Profile: Smartox Biotechnology is a manufacturer and supplier of synthetic peptides issued from venomous animals. Venom peptides are valuable tools for studying ion channels, GPCRs or integrins. They also demonstrate significant potential for the development of drugs for a wide variety of pathologies such as pain, auto-immune diseases, cancer or diabetes. Purotoxin1 (PT-1) is a peptide which is shown to inhibit selectively P2X3 receptor channels at a 100 nM concentration. Patch-clamp experiments did not show any inhibitory effect of PT-1 on voltage-gated channels (potentials range tested from -100 to 20 mV), neither on TRPV1 (after activation with 500 nM capsaicin). P2X3-mediated current was fully inhibited with 100 nM PT-1, making it the most potent and selective ligand for P2X3.