Guangxitoxin 1E

Guangxitoxin 1E is a potent and selective blocker of KV2.1 and KV2.2 channels. Guangxitoxin 1E inhibits KV2 with an IC50 of 1-3 nM. KV2 channels underlie delayed-rectifier potassium currents in various neurons[1][2].

IC50: 1-3 nM (KV2 channels); 24-54 nM (KV4.3 channels)[2]

Guangxitoxin 1E inhibits KV2 with an IC50 of 1-3 nM but has no significant effect on KV1.2, KV1.3, KV1.5, KV3.2 and BK potassium channels, nor on calcium and sodium channels CaV1.2, CaV2.2, NaV1.5, NaV1.7, NaV1.8, whereas the IC50 for KV4.3 channels is 24-54 nM[2]. In mouse β-cells, Guangxitoxin 1E inhibits 90% of IDR and, as for KV2.1, shifts the voltage dependence of channel activation to more depolarized potentials, a characteristic of gating-modifier peptides. Guangxitoxin 1E broadens theβ-cell action potential, enhances glucose-stimulated intracellular calcium oscillations, and enhances insulin secretion from mouse pancreatic islets in a glucose-dependent manner[2].

[1]. Hönigsperger C, et al. Physiological roles of Kv2 channels in entorhinal cortex layer II stellate cells revealed by Guangxitoxin-1E. J Physiol. 2017 Feb 1;595(3):739-757.

[2]. Herrington J, et al. Blockers of the delayed-rectifier potassium current in pancreatic beta-cells enhance glucose-dependent insulin secretion. Diabetes. 2006 Apr;55(4):1034-42.