Method for increasing the yield of properly folded recombinant human gamma interferon from inclusion bodies.
A strategy is described for improved refolding and purification of recombinant human gamma interferon (rh-IFN gamma), which could warrant a higher yield and specific activity than reported previously. The optimal conditions of refolding are obtained by addition of a labilizing agent, L-arginine, in the refolding buffer. A 10-fold increase in the yield was observed with 0.5 M L-arginine, compared with renaturation in its absence. By varying renaturation parameters, the conditions that allow functional refolding of approximately 25-30% of the recombinant protein have been standardized. A simple process is also described for the purification of rh-IFN gamma. The purification involves a single-column chromatography on S-Sepharose, after refolding of rh-IFN gamma in arginine containing buffer. This procedure has consistently produced rh-IFN gamma having a purity of at least 97%, the rest being the aggregated form of gamma interferon. The purified protein is a dimer under non-denaturing conditions and has a specific activity of 2 x 10(8) IU mg-1 protein, as measured by viral cytopathic assay.
Arora
D
D
Recombinant Gene Products Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
Khanna
N
N
D001120:Arginine / Q000494:pharmacology; D002845:Chromatography / Q000379:methods; D002850:Chromatography, Gel; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D002479:Inclusion Bodies / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D007371:Interferon-gamma / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D017510:Protein Folding; D011994:Recombinant Proteins; D012685:Sepharose
D011994:Recombinant Proteins; D007371:Interferon-gamma; D012685:Sepharose; D001120:Arginine