ID   VKT12_MESMA             Reviewed;          70 AA.
AC   P0DJ47;
DT   11-JUL-2012, integrated into UniProtKB/Swiss-Prot.
DT   11-JUL-2012, sequence version 1.
DT   25-MAY-2022, entry version 25.
DE   RecName: Full=Kunitz-type serine protease inhibitor BmKTT-3;
DE   AltName: Full=Delta-KTx 1.2;
OS   Mesobuthus martensii (Manchurian scorpion) (Buthus martensii).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34649;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND FUNCTION.
RC   TISSUE=Venom gland;
RX   PubMed=22354971; DOI=10.1074/jbc.m112.343996;
RA   Chen Z.-Y., Hu Y.T., Yang W.S., He Y.W., Feng J., Wang B., Zhao R.M.,
RA   Ding J.P., Cao Z.-J., Li W.-X., Wu Y.-L.;
RT   "Hg1, novel peptide inhibitor specific for Kv1.3 channels from first
RT   scorpion Kunitz-type potassium channel toxin family.";
RL   J. Biol. Chem. 287:13813-13821(2012).
CC   -!- FUNCTION: Dual-function toxin that inhibits 85% of the activity of
CC       trypsin at a molar ratio of 4:1 with a dissociation constant of 760 nM,
CC       and that inhibits mKv1.3/KCNA3 potassium channel currents, but very
CC       weakly. {ECO:0000269|PubMed:22354971}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- MISCELLANEOUS: Has no effect on chymotrypsin and elastase.
CC       {ECO:0000305|PubMed:22354971}.
CC   -!- SIMILARITY: Belongs to the venom Kunitz-type family. Scorpion delta-Ktx
CC       subfamily. Delta-Ktx 1 sub-subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0DJ47; -.
DR   SMR; P0DJ47; -.
DR   GO; GO:0005576; C:extracellular region; NAS:UniProtKB.
DR   GO; GO:0033644; C:host cell membrane; NAS:UniProtKB.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IDA:UniProtKB.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0044562; P:envenomation resulting in negative regulation of voltage-gated potassium channel activity in another organism; IDA:UniProtKB.
DR   CDD; cd00109; KU; 1.
DR   Gene3D; 4.10.410.10; -; 1.
DR   InterPro; IPR002223; Kunitz_BPTI.
DR   InterPro; IPR036880; Kunitz_BPTI_sf.
DR   InterPro; IPR020901; Prtase_inh_Kunz-CS.
DR   Pfam; PF00014; Kunitz_BPTI; 1.
DR   PRINTS; PR00759; BASICPTASE.
DR   SMART; SM00131; KU; 1.
DR   SUPFAM; SSF57362; SSF57362; 1.
DR   PROSITE; PS00280; BPTI_KUNITZ_1; 1.
DR   PROSITE; PS50279; BPTI_KUNITZ_2; 1.
PE   2: Evidence at transcript level;
KW   Disulfide bond; Ion channel impairing toxin;
KW   Potassium channel impairing toxin; Protease inhibitor; Secreted;
KW   Serine protease inhibitor; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   CHAIN           1..70
FT                   /note="Kunitz-type serine protease inhibitor BmKTT-3"
FT                   /id="PRO_0000418101"
FT   DOMAIN          7..57
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            17..18
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        7..57
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        16..40
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        32..53
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   70 AA;  8261 MW;  D6E51B50D96E74B0 CRC64;
     KHGSINCRLP PERGPCRGNI TKYYYHNESR TCRTFSYGGC EGNSNNFRNR HYCMKYCARK
     RHGWLGTGWI