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| Toxin Name |
δ-theraphotoxin-Hm1b |
| Source Species |
Heteroscodra maculata (Togo starburst tarantula) |
| Toxin Group |
Theraphotoxin |
| Description |
δ-theraphotoxin-Hm1b is a gating modifier toxin that inhibits inactivation of voltage-gated sodium channels. When tested against human Nav1.1–1.8 α subunits heterologously expressed in Xenopus oocytes, the toxin specifically inhibited inactivation of Nav1.1 (EC50 = 100 nM), with little effect on Nav1.2–1.8. The toxin is a homolog of δ-theraphotoxin-Hm1a, which was isolated from the venom of the same species.
Intraplantar injection of the toxin in mice causes equivalent mechanical sensitisation to its paralog δ-theraphotoxin-Hm1a. |
| Discovered |
2016 |
|
Sex: female, Prosoma length: 20mm
Photo courtesy of Bastian Rast
Use of photo governed by creative
commons noncommercial license
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| This toxin last updated on Nov 01, 2016 |
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| Current Taxonomy |
Historic Taxonomy |
| Kingdom |
Animalia |
| Phylum |
Arthropoda |
| Class |
Arachnida |
| Order |
Araneae |
| Infra-order |
Mygalomorphae |
| Family |
Theraphosidae |
| Genus |
Heteroscodra |
| Species |
maculata |
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| Heteroscodra maculata |
| Heterscodra maculata |
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| Molecular Target |
ED50 |
IC50 |
Kd |
Pharmacophore |
Comment |
| Sodium channel, voltage-gated (vertebrate): NaV1.1 |
100.0
nM
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Inhibits the inactivation of heterologously expressed Nav1.1 α subunits in Xenopus oocytes. |
|
| Source |
Accession |
| ArachnoServer
|
AS002363 |
| NCBI_Taxon
|
268413
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| Original Deposition References |
Osteen J.D., Herzig V., Gilchrist J., Emrick J.J., Zhang C., Wang X., Castro J., Garcia-Caraballo S., Grundy L., Rychkov G.Y., Dekan Z., Undheim E.A.B., Alewood P., Brierley S.M., Basbaum A.I., Bosmans F., King G.F., Julius D.
Nature 534: 494-499 (2016)
Subtype-selective spider toxins implicate Nav1.1 voltage-gated sodium channels in mechanical pain.
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| Disulfide Bonds |
Posttranslational modifications |
| Left Residue |
Right Residue |
Evidence |
| 2 |
16 |
By homology |
| 9 |
21 |
By homology |
| 15 |
28 |
By homology |
|
| Residue Number |
Type |
Symbol |
| 34 |
C-terminal amidation |
NH₂ |
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| Peptide Sequences |
>as:δ-theraphotoxin-Hm1b| Toxin from venom of the spider Heteroscodra maculata that inhibits the inactivation of voltage-gated sodium channels
ECRYLFGGCKTTADCCKHLGCRTDLYYCAWDGTF |
Full BLAST |
BLAST mature toxin only
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| Synonym |
Type |
| δ-theraphotoxin-Hm1a |
Recommended full name |
| δ-TRTX-Hm1a |
Recommended abbreviation |
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