ID   TXHP2_HETVE             Reviewed;          30 AA.
AC   P58426;
DT   05-DEC-2001, integrated into UniProtKB/Swiss-Prot.
DT   05-DEC-2001, sequence version 1.
DT   25-MAY-2022, entry version 79.
DE   RecName: Full=Kappa-sparatoxin-Hv1b;
DE            Short=Kappa-SPRTX-Hv1b;
DE   AltName: Full=Heteropodatoxin-2;
DE            Short=HpTX2;
DE   AltName: Full=Toxin KJ6;
OS   Heteropoda venatoria (Brown huntsman spider) (Aranea venatoria).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Dionycha; Sparassidae; Heteropoda.
OX   NCBI_TaxID=152925;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AMIDATION AT TRP-30, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=9058605;
RA   Sanguinetti M.C., Johnson J.H., Hammerland L.G., Kelbaugh P.R.,
RA   Volkmann R.A., Saccomano N.A., Mueller A.L.;
RT   "Heteropodatoxins: peptides isolated from spider venom that block Kv4.2
RT   potassium channels.";
RL   Mol. Pharmacol. 51:491-498(1997).
RN   [2]
RP   PROTEIN SEQUENCE, FUNCTION, DISULFIDE BONDS, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RA   Kelbaugh P.R., Saccomano N.A., Volkmann R.A.;
RT   "Calcium channel blocking polypeptides from Heteropoda venatoria.";
RL   Patent number US5627154, 06-MAY-1997.
RN   [3]
RP   FUNCTION.
RX   PubMed=15733564; DOI=10.1016/j.toxicon.2004.11.015;
RA   Zarayskiy V.V., Balasubramanian G., Bondarenko V.E., Morales M.J.;
RT   "Heteropoda toxin 2 is a gating modifier toxin specific for voltage-gated
RT   K+ channels of the Kv4 family.";
RL   Toxicon 45:431-442(2005).
RN   [4]
RP   STRUCTURE BY NMR, AND DISULFIDE BONDS.
RC   TISSUE=Venom;
RX   PubMed=11152117;
RA   Bernard C., Legros C., Ferrat G., Bischoff U., Marquardt A., Pongs O.,
RA   Darbon H.;
RT   "Solution structure of hpTX2, a toxin from Heteropoda venatoria spider that
RT   blocks Kv4.2 potassium channel.";
RL   Protein Sci. 9:2059-2067(2000).
CC   -!- FUNCTION: Inhibitor of voltage-gated potassium channels of the Kv4/KCND
CC       family. Inhibition of Kv4.3/KCND3 and Kv4.2/KCND2 is strongly voltage-
CC       dependent, while inhibition of Kv4.1/KCND1 shows less voltage-
CC       dependence. Its binding site may be near the potassium channel voltage
CC       sensor. Also blocks calcium channels. {ECO:0000269|PubMed:15733564,
CC       ECO:0000269|PubMed:9058605, ECO:0000269|Ref.2}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000269|PubMed:11152117}.
CC   -!- MASS SPECTROMETRY: Mass=3412.70; Method=Electrospray;
CC       Evidence={ECO:0000269|Ref.2};
CC   -!- MASS SPECTROMETRY: Mass=3412.72; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:9058605};
CC   -!- MISCELLANEOUS: Has no affinity for Kv1.4/KCNA4, Kv2.1/KCNB1, and
CC       Kv3.4/KCNC4. {ECO:0000305|PubMed:15733564}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 10 (Hwtx-1) family. 19 (HpTX2)
CC       subfamily. {ECO:0000305}.
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DR   PDB; 1EMX; NMR; -; A=1-30.
DR   PDBsum; 1EMX; -.
DR   AlphaFoldDB; P58426; -.
DR   BMRB; P58426; -.
DR   SMR; P58426; -.
DR   TCDB; 8.B.5.2.2; the na(+)/k(+)/ca(2+) channel targeting tarantula huwentoxin (tht) family.
DR   ArachnoServer; AS000345; kappa-sparatoxin-Hv1b.
DR   EvolutionaryTrace; P58426; -.
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:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR011696; Huwentoxin-1.
DR   Pfam; PF07740; Toxin_12; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Amidation; Calcium channel impairing toxin;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Knottin; Neurotoxin; Potassium channel impairing toxin; Secreted; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   PEPTIDE         1..30
FT                   /note="Kappa-sparatoxin-Hv1b"
FT                   /id="PRO_0000044552"
FT   MOD_RES         30
FT                   /note="Tryptophan amide"
FT                   /evidence="ECO:0000269|PubMed:9058605"
FT   DISULFID        3..17
FT                   /evidence="ECO:0000269|PubMed:11152117,
FT                   ECO:0007744|PDB:1EMX"
FT   DISULFID        10..22
FT                   /evidence="ECO:0000269|PubMed:11152117,
FT                   ECO:0007744|PDB:1EMX"
FT   DISULFID        16..26
FT                   /evidence="ECO:0000269|PubMed:11152117,
FT                   ECO:0007744|PDB:1EMX"
FT   STRAND          23..25
FT                   /evidence="ECO:0007829|PDB:1EMX"
SQ   SEQUENCE   30 AA;  3420 MW;  F2A1DC16B695CFCF CRC64;
     DDCGKLFSGC DTNADCCEGY VCRLWCKLDW