ID   KAX46_TITST             Reviewed;          37 AA.
AC   P0CB56;
DT   03-NOV-2009, integrated into UniProtKB/Swiss-Prot.
DT   03-NOV-2009, sequence version 1.
DT   25-MAY-2022, entry version 28.
DE   RecName: Full=Potassium channel toxin alpha-KTx 4.6 {ECO:0000303|PubMed:19500613};
DE   AltName: Full=Tst26 {ECO:0000303|PubMed:19500613};
OS   Tityus stigmurus (Brazilian scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Tityus.
OX   NCBI_TaxID=50344;
RN   [1]
RP   PROTEIN SEQUENCE, IDENTIFICATION BY MASS SPECTROMETRY, FUNCTION, AND
RP   SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=19500613; DOI=10.1016/j.toxicon.2009.05.023;
RA   Papp F., Batista C.V., Varga Z., Herceg M., Roman-Gonzalez S.A., Gaspar R.,
RA   Possani L.D., Panyi G.;
RT   "Tst26, a novel peptide blocker of Kv1.2 and Kv1.3 channels from the venom
RT   of Tityus stigmurus.";
RL   Toxicon 54:379-389(2009).
CC   -!- FUNCTION: Blocks potassium channels Kv1.2/KCNA2 and Kv1.3/KCNA3 with
CC       high affinity (K(d)=1.9 nM and 10.7 nM, respectively). The voltage-
CC       dependent steady-state parameters of potassium channel gating are
CC       unaffected by the toxin in both channels, but due to the fast
CC       association and dissociation kinetics the toxin slows the rate of
CC       inactivation of Kv1.3/KCNA3 channels. {ECO:0000269|PubMed:19500613}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:19500613}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:19500613}.
CC   -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC       antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC       {ECO:0000305}.
CC   -!- MISCELLANEOUS: This toxin has no effects on Kv1.1/KCNA1, Kv1.4/KCNA4,
CC       Kv1.5/KCNA5, Kv11.1/KCNH2, KCa3.1/KCNN4, BK/KCNMA1, and Nav1.5/KCNA5
CC       (when tested at 10 nM). {ECO:0000305|PubMed:19500613}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 04 subfamily. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   AlphaFoldDB; P0CB56; -.
DR   SMR; P0CB56; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR001947; Scorpion_toxinS_K_inh.
DR   Pfam; PF00451; Toxin_2; 1.
DR   PRINTS; PR00286; CHARYBDTOXIN.
DR   SUPFAM; SSF57095; SSF57095; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Potassium channel impairing toxin; Secreted; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   PEPTIDE         1..37
FT                   /note="Potassium channel toxin alpha-KTx 4.6"
FT                   /id="PRO_0000388240"
FT   SITE            27
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
FT   SITE            36
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250|UniProtKB:O46028"
FT   DISULFID        7..28
FT                   /evidence="ECO:0000250|UniProtKB:P46114"
FT   DISULFID        13..33
FT                   /evidence="ECO:0000250|UniProtKB:P46114"
FT   DISULFID        17..35
FT                   /evidence="ECO:0000250|UniProtKB:P46114"
SQ   SEQUENCE   37 AA;  3947 MW;  639B8273B7335929 CRC64;
     VFINAKCRGS PECLPKCKQA IGKAAGKCMN GKCKCYP