title: Studies on prolactin 48: isolation and properties of the hormone from horse pituitary glands.
abstract: Isolation of prolactin from equine pituitary glands has been described. It has a potency of 42 IU/mg in the pigeon crop-sac test and consists of 199 amino acids. The hormone has only four half-cystine residues in contrast to other mammalian prolactins which have six residues. From NH2-terminal sequence analysis and amino acid composition of cyanogen bromide fragments, the NH2-terminal disulfide loop is missing in the equine prolactin molecule. Circular dichroism spectra indicate that the alpha-helical content of equine prolactin appears to be lower (50%) than that found in the ovine hormone (65%).
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D006736:Horses; D010902:Pituitary Gland / Q000032:analysis*; D011388:Prolactin / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D011388:Prolactin