title: Duck-billed platypus venom peptides induce Ca2+ influx in neuroblastoma cells.
abstract: The duck-billed platypus (Ornithorhynchus anatinus) is one of the few venomous Australian mammals. We previously found that its crude venom potently induces Ca(2+) influx in human neuroblastoma IMR-32 cells. Guided by this bioassay, we identified 11 novel peptides, including the heptapeptide H-His-Asp-His-Pro-Asn-Pro-Arg-OH (1). Compounds 1-4 and 5-11 coincided with the 6-9 N-terminal residues of Ornithorhynchus venom C-type natriuretic peptide (OvCNP) and the 132-150 part of OvCNP precursor peptide, respectively. Heptapeptide 1, which is one of the primary components of the venom fluid (approximately 200 ng/microL), induced a significant increase in [Ca(2+)](i) in IMR-32 cells at 75 microM. To the best of our knowledge, this is the first example of the isolation of the N-terminal linear fragments of CNPs in any mammal.
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan. mkita@chem.tsukuba.ac.jp
authors.forename: Masaki
authors.initials: M
authors.lastname: Kita
authors.forename: David StC
authors.initials: DS
authors.lastname: Black
authors.forename: Osamu
authors.initials: O
authors.lastname: Ohno
authors.forename: Kaoru
authors.initials: K
authors.lastname: Yamada
authors.forename: Hideo
authors.initials: H
authors.lastname: Kigoshi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Uemura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008969:Molecular Sequence Data; D020098:Natriuretic Peptide, C-Type / Q000737:chemistry; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010987:Platypus; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014688:Venoms / Q000737:chemistry*
chemical_list: D010455:Peptides; D014688:Venoms; D020098:Natriuretic Peptide, C-Type; D002118:Calcium