121 990 


ProTx-III, new selective Nav1.7 blocker

ProTx-III (µ-TRTX-Tp1a; belongs to NaSpTx family 1) has been isolated from the venom of the Peruvian green-velvet tarantula Thrixopelma pruriens at the University of Queensland (Australia). ProTx-III has been described to be a selective inhibitor of Nav1.7 with an IC50 value around 2 nM. The synthetic version of Tp1a produced by Smartox yields similar results in terms of Nav1.7 inhibition (see Figure 1). Queensland scientists have described that ProTx-III induces no significant changes in the voltage dependence of activation or steady-state inactivation of Nav1.7. ProTx-III also inhibits Nav1.1, Nav1.2 and Nav1.6 at nanomolar concentrations and does not affects Cav channels and nicotinic acetylcholine receptors. ProTx-III demonstrates analgesic properties in vivo when injected intraplantary in mice prior treatment with OD1, an activator of Nav1.7, which induces spontaneous pain.

Tp1a - selective blocker of Nav1.7 sodium channel

Fig 1: effect of 5nM Smartox ProTx-III on hNav1.7 current studied by eliciting voltage steps from -60 to +40 mV at a holding potential of -90 mV.

View bioassay report

SKU: PTX003 Category: Tags: , ,


AA sequence:   Asp-Cys2-Leu-Lys-Phe-Gly-Trp-Lys-Cys9-Asn-Pro-Arg-Asn-Asp-Lys-Cys16-Cys17-Ser-Gly-Leu-Lys-Cys22-Gly-Ser-Asn-His-Asn-Trp-Cys29-Lys-Leu-His-Ile-NH2
Disulfide bonds:    Cys2-Cys17, Cys9-Cys22, Cys16-Cys29
Length (aa): 33
Formula:      C162H246N52O43S6
Appearance: White lyophilized solid
CAS number:
Molecular Weight: 3802.47 Da
Source: Synthetic
Solubility: Water or saline buffer, 5 mg/mL maximum (recommendation)
Counterion: TFA salts

Identification and Characterization of ProTx-III

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