Effects of thioredoxin: Sumo and intein on soluble fusion expression of an antimicrobial peptide OG2 in escherichia coli

Og2 is a modified antimicrobial peptide of palustrin-og1 (og1),which is derived from odorrana grahami frog. og2 has shown much higher selective antimicrobial activity and lower hemolytic activity than og1,indicating og2 may be a promising antimicrobial agent. in this study,we investigated three fusion partners,including thioredoxin,mxe gyra intein,and small ubiquitin-like modifier (sumo),each fused with og2,and examined their effects on the expression level and solubility of og2 in escherichia coli. the codon-optimized og2 gene was cloned into pet32a (+) and ptwin1 for fusion with thioredoxin and mxe gyra intein,respectively. in addition,the sumo-og2 gene was amplified by splice overlap extension pcr method and was cloned into pet30a (+). all recombinant plasmids were then transformed into e. coli bl21(de3)plyss,and the expressed fusion proteins were verified. upon isopropyl α-d-1- thiogalactopyranoside (iptg) induction,og2 fused with thioredoxin (trx-og2) showed the highest yield as a soluble fusion protein (50 mg/l),followed by mxe gyra intein (44 mg/l) and sumo (11 mg/l). the thioredoxin-fused protein (trx-og2) was then purified by nickel-nitrilotriacetic acid chromatography and desalted by sephadex g25. the og2 released by both tobacco etch virus protease and enterokinase from trx-og2 showed strong antimicrobial activity against staphylococcus aureus atcc25923. copyright © 2012 bentham science publishers. all rights reserved.