title: Characterization of triacetyl-α-melanocyte-stimulating hormone in carp and goldfish.
abstract: A triacetyl form of α-melanocyte-stimulating hormone (MSH) was found in carp (Cyprinus carpio) and goldfish (Carassius auratus), by selective detection of mass profile for cell secretory granules using direct tissue matrix-assisted laser desorption ionization with time-of-flight mass spectrometry (MALDI-TOF MS) analysis during the investigation of fish pituitaries. The structure of triacetyl-α-MSH in carp and goldfish was further analyzed using a collision-induced dissociation with electrospray ionization mass spectrometry, and determined to be N,O-diacetyl Ser as the N-terminal residue and O-acetyl Tyr at position 2. These modifications for α-MSH in carp and goldfish are structurally different from that of medaka hormone, in which [N,O-diacetyl Ser(1), O-acetyl Ser(3)]-α-MSH has been identified. The profiles of four α-MSH variants, des-, mono-, di- and tri-acetyl forms in goldfish and medaka pituitaries were also examined by direct tissue MALDI-TOF MS analysis, and the percentages as a total of α-MSH molecules were compared for fish reared in a white or black tank for 5 days. Among structural variants, diacetyl-α-MSH was the predominant form in goldfish and N-desacetyl-α-MSH in medaka, respectively. In both species, the relative level of the predominant form in the pituitary of white-adapted fish tended to be lower than that of black-adapted fish. In goldfish, no significant difference was observed in the relative content of triacetyl-α-MSH in both backgrounds, whereas the lowest content of triacetyl-α-MSH was found in black-adapted medaka. These preliminary data indicate that it is difficult to elucidate the relations between the physiological roles and acetylated pattern of α-MSH molecule, depending on species.
authors: Health Research Institute, National Institute of Advanced Industrial Science and Technology, Midorigaoka, Ikeda, Osaka 563-8577, Japan. yasuda-a@aist.go.jp
authors: Akikazu
authors: A
authors: Yasuda
authors: Yoshiro
authors: Y
authors: Tatsu
authors: Yasushi
authors: Y
authors: Shigeri
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002347:Carps / Q000378:metabolism*; D006054:Goldfish / Q000378:metabolism*; D009074:Melanocyte-Stimulating Hormones / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D009074:Melanocyte-Stimulating Hormones