[Isolation and partial characterization of the amino acid sequence of sea whale prolactin]

The protein hormone prolactin was isolated from sea whale hypophysis and its amino acid sequence was partially characterized. The hormone was hydrolyzed by BrCN and trypsin, the products of hydrolysis were separated and purified by gel filtration on Sephadex G-50, G-100 and G-25, by ion-exchange chromatography on CM-cellulose and on Dowex 50 x 8 and by partition paper chromatography. The structure of the obtained peptides was determined by the Edman method and by carboxypeptidase A hydrolysis. The partial amino acid sequence of sea whale prolactin making up to 75% of the hormone molecule was established.