Cell-penetrating peptide (CPP) with defensive purpose that induces pain by specifically activating mammalian sensory neuron TRPA1 channels. It non-covalently binds to the same region than other TRPA1 agonists (irritants), but acts via a distinct biochemical mechanism. Its binding stabilizes the TRPA1 open state and diminishes calcium-permeability. Consequently, it produces pain and pain hypersensitivity, but fails to trigger efferent release of neuropeptides (CGRP) and neurogenic inflammation typically produced by noxious electrophiles. Is not active on voltage-gated potassium channels and other TRP channels. Monomer. Penetrates into cell via passive diffusion and binds to the cytoplasmic side of TRPA1 (PubMed:31447178). Expressed by the venom gland. Has the structural arrangement of two alpha-helices stabilized by disulfide bonds (CSalpha/alpha 2(S-S)). Monoisotopic mass. Could be used, as a first step, as a pharmacological probe for dissecting TRPA1 function and its contribution to acute and persistent pain. Has no effect on Kv1.2/KCNA2, Kv2.1/KCNB1, Kv3.1/KCNC1, Kv4.3/KCND3, TRPM8, and TRPV1. Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor kappa-KTx family. Kappa-KTx 1 subfamily. Sting - Issue 219 of November 2019