Publication Date:
2019
Description:
Neurotoxins are among the main components of scorpion and snake venoms. Scorpion neurotoxins affect voltage‐gated ion channels, while most snake neurotoxins target ligand‐gated ion channels, mainly nicotinic acetylcholine receptors (nAChRs). We report that scorpion venoms inhibit α‐bungarotoxin binding to both muscle‐type nAChR from Torpedo californica and neuronal human α7 nAChR. Toxins inhibiting nAChRs were identified as OSK‐1 (α‐KTx family) from Orthochirus scrobiculosus and HelaTx1 (κ‐KTx family) from Heterometrus laoticus, both being blockers of voltage‐gated potassium channels. With an IC50 of 1.6 μm, OSK1 inhibits acetylcholine‐induced current through mouse muscle‐type nAChR heterologously expressed in Xenopus oocytes. Other well‐characterized scorpion toxins from these families also bind to Torpedo nAChR with micromolar affinities. Our results indicate that scorpion neurotoxins present target promiscuity.
Print ISSN:
0014-5793
Electronic ISSN:
1873-3468
Topics:
Biology
,
Chemistry and Pharmacology
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