AMINO-ACID-SEQUENCE OF SARDINE CALCITONIN AND ITS HYPOCALCEMIC ACTIVITY IN RATS

A novel calcitonin (CT) was isolated from the spotlined sardine, Sardi nops melanostictus. The primary structure of sardine CT was determined as follows: r-Tyr-Pro-Arg-Thr-Asn-Val-Gly-Ala-Gly-Thr-Pro-NH2. This a mino acid sequence was different from that of salmon CT in 4 amino aci d residues at positions 8th, 21th, 27th and 29th. As judged by the int ernational method of CT bioassay, hypocalcemic activity of sardine CT was calculated as 4156 IU/mg. When compared for durability of CTs, it was found that sardine CT was significantly more potent than that of s almon CT. This is the first report of CT from a marine species of tele ost.