单宁酸与固定化胰蛋白酶相互作用的研究

研究了单宁酸(TA)对硅胶固定化胰蛋白酶活性的影响,通过酶活抑制测定方法和紫外分光光度法测定了TA与固定化胰蛋白酶作用的最适浓度与最适反应时间,研究了在pH 8.0 Tris-HCl、pH 2.4的甘氨酸-HCl以及含有1 mol/mL NaCl的Tris-HCl三种缓冲液中TA与固定化酶作用的平衡常数KA和结合位点数n.结果表明:TA对固定化胰蛋白酶有不同程度的抑制作用,当反应体系中TA的浓度为7.5×10-6mol/L时,固定化酶活力为91.1 U,抑制率大约为50%,TA与固定化胰蛋白酶最适反应时间为30 s,在pH 2.4的甘氨酸-HCl及含1 mol/mL NaCl的Tris-HCl中,TA与固定化酶的平衡常数KA减小了100倍,结合位点数n也有不同程度的降低.

Study of Interaction between Immobilized Trypsin and Tannic Acid

The effect of tannic acid（ TA） on enzyme activity of immobilization of trypsin was studied. The optimum concentration and time between immobilized trypsin and TA were investigated by means of absorption spectrometry. The binding constants（ KA） and binding sites（ n） between TA and immobilized trypsin in three buffer solutions,such as Tris-Hce（ pH =8.0）,Gly-Hcl（ pH =2.4） and Tris-hcl added by1 mol/L NaCl,were calculated. The result showed that activity of immobilized trypsin was inhibited by adding TA. When the concentration of TA was 7. 5 × 10^-6 mol /L,the activity of immobilized trypsin was 91. 1 U. The inhibition rate was about 50%. The optimum reaction time between immobilized trypsin and TA were 30 s. The KAreduced 100 times and the n reduced at different levels in pH 2. 4 Gly-HCl and 1 mol /mL NaCl Tris-HCl buffer solution.