马铃薯胰凝乳蛋白酶抑制剂活力的测定  

Determination of Potato Chymotrypsin Inhibitor Activity

作　　者：曾凡逵[1] 周添红[1] 康克归 刘刚[1] 

机构地区：[1]中国科学院兰州化学物理研究所,环境材料与生态化学研究发展中心,甘肃兰州730000 [2]甘肃薯界淀粉有限公司,甘肃定西730510

出　　处：《现代食品科技》2015年第2期274-279,共6页Modern Food Science and Technology

基　　金：国家马铃薯产业技术体系专项(nycytx-15);国家自然科学基金青年科学基金项目(31301532);中国科学院"西部之光"人才培养计划项目(科发人字[2013]165号)

摘　　要：胰凝乳蛋白酶抑制剂的活力测定对于马铃薯块茎蛋白研究非常重要,特别是对于马铃薯蛋白的分离纯化,本文将会详细阐述马铃薯胰凝乳蛋白酶抑制剂的活力测定方法。本文所描述的方法是以酪蛋白为底物,在275 nm检测波长下采用分光光度法,在存在和不存在抑制剂的情况下,用一定量胰凝乳蛋白酶水解酪蛋白,测定酪蛋白分解产物的生成量。检测结果表明,从马铃薯块茎中提取的粗蛋白溶液其胰凝乳蛋白酶抑制剂活力为98.31 CUI/mg,按另外一种表达方式为82.11μg/mg,即每毫克胰凝乳蛋白酶抑制剂能抑制82.11μg胰凝乳蛋白酶。理论上,每100 g马铃薯块茎所含的胰凝乳蛋白酶抑制剂能抑制147.43 mg胰凝乳蛋白酶的活力。该方法不仅适用于马铃薯胰凝乳蛋白酶抑制剂的活力测定,对其他所有来源的胰凝乳蛋白酶抑制剂活力测定同样适用。Determination of chymotrypsin inhibitor activity is very important for the study of proteins in potato tubers, particularly for protein separation and purification. In this study, a method to evaluate the activity of a potato-derived chymotrypsin inhibitor was explored. This method was based on the spectrophotometric determination（275 nm） of the hydrolysis products of casein that were produced by a specific concentration of chymotrypsin, in the presence or absence of the inhibitor. The results showed that the chymotrypsin inhibitor activity of a crude protein solution extracted from potato tubers was 98.31 CUI/mg（82.11 μg/mg）. In other words, each milligram of chymotrypsin inhibitor inhibited 82.11 μg chymotrypsin. Theoretically, the chymotrypsin inhibitor content in 100 g potato tubers can inhibit the activity of 147.43 mg chymotrypsin. Thus, this method is suitable to determine the activity of chymotrypsin inhibitors from potatoes and other sources.

关 键 词：马铃薯 胰凝乳蛋白酶抑制剂 活力测定 酪蛋白 

分 类 号：TS201.25[轻工技术与工程—食品科学]