应用胰凝乳蛋白酶消化法比较冬季和夏季鲢鱼肉肌球蛋白的构造特性  

Biochemical properties of muscle proteins between summer and winter silver carp by chymotryptic digestion

作　　者：于克锋[1] 袁春红[2,3] 陈舜胜[2] 王锡昌[2] 今野久仁彦[3] 

机构地区：[1]上海海洋大学水产与生命学院,上海201306 [2]上海海洋大学食品学院,上海201306 [3]日本北海道大学水产科学院

出　　处：《水产学报》2011年第6期940-947,共8页Journal of Fisheries of China

基　　金：上海市教育委员会重点学科建设项目(J50704)

摘　　要：以夏季和冬季鲢为研究对象,利用胰凝乳蛋白酶能水解羧基端含芳香族氨基酸残基肽键的特性,根据其特异性酶切部位,结合电泳手段来分析肌球蛋白的内部构造差异性。结果表明,与夏季样品相比,冬季鲢的肌原纤维蛋白经酶切生成的肌球蛋白头部S-1较长,在高温下分子量为165 ku的重酶解肌球蛋白HMM容易被再降解成小片段的135 ku HMM,呈现出冬季肌球蛋白的结构不稳定性。在不同温度下加热夏季和冬季肌球蛋白,其ATPase失活速度和酶解肌球蛋白生成S-1的产生量的减少速度呈现一致性,说明酶解生成的S-1只来源于有活性的肌球蛋白。同时,冬季肌球蛋白热变性温度较夏季肌球蛋白要低6℃,表明冬季肌球蛋白的不稳定性。Summer（Aug.） and winter（Dec.） silver carp,Hypophthalmichthys molitrix were studied.Because chymotrypsin catalyzes the hydrolysis of peptide bonds adjacent aromatic amino acids,it can be used to detect the difference in the protein internal structure combining with SDS-PAGE technique.The objective of the study is to characterize the structural stability and thermal stability of myosin from summer and winter silver carp by using chymotryptic digestion.The results showed that there was a longer subfragment of myosin S-1 produced by chymotrytic digestion for winter myosin,compared with that of summer one.If myosin was cleaved into HMM and LMM,the winter sample was liable to be cleaved into a shorter fragment as 135 ku HMM,while summer myosin still produced long 165 ku HMM even if digested at high temperatures（30 ℃）.These results indicated the instability of winter myosin.Heating summer and winter myofibril at different temperatures,and then measuring the remaining ATPase activity and the amount of S-1 produced by chymotyptic digestion,it was found that the decreasing rate of ATPase activity and S-1 produced was similar to decreasing temperature.This indicated that S-1 produced by chymotryptic digestion only originated from native myosin.Furthermore,as the denaturation temperature for summer myosin was 6 ℃ higher than winter myosin,it indicated that summer myosin was more stable than winter one.This paper introduced chmotrypsin digestion as a very useful method to study the biochemical properties of muscle proteins such as myosin,which is a very important protein for gel formation.The information will be very useful for producing surimi from freshwater fish species in different seasons.

关 键 词：鲢 胰凝乳蛋白酶 肌球蛋白 肌球蛋白S-1 热稳定性 ATPASE活性 

分 类 号：TS254.1[轻工技术与工程—水产品加工及贮藏工程]