Guangxitoxin 1E TFA is the TFA salt form of Guangxitoxin 1E. Guangxitoxin 1E TFA is a peptide toxin and a selective inhibitor for voltage-gated potassium channel K V 2.1 and K V 2.2 with IC 50 of 1-3 nM. Guangxitoxin 1E TFA enhances glucose-stimulated intracellular calcium ion oscillations and increases insulin secretion in a glucose-dependent manner.