APETx2

APETx2 is a 42-amino-acid disulfide-rich peptide toxin originally isolated from the sea anemone Anthopleura elegantissima. It is a highly potent and selective inhibitor of acid-sensing ion channel 3 (ASIC3), a proton-gated sodium channel implicated in pain perception and acidosis-related tissue injury. APETx2 blocks homomeric ASIC3 channels (IC50 = 63 nM), with reduced affinity for heteromeric ASIC channels containing ASIC3 subunits, while exhibiting negligible activity against ASIC1a, ASIC1b, ASIC2a, and major voltage-gated sodium or potassium channels. Its analgesic properties have been demonstrated in rodent pain models, and recent research also suggests cardioprotective effects in myocardial ischemia-reperfusion injury models, likely by inhibiting ASIC3 and exerting downstream metabolic and signaling effects. Structurally, APETx2 features three disulfide bridges stabilizing a four-stranded β-sheet fold, sharing a structural family with other sea anemone toxins but exhibiting a unique pharmacological profile. The APETx2 peptide is primarily used as a research tool for deciphering ASIC3 biology and as a template for developing novel analgesic or cardioprotective agents[1][3][4][5][6].

Other names

APETx2APETx-2APETx 2Acid-sensing ion channel 3 (ASIC3) inhibitor peptideSea anemone toxin APETx2