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| Toxin Name |
β/ω-theraphotoxin-Tp1a |
| Source Species |
Thrixopelma pruriens (Green velvet tarantula) |
| Toxin Group |
Theraphotoxin |
| Description |
A toxin that blocks several types of voltage-gated ion channels (sodium, calcium and to a lesser extent potassium) by shifting the voltage dependence of channel activation to more depolarized potentials. It is potent blocker of the voltage-gated sodium channels Nav1.7 and Nav1.8, but also blocks Nav1.5. |
| Discovered |
2002 |
|
Sex: female, Prosoma length: 27mm
Photo courtesy of Bastian Rast
Use of photo governed by creative
commons noncommercial license
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| This toxin last updated on Oct 29, 2011 |
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| Current Taxonomy |
Historic Taxonomy |
| Kingdom |
Animalia |
| Phylum |
Arthropoda |
| Class |
Arachnida |
| Order |
Araneae |
| Infra-order |
Mygalomorphae |
| Family |
Theraphosidae |
| Genus |
Thrixopelma |
| Species |
pruriens |
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| Paraphysa scrofa |
| Thrixopelma pruriens |
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| Molecular Target |
ED50 |
IC50 |
Kd |
Pharmacophore |
Comment |
| Sodium channel, voltage-gated (vertebrate): NaV1.7 |
|
51.0
nM
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Inhibition of human Nav1.7 expressed in oocytes by native toxin. |
| Sodium channel, voltage-gated (vertebrate): NaV1.8 |
|
27.0
nM
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Inhibition of rat Nav1.8 expressed in oocytes by native toxin. |
| Potassium channel, voltage-gated (vertebrate): KV2.1 (drk1) |
|
411.0
nM
|
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Inhibition of Kv2.1 expressed oocytes cells by native toxin. |
| Calcium channel, voltage-gated (vertebrate): CaV3.1 |
|
53.0
nM
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Inhibition of rat Cav3.1 expressed in HEK-293 cells by native toxin. |
| Sodium channel, voltage-gated (vertebrate): NaV1.5 |
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IC50 not determined but 365 nM toxin shifts the voltage of half-maximal activation of human Nav1.5 by +37 mV. |
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| Original Deposition References |
Middleton R.E., Warren V.A., Kraus R.L., Hwang J.C., Liu C.J., Dai G., Brochu R.M., Kohler M.G., Gao Y.-D., Garsky V.M., Bogusky M.J., Mehl J.T., Cohen C.J., Smith M.M.
Biochemistry 41:14734-14747(2002).
Two tarantula peptides inhibit activation of multiple sodium channels.
|
Priest B.T., Blumenthal K.M., Smith J.J., Warren V.A., Smith M.M.
Toxicon 49:194-201(2007).
ProTx-I and ProTx-II: gating modifiers of voltage-gated sodium channels.
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| Disulfide Bonds |
| Left Residue |
Right Residue |
Evidence |
| 2 |
16 |
By homology |
| 9 |
21 |
By homology |
| 15 |
28 |
By homology |
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| Peptide Sequences |
>as:β/ω-theraphotoxin-Tp1a|sp:P83480 Toxin from venom of the spider Thrixopelma pruriens that inhibits voltage-gated ion channels (Na, Ca, K)
ECRYWLGGCSAGQTCCKHLVCSRRHGWCVWDGTFS |
Full BLAST |
BLAST mature toxin only
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| Synonym |
Type |
| β/ω-theraphotoxin-Tp1a |
Recommended full name |
| β/ω-TRTX-Tp1a |
Recommended abbreviation |
| Protoxin I |
Synonym |
| ProTx-I |
Synonym (abbreviation) |
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