Production of recombinant RC-1 and dengue NS2B-NS3pro by
E. coli. The sequence of RC-1 was linked by 10 amino acids to a 6XHis tag in pET 303/CT His vector. Factor Xa recognition sequence was inserted to cleave both the linker and 6XHis tag after purification. (A). The NS2B unit of dengue protease was linked to the NS3 by 9 amino acids and the entire DNA fragment was cloned into pQE30 vector downstream of a 6XHis tag (B). The recombinant E. coli were cultured in Luria-Bertani liquid medium and induced with Isopropylthio-β-D-galactoside (IPTG) to produce recombinant RC-1 (C, L1 before induction and L2 after induction) and the same procedure was applied to produce recombinant NS2B-NS3pro. The recombinant RC-1 and NS2B-NS3pro were purified by Ni-affinity column (D, L1 purified dengue protease, L2 NS2B-NS3pro before purification, L3 purified RC-1 and L4 purified RC-1 after refolding).