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The Dinoflagellate Toxin 20-Methyl Spirolide-G Potently Blocks Skeletal Muscle and Neuronal Nicotinic Acetylcholine Receptors.

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  • معلومة اضافية
    • Contributors:
      Institut des Neurosciences Paris-Saclay (NeuroPSI); Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS); Institut de Biologie et de Technologies de Saclay (IBITECS); Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay; Institut de Chimie des Substances Naturelles (ICSN); Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS); This work was supported by the Agence Nationale de la Recherche (France) by Grant ANR-12-ASTR-0037-AQUANEUROTOX.; ANR-12-ASTR-0037,AquaNeuroTox,Identification et caractérisation du mode d'interaction de phycotoxines neurotoxiques présentant un risque biologique - Développement de nouveaux systèmes de détection.(2012)
    • بيانات النشر:
      HAL CCSD
      MDPI
    • الموضوع:
      2016
    • Collection:
      HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives)
    • نبذة مختصرة :
      International audience ; The cyclic imine toxin 20-methyl spirolide G (20-meSPX-G), produced by the toxigenic dinoflagellate Alexandrium ostenfeldii/Alexandrium peruvianum, has been previously reported to contaminate shellfish in various European coastal locations, as revealed by mouse toxicity bioassay. The aim of the present study was to determine its toxicological profile and its molecular target selectivity. 20-meSPX-G blocked nerve-evoked isometric contractions in isolated mouse neuromuscular preparations, while it had no action on contractions elicited by direct electrical stimulation, and reduced reversibly nerve-evoked compound muscle action potential amplitudes in anesthetized mice. Voltage-clamp recordings in Xenopus oocytes revealed that 20-meSPX-G potently inhibited currents evoked by ACh on Torpedo muscle-type and human α7 nicotinic acetylcholine receptors (nAChR), whereas lower potency was observed in human α4β2 nAChR. Competition-binding assays showed that 20-meSPX-G fully displaced [³H]epibatidine binding to HEK-293 cells expressing the human α3β2 (Ki = 0.040 nM), whereas a 90-fold lower affinity was detected in human α4β2 nAChR. The spirolide displaced [(125)I]α-bungarotoxin binding to Torpedo membranes (Ki = 0.028 nM) and in HEK-293 cells expressing chick chimeric α7-5HT₃ nAChR (Ki = 0.11 nM). In conclusion, this is the first study to demonstrate that 20-meSPX-G is a potent antagonist of nAChRs, and its subtype selectivity is discussed on the basis of molecular docking models.
    • Relation:
      info:eu-repo/semantics/altIdentifier/pmid/27563924; hal-01443823; https://hal.science/hal-01443823; https://hal.science/hal-01443823/document; https://hal.science/hal-01443823/file/toxins-08-00249-v2.pdf; PUBMED: 27563924; PUBMEDCENTRAL: PMC5037475
    • الرقم المعرف:
      10.3390/toxins8090249
    • Rights:
      info:eu-repo/semantics/OpenAccess
    • الرقم المعرف:
      edsbas.FAAA74DD