Removing protease and acetylated impurities from insulin

摘要

Recovery of insulin practically free of proteases and/or A9-acetylated insulin, comprises: (1) dissolving the crude material in a buffer; (2) chromatography of this soln. on lipophilically modified (reverse phase) silica gel using a buffer contg. zwitterions and water-miscible organic solvent, opt. adjusted to a pH close to the isoelectric point of insulin; opt. (3) concn. of the recovered insulin fractions; (4) dissolving these fractions in a dissolution buffer (A) contg. acetone or MeCN; (5) applying the soln. to the same sort of column as used in (2); (6) washing with (A) and (7) eluting with the same sort of buffer as used in (2). Steps (4)-(7) can be used alone. Pref. DB contains 10-40 vol.% acetone and has pH 3-4.