title: Purification and renaturation of recombinant human interleukin-2.
abstract: Recombinant human interleukin-2 (IL-2) expressed as Escherichia coli was isolated as insoluble aggregates of protein (inclusion bodies) after cell breakage. IL-2 and contaminants were dissolved in 6 M-guanidinium chloride/10 mM-dithiothreitol, pH 8.5, and further purified in reduced and denatured form by gel-permeation chromatography in the same solvent. Renaturation was effected by dilution and autoxidation; IL-2 of native specific activity was isolated at over 95% purity by reversed-phase h.p.l.c.; an additional peak of reduced protein was also observed. Most losses of native IL-2 occurred on refolding, probably because of an aggregation process; concentrations around 1 microgram/ml were necessary to achieve 30% recovery. It was essential to maintain the denatured protein in reduced form before renaturation and autoxidation, which was most efficient at pH 8.5 with 1.5 microM-CuSO4. A procedure based on these observations has been used to prepare IL-2 on the 50 micrograms scale.
mesh_terms: D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007376:Interleukin-2 / Q000302:isolation & purification* / Q000378:metabolism*; D046911:Macromolecular Substances; D010084:Oxidation-Reduction; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility
chemical_list: D007376:Interleukin-2; D046911:Macromolecular Substances; D011994:Recombinant Proteins