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The Tarantula Venom Peptide Eo1a Binds to the Domain II S3-S4 Extracellular Loop of Voltage-Gated Sodium Channel NaV1.8 to Enhance Activation.
- Source :
- Frontiers in Pharmacology; 1/14/2022, Vol. 12, p1-10, 10p
- Publication Year :
- 2022
-
Abstract
- Venoms from cone snails and arachnids are a rich source of peptide modulators of voltage-gated sodium (Na<subscript>V</subscript>) channels, however relatively few venom-derived peptides with activity at the mammalian Na<subscript>V</subscript>1.8 subtype have been isolated. Here, we describe the discovery and functional characterisation of β-theraphotoxin-Eo1a, a peptide from the venom of the Tanzanian black and olive baboon tarantula Encyocratella olivacea that modulates Na<subscript>V</subscript>1.8. Eo1a is a 37-residue peptide that increases Na<subscript>V</subscript>1.8 peak current (EC<subscript>50</subscript> 894 ± 146 nM) and causes a large hyperpolarising shift in both the voltage-dependence of activation (ΔV<subscript>50</subscript>–20.5 ± 1.2 mV) and steady-state fast inactivation (ΔV<subscript>50</subscript>–15.5 ± 1.8 mV). At a concentration of 10 μM, Eo1a has varying effects on the peak current and channel gating of Na<subscript>V</subscript>1.1–Na<subscript>V</subscript>1.7, although its activity is most pronounced at Na<subscript>V</subscript>1.8. Investigations into the binding site of Eo1a using Na<subscript>V</subscript>1.7/Na<subscript>V</subscript>1.8 chimeras revealed a critical contribution of the DII S3-S4 extracellular loop of Na<subscript>V</subscript>1.8 to toxin activity. Results from this work may form the basis for future studies that lead to the rational design of spider venom-derived peptides with improved potency and selectivity at Na<subscript>V</subscript>1.8. [ABSTRACT FROM AUTHOR]
- Subjects :
- SODIUM channels
PEPTIDES
VENOM
TARANTULAS
CONUS
BINDING sites
Subjects
Details
- Language :
- English
- ISSN :
- 16639812
- Volume :
- 12
- Database :
- Complementary Index
- Journal :
- Frontiers in Pharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 154693034
- Full Text :
- https://doi.org/10.3389/fphar.2021.789570