THE COMPLETE AMINO-ACID-SEQUENCE OF CHUM SALMON STANNIOCALCIN, A CALCIUM-REGULATING HORMONE IN TELEOSTS

Stanniocalcin (STC) is a hypocalcemic hormone secreted from the corpuscles of Stannius of bony fish. Chum salmon STC was isolated in pure form by ion-exchange chromatography and reversed phase high performance liquid chromatography following ethanol-ammonium extraction of the tissues. A cDNA was cloned from cDNAs of the tissue by the PCR method using two primers corresponding to the N- and C-terminal amino acid sequence of the hormone. Sequence analysis of the protein and the cDNA revealed that chum salmon STC is a homodimer, and that the monomer consists of 179 amino acids including 11 half-Cys residues and one N-linked glycosylation site, which is 44 residues smaller at the C-terminal region than the sequence deduced from coho salmon STC cDNA.