Affinity purification of recombinant interferon-αon a mimetic ligand adsorbent

A method for improved refolding and purification of recombinant human interferon-α (rh-IFN-α) from inclusion bodies is described. The optimal conditions of refolding were obtained by the addition of 0.5 Ml-arginine to the refolding buffer. The rh-IFN-α was purified to near homogeneity utilizing a single-step chromatography on a mimetic dye-ligand matrix. Improved refolding, coupled to a single-column affinity purification strategy, resulted in a 10-fold increase in the yield of rh-IFN-α. This single-step purification protocol yielded ∼50 mg of purified rh-IFN-α from 1 liter of shake flask culture. The rh-IFN-α prepared by this protocol was found to be essentially monomeric based on HPLC gel filtration and nonreducing SDS–PAGE. It had a specific activity of ∼2.8 × 108 IU/mg, measured as inhibition of cytopathic effect of encephalomyocarditis virus on A549 human lung carcinoma cells