Purification of recombinant human interleukin-3 expressed as inclusion bodies in <i>Escherichi coli</i>

Human interleukin-3 (IL-3) is a hematopoietic growth factor involved in the survival, proliferation and differentiation of multipotent cells. However, recombinant IL-3 usually expressed as insoluble form (inclusion bodies) Escherichia coli This state protein often shows no bioactivity. Herein, we report simple method for solubilization, refolding purification human E. First, was JM109 (DE3) after being induced with 0.05 mM IPTG at 25 oC. Under these conditions, produced inclusion bodies molecular weight approximately 15 kDa on SDS-PAGE gel (14%). Next, pellet separated from host soluble proteins using sonication followed centrifugation. Then, two strong denaturants such urea or guanidine hydrochloride were used to test solubilization IL-3. After that, resulting renatured subjected filtration chromatography collect purified protein. Our results showed that fractionates contained single band recovery rate about 30%. Several characteristics then analyzed. The cytokine its high purity sharp peak RP-HPLC chromatagram. Western blot clear signal PVDF membrane demonstrate right antigenecity against antibody. Besides, amino acid sequence this confirmed by mass spectrophotometry method. potential material further tests.