不同底物体系下漆酶的失活动力学研究

本文对三种体系的漆酶热失活动力学进行了研究,并对动力学参数进行了相应的分析。结果显示,漆酶在纯水溶液中的失活符合一级动力学模型,其失活方程为lnA=-0. 1353t-2. 2522。在有毒有机物体系(2,4-二氯酚和吲哚溶液)中漆酶的失活仍符合一级失活动力学模型,失活速率常数减小,但半衰期增大。在极性溶液(乙醇)中,漆酶的反应速率常数最小,可能是因为漆酶分子内部作用力的变化导致了漆酶反应变缓;在非极性体系(异辛烷溶液)中,水-疏水体系减少了对酶的伤害,利于酶的稳定,延长了漆酶半衰期;极性或非极性体系中的漆酶失活均符合一级动力学失活模型。

Inactivation Kinetics of Laccase under Different Reaction Systems

In this paper, the kinetic thermal activity of laccases in three systems was studied, and the kinetic parameters were analyzed accordingly. The results showed that the inactivation of laccase in pure aqueous solution accorded with the first-order kinetic inactivation model, and the inactivation equation was lnA=-0.1353t-2.2522. The inactivation of laccase in the toxic organic system (2,4-dichlorophenol and indole solution) is still in accordance with the first-order inactivation mechanical model. The inactivation rate constant is reduced, but the half-life is increased. In polar solution(ethanol solution), the reaction rate constant of laccase is the smallest, probably because the change of internal force in laccase molecule causes the laccase reaction to be slow; In the non-polar system(isooctane solution), water-hydrophobic system reduces the damage to the enzyme, which is beneficial to the stability of the enzyme and prolongs the half-life of laccase. The laccase inactivation in the polar or non-polar system is consistent with the first-order kinetic inactivation model.