以毛西番莲的叶片为材料,经水提、过滤、旋转蒸发浓缩,得到毛西番莲酪氨酸酶抑制剂的提取物.研究该提取物对蘑菇酪氨酸酶的效应,结果表明,毛西番莲提取物对蘑菇酪氨酸酶有较强的抑制作用,其IC50值为0.47mg/mL,抑制机理为可逆混合型,其对游离酶的抑制常数(K)0.56mg/mL和对酶-底物络合物的抑制常数(KIS)为1.10mg/mL.
Tyrosinase is an enzyme that is very important in the browning of fruit and vegetable and melanin synthesis. The water-solvable extraction from Passiflora foetidawas was obtained by filtrating, extracting, and concentrating. We measured the inhibitory effects of this extraction on mushroom tyrosinase,including the inhibit rating and the mechanism of inhibition. Results obtained shows that the concentration leading to 50% activity lost ( IC50 ) of the enzyme is 0.47 mg/mL. The mechanism of this extraction effecting on enzyme is reversible and the inhibition type is mixed-type inhibition. The inhibition constant (KI) was determined to be 0.56 mg/mL and KIS was determined to be 1.10 mg/mL.