蛋清蛋白酶解物的抗氧化、抗凝血酶活性及生化特性的研究

Study on Antioxidant and Antithrombin Acitivities of Egg White Protein Hydrolysates and Their Biochemical Properties

研究了蛋清蛋白酶解物可能具有的抗氧化和抗凝血酶活性。水解用酶为Alcalase2.4L碱性蛋白酶和Pro-teaseN蛋白酶;测定了4个水解度的酶解物(采用pH-stat法控制反应终点而得到)的抗氧化和抗凝血酶活性,分析了活性最高的酶解物的氨基酸组成和相对分子量分布。结果表明,ProteaseN蛋白酶的酶解物活性要高于Alcalase酶解物,在水解度为15%时抗凝血酶活性最高;两种来源的、水解度为15%的酶解物的7种必需氨基酸质量分数分别达到了48.11%与45.80%,远高于天然蛋清的7种必需氨基酸质量分数35.65%,说明两种酶解物具有很高的营养价值。相对分子量分布显示两种酶解物(水解度为15%)的多肽组成相似,因此活性的差异可能是因水解酶种类不同而导致的产物多肽的氨基酸序列不同的缘故。

The antioxidant and antithrombin properties of egg white protein hydrolysates were studied in this experiment. Four hydrolysates with different degrees of hydrolysis （DH） were obtained using Alcalase 2.4L and Protease N by pH-stat method. The antioxidant and antithrombin properties of hydrolysates were determined. Also, the amino acid composition and the molecular weight distribution of hydrolysates with the highest activities were analyzed. The results showed that the activities of Protease N hydrolysates are higher than those of Alcalase hydrolysates, with the hydrolysate （DH 15%） having the highest antithrombin activity. The amino acids analysis results showed that the contents of seven essential amino acids in two kinds of hydrolysates with DH 15% are 48.11% and 45.80%, respectively, much higher than the content 35.65% of native egg white proteins.Molecular weight distribution analysis results showed that the two hydrolysates with DH 15% have similar peptides compositions. The difference on activities is due to enzyme species used in the hydrolysis for producing peptides with different amino acid sequences.