Purification and characteristics of porcine growth hormone.

A simple procedure is described for the isolation of porcine growth hormone from the filtrate remaining after the adsorption of adrenocorticotropic hormone (ACTH) onto oxidized cellulose during the commercial manufacture of ACTH. Growth hormone is purified by ion exchange chromatography on diethylaminoethylcellulose. The purified hormone has a specific biological activity nearly twice that of the international standard of growth hormone (bovine, for bioassay), and is essentially free of other activities of the anterior pituitary. Its isoelectric point is at pH 6.3. The molecule appears to be a single polypeptide chain with phenylalanine at both the NH2-terminal and COOH-terminal residues. The amino acid composition resembles that of bovine, canine, and human growth hormone.