[Recombinant human insulin: X. Simplification of folding of the biotechnological precursor of recombinant human insulin].

The folding of biotechnological precursor of human insulin precursor was carried out from solubilized inclusion bodies without a preliminary oxidizing or reducing of Cys residues. The inclusion bodies were dissolved in 8 M urea with addition of 10 mM 2-mercaptoethanol. Hydrophobic cell components were removed from the solution by passing through a neutral weakly hydrophobic sorbent, the solution was five times diluted and refolded upon addition of 0.3 mM cystine for initiation of disulfide rearrangement. The presence of nucleic acids and cell protein impurities does not affect the folding efficiency. The resulting precursor of folded human insulin was purified by metal-chelate affinity chromatography and converted into insulin by two-stage enzymatic cleavage.