title: Novel natriuretic peptides from the venom of the inland taipan (Oxyuranus microlepidotus): isolation, chemical and biological characterisation.
abstract: Three natriuretic-like peptides (TNP-a, TNP-b, and TNP-c) were isolated from the venom of Oxyuranus microlepidotus (inland taipan) and were also present in the venoms of Oxyuranus scutellatus canni (New Guinea taipan) and Oxyuranus scutellatus scutellatus (coastal taipan). They were isolated by HPLC, characterised by mass spectrometry and Edman analysis, and consist of 35-39 amino acid residues. These molecules differ from ANP/BNP through replacement of invariant residues within the 17-membered ring structure and by inclusion of proline residues in the C-terminal tail. TNP-c was equipotent to ANP in specific GC-A assays or aortic ring assays whereas TNP-a and TNP-b were either inactive (GC-A over-expressing cells and endothelium-denuded aortic rings) or weakly active (endothelium-intact aortic rings). TNP-a and TNP-b were also unable to competitively inhibit the binding of TNP-c in endothelium-denuded aortae (GC-A) or endothelium-intact aortae (NPR-C). Thus, these naturally occurring isoforms provide a new platform for further investigation of structure-function relationships of natriuretic peptides.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld 4072, Australia.
authors.forename: Bryan G
authors.initials: BG
authors.lastname: Fry
authors.forename: Janith C
authors.initials: JC
authors.lastname: Wickramaratana
authors.forename: Scott
authors.initials: S
authors.lastname: Lemme
authors.forename: Anne
authors.initials: A
authors.lastname: Beuve
authors.forename: David
authors.initials: D
authors.lastname: Garbers
authors.forename: Wayne C
authors.initials: WC
authors.lastname: Hodgson
authors.forename: Paul
authors.initials: P
authors.lastname: Alewood
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000187:drug effects; D002853:Chromatography, Liquid; D004546:Elapid Venoms / Q000737:chemistry* / Q000494:pharmacology; D017815:Elapidae; D042783:Endothelial Cells / Q000187:drug effects; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D045265:Natriuretic Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D051381:Rats; D016415:Sequence Alignment
chemical_list: D004546:Elapid Venoms; D045265:Natriuretic Peptides