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Processed protoxin-1 (ProTx1; ProTx-I) of 35 aas.  Inhibits voltage-gated calcium channels Cav3.1/CACNA1G, voltage-gated potassium channels Kv2.1/KCNB1 and all sodium channels tested (Nav1.2/SCN2A, Nav1.5/SCN5A, Nav1.7/SCN9A, and Nav1.8/SCN10A). Shifts the voltage-dependence of channel activation to more positive potentials. Most potent against Nav1.8/SCN10A (Middleton et al. 2002; Priest et al. 2007).  A hydrophobic patch on the ProTx-II surface anchors it at the cell surface in a position that optimizes interaction of the peptide with the binding site on the voltage sensor domain. Binding of ProTx-II to the lipid membrane is directly linked to its potency as a hNaV1.7 channel inhibitor (Henriques et al. 2016).

Accession Number:P83480
Protein Name:Protoxin-1 aka ProTx1
Molecular Weight:3994.00
Species:Thrixopelma pruriens (Green velvet) [213387]
Location1 / Topology2 / Orientation3: Secreted1
Substrate NONE

Cross database links:

Pfam: PF07740   

Gene Ontology

GO:0005576 C:extracellular region
GO:0019855 F:calcium channel inhibitor activity
GO:0019870 F:potassium channel inhibitor activity
GO:0019871 F:sodium channel inhibitor activity
GO:0009405 P:pathogenesis

References (2)

[1] “Two tarantula peptides inhibit activation of multiple sodium channels.”  Middleton   12475222
[2] “ProTx-I and ProTx-II: gating modifiers of voltage-gated sodium channels.”  Priest   17087985

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FASTA formatted sequence