Overview
Soluble in DMSO. Prepare a concentrated stock solution by dissolving the lyophilized peptide in DMSO first (e.g., at a concentration between 100-1000x of the final working concentration). Once the peptide is completely dissolved in DMSO, slowly dilute the solution into the working buffer (or water) to the desired final working concentration.
Centrifuge all product preparations before use. It is recommended to keep the DMSO concentration as low as possible. For cell assays, a final concentration of 0.1%–0.5% DMSO (v/v) is considered safe. For other experiments, a 5% DMSO (v/v) concentration is recommended.
Myrmicitoxin1-Pm2a (Pm2a) is a 27-amino acid peptidyl toxin originally isolated from the venom of the harvester ant, Pogonomyrmex maricopa. Pm2a toxin is a potent modulator of mammalian voltage-gated sodium (NaV) channels, reducing the voltage threshold for activation and inhibiting channel inactivation. This toxin has been shown to be particularly potent in modulating NaV1.7 (EC50=154 ± 17 nM), NaV1.6 (EC50 = 176 ± 56 nM), NaV1.8 (EC50=2600 ± 700 nM), and NaV1.9 (EC50=<1000 nM) channels 1.
Pm2a toxin, along with Myrmicitoxin1-Pm1a and orthologues from other ant species (e.g., Ectatotoxin-Rm4a, Delta-myrmicitoxin-Ta3a, and Poneratoxin), represents a new class of NaV channel modulators. These toxins are structurally and functionally distinct from previously described peptide-based NaV modulators, providing important insights into the evolutionary adaptations of ant venom. Their complex effects on NaV channel currents more closely resemble those of “site 2” alkaloid toxins, such as batrachotoxin1,2.
In animal models, Pm2a toxin induces nocifensive behaviors in mice and increases intracellular Ca²⁺ concentration in dorsal root ganglion (DRG) cells, effects linked to pain perception and neuronal hyperexcitability1. Myrmicitoxin1-Pm2a’s selectivity for sensory neuron NaV channels highlights its potential in neuropathic pain research, providing a unique tool for investigating NaV channel function and sensory neuron excitability, and advancing our understanding of pain signaling pathways.
