Construction of Escherchia coli strain for producing recombinant antioxidative peptide from longan seeds

Antioxidants, substances that prevent damage from free radicals ,have originally been discovered in various natural sources including fruit seeds. In longan seeds, a potential antioxidative peptide with amino acid sequence as ISYVVPVYIAEITPKT - FRGGF, was found. In this research, to overcome protein hydrolysate preparation problems, genetic engineering was used to produce arecombinant version of this antioxidative peptide in Escherichia coli. For the easier genetic manipulation, the DNA fragment for encoding the target peptide was designed by containing 4 copies of the interested peptide and each copy was linked by a codon of Aspartic acid. After IPTG induction, the recombinant peptide was successfully expressed and purified. The recombinant peptide was verified by Endoproteinase AspN digestion and MALDI - TOF-MS. The antioxidant activity of this recombinant peptide will be further studied