ID   3L2L_OXYSC              Reviewed;          28 AA.
AC   P0CJ35;
DT   31-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT   31-MAY-2011, sequence version 1.
DT   23-FEB-2022, entry version 26.
DE   RecName: Full=Taicatoxin, alpha-neurotoxin-like component;
DE            Short=TCX, alpha-neurotoxin-like component;
DE   Flags: Fragment;
OS   Oxyuranus scutellatus scutellatus (Australian taipan) (Coastal taipan).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Acanthophiinae; Oxyuranus.
OX   NCBI_TaxID=8667;
RN   [1]
RP   PROTEIN SEQUENCE, SUBUNIT, SUBCELLULAR LOCATION, AND TOXIC DOSE.
RC   TISSUE=Venom;
RX   PubMed=1485334; DOI=10.1016/0041-0101(92)90511-3;
RA   Possani L.D., Martin B.M., Yatani A., Mochca-Morales J., Zamudio F.Z.,
RA   Gurrola G.B., Brown A.M.;
RT   "Isolation and physiological characterization of taicatoxin, a complex
RT   toxin with specific effects on calcium channels.";
RL   Toxicon 30:1343-1364(1992).
RN   [2]
RP   FUNCTION.
RX   PubMed=8901456; DOI=10.1007/bf00240032;
RA   Fantini E., Athias P., Tirosh R., Pinson A.;
RT   "Effect of TaiCatoxin (TCX) on the electrophysiological, mechanical and
RT   biochemical characteristics of spontaneously beating ventricular
RT   cardiomyocytes.";
RL   Mol. Cell. Biochem. 160:61-66(1996).
RN   [3]
RP   FUNCTION.
RX   PubMed=9242659; DOI=10.1074/jbc.272.32.19925;
RA   Doorty K.B., Bevan S., Wadsworth J.D.F., Strong P.N.;
RT   "A novel small conductance Ca2+-activated K+ channel blocker from Oxyuranus
RT   scutellatus taipan venom. Re-evaluation of taicatoxin as a selective Ca2+
RT   channel probe.";
RL   J. Biol. Chem. 272:19925-19930(1997).
RN   [4]
RP   FUNCTION.
RX   PubMed=15855042; DOI=10.1016/j.heares.2004.12.003;
RA   Su M.-C., Lee S.-Y., Tan C.-T., Su C.-C., Li S.-Y., Lin R.-H., Hung C.-C.,
RA   Lin M.-J.;
RT   "Taicatoxin inhibits the calcium-dependent slow motility of mammalian outer
RT   hair cells.";
RL   Hear. Res. 203:172-179(2005).
CC   -!- FUNCTION: The heterotrimer blocks the voltage-dependent L-type calcium
CC       channels (Cav1/CACNA1) from the heart, and the small conductance
CC       calcium-activated potassium channels (KCa2/KCNN) in the chromaffin
CC       cells and in the brain. Is very toxic to mice.
CC       {ECO:0000269|PubMed:15855042, ECO:0000269|PubMed:8901456,
CC       ECO:0000269|PubMed:9242659}.
CC   -!- SUBUNIT: Heterotrimer composed of this alpha-neurotoxin-like peptide of
CC       8 kDa, a neurotoxic phospholipase of 16 kDa (AC Q7LZG2) and a serine
CC       protease inhibitor of 7 kDa (AC B7S4N9) at an approximate stoichiometry
CC       of 1:1:4; non-covalently linked. {ECO:0000269|PubMed:1485334}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:1485334}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:1485334}.
CC   -!- TOXIC DOSE: LD(50) of the heterotrimer is 50-100 ug/kg to mice.
CC       {ECO:0000269|PubMed:1485334}.
CC   -!- MISCELLANEOUS: Is composed of 65-68 amino acid residues.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Long-chain
CC       subfamily. Type II alpha-neurotoxin sub-subfamily. {ECO:0000305}.
CC   -!- WEB RESOURCE: Name=Wikipedia; Note=Taicatoxin entry;
CC       URL="https://en.wikipedia.org/wiki/Taicatoxin";
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DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
PE   1: Evidence at protein level;
KW   Calcium channel impairing toxin;
KW   Calcium-activated potassium channel impairing toxin;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Potassium channel impairing toxin; Secreted; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   CHAIN           1..>28
FT                   /note="Taicatoxin, alpha-neurotoxin-like component"
FT                   /id="PRO_0000408516"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250"
FT   NON_TER         28
SQ   SEQUENCE   28 AA;  3209 MW;  6AB874D006914C79 CRC64;
     RRCFITPNVR SERCPPGQEV CFTKTXDG