AUTHOR=Antunes Aurélie , Montnach Jérôme , Khakh Kuldip , Lopez Ludivine , Thomas Baptiste , Ribeiro Oliveira-Mendes Barbara , Jaquillard Lucie , Servent Denis , Béroud Rémy , Cohen Charles J. , Benoit Evelyne , De Waard Michel TITLE=The venom of Cyriopagopus schmidti spider contains a natural huwentoxin-IV analogue with unexpected improved analgesic potential JOURNAL=Frontiers in Pharmacology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1566312 DOI=10.3389/fphar.2025.1566312 ISSN=1663-9812 ABSTRACT=The venom of Cyriopagopus schmidti spider has been extensively investigated, thereby allowing the identification of numerous new natural peptides. Many of these peptides are active on ion channels and several of them occur from post-translational processing. In order to further identify new entities, we screened this venom against five different human voltage-gated sodium (hNav) channels. We illustrate the unusual richness of this venom in targeting this wide variety of hNav channels. We confirm the identity of previously discovered peptides active on these ion channels type (huwentoxin (HwTx)-I, HwTx-II and HwTx-IV), indicating the efficacy of the screening process by automated patch-clamp. We also identified a novel analogue of HwTx-IV that differs by the absence of amidation and the presence of an extra C-terminal Gly residue. Interestingly, this analogue is less potent than HwTx-IV itself in blocking hNav1.7 in cell lines, but turns out to be significantly more potent in TTX-sensitive dorsal root ganglia neurons. Because of this unexpected finding, this novel analogue turns out to be a more potent analgesic than HwTx-IV itself without presenting most of the Nav1.6-related toxic effects of HwTx-IV.