It primarily inhibits outward voltage-gated Kv2.1 potassium channel currents, which are prominently expressed in pancreatic β-cells, thus increasing insulin secretion.

[1][2] Guangxitoxin is found in the venom of the tarantula Plesiophrictus guangxiensis, which lives mainly in Guangxi province of southern China.

[1] GxTX-2 shows sequence similarities with Hanatoxin (HaTX), Stromatoxin-1 (ScTx1), and Scodra griseipes toxin (SGTx) peptides.

[9] Dissimilarities in orientation of loops and turns compared to JZTX-III may contribute to the discrepancy in selectivity of GxTX-1E to the Kv2.1 channel.

[20] Furthermore, the Kv2.1 channel shows similar biophysical properties to the delayed rectifier K+ current (IDR) of the β-cells.

[21] This makes GxTX appropriate to study the physiological role of the aforementioned current as it inhibits 90% of the β-cell IDR.