[Cloning and expression in Escherichia coli of secondary lymphoid-tissue chemokine (SLC) gene]

Secondary lymphoid-tissue chemokine (SLC) is a type of CC chemokine identified by searching the Expressed Sequence Tag (EST) database. The full-length SLC gene was synthesized based on human SLC sequence using SOE-PCR. The sequenced SLC gene was cloned into expression vector pTMF and pALM, which used to transform Escherichia coli. Then the E. coli was cultured and induced according to protocol. The expressed target protein was identified by Western blotting. The target protein was expressed as soluble protein as well as inclusion bodies, the ratio of these two forms target protein varied with the difference conditions of culture and induction. The target protein was purified with the methods of nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography. The results of electrophoresis of the purified target protein showed that the molecular weight was larger than the predicted molecular weight.