title: Conotoxin αD-GeXXA utilizes a novel strategy to antagonize nicotinic acetylcholine receptors.
abstract: Nicotinic acetylcholine receptors (nAChRs) play essential roles in transmitting acetylcholine-mediated neural signals across synapses and neuromuscular junctions, and are also closely linked to various diseases and clinical conditions. Therefore, novel nAChR-specific compounds have great potential for both neuroscience research and clinical applications. Conotoxins, the peptide neurotoxins produced by cone snails, are a rich reservoir of novel ligands that target receptors, ion channels and transporters in the nervous system. From the venom of Conus generalis, we identified a novel dimeric nAChR-inhibiting αD-conotoxin GeXXA. By solving the crystal structure and performing structure-guided dissection of this toxin, we demonstrated that the monomeric C-terminal domain of αD-GeXXA, GeXXA-CTD, retains inhibitory activity against the α9α10 nAChR subtype. Furthermore, we identified that His7 of the rat α10 nAChR subunit determines the species preference of αD-GeXXA, and is probably part of the binding site of this toxin. These results together suggest that αD-GeXXA cooperatively binds to two inter-subunit interfaces on the top surface of nAChR, thus allosterically disturbing the opening of the receptor. The novel antagonistic mechanism of αD-GeXXA via a new binding site on nAChRs provides a valuable basis for the rational design of new nAChR-targeting compounds.
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Shaoqiong
authors.initials: S
authors.lastname: Xu
authors.affiliation: National Center for Protein Science Shanghai and State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, CAS, 320 Yueyang Road, Shanghai 200031, China.
authors.forename: Tianlong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Health Innovations Research Institute, RMIT University, Melbourne, VIC 3083, Australia.
authors.forename: Shiva N
authors.initials: SN
authors.lastname: Kompella
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Mengdi
authors.initials: M
authors.lastname: Yan
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Lu
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Shao
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.|National Center for Protein Science Shanghai and State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, CAS, 320 Yueyang Road, Shanghai 200031, China.
authors.forename: Chengwu
authors.initials: C
authors.lastname: Chi
authors.affiliation: Health Innovations Research Institute, RMIT University, Melbourne, VIC 3083, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Adams
authors.affiliation: National Center for Protein Science Shanghai and State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, CAS, 320 Yueyang Road, Shanghai 200031, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Ding
authors.affiliation: Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Chunguang
authors.initials: C
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D020916:Conotoxins / Q000494:pharmacology*; D052078:Conus Snail / Q000378:metabolism*; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000494:pharmacology*; D018733:Nicotinic Antagonists / Q000494:pharmacology*; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: C470699:Chrna10 protein, rat; D020916:Conotoxins; D009498:Neurotoxins; D018733:Nicotinic Antagonists; D021122:Protein Subunits; D011978:Receptors, Nicotinic