摘要
目的:以罗非鱼加工下脚料肠道为原料,分离提取其中的蛋白酶,并对其部分性质进行研究,旨在提供一种简便的食品级蛋白酶制备方法。方法:用茶多酚络合沉淀,Sephadex G-50分离纯化蛋白酶,SDS-PAGE检测分离效果及相对分子质量;以酪蛋白溶液为底物,采用Folin-酚法测定蛋白酶活力。结果:经茶多酚络合沉淀,得到一种复合蛋白酶,命名为TP-肠道蛋白酶;经Sephadex G-50凝胶层析除去茶多酚,得到游离肠道蛋白酶。TP-肠道蛋白酶的最适温度50℃,pH7.2～9.6,米氏常数Km=1.125×103mg/L;游离肠道蛋白酶的最适温度50℃,pH7.2～10.0,米氏常数Km=8.5×102mg/L。结论:TP-肠道蛋白酶和游离肠道蛋白酶均为复合蛋白酶,有望开发成食品级蛋白酶制剂。
Objective：To extract and purify the proteases from Tilapia intestine and study on their properties.Methods：Tea polyphenols complex precipitation was used to separate proteins.The active fraction was taken into a Sephadex G-50 column and washed with phosphate buffer（0.02 mol/L,pH 7.5）.The purification effect and molecular weight were determined by SDS-PAGE.The protease activity was detected by Folin method.Results：A protease named as TP-protease was purified after polyphenols complex precipitation and a compound protease named as Free-protease was obtained by removing tea polyphenols with the Sephadex G-50 column.TP-protease had a Km of 1.125×103 mg/L.The optimal temperature was 50 ℃.The optimal pH value was in the range of 7.2～9.6.The Free-protease had a Km of 8.5×102 mg/L.The optimal temperature was 50 ℃.The optimal pH value was in the range of 7.2～10.0.Conclusion：TP-protease and the Free-protease were compound proteases,which have the potential commercial use in food processing for protease preparations.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2010年第4期100-105,共6页
Journal of Chinese Institute Of Food Science and Technology
基金
福建省自然科学基金项目(No.2006J0418)
关键词
罗非鱼
蛋白酶
茶多酚
性质
tilapia
protease
tea polyphenols
properties
