3-羟基苯甲酸对酪氨酸酶的抑制作用和抑菌作用

酪氨酸酶是一种金属铜蛋白,广泛存在于自然界中,在生物体合成黑色素过程中起着关键作用.以3-羟基苯甲酸为效应物,研究对蘑菇酪氨酸酶活力的影响和对化妆品中的主要腐败菌的抑制作用.结果表明:3-羟基苯甲酸对酪氨酸酶有明显的抑制作用,其半抑制率(IC50)为4.20 mmol/L.抑制作用表现为可逆的竞争型,抑制常数KI为2.38 mmol/L.3-羟基苯甲酸对大肠杆菌(E.coli)、金黄色葡萄球菌(St.aureus)和枯草芽孢杆菌(B.subtilis)有显著的抑制作用.本文通过研究3-羟基苯甲酸的抑酶和抑菌作用,为进一步研究设计新型化妆品添加剂奠定了理论基础.

Inhibition of 3-hydroxylbenzoic Acid on Tyrosianse and Its Bacteriostatic Activity

Tyrosinase(1.14.18.1) is a key enzyme during melanin-biosynthesis,widely distributed in nature.The active site of this enzyme consists of two copper atoms.This paper reports that 3-hydroxylbenzoic acid can inhibit o-diphenolase activity of mushroom tyrosinase.The inhibition kinetics and mechanism of the enzyme by 3-hydroxylbenzoic acid were studied.The results showed that 3-hydroxylbenzoic acid was a reversible inhibitor of mushroom tyrosinase.With the concentration of this inhibitor increasing,the activity of the diphenolase reduced exponentially.The inhibitor concentration leading to 50% activity lost(IC_(50)) was estimated to be 4.20 mmol/L for diphenolase.The inhibition kinetics analyzed by Lineweaver-Burk plots showed that 3-hydroxylbenzoic acid was a competitive type inhibitor,and the inhibition constants for free enzyme(K_I) was determined to be 2.38 mmol/L.The bacteriostatic activity of 3-hydroxylbenzoic acid was investigated by the agar diffusion method.The result showed that 3-hydroxylbenzoic acid could inhibit E.coli,B.subtilis and St.aureus,which usually exist in putrefactive cosmetic.