Spider Venom Nav1.7 Inhibitors for Pain Relief

This book describes the discovery and engineering of spider venom peptides that selectively inhibit the Nav1.7 sodium channel, a validated target for chronic pain relief. It begins with the identification of two novel toxins, µ-TRTX-Ca1a and µ-TRTX-Ca2a, from the Thai zebra tarantula Cyriopagopus albostriatus. Both peptides show potent, dose-dependent analgesia in rodent pain models. The authors then demonstrate that inactive HNTX¿I can be transformed into a potent Nav1.7 blocker by introducing conserved residues, creating a 36 nM inhibitor. Finally, through systematic alanine scanning and molecular docking of HNTX¿III, they engineer the optimized variant H4, which achieves an IC¿¿ of 7 nM, >1400¿fold selectivity over cardiac and muscle sodium channels, and superior analgesic efficacy compared to morphine in inflammatory and neuropathic pain models. The book illustrates a complete arc from natural venom prospecting to rational peptide engineering and preclinical validation for safer pain therapeutics.