A1/A2β-酪蛋白基因型的鉴定及其消化性能的比较  

Identification of A1/A2β-Casein Genotypes and Comparison of Their Digestive Properties

作　　者：李师行 徐洪涛 李笑 孙美玲 杨鑫焱 项鹏宇 杨智浩 满朝新[1] 姜毓君[1] LI Shihang;XU Hongtao;LI Xiao;SUN Meiling;YANG Xinyan;XIANG Pengyu;YANG Zhihao;MAN Chaoxin;JIANG Yujun(Key Lab of Dairy Science,Ministry of Education,College of Food Science,Northeast Agricultural University,Harbin 150030,China;Hangzhou Chaomu Electronic Commerce Company Limited,Hangzhou 311000,China)

机构地区：[1]东北农业大学食品学院乳品科学教育部重点实验室,黑龙江哈尔滨150030 [2]杭州认养一头牛生物科技有限公司,浙江杭州311000

出　　处：《食品工业科技》2025年第5期160-167,共8页Science and Technology of Food Industry

摘　　要：A1β-酪蛋白和A2β-酪蛋白由于一级结构上的差异,消化后产生的物质也不相同。为了更全面地探究其对人体可能产生的生物活性影响,通过分析和监测该蛋白质在消化过程中的变化情况,进一步实现对A1/A2β-酪蛋白生物功能的探索。在本研究中,对采自某一牧场不同奶牛的牛奶进行等位基因特异性PCR鉴别,并借助阴离子交换色谱和十二烷基硫酸钠聚丙烯酰胺凝胶电泳法对牛奶分离出的β-酪蛋白进行纯化和鉴定,最后构建静态体外消化模型比较β-酪蛋白在消化性能上的差异。结果显示,分离纯化的A1和A2β-酪蛋白的浓度分别为0.62 mg/mL和0.66 mg/mL,纯度分别为95.28%和96.60%。两种β-酪蛋白的最终消化率均在90%左右,差异不显著。A2β-酪蛋白自肠消化阶段开始直至消化结束表现出了更高的水解度,为25.34%。随着胃肠消化时间的增加,两种β-酪蛋白的粒径不断减小,电位绝对值不断增大,并且A2β-酪蛋白在粒径和电位上的变化程度大于A1β-酪蛋白。综上所述,本研究揭示了A1和A2β-酪蛋白在静态体外消化过程中的理化特性差异,并在一定程度上表明A2β-酪蛋白可能具有比A1β-酪蛋白更好的消化性能,为进一步拓宽A2β-酪蛋白在乳制品中的应用提供一定科学依据。A1β-casein and A2β-casein produce different substances after digestion due to differences in primary structure.To more comprehensively explore the possible biological activity effects on the human body,by analyzing and monitoring the changes of this protein during the digestion process,the exploration of the biological functions of A1/A2β-casein is further achieved.In this study,allele-specific PCR was initially performed on milk samples collected from different cows in the pasture to identify A1 and A2 milk types.Afterwards,β-casein isolated from A1 and A2 milk was purified and characterized with the help of anion exchange chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis.Finally,a static in vitro digestion model was constructed to compare A1 and A2β-casein in terms of digestive properties.The results showed that the concentrations of isolated and purified A1 and A2β-casein were 0.62 mg/mL and 0.66 mg/mL and the purities were 95.28%and 96.60%.After 5.0 h of static in vitro simulated digestion,the final digestibility of bothβ-caseins was around 90%,and the difference was not significant.A2β-casein exhibited a higher degree of hydrolysis of 25.34%from the beginning of the intestinal digestion phase until the end of digestion.With the increase of gastrointestinal digestion time,the particle size of the twoβ-caseins decreased and the absolute value of the potential increased,and the degree of change in particle size and potential was greater for A2β-casein than for A1β-casein.In conclusion,the present study revealed the differences in the physicochemical properties of A1 and A2β-caseins during static in vitro digestion and indicated to some extent that A2β-caseins might have better digestive properties than A1β-caseins,which provided a certain scientific basis for further expanding the application of A2β-caseins in dairy products.

关 键 词：A1 Β-酪蛋白 A2 Β-酪蛋白 等位基因特异性PCR 体外模拟消化 消化性能 

分 类 号：Q512[生物学—生物化学]