165 660 


ASIC3 selective inhibitor

APETx2 is a toxin that was originally isolated from Anthopleura elegantissima (Sea anemone). APETx2 selectively blocks the H(+)-gated sodium channel ASIC3 (ACCN3). The blockage is rapid and reversible. This toxin does not block isoform ASIC1a (unlike Psalmotoxin 1) and isoform ASIC1b of ASIC1 (ACCN2), nor ASIC2 (ACCN1). It also inhibits the heteromeric ASIC2b-ASIC3 channel, and has less affinity for ASIC1b-ASIC3, ASIC1a-ASIC3, and no effect on the ASIC2a-ASIC3 channels. IC50 is 63 nM on ASIC3 channel. IC50 is 117 nM on ASIC2b-ASIC3 heteromeric channel. IC50 is 0.9 µM on ASIC1b-ASIC3 heteromeric channel. IC50 is 2 µM on ASIC1a-ASIC3 heteromeric channel. Interestingly, recent studies demonstrated that APETx2 also inhibits Nav1.8 currents with an IC50 of around 2 µM.

Recently quoted in Scientific reports

APETx2 #07APE002 ASIC3 channel blocker

Fig 1: Dose-response curve of the effect of synthetic APETx2 #07APE002 on rat ASIC3 current recorded in Xenopus oocytes. In this system, an IC50 of 80.5 nM was determined for APETx2 (N=5).

SKU: 07APE002 Category: Tags: ,


AA sequence: H-Gly-Thr-Ala-Cys4-Ser-Cys6-Gly-Asn-Ser-Lys-Gly-Ile-Tyr-Trp-Phe-Tyr-Arg-Pro-Ser-Cys20-Pro-Thr-Asp-Arg-Gly-Tyr-Thr-Gly-Ser-Cys30-Arg-Tyr-Phe-Leu-Gly-Thr-Cys37-Cys38-Thr-Pro-Ala-Asp-OH
(Disulfide bonds between Cys4-Cys37, Cys6-Cys30 and Cys20-Cys38)
Length (aa): 42
Formula: C196H280N54O61S6
Molecular Weight: 4561.13 Da
Appearance: White lyophilized solid
Solubility: water and saline buffer
CAS number: not available
Source: Synthetic
Purity rate: > 98%




Human ASIC3 channel dynamically adapts its activity to sense the extracellular pH in both acidic and alkaline directions.

Solution structure of APETx2, a specific peptide inhibitor of ASIC3 proton-gated channels.

A new sea anemone peptide, APETx2, inhibits ASIC3, a major acid-sensitive channel in sensory neurons.

Sign Up to our Newsletter



    165 660 Quote request