title: First cyclotide from Hybanthus (Violaceae).
abstract: Hypa A, a novel macrocyclic polypeptide containing 30 amino acid residues, has been isolated from the n-butanol extract of the Argentine plant Hybanthus parviflorus. The sequence, cyclo-(SCVYIPCTITALLGCSCKNKVCYNGIPCAE), was determined by automated Edman degradation, quantitative amino acid analysis and nanospray MS/MS(2). Three intramolecular disulfide bridges stabilize the cyclic peptide backbone of hypa A. Using these structural features to classify the peptide as a cyclotide, we extended the distribution of that substance class to a new genus, and now propose a uniform nomenclature for cyclotides.
authors.affiliation: Instituto de Química y Metabolismo del Fármaco (IQUIMEFA) (UBA-CONICET), Cátedra de Farmacognosia, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
authors.forename: A M
authors.initials: AM
authors.lastname: Broussalis
authors.forename: U
authors.initials: U
authors.lastname: Göransson
authors.forename: J D
authors.initials: JD
authors.lastname: Coussio
authors.forename: G
authors.initials: G
authors.lastname: Ferraro
authors.forename: V
authors.initials: V
authors.lastname: Martino
authors.forename: P
authors.initials: P
authors.lastname: Claeson
mesh_terms: D000595:Amino Acid Sequence; D001118:Argentina; D004220:Disulfides / Q000737:chemistry; D004355:Drug Stability; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000302:isolation & purification; D027824:Rosaceae / Q000737:chemistry*; D009626:Terminology as Topic
chemical_list: D004220:Disulfides; D010456:Peptides, Cyclic