Isolation and Properties of a New, Biologically Active Peptide from Sheep Pituitary Glands.

In an earlier paper (l), a simplified method was described for the isolation, in high yield, of sheep adrenocorticotropin from acid-acetone extracts of sheep pituitaries. In the course of purification by means of column chromatography on carboxymethyl cellulose, a new component of proteinaceous nature appeared. Since the pituitary hormones have been the subject of so much interest and have received such intensive investigation, it was surprising to encounter a new, hitherto unknown peptide. Its appearance led to speculation as to whether it was a precursor or breakdown product of sheep adrenocorticotropin, or an inert-or functional new natural product. In this report, we will describe the isolation and properties of this natural product and provide evidence that it is neither a precursor nor a breakdown product of sheep adrenocorticotropin, but another functional peptide. Since some of the biolwical activities of the new peptide simulated those of sheep adrenocorticotropin, we performed several comparative studies on both polypeptides.