The expression of recombinant human FLT3 ligand cDNA with pProEXHT vector and the purification of its product by metal-chelating affinity chromatography

The cDNA encoding human FMS-like tyrosine kinase 3 ligand (FL) was inserted into pProEXHT vector and expressed as a 6×His-FL fusion protein in E. coli. After isolating and refolding the inclusion bodies, the fusion protein was purified by chromatography on a Ni~(2+)-chelating affinity column. An expression amount of 6×His-FL fusion protein up to 15% of total bacterial protein was obtained. The purity of fusion protein just by one-step metal-chelating affinity chromatography could reach over 90%.