Expression of recombinant antioxidative peptides from hairy basil ocimum basilicum L. Seed waste in escherichia coli

Abstract

Antioxidant activities in plants were widely investigated due to reduction of free radicals which are risks of some diseases. Previously report revealed a potential antioxidative peptide from seed waste of hairy basil. The peptide with amino acid sequence as QTFQYSRGWTN was selected for synthesizing recombinant antioxidant peptide and expressed in Escherichia coli MG1655. This recombinant E. coli named as OSW strain containing the DNA fragment encoding seven copies of the target peptide on pQE-30 Xa expression vector. The OSW strain could express the recombinant OSW peptide in the soluble fraction. The recombinant OSW peptide elution from Ni2+ affinity column was contaminated with other proteins. The expected 15 kDa OSW peptide band was further extracted from SDS gel, resulted in the loss of more target peptide, was verified by modified dot blot analysis with antiHis-HPR antibody. Moreover, the recombinant OSW peptide expression was verified by qRT-PCR. The elution of recombinant OSW peptide was examined for the DPPH and ABTS radical scavenging activities, and in vitro protective effect on DNA damage induced by hydroxyl radical. The recombinant OSW elution revealed significantly higher antioxidant activities that those of the chemical synthesized one, particularly the DNA damage prevention. However, for further study, this strain should be subjected for optimizing factors involved in recombinant peptide production and additional purification.