草鱼丝氨酸蛋白粗酶的提取、酶学特性及大豆胰蛋白酶抑制剂对其活性的影响  

Extraction and Enzymatic Characteristics of Serine Protease from Grass Carp(Ctenopharyngodon idellus)Musle and the Effect of Soybean Trypsin Inhibitor on Its Activity

作　　者：周佳怡 洪惠[1] 罗永康[1] 谭雨青 ZHOU Jiayi;HONG Hui;LUO Yongkang;TAN Yuqing(College of Food Science and Nutritional Engineering,China Agricultural University,Beijing 100083,China)

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《广东海洋大学学报》2024年第3期112-118,共7页Journal of Guangdong Ocean University

基　　金：国家自然科学基金(32101863)。

摘　　要：【目的】探究草鱼(Ctenopharyngodon idellus)肌原纤维结合型丝氨酸蛋白酶(MBSP)粗酶的提取方法、酶学特性,以及大豆胰蛋白酶抑制剂(STI)对草鱼鱼糜凝胶品质的影响,为改善传统草鱼鱼糜制品品质提供理论基础。【方法】从草鱼背肌中提取MBSP粗酶液,探究提取过程中漂洗次数(1~5次)、热处理温度(35、40、45、50、55℃)、酸洗脱pH值(pH 4.0、pH 5.5)对提取液酶活性的影响,获得最佳提取条件;设置梯度实验探究所得酶的最适温度、pH、稳定性等酶学特性,最后探究大豆胰蛋白酶抑制剂对粗酶酶活性的影响及其对草鱼鱼糜凝胶性能的调控。【结果及结论】经3次漂洗、45℃热处理、pH 4.0酸洗脱后得到的草鱼MBSP粗酶液酶活性最高(P<0.05);所得MBSP最适pH值在9.0附近,最适温度为45℃,具有较好的温度稳定性(P<0.05),其活性可被Na^(+)在一定程度上抑制且被K+、Ca^(2+)激活(P<0.05);STI添加可以显著改善草鱼鱼糜质构,其对草鱼肌原纤维结合型丝氨酸蛋白酶有可逆竞争性抑制作用,半抑制质量浓度为10.85μg/mL,抑制常数Ki=0.24μmol/L。【Objective】To investigate the extraction method and enzymatic properties of crude enzyme of myofibrill-bound serine protease(MBSP)from grass carp(Ctenopharyngodon idellus),as well as the effect of soybean trypsin inhibitor on the quality of grass carp surimi gel,and to provide a theoretical basis for improving the quality of traditional grass carp surimi products in China.【Method】The crude enzyme solution of MBSP was extracted from the dorsal muscle of grass carp,and the optimal rinsing times(1-5 times),heating temperature(35,or 40,45,50,55℃)and pH vaule(pH 4.0,or pH 5.5)during the extraction process were determined by using the enzyme activity of the extract as an indicator.We also extracted the crude MBSP solution under the optimal extraction conditions,set up gradient experiments to explore the enzymatic properties of the crude MBSP,such as optimal temperature,pH,stability,etc.Finally,we investigated the effect of soybean trypsin inhibitor(STI)on the MBSP enzyme activity and its modulation on the properties of grass carp surimi gelatinization.【Result and Conclusion】The crude MBSP solution obtained after three times of rinsing,from heat treatment at 45℃and acid elution at pH 4.0 had the highest enzyme activity(P<0.05).Its optimum pH was around 9.0(P<0.05),and the optimum temperature is 45℃(P<0.05),it has good temperature stability(P<0.05).Besides,its activity could be inhibited to a certain degree by Na+and activated by K^(+)and Ca^(2+)(P<0.05).STI could significantly improve the texture of grass carp surimi,and it has a reversible competitive inhibition on crude MBSP,with a semi-inhibitory concentration of 10.85μg/mL,and an inhibitory constant of Ki=0.24μmol/L.

关 键 词：草鱼 肌原纤维结合型丝氨酸蛋白酶 分离提取 酶学特性 大豆胰蛋白酶抑制剂 

分 类 号：Q55[生物学—生物化学]