title: Inhibition of the norepinephrine transporter by χ-conotoxin dendrimers.
abstract: Peptide dendrimers are a novel class of macromolecules of emerging interest with the potential of delayed renal clearance due to their molecular size and enhanced activity due to the multivalency effect. In this work, an active analogue of the disulfide-rich χ-conotoxin χ-MrIA (χ-MrIA), a norepinephrine reuptake (norepinephrine transporter) inhibitor, was grafted onto a polylysine dendron. Dendron decoration was achieved by employing copper-catalyzed alkyne-azide cycloaddition with azido-PEG chain-modified χ-MrIA analogues, leading to homogenous 4-mer and 8-mer χ-MrIA dendrimers with molecular weights ranging from 8 to 22 kDa. These dendrimers were investigated for their impact on peptide secondary structure, in vitro functional activity, and potential anti-allodynia in vivo. NMR studies showed that the χ-MrIA tertiary structure was maintained in the χ-MrIA dendrimers. In a functional norepinephrine transporter reuptake assay, χ-MrIA dendrimers showed slightly increased potency relative to the azido-PEGylated χ-MrIA analogues with similar potency to the parent peptide. In contrast to χ-MrIA, no anti-allodynic action was observed when the χ-MrIA dendrimers were administered intrathecally in a rat model of neuropathic pain, suggesting that the larger dendrimer structures are unable to diffuse through the spinal column tissue and reach the norepinephrine transporter. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wan
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Andreas
authors.initials: A
authors.lastname: Brust
authors.affiliation: Discipline of Pharmacology, University of Sydney, Sydney, New South Wales, 2006, Australia.
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Bhola
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Prerna
authors.initials: P
authors.lastname: Jha
authors.affiliation: Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mobli
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lewis
authors.affiliation: Discipline of Pharmacology, University of Sydney, Sydney, New South Wales, 2006, Australia.
authors.forename: Macdonald J
authors.initials: MJ
authors.lastname: Christie
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Alewood
mesh_terms: D000818:Animals; D019556:COS Cells; D060326:Chemistry Techniques, Synthetic / Q000379:methods; D057930:Click Chemistry; D020916:Conotoxins / Q000008:administration & dosage* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D061565:Cycloaddition Reaction; D050091:Dendrimers / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004195:Disease Models, Animal; D004220:Disulfides / Q000737:chemistry; D015195:Drug Design; D006930:Hyperalgesia / Q000188:drug therapy*; D008958:Models, Molecular; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000037:antagonists & inhibitors*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D020916:Conotoxins; D050091:Dendrimers; D004220:Disulfides; D050484:Norepinephrine Plasma Membrane Transport Proteins
keywords: click reaction; conotoxin; dendrimer; norepinephrine reuptake (NET) inhibitor; χ-MrIA