Abstract
1. Peptide fragments produced by chy-motryptic, peptic and acid partial hydrolysis of the glycyl chain of oxidized bonito insulin II were analyzed by the usual paper-chro-matographic methods after their purification with paper-electrophoresis and -chromato-graphy.
2. The presence of Tyr-CyS linkage at the 19th and 20th position was confirmed by the N-bromosuccinimide method of Witkop, too.
3. From these results the glycyl chain of bonito insulin II was concluded to possess the following partial structure:
H-Gly-Ileu-{His, Glu-Glu-CySO3H-(CySO3H, Lys, Pro, His), CySO3H, Asp, Leu}-Phe-Glu-Leu-Glu-Asp-Tyr-CySO3H-Asp (NH2)-OH.
4. Some problems on the structure relating to the hormonal activity was discussed by comparing the genetically determined differences in the chemical structure of insu-lins from different classes, fish (bonito) and mammals (cattle).
The author wishes to express his sincere thanks to Prof. K. Satake for his helpful advice and encouragement throughout this investigation. He also wishes to acknowledge Dr. Okuyama and Mrs. S. Sasakawa for their discussion, and Shimizu Seiyaku Co., Ltd., for the kind supply of bonito insulin. This work was supported in part by the grant-in-aid from the Japanese government Ministry of Education.
