P49268 (TXP3_APOSC) Reviewed, UniProtKB/Swiss-Prot
Last modified October 16, 2013. Version 57. History...
Names and origin
|Protein names||Recommended name:|
Short name=Aps III
Paralytic peptide III
Short name=PP III
|Organism||Apomastus schlingeri (Trap-door spider) (Aptostichus schlingeri)|
|Taxonomic identifier||12944 [NCBI]|
|Taxonomic lineage||Eukaryota › Metazoa › Ecdysozoa › Arthropoda › Chelicerata › Arachnida › Araneae › Mygalomorphae › Euctenizidae › Apomastus|
|Sequence length||37 AA.|
|Protein existence||Evidence at protein level|
General annotation (Comments)
The recombinant mu-cyrtautoxin-As1a potently and voltage-independently blocks voltage-gated sodium channels (Nav) of insects. It acts by pluging the outer vestibule of the channel. It acts in combination with a weak (30%) voltage-independent block of insect voltage-gated calcium (Cav) channels (low-voltage and high-voltage channels). Tested on DUM neurons, it inhibits sodium currents with an IC50 of 540 nM (and a Hill coefficient >1, reflecting an incomplete block at higher concentrations). It induces flaccid paralysis in adult Australian sheep blowfly Lucilia cuprina (Ref.2). Is both paralytic and lethal, when injected into lepidopteran larvae. Is a slower acting toxin, being lethal at 24 hours, but not paralytic at 1 hour post-injection (Ref.1). Ref.2
Expressed by the venom gland.
The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin.
Does not modulate the activity of delayed-rectifier, "A-type" or BKCa potassium channels (Ref.2).
Belongs to the insecticidal toxin ABC family.
No comparison between the natural toxin and the recombinant one has been done (Ref.2) to attest that the results can be also attributed to the natural toxin (mode of action and disulfide bonds).
Sequence annotation (Features)
|||"Identification of insecticidal peptides from venom of the trap-door spider, Aptostichus schlingeri (Ctenizidae)."|
Skinner W.S., Dennis P.A., Li J.P., Quistad G.B.
Toxicon 30:1043-1050(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE, BIOASSAY, LETHAL DOSE.
|||"The insecticidal neurotoxin Aps III is an atypical knottin peptide that potently blocks insect voltage-gated sodium channels."|
Bende N.S., Kang E., Herzig V., Bosmans F., Nicholson G.M., Mobli M., King G.F.
Biochem. Pharmacol. 85:1542-1554(2013) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, STRUCTURE BY NMR, DISULFIDE BONDS.
3D structure databases
Protocols and materials databases
|ArachnoServer||AS000403. U2-cyrtautoxin-As1a. |
Family and domain databases
|InterPro||IPR012626. Spider_insecticidal_peptide. |
|Pfam||PF08091. Toxin_21. 1 hit. |
|Accession||Primary (citable) accession number: P49268|
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Animal Toxin Annotation Program|
Index of protein domains and families