Protoxin II (ProTx II)
Protoxin II: toxin properties
Protoxin II (ProTx II) is a toxin that was originally isolated from Thrixopelma pruriens (Peruvian green velvet tarantula). Protoxin II inhibits voltage-gated calcium and sodium channels (site 4). This toxin inhibits activation by shifting the voltage-dependence of channel activation to more positive potentials. The toxin potently inhibits all sodium channel subtypes tested (Nav1.2/SCN2A, Nav1.5/SCN5A, Nav1.7/SCN9A, and Nav1.8/SCN10A). It is approximately 15-fold more potent on Nav1.7/SCN9A than on Nav1.5/SCN5A channels and acts on Cav3.1/CACNA1G and interacts more weakly with the related T-Type channel Cav3.2/CACNA1H but potently inhibits the L-type calcium channel Cav1.2/CACNA1C. Protoxin II also binds to phospholipids. ProTx-II, a selective inhibitor of Nav1.7 sodium channels, blocks action potential propagation in nociceptors.
Product Specification
AA sequence: Tyr-Cys2-Gln-Lys-Trp-Met-Trp-Thr-Cys9-Asp-Ser-Glu-Arg-Lys-Cys15-Cys16-Glu-Gly-Met-Val-Cys21-Arg-Leu-Trp-Cys25-Lys-Lys-Lys-Leu-Trp-OH
(Disulfide bonds between Cys2-Cys16, Cys9-Cys21 and Cys15-Cys25)
Length (aa): 30
Formula: C168H250N46O41S8
Molecular Weight: 3828.00 Da
Appearance: White lyophilized solid
Solubility: water and saline buffer
CAS number: 484598-36-9
Source: Synthetic
Purity rate: > 95 %
Price & Quantities
- 100 µg : 170 €
References
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Edgerton, G. B., et al. (2008) Evidence for multiple effects of ProTxII on activation gating in Na(V)1.5, Toxicon 52, 489-500. PubMed link
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Priest, B. T., et al. (2007) ProTx-I and ProTx-II: gating modifiers of voltage-gated sodium channels, Toxicon 49, 194-201. PubMed link
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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 280, 11127-11133. PubMed link
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Middleton, R. E., et al. (2002) Two tarantula peptides inhibit activation of multiple sodium channels, Biochemistry 41, 14734-14747. PubMed link