title: The investigation of membrane binding by amphibian peptide agonists of CCK2R using (31)P and (2)H solid-state NMR.
abstract: It has been proposed that some neuropeptides may be anchored to the cell membranes prior to attaching to the adjacent active sites of transmembrane receptors. The three amphibian skin neuropeptides signiferin 1 [RLCIPYIIPC(OH)] (smooth muscle active and immunomodulator), riparin 1.1 [[RLCIPVIFPC(OH)] (immunomodulator) and rothein 1 [SVSNIPESIGF(OH)] (immunomodulator) act via CCK2 transmembrane receptors. A combination of (31)P and (2)H solid state NMR studies of each of these three peptides in eukaryotic phospholipid models at 25°C shows that rothein 1 does not interact with the membrane at all. In contrast, both of the cyclic disulfides signiferin 1 and riparin 1.1 interact with phospholipid head groups and partially penetrate into the upper leaflet of the model bilayer, but to different extents. These interactions are not sufficiently effective to cause disruption of the lipid bilayer since the peptides are not antimicrobial, anticancer, antifungal nor active against enveloped viruses.
authors.affiliation: Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Sherman
authors.affiliation: School of Chemistry, Bio21 Institute, University of Melbourne, Victoria 3010, Australia. Electronic address: fs@unimelb.edu.au.
authors.forename: Frances
authors.initials: F
authors.lastname: Separovic
authors.affiliation: Department of Chemistry, The University of Adelaide, South Australia 5005, Australia. Electronic address: john.bowie@adelaide.edu.au.
authors.forename: John H
authors.initials: JH
authors.lastname: Bowie
mesh_terms: D029845:Amphibian Proteins / Q000737:chemistry*; D000818:Animals; D009479:Neuropeptides / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010743:Phospholipids / Q000737:chemistry*; D011485:Protein Binding; D043887:Receptor, Cholecystokinin B / Q000819:agonists
chemical_list: D029845:Amphibian Proteins; D009479:Neuropeptides; D010743:Phospholipids; D043887:Receptor, Cholecystokinin B; C000593717:riparin 1.1 peptide, Crinia riparia; C545669:rothein 1 peptide, Litoria rothii; C000593716:signiferin 1 peptide, Crinia signifera
keywords: (31)P and (2)H solid state NMR; 3D NMR structures; Binding to eukaryotic model phospholipids; Immunological activity; Riparin 1.1; Rothein 1; Signiferin 1; Smooth muscle activity; Trans membrane CCK2 receptors