Studies on Insulin

Peptide fragments produced by tryptic, chymotryptic or peptic partial hydrolysis of oxidized alanyl chain of bonito insulin II were purified by paper-electrophoresis and -chro matography, and the arrangement of these peptides was deduced from their N-terminal- and amino acid-analysis. Analysis of non DNP-peptide fraction derived from DNP alanyl chain with acid partial hydrolysis, though not so effective to develop the struc tural analysis of this region, suggested the presence of -Leu-Val-Glu-Ala-Leu-sequence somewhere in the polypeptide chain. It was concluded that the alanyl chain (B-chain) of bonito insulin II possessed the following partial structure.H-Ala-Ala-Aspn-(pro, His, Leu)-CySO8H -(Gly, Ser His, Leu-Val-Glu-Ala-Leu)-Tyr-Leu-(Val CySO8H, Gly, Glu)-Arg-Gly-Phe-Phe-TyrGlun-Pro-Lys-OH.