玉米抗氧化肽的分离制备及其体外抗氧化活性的研究

Preparation of Corn Antioxidant Peptide and Study on Its Antioxidant Activity in Vitro

本实验以2709碱性蛋白酶水解玉米蛋白粉制备玉米抗氧化肽,SephadexG-25、DEAE52纤维素纯化玉米抗氧化肽,并用几种不同的实验体系研究其体外抗氧化活性。结果表明,玉米抗氧化肽制备的最佳酶解条件为:pH=9.5,[E]/[S]=10%,时间4h,温度55℃。该条件下制备的玉米抗氧化肽对超氧阴离子自由基和羟基自由基有强烈的清除作用,并能显著地抑制细胞和组织脂质过氧化反应的发生(p<0.01)。氨基酸组成分析表明其富含丙氨酸和亮氨酸,摩尔分数分别为17.39%和13.04%,并且含有5种人体必需的氨基酸,占玉米抗氧化肽氨基酸总含量的39.13%,因此在具有较高生物学活性的同时也具有较高的营养价值。

Corn antioxidant peptide was produced by hydrolyzing corn gluten meal （CGM） with 2709 alkaline protease, and was purified with SephadexG -25 and DEAE52 column chromatography. Its antioxidant activity was investigated in several experimental systems in vitro. The results show that the optimum hydrolytic condition for prepa- ration of corn antioxidant peptide are ： Ph 9.5, [ E ] / [ S ] 10%, time 4h, and temperature 55 ℃ . The corn antioxidant peptide produced under this condition exhibits strong scavenging activity to O2^- and · OH,and significantly inhibits the peroxidation of cells and homogenates （ p 〈 0.01 ）. Amino acid composition of the corn antioxidant peptide is shown to be rich in Ala and Leu. Molar content of Ala and Leu are 17.39%, 13.04% respectively; moreover, there are five essential amino acids in it,which account for 39.13% of total amino acids of corn antioxidant peptide. So it has not only strong biological activity, but also good nutritional value.