南美白对虾虾头内源酸性蛋白酶的分离纯化及其酶学特性研究  

Purification and characteristics of endogenous acid protease from shrimp head of Litopenaeus vannamei

作　　者：庄志凯[1,2] 杜嵇华[1] 吉宏武[2] 连文伟[1] 

机构地区：[1]中国热带农业科学院农业机械研究所,广东湛江524091 [2]广东海洋大学食品科技学院,广东湛江524088

出　　处：《食品工业科技》2012年第18期116-120,共5页Science and Technology of Food Industry

基　　金：国家科技支撑计划项目(2007BAD29B09);国家科技支撑计划和政策引导项目(2008BAD94B08);广东省科技计划项目(2008A020100002)

摘　　要：通过10%～50%的硫酸铵盐析和两次柱层析,从南美白对虾虾头的匀浆液中分离纯化出一种内源酸性蛋白酶,经电泳分析测得其分子量为27.45ku,该酶的Km值、Vmax值、最适pH和最适反应温度分别为2.01g/L、26.39μg/min、3.0和30℃。内源酸性蛋白酶的热稳定性较差,Pepstatin A和EDTA对该蛋白酶表现出强烈的抑制作用,Hg+能完全抑制该蛋白酶,但Ca2+却能激活该蛋白酶。据此推断该蛋白酶是一种金属蛋白酶,该酶活性中心含有一些金属离子,其性质类似于胃蛋白酶类。Endogenous acid protease was purified from a shrimp head homogenate of Litopenaeus vannamei by 10%～50% of ammonium sulfate fractions and twice chromatography.Its molecular weight was estimated to be 27.45ku by SDS-PAGE electrophoresis and its apparent Km,Vmax,optimal pH and optimal temperature for casein were 2.01g/L,26.39μg/min,3.0 and 30℃,respectively.The endogenous acid protease had weak thermostability and could be significantly inhibited by Pepstatin A,EDTA and Hg＋,but activated by Ca2＋.It＇s inferred the protease from Litopenaeus vannamei shrimp head was a kind of Metalloproteases and that activity centers might also contain small amounts of metalions,the property of the enzyme was similar to the pepsin.

关 键 词：南美白对虾虾头 内源酸性蛋白酶 分离纯化 酶学性质 

分 类 号：TS254.1[轻工技术与工程—水产品加工及贮藏工程]