Cloning and expression of bovine (<i style="">Bos indicus</i>) interleukin-2 in <i style="">Escherichia coli</i>

Abstract

The gene for interleukin-2 (IL-2) was amplified from cDNA pool prepared from ConA-stimulated peripheral blood mononuclear cells (PBMCs) isolated from Indian cattle (<i style="">Bos indicus</i>). The amplified IL-2 gene was cloned and nucleotide sequences were determined. Homology comparison of nucleotide and predicted amino acid sequences revealed similarity of sequence and conservation of crucial amino acids with exotic cattle (<i style="">B. taurus</i>). The coding sequence of IL-2 (without its own signal sequence) was subsequently expressed as fusion protein with polyhistidine fusion tag in <i style="">Escherichia coli</i>, using prokaryotic expression vector. The expressed protein was present as insoluble inclusion bodies. The recombinant protein was solubilized with urea and purified using Ni-agarose affinity chromatography. The purified recombinant IL-2 was characterized in SDS-PAGE and in western blotting.