ISOLATION, PURIFICATION, AND CHARACTERIZATION OF γ-LIPOTROPIC HORMONE FROM SHEEP PITUITARY GLANDS

Abstract

The isolation and characterization of a new biologically active polypeptide from sheep pituitary glands is described. Considerable evidence suggests that the structure of the new molecule, designated γ-lipotropin, is identical with the N-terminal portion (sequence 1–58) of β-lipotropin and, therefore, that γ-lipotropin contains at its C-terminus the amino acid sequence of β-melanophore-stirnulating hormone (β-MSH). The implications of these results are discussed in relation to the mechanism of pituitary peptide biosynthesis and to the structure–activity relationships between sheep β-MSH and lipotropic hormones.