大蹼铃蟾皮肤白蛋白的胰蛋白酶抑制活性研究

Trypsin Inhibitory Activity of Skin Albumin from Bombina maxima

通过离子交换层析和凝胶过滤层析,在大蹼铃蟾(Bombina maxima)皮肤中得到其白蛋白。该蛋白有强烈抑制胰蛋白酶水解小肽底物的活性,但对其它丝氨酸蛋白酶如凝血酶、糜蛋白酶、弹性蛋白酶及枯草杆菌蛋白酶无抑制。它以1∶1摩尔比同胰蛋白酶形成稳定结合的复合物。经测定发现,该蛋白对温度、pH值及还原剂二硫苏糖醇的耐受性较强,三种因素对其胰蛋白酶抑制活性影响不大。说明大蹼铃蟾皮肤白蛋白具有稳定的胰蛋白酶抑制活性,可能在大蹼铃蟾防御天敌捕食的过程中发挥重要作用。

Skin albumin of Bombina maxima was obtained throught the steps of mixing ion-exchange and gel filtration chromatography. The protein distinctly inhibited trypsin, but no inhibitory effect on thrombin, chymotrypsin, elastase and subtilisin were observed under the assay conditions. It formed a stable complex with trypsin at 1 ： 1 moler ratio. Skin albumin exhibited the trypsin inhibitory stability against temperature, pH, and DTT, which suggested that skin albumin possessed stable trypsin inhibitory activity, and maybe played an important role in against predators.