 |
|
 |
| |
| Toxin Name |
μ-theraphotoxin-Hs2a |
| Source Species |
Haplopelma schmidti |
| Toxin Group |
Theraphotoxin |
| Description |
Toxin inhibits neuronal TTX-sensitive voltage-gated sodium channels. No effect on TTX-resistant Nav. Toxin suppresses peak sodium current without altering the activation or inactivation kinetic, hence it is suggested to act on site 1 of the channel. The toxin does not partition into phospholipid bilayers. The toxin showed no effect after injection of 48799 pmol/g (=0.2 mg/g) into cockroaches (Periplaneta americana). |
| Discovered |
2002 |
|
 schmidti female 20 mm-Bastian Rast-thumb.jpg)
Sex: female, Prosoma length: 20mm
Photo courtesy of Bastian Rast
Use of photo governed by creative
commons noncommercial license
|
| This toxin last updated on Mar 27, 2011 |
|
| Current Taxonomy |
Historic Taxonomy |
| Kingdom |
Animalia |
| Phylum |
Arthropoda |
| Class |
Arachnida |
| Order |
Araneae |
| Infra-order |
Mygalomorphae |
| Family |
Theraphosidae |
| Genus |
Haplopelma |
| Species |
schmidti |
|
| Haplopelma schmidti |
| Haplopelma huwenum |
|
|
| Molecular Target |
ED50 |
IC50 |
Kd |
Pharmacophore |
Comment |
| Sodium channel, voltage-gated (vertebrate): NaV1.7 |
|
22.7
nM
|
|
|
Inhibition of human Nav1.7 expressed in HEK293 cells |
| Sodium channel, voltage-gated (vertebrate): Vertebrate NaV channel, non-selective |
|
30.0
nM
|
|
|
Inhibition of TTX-sensitive Nav currents in rat DRG neurons by native toxin. IC50=400 nM for Nav from rat hippocampus for native and synthetic toxin. |
|
| Original Deposition References |
Peng K., Shu Q., Liang S.-P.
J. Biol. Chem. 277:47564-47571(2002).
Function and solution structure of huwentoxin-IV, a potent neuronal tetrodotoxin (TTX)-sensitive sodium channel antagonist from Chinese bird spider Selenocosmia huwena.
|
Diao J., Lin Y., Tang J., Liang S.-P.
Toxicon 42:715-723(2003).
cDNA sequence analysis of seven peptide toxins from the spider Selenocosmia huwena.
|
| Other References |
Liang S.
Toxicon 43:575-585(2004).
An overview of peptide toxins from the venom of the Chinese bird spider Selenocosmia huwena Wang [=Ornithoctonus huwena (Wang)].
|
Xiao Y., Bingham J.P., Zhu W., Moczydlowski E., Liang S., Cummins T.R.
J. Biol. Chem. 283:27300-27313 (2008)
Tarantula huwentoxin-IV inhibits neuronal sodium channels by binding to receptor site 4 and trapping the domain ii voltage sensor in the closed configuration.
|
|
| Disulfide Bonds |
Posttranslational modifications |
| Left Residue |
Right Residue |
Evidence |
| 2 |
17 |
Experimentally determined |
| 9 |
24 |
Experimentally determined |
| 16 |
31 |
Experimentally determined |
|
| Residue Number |
Type |
Symbol |
| 35 |
C-terminal amidation |
NH₂ |
|
|
| Peptide Sequences |
>as:μ-theraphotoxin-Hs2a_1|sp:P83303 Toxin from venom of the spider Haplopelma schmidti that inhibits voltage-gated sodium channels
MVNMKASMFLALAGLVLLFVVCYASESEEKEFSNELLSSVLAVDDNSKGEERECLEIFKA
CNPSNDQCCKSSKLVCSRKTRWCKYQIGK |
Full BLAST |
BLAST mature toxin only
|
>as:μ-theraphotoxin-Hs2a_2|gb:ABY77744 Toxin from venom of the spider Haplopelma schmidti that inhibits voltage-gated sodium channels
MKASMFLALAGLVLLFVVCYASESEEKEFSNELLSSVLAVDDNSKGEERECLEIFKACNP
SNDQCCKSSKLVCSRKTRWCKYQIGK |
Full BLAST |
BLAST mature toxin only
|
>as:μ-theraphotoxin-Hs2a_3|gb:ABY77746 Toxin from venom of the spider Haplopelma schmidti with unknown molecular target
MKASMFLALAGLVQLFVVCYASESEEKEFSNELLSSVLAVDDNSKGEERECLEIFKACNP
SNDQCCKSSKLVCSRKTRWCKYQIGK |
Full BLAST |
BLAST mature toxin only
|
| mRNA Sequences |
>as:μ-theraphotoxin-Hs2a_2|gb:EU195291 cDNA sequence of a toxin from the venom gland of the spider Haplopelma schmidti
GATCAGTAACGGAAGTTCTCCGTAACACTCTCTTCTCAGAAGATTCTTGGTTTTCTGTTT
TGGTGGTGAACATGAAAGCGTCAATGTTTTTGGCCTTGGCAGGATTAGTCCTGCTTTTCG
TTGTTTGCTATGCCTCCGAATCTGAGGAAAAAGAATTCTCCAACGAACTGCTTTCGTCGG
TTCTTGCAGTTGACGATAACTCCAAGGGCGAAGAAAGGGAGTGCTTAGAGATTTTTAAGG
CATGCAACCCTTCAAATGACCAGTGCTGCAAGAGCTCGAAATTAGTTTGCAGTCGAAAAA
CCAGGTGGTGTAAATACCAAATAGGCAAATGAGATCAATATATGCAGTCCAGTTTTCTAA
CTGGATATACTTGGCCAATGATGGAATTATGTTAAATAATTAATCTGCTTGCCAGTTAAT
GAGTATCAATAAATAATATTTCACCGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA |
Full BLAST
|
>μ-theraphotoxin-Hs2a_1|gb:AY263707 cDNA sequence of a toxin from the venom gland of the spider Haplopelma schmidti
TCTTGCAGTTGACGATAACTCCAAGGGCGAAGAAAGGGAGTGCTTAGAGATTTTTAAGGC
ATGCAACCCTTCAAATGACCAGTGCTGCAAGAGCTCGAAATTAGTTTGCAGTCGAAAAAC
CAGGTGGTGTAAATACCAAATAGGCAAATGAGATCAATATATGCAGTCCAGTTTTCTAAC
TGGATATACTTGGCCAATGATGGAATTATGTTAAATAATTAATCTGCTTGCCAGTTAATG
AGTATCAATAAATAATATTTCACTTTAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA |
Full BLAST
|
>μ-theraphotoxin-Hs2a_3|gb:EU195293 cDNA sequence of a toxin from the venom gland of the spider Haplopelma schmidti
GGTATCAGTAACGGAAGTTCTCCGTAACACTCTCTTCTCAGAAGATTCTTGGTTTTCTGT
TTTGGTGGTGAACATGAAAGCGTCAATGTTTTTGGCCTTGGCAGGATTAGTCCAGCTTTT
CGTTGTTTGCTATGCCTCCGAATCTGAGGAAAAAGAATTCTCCAACGAACTGCTTTCGTC
GGTTCTTGCAGTTGACGATAACTCCAAGGGCGAAGAAAGGGAGTGCTTAGAGATTTTTAA
GGCATGCAACCCTTCAAATGACCAGTGCTGCAAGAGCTCGAAATTAGTTTGCAGTCGAAA
AACCAGGTGGTGTAAATACCAAATAGGCAAATGAGATCAATATATGCAGTCCAGTTTTCT
AACTGGATATACTTGGCCAATGATGGAATTATGTTAAATAATTAATCTGCTTGCCAGTTA
ATGAGTATCAATAAATAATATTTCACTTTAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAA |
Full BLAST
|
|
| Synonym |
Type |
| μ-theraphotoxin-Hs2a |
Recommended full name |
| μ-TRTX-Hs2a |
Recommended abbreviation |
| Huwentoxin-4 |
Synonym |
| μ-theraphotoxin-Hh2a |
Synonym |
| U14-theraphotoxin-Hh1b |
Synonym |
| U14-theraphotoxin-Hh1a |
Synonym |
| Huwentoxin-IVc |
Synonym |
| Huwentoxin-IVb |
Synonym |
| Huwentoxin-IVa |
Synonym |
| Huwentoxin-IV |
Synonym |
| HWTX-IVb |
Synonym (abbreviation) |
| U14-TRTX-Hh1b |
Synonym (abbreviation) |
| HwTx-IV |
Synonym (abbreviation) |
| U14-TRTX-Hh1a |
Synonym (abbreviation) |
| HWTX-IVc |
Synonym (abbreviation) |
| HWTX-IVa |
Synonym (abbreviation) |
| μ-TRTX-Hh2a |
Synonym (abbreviation) |
|
|
|
|
|
 |
|
 |
|
|
 schmidti female 20 mm-Bastian Rast.jpg)
