猪笼草消化液中蛋白酶的活性初探

为了进。步分析猪笼草瓶状体内消化液中蛋白质的性质,本研究在不同的温度和pH条件下测定消化液中蛋白酶的活性,并且比较了3种不同沉淀方法对消化液蛋白进行的浓缩,通过SDS-聚丙烯酰胺电泳对消化液蛋白作了初步分离。结果表明,猪笼草消化液中蛋白酶的最适酶活温度为50℃,且稳定性最高;当pH为5时,该蛋白酶活性出现峰值,采用氯仿-正丁醇法（5：1）沉淀浓缩猪笼草消化液蛋白样品效果最佳。聚丙烯酰胺电泳结果表明,消化液至少包括三种蛋白组分,分子量分别为24.3kD、35．1kD和61．4kD,且35．1kD条带具有抗胰蛋白酶消化活性。本研究为综合开发利用猪笼草野生资源提供理论依据。

Preliminary Study on the Activities of Protease in Digestive Juice of Pitcher Plant

In order to analyze the character of the protein of the digestive juice in the ascidium of pitcher plant, we carried out a study of effect in different temperature and pH on activity ofprotease in digestive juice of pitcher plant we also compared 3 kinds of precipitation methods ofprotease concentrate and isolated protein sample in digestive juice by using SDS-PAGE. The results showed that the optimum temperature ofprotease in digestive juice in the ascidium was 50℃ with the maxlmum stability, and the peak value of activity ofprotease was found with the pHS. Experimental results indicated the best method of the protein concentrate was chloroform/butanol （5：1）, and there were at least three kinds of protein component with different MW, i.e. 24.3 kD, 35.1 kD and 61.4 kD, respectively, it was also shown that the protein with 35.1kD has the character of antitrypsine. This research should supply some evidences for the exploitation and utilization reasonable in wild resource of pitcher plant.