抄録
1. Bonito insulin-II contained two differ-ent polypeptide chains, glycyl (A) and alanyl (B), which could be resolved only after treat-ment with performic acid.
2. Electrophoretic and amino acid analy-ses suggested the presence of three disulfide linkages, two as interpeptide linkage and one as intra-peptide linkage in the A-chain.
3. Amino acid compositions of alanyl (bonito) and phenylalanyl (bovine) chains were fairly similar, although the sequences of ala-nyl chain was H-Ala-Ala-Asp (or AspNH2)-Glu (or GluNH2)-Pro-Lys-OH instead of H-Phe-Val-AspNH2-Thr-Pro-Lys-Ala-OH in the mammalian insulins.
4. Amino acid composition of the A-chain differed as much as 30 per cent (=6/21) from the corresponding bovine one although they had just the same N-and C-terminals.
The author wishes to express his thanks to Prof. K. Satake for his valuable guidance and encourage-ment during the cource of this work.
