酶法制备牡蛎抗氧化肽研究

Study on the preparation of antioxidative peptides from Crassostrea gigas by enzymolysis

目的优化牡蛎酶解制备抗氧化肽的工艺。方法通过正交试验法确定胃蛋白酶、胰蛋白酶及这两种蛋白酶的酶解液抗氧化(Fenton体系)的最佳工艺条件;采用Sephadex G-25葡聚糖凝胶柱层析法对酶解液中抗氧化肽进行分离纯化。结果胃蛋白酶最佳酶解条件:温度35℃、加酶量2.5%、时间6h、pH 2.0,在此条件下清除率达到50%时的酶解液浓度(EC50)为1.929mg.mL-1;胰蛋白酶最佳酶解条件:温度45℃、加酶量2%、时间8h、pH 7.5,EC50为1.165mg.mL-1;胰蛋白酶、胃蛋白酶分步酶解法的酶解液EC50为0.869mg.mL-1。双酶酶解液经纯化后,得相对分子质量为751的抗氧化活性肽组分(BPO-Ⅱ),其EC50为0.529mg.mL-1。结论双酶酶解法优于单酶酶解法,从双酶酶解液中分离纯化得抗氧化肽BPO-Ⅱ。

Objective To optimize the preparation of antioxidative peptides from oyster by enzymolysis. Methods The antioxidation activities of oyster enzymolysates, measured in Fenton, were optimized in orthogonal experiments with pepsin, trypsin and both of the two proteinases,respectively. The antioxidative peptides in oyster enzymolysates were purified with Sephadex G-25 gel chromatography. Results The optimal enzymolysis conditions of pepsin were： 35℃, 2. 5%（E/S）, 6 h, pH 2.0, and the enzymolysates＇ EC50 was 1. 929 mg· mL^-1; the optimal conditions of trypsin were： 45℃, 2%（E/S）, 8h, pH 7. 5, and the EC50 was 1. 165mg· mL^-1 the ECs0 of enzymolysates with trypsin and pepsin successively was 0. 869 mg· mL^-1. It showed that the relative molecular mass of the antioxidative peptides, named BPO-Ⅱ, was 751. Conclusion The enzymolysis of two enzymes was better than that of a single one, and the antioxidative peptides BPO-Ⅱ were prepared by enzymolysis and purification.