On-column refolding of consensus interferon at high concentration with XXXX and @entity968 gradients.

@entity2097 @entity5828 @entity970 @entity968
Dilution refolding of consensus interferon (C-IFN) had a limit on final concentration not exceeding 0.1 mg ml(-1) in order to achieve specific activity of 2.2x10(8) U mg(-1). Addition of @entity968 ( @entity970 ) only gave a marginal improvement on the specific activity. Hydrophobic interaction chromatography (HIC) was tried but a simple step-wise elution could not refold the protein. Successful refolding was achieved by gradient elution with the decreasing of @entity2097 ( @entity2097 - @entity5828 ) concentration. The column was packed with a commercially available HIC medium that was designed for protein separation. @entity968 was found to possess better effect on the column than in the dilution for promotion of correct refolding, especially in gradient mode. A novel dual-gradient strategy, consisting of decreasing @entity2097 - @entity5828 concentration and increasing @entity970 concentration, was developed to enhance the refolding yield. Denatured C-IFN was allowed to adsorb and elute from the HIC column through a gradually changed solution environment. Compared with dilution refolding, the gradient HIC process, in the presence of @entity970 , gave about 2.6-folds of increase in specific activity, 30% increase in soluble protein recovery. Partial purification was also achieved simultaneously.
