Preparation and antioxidant characters of selenium-containing soybean peptide with glutathione peroxidase activity

The two soybean peptides (SP), SP-1 and SP-2, were obtained after hydrolyzing the Soybean Isolated Protein (SIP) by alcalase protease. And then, the SPs were converted into selenium-containing SPs (Se-SP) by chemically modification. The Se-SPs showed higher GPX activity than Ebselen, the first mimic of GPX, but they were much lower than native GPX. The characters of Se-SPs were also determined such as the selenium content, binding constant of active for GSH. In addition, antioxidant activity experiment indicated that Se-SPs has potential application. The Se-SPs possessed high scavenging ability to super-oxide anion, and they can protect mitochondria against oxidative damage with ferrous sulfate/ascorbate-(Fe²⁺/Vc) induced mitochondria damage model. This not only increases the practical value of SPs, but also increased value-added products to market was provided.