Observations on the lipolytic and melanotropic properties of neurophysin proteins.
Previous work indicated that brain contains 3 types of lipolytic-melanotropic peptide: (1) in adenohypophysis: ACTH, alpha-MSH, beta-MSH, peptide I, peptide L', beta-lipotropin and gamma-lipotropin; (2) in neurohypophysis: peptide 7D6, also termed neurophysin I, peptide II or Wuu-Saffran peptide; (3) in extrahypophyseal regions: peptide IIF. Bovine and human neurophysin I prepared by R. Walter has now been found devoid of lipolytic and melanotropic activities. Porcine and bovine peptide 7D6, closely similar or identical to bovine neurophysin I in electrophoretic mobility and amino acid composition, were therefore reexamined to determine whether their lipolytic-melanotropic property resided in a contaminating factor. When peptide 7D6 was analyzed in 100 transfer counter current distribution (1 butanol/0.1M NH4 HCO3), the neurophysin was recovered in tubes 1-9 (7D6-alpha) representing 95% of 7D6. 7D6-alpha was inactive in lipolytic and melanotropic assays. The biologic activities of 7D6 were recovered instead in tubes 50-70 (labeled 7D6-beta), representing 5% of 7D6. 7D6-beta proved to be a peptide with MW 1000-3000, closely similar to peptide IIF in amino acid composition, MW, and Rf values in 4 systems of paper chromatography.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001921:Brain / Q000502:physiology; D002417:Cattle; D002850:Chromatography, Gel; D008053:Lipid Mobilization / Q000187:drug effects*; D008543:Melanins / Q000378:metabolism*; D009481:Neurophysins / Q000494:pharmacology / Q000502:physiology*; D010902:Pituitary Gland / Q000502:physiology; D011817:Rabbits; D013045:Species Specificity; D013552:Swine
D000596:Amino Acids; D008543:Melanins; D009481:Neurophysins