勐库大叶茶蛋白降血脂肽的酶解制备及活性分析

Preparation and Activity of Hypolipidemic Peptides from Mengkudayecha Protein by Enzymatic Hydrolysis

以碱提酸沉法提取的勐库大叶茶蛋白为研究对象,以牛磺胆酸钠结合能力为考察指标,通过单因素实验和响应面分析法优化勐库大叶茶蛋白降血脂肽的制备工艺,并对最优工艺条件下的酶解物进行降血脂活性评价和氨基酸组成分析。结果表明,勐库大叶茶蛋白降血脂肽的最佳制备条件为胃蛋白酶酶解3 h、pH2.1、底物浓度2.7%、酶底比0.3%、温度37℃,此条件下酶解物的牛磺胆酸钠结合率为(70.92%±0.12%)。活性评价结果表明,茶叶蛋白酶解物在牛磺胆酸钠结合能力(EC50=6.466 mg/mL)、胰脂肪酶抑制作用(IC_(50)=0.310 mg/mL)和胆固醇酯酶抑制作用(IC_(50)=1.557 mg/mL)三个体外降血脂活性评价指标方面均表现出良好的活性。氨基酸分析表明,所得勐库大叶茶蛋白降血脂肽含有丰富的必需氨基酸(34.35%)、疏水性氨基酸(31.94%)和酸性氨基酸(41.06%)。

Taking the Mengku-dayecha protein extracted by alkaline extraction and acid precipitation method as the research object,taking the binding capacity of sodium taurocholate as the inspection index,the preparation process of Mengku-dayecha protein hypolipidemic peptides was optimized through single factor experiment and response surface analysis,and the optimal technology was determined.Under the conditions,the enzymatic hydrolysate was evaluated for lipid-lowering activity and amino acid composition analysis.The results showed that the best preparation conditions for Mengku-dayecha protein hypolipidemic peptides were pepsin hydrolysis for 3 h,pH2.1,substrate concentration 2.7%,enzyme substrate ratio 0.3%,and temperature 37 ℃.Under these conditions,the binding capacity of sodium taurocholate was(70.92%±0.12%).The activity evaluation results showed that the tea protein hydrolysate showed good activity in three in vitro evaluation indicators of lipid-lowering activity:The binding capacity of sodium taurocholate(EC50=6.466 mg/mL),the inhibition of pancreatic lipase(IC_(50)=0.310 mg/mL) and the inhibition of cholesterol esterase(IC_(50)=1.557 mg/mL).Amino acid analysis showed that the obtained Mengku-dayecha protein hypolipidemic peptides was rich in essential amino acids(34.35%),hydrophobic amino acids(31.94%) and acidic amino acids(41.06%).