Optimizing factors for the efficient expression and purification of spao and lamb from Salmonella typhi

We optimized the expression and purification of outer membrane proteins SpaO LamB from Salmonella typhi. investigated various factors in processes, including use isopropyl β-d-1 thiogalactopyranoside (IPTG), imidazole, urea. First, PCR amplification was carried out on genes. The genes were then cloned pTZ57R/T, expressed pET28a vector transformed into Escherichia coli BL21 (DE3). Gene insertion confirmed by enzymatic digestion with NdeI XhoI. Inclusion bodies expressing recombinant induced 200 400 µL 0.5 mM IPTG, respectively. formed protein inclusion isolated pellet solubilized IB buffer containing 8 M urea for 6 LamB. Proteins refolded dialysis 3M Purified nickel-nitrilotriacetic acid affinity chromatography eluted 250 imidazole 150 profiles analyzed SDS-PAGE, which identified 33 49 kDa bands corresponding to rSpaO rLamB. Western blotting Purification nickel resin rLamB through stepwise anti-His tag antibodies their expression. These methods can be used generate development future vaccines.