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Record Information
Version2.0
Creation Date2009-07-03 22:19:00 UTC
Update Date2014-12-24 20:25:37 UTC
Accession NumberT3D2499
Identification
Common NameHuwentoxin
ClassProtein
DescriptionHuwentoxin is a peptide toxin produced by the Chinese bird spider (Haplopelma schmidti). It blocks neuromuscular transmission by binding to the nicotinic acetylcholine receptor and also selectively inhibits N-type calcium channels. (1)
Compound Type
  • Amide
  • Amine
  • Animal Toxin
  • Natural Compound
  • Organic Compound
  • Protein
  • Spider Toxin
Protein StructureT3d2499
Synonyms
Synonym
Huwentoxin IV
Huwentoxin-IV
HWTX
Chemical FormulaNot Available
Average Molecular Mass9318.830 g/mol
CAS Registry Number526224-73-7
SequenceNot Available
Chemical Taxonomy
DescriptionNot Available
KingdomOrganic Compounds
Super ClassOrganic Acids
ClassCarboxylic Acids and Derivatives
Sub ClassAmino Acids, Peptides, and Analogues
Direct ParentPeptides
Alternative ParentsNot Available
SubstituentsNot Available
Molecular FrameworkNot Available
External DescriptorsNot Available
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular LocationsNot Available
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
StateLiquid
AppearanceClear solution.
Experimental Properties
PropertyValue
Melting PointNot Available
Boiling PointNot Available
Solubility>10 mg/mL
LogPNot Available
Predicted PropertiesNot Available
Spectra
Spectra
Spectrum TypeDescriptionSplash KeyView
Toxicity Profile
Route of ExposureInjection (sting/bite) (2)
Mechanism of ToxicityHuwentoxin blocks neuromuscular transmission by binding to the nicotinic acetylcholine receptor, which affects the release of neurotransmitters from autonomic nerve endings of both cholinergic and adrenergic neuroeffector junctions. It also selectively inhibits N-type calcium channels. (1)
MetabolismFree toxin may be removed by opsonization via the reticuloendothelial system (primarily the liver and kidneys) or it may be degraded through cellular internalization via the lysosomes. Lysosomes are membrane-enclosed organelles that contain an array of digestive enzymes, including several proteases.
Toxicity ValuesNot Available
Lethal DoseNot Available
Carcinogenicity (IARC Classification)No indication of carcinogenicity to humans (not listed by IARC).
Uses/SourcesHuwentoxin is a peptide toxin produced by the Chinese bird spider (Haplopelma schmidti). (1)
Minimum Risk LevelNot Available
Health EffectsHuwentoxin is neurotoxic. (1)
SymptomsHuwentoxin is a peptide toxin produced by the Chinese bird spider (Haplopelma schmidti). (1)
TreatmentNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
HMDB IDNot Available
PubChem Compound IDNot Available
ChEMBL IDNot Available
ChemSpider IDNot Available
KEGG IDNot Available
UniProt IDP56676
OMIM ID
ChEBI IDNot Available
BioCyc IDNot Available
CTD IDNot Available
Stitch IDNot Available
PDB ID1QK6
ACToR IDNot Available
Wikipedia LinkNot Available
References
Synthesis ReferenceNot Available
MSDSNot Available
General References
  1. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
  2. Wikipedia. Spider toxin. Last Updated 9 January 2009. [Link]
Gene Regulation
Up-Regulated GenesNot Available
Down-Regulated GenesNot Available

Targets

General Function:
Ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNA1
Uniprot ID:
P02708
Molecular Weight:
54545.235 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNB1
Uniprot ID:
P11230
Molecular Weight:
56697.9 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Acetylcholine-activated cation-selective channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRND
Uniprot ID:
Q07001
Molecular Weight:
58894.55 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Cation transmembrane transporter activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNE
Uniprot ID:
Q04844
Molecular Weight:
54696.54 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNG
Uniprot ID:
P07510
Molecular Weight:
57882.8 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Receptor binding
Specific Function:
Ionotropic receptor with a probable role in the modulation of auditory stimuli. Agonist binding may induce an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. The channel is permeable to a range of divalent cations including calcium, the influx of which may activate a potassium current which hyperpolarizes the cell membrane. In the ear, this may lead to a reduction in basilar membrane motion, altering the activity of auditory nerve fibers and reducing the range of dynamic hearing. This may protect against acoustic trauma.
Gene Name:
CHRNA10
Uniprot ID:
Q9GZZ6
Molecular Weight:
49704.295 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Drug binding
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNA2
Uniprot ID:
Q15822
Molecular Weight:
59764.82 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNA3
Uniprot ID:
P32297
Molecular Weight:
57479.54 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane permeable to sodium ions.
Gene Name:
CHRNA4
Uniprot ID:
P43681
Molecular Weight:
69956.47 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNA5
Uniprot ID:
P30532
Molecular Weight:
53053.965 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Acetylcholine-activated cation-selective channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNA6
Uniprot ID:
Q15825
Molecular Weight:
56897.745 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Toxic substance binding
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. The channel is blocked by alpha-bungarotoxin.
Gene Name:
CHRNA7
Uniprot ID:
P36544
Molecular Weight:
56448.925 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Calcium channel activity
Specific Function:
Ionotropic receptor with a probable role in the modulation of auditory stimuli. Agonist binding induces a conformation change that leads to the opening of an ion-conducting channel across the plasma membrane (PubMed:11752216, PubMed:25282151). The channel is permeable to a range of divalent cations including calcium, the influx of which may activate a potassium current which hyperpolarizes the cell membrane (PubMed:11752216, PubMed:25282151). In the ear, this may lead to a reduction in basilar membrane motion, altering the activity of auditory nerve fibers and reducing the range of dynamic hearing. This may protect against acoustic trauma. May also regulate keratinocyte adhesion (PubMed:11021840).
Gene Name:
CHRNA9
Uniprot ID:
Q9UGM1
Molecular Weight:
54806.63 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane permeable to sodiun ions.
Gene Name:
CHRNB2
Uniprot ID:
P17787
Molecular Weight:
57018.575 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Drug binding
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNB3
Uniprot ID:
Q05901
Molecular Weight:
52728.215 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.
Gene Name:
CHRNB4
Uniprot ID:
P30926
Molecular Weight:
56378.985 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.
General Function:
Voltage-gated calcium channel activity
Specific Function:
Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1B gives rise to N-type calcium currents. N-type calcium channels belong to the 'high-voltage activated' (HVA) group and are blocked by omega-conotoxin-GVIA (omega-CTx-GVIA) and by omega-agatoxin-IIIA (omega-Aga-IIIA). They are however insensitive to dihydropyridines (DHP), and omega-agatoxin-IVA (omega-Aga-IVA). Calcium channels containing alpha-1B subunit may play a role in directed migration of immature neurons.
Gene Name:
CACNA1B
Uniprot ID:
Q00975
Molecular Weight:
262493.84 Da
References
  1. Armas LA, Hollis BW, Heaney RP: Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91. [15531486 ]
  2. The UniProt Consortium. The Universal Protein Resource (UniProt) Nucleic Acids Res. 2008;36:D190-D195.