紫菜活性肽复合酶法制备与清除羟自由基作用

以条斑紫菜为原料,利用胰蛋白酶和木瓜蛋白酶组成的复合酶水解紫菜蛋白制备生物活性肽并研究清除羟自由基作用。采用单因素试验考察胰蛋白酶与木瓜蛋白酶的比例、底物质量浓度、酶用量、水解温度、水解时间、pH对羟自由基清除率及水解度的影响,响应面法优化酶解条件,SephadexG-15凝胶层析法测定活性肽的分子质量分布。试验结果表明,复合酶最佳酶解工艺条件为胰蛋白酶与木瓜蛋白酶复合酶比例1.67,底物质量浓度20mg/mL,酶用量1.67%,pH 7.0,温度55℃,酶解4h,紫菜活性肽对羟自由基的清除率为80.6%,清除率为50%时的质量浓度为0.744mg/mL,分子质量大多分布于500～1500ku。

Preparation and Scavenging Activity of Bioactive Peptides from Laver Porphyra yezoensis by an Enzyme Complex

The bioactive peptides were prepared from laver Porphyra yezoensis by trypsin and papain hydrolysis,and their scavenging activity of hydroxyl free radicals was determined.The effects of ratio of trypsin to papain,substrate concentration,amount of enzyme,reaction temperature,hydrolyzation time,and pH on elimination of the hydroxyl free radicals were investigated in a single factor experiment and response surface method.The molecular weight of the enzymatic hydrolysates of the laver proteins was determined by a SephadexG-15 gel column.The optimum hydrolysis by trypsin and papain were conducted under condition of the ratio of trypsin to papain=1.67,the substrate concentration of 20 mg/mL,the enzyme amount of 1.67%,pH 7.0,55 ℃,and 4 h reaction,with the scavenging activity of hydroxyl free radical at a rate of 80.6%.The IC50 of enzymatic hydrolysates was found at 0.744 mg/mL.The molecular weight of bioactive peptides from the laver proteins by the complex enzyme was mostly ranged from 500 to 1500 ku.