University of Queensland
A Single Stable Topological Stereoisomer of a two Disulfide-bonded Peptide Demonstrates Full Potency on the Human Norepinephrine Transporter and Blocks Chronic Neuropathic Pain
Conotoxin χ Mr1a is a 13 residue peptide with two disulfide bonds that noncompetitively inhibits the human norepinephrine transporter, hNET, leading to reduced allodynia in a mouse models of neuropathic pain. We grafted the 4-residue pharmacophore of Mr1a into a smaller disulfide framework that subsequently led to the discovery of an equipotent mimetic with a unique topological fold. Selective chemistry led to the discovery of two stereotopological isomers one of which in the globular fold was >1000 fold more potent than the other both in vitro and in vivo. These unusual isomers represent an additional level of structural complexity in multiply disulfide bonded peptides that are rarely observed and have implications for drug design, chemical synthesis and a deeper understanding of the structural diversity of cysteine rich peptides.
AuthorsP. Wilhelm, S. Mohammadi, L.J. Whish, M. Bongers, A. Brust, Å. Anderson, L. Ragnarsson, M. Moblic, R.J. Lewis, M.J. Christie, and P. Alewood