的漆酶活性值ＥＡ＝０．１９０（ＩＵ）。

The total molar enthalpy and the Michaelis constant and the observed first ordor velocity constant of the reaction between the Rhus vernicifera laccase and O aminophenol have been determined at 298.15K by microcalorimetry in 0.1mol/L phosphate salt buffer (pH7.4).ΔrHm=-252.21±3.59kJ/mol and Km =7.77×10 -3 mol/L and k 1=7.23×10 -3 s -1 ,correspond.The enzymatic activity of the laccase have been determined to be EA=0.190(IU) under such conditions by using the O aminophenol as the substrate.