| 摘要 |
A process for preparing an insulin precursor is described, of the formula <CHEM> in which R is hydrogen, a chemically or enzymatically cleavable amino acid residue, or a chemically or enzymatically cleavable peptide moiety having at least two amino acid residues; Y is <CHEM> in which Z is Ala, Thr, or Ser; the moiety from A-1 to A-21 is an insulin A-chain; the moiety from B-1 to B-30 is an insulin B-chain; and X is a moiety which is joined to the insulin A-chain at the amino group of A-1 and to the insulin B-chain at the epsilon -amino group of B-29 or the carboxy group of B-30, which moiety can be enzymatically or chemically cleaved from and without disruption of both the A-chain and the B-chain, which comprises reacting an S-sulfonate of the formula <CHEM> in which R, X, Y are as defined above, with a mercaptan in an amount which provides from about 1 to about 5 -SH moieties per each -SSO3- moiety in an aqueous medium at a pH of from about 7 to about 11.5 and at an S-sulfonate concentration of up to about 10 mg. per ml. of aqueous medium. |
