【摘要】 以舞毒蛾为材料,分离提取酚氧化酶,研究4-己基间苯二酚(4HR)和曲酸对舞毒蛾酚氧化酶活力的影响。结果表明:4HR对该虫的单酚酶和二酚酶活性均表现很强的抑制作用,其IC50分别为0.00041和0.00035mmol.L-1。其中,4HR对单酚酶活力表达的迟滞时间有明显的延长效应,浓度为0.0002mmol.L-1时可使单酚酶活力表达迟滞时间从181s延长到253s;而当浓度为0.0005mmol.L-1时,其迟滞时间则延长至372s。以邻苯二酚为底物时,4HR对二酚酶的抑制作用表现为典型的竞争型抑制类型,抑制常数KI为0.00015mmol.L-1。曲酸对舞毒蛾的单酚酶和二酚酶活性均表现较强的抑制作用,其IC50分别为0.06和0.92mmol.L-1。曲酸对单酚酶活力表达的迟滞时间也有明显的延长效应,浓度为0.1mmol.L-1时可使单酚酶活力表达迟滞时间从306s延长到732s;而当浓度为0.15mmol.L-1时,其迟滞时间则延长至900s。以邻苯二酚为底物时,曲酸对二酚酶的抑制作用表现为典型的竞争型抑制类型,抑制常数Ki为0.51mmol.L-1。更多还原

【Abstract】 The inhibitory effects of tetra-hexylresorcinol and kojic acids on the phenoloxidase from Lymantria dispar were investigated.The results showed that the IC_ 50 of tetra-hexylresorcinol was 0.000 41 mmol·L-1 for monophenolase activity and 0.000 35 mmol·L-1 for diphenolase,respectively.Tetra-hexylresorcinol extended the lagtime of the enzyme for oxidation of L-tyrosine.The lagtime extended from 181 s to 253 s by 4-hexylresorcinol with 0.000 2 mmol·L-1,and the lagtime extended from 181 s to 372 s by the chemical with 0.000 5 mmol·L-1.The inhibition kinetics analyzed by Lineweaver-Burk plots indicated that 4-hexylresorcinol was a competitive inhibitor for the oxidation of catechol and the inhibition constant was 0.000 15 mmol·L-1.The IC_ 50 of kojic acids were 0.06 mmol·L-1 for monophenolase activity and 0.92 mmol·L-1 for diphenolase,respectively.Kojic acids extended the lagtime of the enzyme for oxidation of L-tyrosine.The lagtime extended from 306 s to 702 s by the kojic acids with 0.1 mmol·L-1,and the lagtime extended from 306 s to 900 s by the compound with 0.15 mmol·L-1.The inhibition kinetics analyzed by Lineweaver-Burk plots indicated that kojic acids was a competitive inhibitor for the oxidation of catechol,and the inhibition constant was 0.51 mmol·L-1.更多还原