亚麻种子中胰蛋白酶抑制剂的分离纯化及性质研究  

Purfication and properies of the trypsin inhibitor from flax seeds

作　　者：陈颖璐 石亚伟[1] 

机构地区：[1]山西大学生物技术研究所,教育部化学生物学与分子工程重点实验室,山西太原030006

出　　处：《食品工业科技》2016年第22期234-239,共6页Science and Technology of Food Industry

基　　金：2016年山西农业特色资源创新专项支持

摘　　要：将亚麻种子去壳粉碎,经丙酮脱脂和Tris-HCl缓冲液提取后,Q-Sepharose^(TM) Fast flow离子交换层析一步纯化,获得电泳纯的亚麻胰蛋白酶抑制剂(LUTI),纯化倍数可达9.62,活力回收率为6.25%,比活力为55.35 U/mg,SDSPAGE电泳显示LUTI分子量大小约为8 ku。质谱鉴定属于Potato型胰蛋白酶抑制剂,其抑制活性在p H2.0~6.0以及70℃以下有较好的稳定性,最适p H为6.0,最适温度为40℃,属于一种非竞争性抑制剂,Ki值为9.18×10^(-4)mol/L。DTNB法检测LUTI含有一对二硫键,二硫键存在有助于提高LUTI的稳定性和活性。The Linum usitatissimum trypsin inhibitor（LUTI） had been isolated from naked flax seeds by acetone fractionation,Tris-HCI buffer extraction and Q-SepharoseTM Fast flow.With the purification steps mentioned above, the overall recovery of enzymatic activity of 6.25% ,the specific activity of 55.35 U/mg and the purification fold of 9.62 for LUTI from crude extraction was achieved.The LC-ESI-MS showed LUTI belonged to Potato trypsin inhibitor family and the relative molecular weight was 8 ku by SDS-PAGE.The trypsin inhibitory activity of LUTI was stable below 70 ℃,as well as pH2.0~6.0. The optimum temperature of LUTI was 40 ℃ and the optimum pH was 6.0.LUTI was a non-competitive inhibitor by kinetic assay with an inhibition constant Ki of 9.18 × 10^-4 mol/L and contained a pair of disulfide bond by DTNB assay,which was related with the stability and activity of LUTI.

关 键 词：亚麻种子 胰蛋白酶抑制剂 分离纯化 酶活测定 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]