Patent ID: 6380355
Filing Date: 2002-04-30
Classification: A61K,A61P,C07K

Abstract:
A process for obtaining an insulin or an insulin derivative thereof having correctly bonded cystine bridges in the presence of cysteine or cysteine hydrochloride and of a chaotropic auxiliary, which comprises the following steps:(a) mixing an aqueous suspension of a precursor of insulin or insulin derivative with an amount of cysteine or cysteine hydrochloride which results in approximately 1 to 15 SH residues of the cysteine or cysteine hydrochloride per cysteine residue of the precursor; (b) adding the cysteine- or cysteine hydrochloride-containing suspension of the precursor into an approximately 4 to 9 molar solution of the chaotropic auxiliary at a pH of approximately 8 to 11.5 and a temperature of approximately 15Â° C. to 55Â° C., keeping the mixture obtained at this temperature for approximately 10 to 60 minutes; (c) diluting the cysteine or the cysteine hydrochloride concentration to approximately 1 to 5 mM and diluting the chaotropic auxilary concentration to approximately 0.2 to 1.0 M in the mixture at a pH of approximately 8 to 11.5 and a temperature of approximately 5Â° C. to 30Â° C.; (d) cleaving with trypsin or a trypsin-like enzyme-the precursor of the insulin or insulin derivative obtained by this process; and (e) purifying the insulin or insulin derivative having correctly bonded cystine bridges.