Insulin peptides. Part XXIV. A novel synthesis of the human insulin B chain S-sulphonate

Abstract

The fragment condensation method was employed to construct the protected triacontapeptide which contains the amino-acid sequence of the human B chain. The four peptide fragments used in this synthesis were prepared stepwise. The protected triacontapeptide was deblocked by treatment with liquid hydrogen fluoride and the resulting reduced peptide chain was converted into the S-sulphonated derivative by oxidative sulphitolysis. The S-sulphonated chain, purified by chromatography on a CM-cellulose column with a urea–acetate buffer at pH 4·0. was obtained in 33% overall yield, based on the amount of the protected B chain used; a yield of 6–7% was obtained in our original synthesis.