萝卜CBPs溶菌酶活性的稳定性研究

摘要

Plant lysozyme played an important role in plant defense.There are two chitin-binding proteins (CBP) with lysozyme activity purified from Raphanus sativus L.which were named as CBP1 and CBP2.The stability of lysozyme activity of CBPs was studied to understand the catalysis mechanism and physiology function of CBPs.Results showed that CBPs were stable at 25 ℃ in pH 3.4～10.6 and inactive quickly at 65 ℃ in pH 5.4; CBP1 was more sensitive to H2O2 and NaClO and less sensitive to papain than CBP2; Both CBP1 and CBP2 were sensitive to trypsin.%植物溶茵酶是植物防御体系中的一部分,在植物防卫体系中具有重要作用.萝卜中有2个具溶菌酶活性的几丁质结合蛋白(Chitin-binding proteins,CBPs),分别是CBP1、CBP2组分.为了解CBPs的作用机制以及在萝卜中的生理功能,试验研究了CBP1、CBP2溶茵酶组分酶活性的稳定性.结果显示,CBP1、CBP2在pH 5.4、65℃条件下迅速失活,在pH 3.4～10.6、25℃条件下较稳定；CBP1较CBP2对氧化剂H2O2、NaC1O敏感；CBP2较CBP1对木瓜蛋白酶敏感;2个组分对胰蛋白酶均敏感.