Size exclusion chromatography with an artificial chaperone system enhanced lysozyme renaturation

Abstract

Protein renaturation is of importance in the recovery of inclusion-body protein produced by recombinant microbial cells. It has been recognized that the artificial chaperone system, Cetyltrimethylammonium bromide and β-cyclodextrin, are effective in enhancing protein renaturation. Using chicken egg white lysozyme as a model protein, this work studied protein renaturation by size exclusion chromatography (SEC) incorporating with the artificial chaperone system. At first, a cooperative effect of the artificial chaperones and guanidinium chloride (GdmCl) on the protein renaturation was confirmed, and it was concluded that the artificial chaperone system promoted the renaturation of lysozyme (1.05 mg/ml) in the presence of 1 mol/liter GdmCl. Using the SEC (29.5 × 2.6 cm I.D., packed with Sephacryl S-100 h gel) incorporating with the artificial chaperones, higher renaturation yield was obtained at high flow rate (0.8–2.2 ml/min). In contrast, using the SEC without the artificial chaperones, very low flow rate (i.e. < 0.4 ml/min) should be used to receive a comparable renaturation yield. Thus, use of the SEC incorporating with the artificial chaperone system would greatly benefit in reaching a high refolding productivity.