ProTx-III, potent and selective Nav1.7 blocker
Bioassay results
ProTx-III is a peptide isolated from a spider venom which potently blocks Nav1.7. The synthetic ProTx-III #PTX003 from Smartox Biotechnology was tested on Nav1.7. Results are below:
A, B, C Representative recording traces of hNav1.7 current in the presence of increasing concentrations of ProTx-III (0.5, 5 and 50 nM). The current was elicited by a 50 ms-depolarizing pulse to -10 mV from a holding potential of -90 mV. Inter-sweep period was 10 s. Current amplitudes were plotted against time. Black bar indicates toxin application. D, Dose-inhibition histogram was obtained from A, B and C. (n = 3 for each group). E, Families of transiently-expressed human Nav1.7 current traces in control and in the presence of 5 nM Tp1a. Currents were evoked by depolarizing pulses from -60 to 40 mV, while the cell was hold at -90 mV. F, Amplitude-voltage relationships obtained from E.