槲皮素对胰蛋白酶活性的影响

通过测定槲皮素对胰蛋白酶催化活性、催化反应动力学以及内源荧光光谱的影响,对槲皮素和胰蛋白酶相互作用特性进行研究.结果表明:槲皮素对胰蛋白酶催化活性有明显的抑制作用,当槲皮素与胰蛋白酶的摩尔比为44∶1,在37℃反应10min,抑制率达到32.5％;反应时间对两者的作用影响并不明显；槲皮素对胰蛋白酶催化活性的抑制作用属于可逆的竞争性抑制；槲皮素可使胰蛋白酶的内源荧光发生猝灭现象,猝灭常数Kq是4.7415×1012 (mol/L)1·S-1,猝灭类型为静态猝灭,结合位点数N为0.9206.

The Influence of Quercetin on the Trypsin Properties

The interaction between quercetin and trypsin was studied by measuring the catalytic activity,the enzymatic kinetic analysis and fluorescence spectra.Quercetin showed inhibition effect on catalytic activity of trypsin.When trypsin was treated by quercetin with the molar ratio of quercetin to trypsin of 44:1 for 10mins under 37 ℃,the inhibition rate reached 32.5%.Reaction time had little effect on the inhibition rate.The type of inhibition effect was reversible competitive inhibition.Quercetin can cause the quenching of intrinsic fluorescence of trypsin in physiological condition.With fluorescence quenching method,the quenching constant Kq was found to be 4.7415×1012(mol/L)-1?S-1 and the number of binding site N was 0.9206.