【摘要】 为研究广玉兰花酪氨酸酶的活性及影响因素,从广玉兰花中提取酪氨酸酶,以邻苯二酚为底物,在不同温度、pH值、底物浓度下研究酪氨酸酶的活性,并研究了效应物苔黑酚对酪氨酸酶活性的影响。结果表明:广玉兰花酪氨酸酶催化的是单酶单底物的酶促反应;广玉兰花酪氨酸酶的最适温度为35℃,最适p H值为6. 5;以邻苯二酚作底物时的广玉兰花酪氨酸酶的Km=0. 025 mol/L,Vmax=166. 7 U/min;在0. 05～0. 25 mmol/L浓度范围内,苔黑酚对酪氨酸酶有抑制作用,抑制率随抑制物浓度的增大而增大。更多还原

【Abstract】 The tyrosinase was extracted from Magnolia grandiflora L. flower for preliminary research on the tyrosinase activity and its influence factors with catechol as substrate. The tyrosinase activity was studied under various temperatures,pH values,substrate concentrates and effect material. The results showed that the catalytic reaction of the tyrosinase was enzymatic reaction of single enzyme and single substrate. The optimal temperature in catalyzed reaction of the tyrosinase was 35℃,the optimal pH was 6. 5. The catalyzed kinetic constants were Km = 0. 025 mol/L and Vmax = 166. 7 U/min. Orcinol had the inhibitory effect on the tyrosinase in a concentration range of0. 05-0. 25 mmol/L,the inhibition rate increases with the increasing of the concentration of the inhibitor.更多还原