Chromatographic refolding of recombinant human interferon gamma by an immobilized sht GroEL191-345 column

Minichaperone sht GroEL191-345 was covalently coupled to NHS-activated Sepharose Fast Flow gel. Refolding of recombinant human interferon gamma (rhIFN-γ) was carried out on a chromatographic column packed with immobilized minichaperone. The effects of salt concentration, urea concentration gradient, elution flow rate and protein loading on the refolding efficiency were investigated. The results indicated that immobilized sht GroEL191-345 chromatography was an effective protocol for the refolding of rhIFN-γ. When loading 100 μl denatured rhIFN-γ (17.8 mg/ml), the protein mass recovery and total activity obtained in this optimal process reached 74.25% and 6.74 × 106 IU/ml, respectively with the immobilized minichaperone column which was reused for 10 times with 25% decrease of renaturation capacity.