Expression and purification of p70ΔCT104 S6 K, a 72kDa c-terminal truncated p70S6 kinase-GST fusion protein in bacterial expression system.

ABSTRACT

The p70ΔCT104 S6K is a 421 amino acid residue long truncated form of p70S6 kinase, with 104 amino acids residues cleaved from the carboxyl terminal end of the original protein. The p70ΔCT104 S6K was cloned in E. coli DH5α and successfully expressed in E. coli BL21 (DE3) strain. Western blot with rabbit polyclonal anti-GST antibody was used to follow the protein during expression and purification. The protein purification was achieved by affinity chromatography using Glutathione resin-agarose beads, followed by chromatography on a spin concentration column. The purified protein was confirmed by rabbit polyclonal anti-p70S6 kinase antibody. MALDI/MS Peptide mass fingerprinting confirmed identity of the expressed product.