INSULIN VOM SCHLEIMFISCH (MYXINE GLUTINOSA CYCLOSTOMATA)

The insulin of the hag fish Myxine glutinosa was isolated, cleaved by oxidation and separated into A and B chains. The N-terminal amino acids are glycine (A-chain) and phenyla-lanine (B-chain); the C-terminal amino acids are asparagine (A-chain) and probably a basic amino acid (B -chain). The A-chain contains no phenylalanine. One histidine of the B-chain is replaced by a different amino acid. The intact insulin and its separate chains, especially the A-chain, are more basic than any other hitherto known insulin or its chains. In the immunological test with the double antibody method, the activity is about 0.1%. In the fatpad assay with the rat, the hag fish insulin has an activity of about 7% (bovine insulin = 100%), equivalent to about 2 lU/mg. The yield is about 3 mg insulin/g. fresh endocrinal pancreas.