Discovery of Tarantula Venom-Derived Na_V1.7-Inhibitory JzTx-V Peptide 5-Br-Trp24 Analogue AM-6120 with Systemic Block of Histamine-Induced Pruritis

Abstract

Inhibitors of the voltage-gated sodium channel Na V 1.7 are being investigated as pain therapeutics due to compelling human genetics. We previously identified Na V 1.7-inhibitory peptides GpTx-1 and JzTx-V from tarantula venom screens. Potency and selectivity were modulated through attribute-based positional scans of native residues via chemical synthesis. Herein, we report JzTx-V lead optimization to identify a pharmacodynamically active peptide variant. Molecular docking of peptide ensembles from NMR into a homology model-derived Na V 1.7 structure supported prioritization of key residues clustered on a hydrophobic face of the disulfide-rich folded peptide for derivatization. Replacing Trp24 with 5-Br-Trp24 identified lead peptides with activity in electrophysiology assays in engineered and neuronal cells. 5-Br-Trp24 containing peptide AM-6120 was characterized in X-ray crystallography and pharmacokinetic studies and blocked histamine-induced pruritis in mice after subcutaneous administration, demonstrating systemic Na V 1.7-dependent pharmacodynamics. Our data suggests a need for high target coverage based on plasma exposure for impacting in vivo end points with selectivity-optimized peptidic Na V 1.7 inhibitors.

Use of Cryopreserved Hepatocytes as Part of an Integrated Strategy to Characterize In Vivo Clearance for Peptide-Antibody Conjugate Inhibitors of Nav1.7 in Preclinical Species

“…Previous reports have described internal efforts to identify potent inhibitory peptides of Nav1.7 based on GpTx-1 and JzTx-V peptide scaffolds that have been identified and isolated from tarantula spider venom (Biswas et al, 2017;Moyer et al, 2018;Wu et al, 2018). Because many therapeutic peptides suffer from poor pharmacokinetic profiles due to proteolysis and/or renal filtration (Diao and Meibohm, Fig.…”

“…activity have been reported in the literature. Recently, we described the engineering of two series of inhibitory Nav1.7 peptide-antibody conjugates, linking peptides based on the GpTx-1 or JzTx-V toxins found in tarantula venom to nontargeting antibodies to increase the halflife and stability of the inhibitory peptides (Biswas et al, 2017;Moyer et al, 2018;Wu et al, 2018;Murray et al, 2019).…”

Discovery of a Selective, State-Independent Inhibitor of NaV1.7 by Modification of Guanidinium Toxins

“…(8) Examples include a cystine knot toxin that binds to VSD II and select sulfonamide inhibitors that bind to VSD IV. (44,(51)(52)(53). For this latter class of inhibitors, determining the level 40 of NaV1.7 target occupancy reached at these exposures is difficult given the variation in potency (i.e., IC50 values determined by electrophysiology) against resting and inactivated conformational states of the channel.…”

Mechanisms Underlying Gastrodin Alleviating Vincristine-Induced Peripheral Neuropathic Pain

“…Second, GAS was sketched by ChemDraw 19.0, and prepared by the “Prepare Ligands module,” consisting of pH-based ionization, tautomers generation, generating 3D coordinates, rearranging hydrogens, and minimization. Then, the binding sites of the receptor were defined by the “From Receptor Cavities” method within the “Define and Edit Binding Site module,” and referring to the active sites reported in the literature ( Ito et al, 1989 ; Swain et al, 2017 ; Moyer et al, 2018 ; Wu et al, 2018 ; Xu et al, 2019 ). Finally, the CDOCKER method was applied to evaluate the binding interactions of GAS at different sites with the docking score as an important criterion ( Zhang et al, 2019a ; Zhang et al, 2020a ).…”