Product ID L8443-100UG 
Molecular formula C168H250N46O41S8
A 30 amino-acids peptide with 3 disulfide bridges , synthetic, initially isolated from the venom of the Peruvian green velvet tarantula Thrixopelma pruriens.
Biological activity

ProTx-II (ProTx-2, Protoxin II) is a gating-modifier toxin that targets voltage-gated sodium channels with a preferential activity on Nav1.7/SCN9A. It inhibits both activation and inactivation.
For inhibition of activation, it is 100-fold more selective for Nav1.7/SCN9A (IC50=0.3-3) than for other sodium channels (Nav1.2/SCN2A IC50=40-540 nM, Nav1.3/SCN3A IC50=102 nM, Nav1.4/SCN4A IC50=30-39 nM, Nav1.5/SCN5A IC50=19-90 nM, Nav1.6/SCN8A IC50=26 nM, and Nav1.8/SCN10A IC50=146 nM).
For inhibition of inactivation, it is 20-fold more potent in inhibiting inactivation on Nav1.7/SCN9A (IC50=250 nM) than other channels (about 4.6 µM for all channels).
It also inhibits Cav1.2/CACNA1C, Cav3.2/CACNA1H (29% block at 1 µM). It inhibits Nav1.7/SCN9A activation by interacting with DII and impairs Nav1.7/SCN9A inactivation by interacting with DIV. This toxin binds to lipid membrane. This ability correlates with hNav1.7/SCN9A inhibition, showing that membrane binding is the first step in the inhibitory mechanism of this toxin.

 Packaging and Prices

Packaging Price (€) Quantité Buy Now
1 Unité(s) 110.00

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5 Unité(s) 440.00

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 Product Technical Documents
Safety Data Sheet Available on request, please Contact us
Ref. SDS_L8443-100UG : unit price : free of charge
 Chemical and Physical Properties
Product code L8443-100UG  Molecular weight 3826.65 Da
Product name PROTOXIN II  Physical form White lyophilized solid
CAS No. 484598-36-9 Melting point
RTECS NA Solubility water and saline buffer
UNIPROT P83476 Optical Activity
PubChem SID    
PubChem CID 90488904    
Purity > 98 %    
Toxicity(LD50) No Data    
Chemical Name    
Storage & Reconstitution

Stable at room temperature, store preferably at 4°C

Savety Recommandations  
 Bibliographic References
Product code L8443-100UG 
Product name PROTOXIN II 

- 1. Edgerton G. B., et al. (2008) Evidence for multiple effects of ProTxII on activation gating in Na(V)1.5, Toxicon.  ;
2. Klint JK., et al. (2012) Spider-venom peptides that target voltage-gated sodium channels: pharmacological tools and potential therapeutic leads. Toxicon.  ;
3. Middleton R. E., et al. (2002) Two tarantula peptides inhibit activation of multiple sodium channels, Biochemistry.  ;
4. Priest B. T., et al. (2007) ProTx-I and ProTx-II: gating modifiers of voltage-gated sodium channels, Toxicon.  ;
5. Smith J. J., et al. (2005) Differential phospholipid binding by site 3 and site 4 toxins. Implications for structural variability between voltage-sensitive sodium channel domains, J Biol Chem.  ;
6. William A., et al. (2007) ProTx-II, a selective inhibitor of Nav1.7 sodium channels, blocks action potential propagation in nociceptors. Mol. Pharm.
Product code L8443-100UG 
Product name PROTOXIN II 
External Links PubMed
Biomedical Citations From PubMed
Toxicology Citations From PubMed
PubChem CID
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