D-Amino acid residue in the C-type natriuretic peptide from the venom of the mammal, Ornithorhynchus anatinus, the Australian platypus

• Published in: FEBS letters 2002-07, Vol.524 (1), p.172-176
• Main Authors: Torres, Allan M, Menz, Ian, Alewood, Paul F, Bansal, Paramjit, Lahnstein, Jelle, Gallagher, Clifford H, Kuchel, Philip W
• Format: Article
• Language: English
• Subjects: Amino Acids - analysis; Animals; C-type natriuretic peptide; Chromatography, High Pressure Liquid; D-Amino acid; DLP, defensin-like peptide; DLP-2, defensin-like peptide-2; DLP-4, defensin-like peptide-4; HPLC, high performance liquid chromatography; LAP, leucine amino peptidase; Mass Spectrometry; Natriuretic Peptide, C-Type - chemistry; NMR, nuclear magnetic resonance; Nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; OvCNP, Ornithorhynchus venom C-type natriuretic peptide; OvCNPa, Ornithorhynchus venom C-type natriuretic peptide A; OvCNPb, Ornithorhynchus venom C-type natriuretic peptide B; Platypus; Platypus venom; Posttranslational modification; RP-HPLC, reverse-phase high performance liquid chromatography; TOCSY, total correlation spectroscopy; Toxin; Venoms - chemistry
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(02)03050-8

The C-type natriuretic peptide from the platypus venom (OvCNP) exists in two forms, OvCNPa and OvCNPb, whose amino acid sequences are identical. Through the use of nuclear magnetic resonance, mass spectrometry, and peptidase digestion studies, we discovered that OvCNPb incorporates a D-amino acid at position 2 in the primary structure. Peptides containing a D-amino acid have been found in lower forms of organism, but this report is the first for a D-amino acid in a biologically active peptide from a mammal. The result implies the existence of a specific isomerase in the platypus that converts an L-amino acid residue in the protein to the D-configuration.