title: Isolation and characterization of a neurophysin from ostrich neurohypophyses.
abstract: A neurophysin has been isolated from ostrich neurohypophyses using acid acetone extraction, salt fractionation and Sephadex G-75 chromatography. The crude neurophysin eluting from the Sephadex G-75 column was subjected to a) reverse-phase HPLC followed by Sephadex G-75 chromatography, b) DEAE-Sephadex A-50 chromatography or c) isoelectric focusing. The different homogeneous ostrich neurophysin fractions so obtained were compared i.t.o. amino acid composition, spectral properties, N-terminal amino acid residues and PAGE. They all revealed a single N-terminal Ala residue and displayed spectral properties (A280/A260 less than 1) which are typical of mammalian neurophysin-like polypeptides. Ultracentrifugation studies on purified ostrich neurophysin over a range of concentrations revealed a reversible concentration dependent association behaviour characterized by the presence of dimeric complexes at higher concentrations. Partial sequencing from the N-terminus revealed the molecule to be VLDV-like. The purified molecule was also submitted to CNBr fragmentation.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001717:Birds / Q000502:physiology*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003488:Cyanogen Bromide; D004591:Electrophoresis, Polyacrylamide Gel; D007525:Isoelectric Focusing; D008970:Molecular Weight; D009481:Neurophysins / Q000302:isolation & purification*; D010446:Peptide Fragments / Q000032:analysis; D010904:Pituitary Gland, Posterior / Q000032:analysis*
chemical_list: D000596:Amino Acids; D009481:Neurophysins; D010446:Peptide Fragments; D003488:Cyanogen Bromide