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B7S4N9 (IVBTI_OXYSC) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 28. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Taicatoxin, serine protease inhibitor component

Short name=TCX, serine protease inhibitor component
Short name=TSPI
Alternative name(s):
Venom protease inhibitor 1
Venom protease inhibitor 2
OrganismOxyuranus scutellatus scutellatus (Australian taipan) (Coastal taipan)
Taxonomic identifier8667 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiLepidosauriaSquamataBifurcataUnidentataEpisquamataToxicoferaSerpentesColubroideaElapidaeAcanthophiinaeOxyuranus

Protein attributes

Sequence length88 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Heterotrimer: blocks the voltage-dependent L-type calcium channels (Cav) from the heart, and the small conductance calcium-activated potassium channels (KCa) in the chromaffin cells and in the brain. Is very toxic to mice. Ref.3 Ref.4 Ref.5 Ref.6 Ref.7

Monomer: inhibits plasma kallikrein (Ki=0.057 nM), tissue kallikrein (Ki=0.23 nM), trypsin (Ki=0.31 nM), plasmin (Ki=6.1 nM), elastase (Ki=201 nM), factor Xa (Ki=871 nM), alpha-factor XIIa (Ki=2380 nM). Does not inhibit APC, urokinase, t-PA, thrombin and factor VIIa. In addition, the monomer inhibits fibrinolysis in whole blood and prolonged the intrinsec clotting time. Ref.3 Ref.4 Ref.5 Ref.6 Ref.7

Subunit structure

Heterotrimer composed of an alpha-neurotoxin-like peptide of 8 kDa (AC P0CJ35), a neurotoxic phospholipase of 16 kDa (AC Q7LZG2) and this serine protease inhibitor of 7 kDa at an approximate stoichiometry of 1:1:4; non-covalently linked. Ref.3

Subcellular location

Secreted Ref.3.

Tissue specificity

Expressed by the venom gland. Ref.3

Toxic dose

LD50 of the heterotrimer is 50-100 µg/kg to mice. Ref.3

Sequence similarities

Belongs to the venom Kunitz-type family.

Contains 1 BPTI/Kunitz inhibitor domain.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 2424 Ref.3 Ref.4
Chain25 – 8662Taicatoxin, serine protease inhibitor component
PRO_0000155443
Propeptide87 – 882
PRO_0000376929

Regions

Domain31 – 8151BPTI/Kunitz inhibitor

Amino acid modifications

Disulfide bond31 ↔ 81 By similarity
Disulfide bond40 ↔ 64 By similarity
Disulfide bond56 ↔ 77 By similarity

Experimental info

Sequence conflict17 – 182EV → AE in ACC77765. Ref.2
Sequence conflict24 – 252SK → GQ in ACC77765. Ref.2
Sequence conflict251K → Q in ACC77765. Ref.2
Sequence conflict361K → N in ACC77765. Ref.2
Sequence conflict361K → N in ABO31437. Ref.1
Sequence conflict701S → K AA sequence Ref.3

Sequences

Sequence LengthMass (Da)Tools
B7S4N9 [UniParc].

Last modified February 10, 2009. Version 1.
Checksum: BA22F6D73E1D6F38

FASTA889,711
        10         20         30         40         50         60 
MSSGGLLLLL GLLTLWEVLT PVSSKDRPKF CHLPPKPGPC RAAIPRFYYN PHSKQCEKFI 

        70         80 
YGGCHGNANS FKTPDECNYT CLGVSLPK 

« Hide

References

[1]"Characterization of a serine protease inhibitor from Oxyuranus scutellatus venom."
Earl S.T., Flight S., Liao A., Masci P.P., de Jersey J., Lavin M.F.
Submitted (NOV-2006) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [MRNA].
Tissue: Venom gland.
[2]"Common evolution of waprin and Kunitz-like toxin families in Australian venomous snakes."
St Pierre L., Earl S.T., Filippovich I., Sorokina N., Masci P.P., De Jersey J., Lavin M.F.
Cell. Mol. Life Sci. 65:4039-4054(2008) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
Tissue: Venom gland.
[3]"Isolation and physiological characterization of taicatoxin, a complex toxin with specific effects on calcium channels."
Possani L.D., Martin B.M., Yatani A., Mochca-Morales J., Zamudio F.Z., Gurrola G.B., Brown A.M.
Toxicon 30:1343-1364(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE OF 25-86, FUNCTION, SUBUNIT, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, LETHAL DOSE.
Tissue: Venom.
[4]"Identification and characterisation of Kunitz-type plasma kallikrein inhibitors unique to Oxyuranus sp. snake venoms."
Earl S.T., Richards R., Johnson L.A., Flight S., Anderson S., Liao A., de Jersey J., Masci P.P., Lavin M.F.
Biochimie 94:365-373(2012) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE OF 25-36, FUNCTION OF THE MONOMER, IDENTIFICATION BY MASS SPECTROMETRY.
[5]"Effect of TaiCatoxin (TCX) on the electrophysiological, mechanical and biochemical characteristics of spontaneously beating ventricular cardiomyocytes."
Fantini E., Athias P., Tirosh R., Pinson A.
Mol. Cell. Biochem. 160:61-66(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[6]"A novel small conductance Ca2+-activated K+ channel blocker from Oxyuranus scutellatus taipan venom. Re-evaluation of taicatoxin as a selective Ca2+ channel probe."
Doorty K.B., Bevan S., Wadsworth J.D.F., Strong P.N.
J. Biol. Chem. 272:19925-19930(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[7]"Taicatoxin inhibits the calcium-dependent slow motility of mammalian outer hair cells."
Su M.-C., Lee S.-Y., Tan C.-T., Su C.-C., Li S.-Y., Lin R.-H., Hung C.-C., Lin M.-J.
Hear. Res. 203:172-179(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.

Web resources

Wikipedia

Taicatoxin entry

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
EF112394 mRNA. Translation: ABO31438.1.
EF112393 mRNA. Translation: ABO31437.1.
EU401816 Genomic DNA. Translation: ACC77765.1.
PIRA44180.

3D structure databases

ModBaseSearch...
MobiDBSearch...

Protein family/group databases

MEROPSI02.062.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Phylogenomic databases

HOVERGENHBG006193.

Family and domain databases

Gene3D4.10.410.10. 1 hit.
InterProIPR002223. Prot_inh_Kunz-m.
IPR020901. Prtase_inh_Kunz-CS.
[Graphical view]
PfamPF00014. Kunitz_BPTI. 1 hit.
[Graphical view]
PRINTSPR00759. BASICPTASE.
SMARTSM00131. KU. 1 hit.
[Graphical view]
SUPFAMSSF57362. SSF57362. 1 hit.
PROSITEPS00280. BPTI_KUNITZ_1. 1 hit.
PS50279. BPTI_KUNITZ_2. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameIVBTI_OXYSC
AccessionPrimary (citable) accession number: B7S4N9
Secondary accession number(s): B5L5M8, B7S4N8, Q7LZE4
Entry history
Integrated into UniProtKB/Swiss-Prot: June 16, 2009
Last sequence update: February 10, 2009
Last modified: April 16, 2014
This is version 28 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program
Annotation programChordata Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families