乳清蛋白水解法及其多肽对KKAy小鼠血糖的影响

Hydrolysis method for whey protein and the hypoglycemic activity of its peptides in Diabetic KKAy mice

目的研究乳清蛋白的水解方法,并观察其水解多肽对KKAy糖尿病小鼠的降血糖作用。方法采用碱性蛋白酶水解乳清蛋白,透析后检测其水解度、含氮量、氨基酸含量、多肽图谱、质谱分析,并进行动物实验,检测其对KKAy小鼠糖耐量、空腹血糖和随机血糖以及血清胰岛素水平的影响。结果乳清蛋白水解多肽水解度为14.8%,含氮量68.2%,多肽分子量分布在900-1900,大部分集中在1800-1900。乳清蛋白水解多肽能降低灌胃后KKAy糖尿病小鼠血糖、显著升高灌胃后0.5h血清胰岛素水平。结论乳清蛋白水解多肽能有效降低KKAy小鼠空腹血糖、随机血糖和改善糖耐量。

Objective To explore the hydrolysis method for whey protein with alkaline proteinase,and to investigate the hypoglycemic activity of the peptides in diabetic KKAy mice.Methods Whey protein was hydrolyzed with alkaline proteinase,and the degree of hydrolysis,nitrogen and amino acid content,mass spectrographic analysis of the peptides were determined.Changes of fasting blood glucose,random blood glucose,glucose tolerance and insulin levels in diabetic KKAy mice were measured after the peptides were given by gavage.Results The degree of hydrolysis of whey protein was 14.8%,the nitrogen in the peptides was 68.2%,and the molecular weight of the peptides was 900-1900Dal,mostly was 1800-1900Dal.Blood glucose of KKAy mice was decreased at 0.5 and 1 h after oral injection of the peptides,and insulin level was increased at 0.5h after ingestion of the peptides.Conclusion Fasting blood glucose and random blood glucose levels of type 2 diabetic KKAy mice could be significantly decreased,and the glucose tolerance and insulin secretion of mice could be improved by whey protein peptides.