Isolation and Chemical Characterization of a β -CRF from Pig Posterior Pituitary Glands. ∗

Abstract

Summary

A basic peptide with corticotropin releasing activity, no inherent ACTH-like or MSH activity and a pressor activity of 45 u/mg was isolated from pig posterior pituitary glands by the Kamm procedure followed by chromatography on carboxymethylcellulose (CMC), countercurrent distribution and rechromatography on CMC. The amino acid composition showed that the peptide is related to lysine-vasopressin, but with additional amino acids being present; the peptide belongs thus to a group designated β-CRF. The N-terminal and C-terminal amino acid sequences show sequential similarities with those of α-MSH and lysine vasopressin, respectively. This could perhaps explain inherent pressor activity of CRF and CRF activity of LVP and α-MSH analogs (α₂-CRF).