The presence of D-amino-acid-containing polypeptides, defensin-like peptide (DLP)-2 and Ornithorhyncus venom C-type natriuretic peptide (OvCNP)b, in platypus venom suggested the existence of a mammalian d-amino-acid-residue isomerase(s) responsible for the modification of the all-l-amino acid precursors. We show here that this enzyme(s) is present in the venom gland extract and is responsible for the creation of DLP-2 from DLP-4 and OvCNPb from OvCNPa. The isomerisation reaction is freely reversible and under well defined laboratory conditions catalyses the interconversion of the DLPs to full equilibration. The isomerase is ∼50-60 kDa and is inhibited by methanol and the peptidase inhibitor amastatin. This is the first known L-to-D-amino-acid- residue isomerase in a mammal. © 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Torres, A. M., Tsampazi, M., Tsampazi, C., Kennett, E. C., Belov, K., Geraghty, D. P., … Kuchel, P. W. (2006). Mammalian L-to-D-amino-acid-residue isomerase from platypus venom. FEBS Letters, 580(6), 1587–1591. https://doi.org/10.1016/j.febslet.2006.01.089