ID   SC18_MESMA              Reviewed;          20 AA.
AC   P58570;
DT   23-JAN-2002, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2002, sequence version 1.
DT   25-MAY-2022, entry version 52.
DE   RecName: Full=Neurotoxin BmK 18(2);
DE   Flags: Fragment;
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   PROTEIN SEQUENCE, AND CHARACTERIZATION.
RC   TISSUE=Venom;
RX   PubMed=11491460;
RA   Hahin R., Chen Z., Reddy G., Li Y.;
RT   "Isolation, purification and N-terminal sequencing of a bioactive peptide
RT   that alters action potentials from the venom of Buthus martensii Karsch.";
RL   J. Nat. Toxins 10:199-212(2001).
CC   -!- FUNCTION: Binds to sodium channels (Nav) and inhibits the inactivation
CC       of the activated channels, thereby blocking neuronal transmission.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
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   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P58570; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR   InterPro; IPR002061; Scorpion_toxinL/defensin.
DR   Pfam; PF00537; Toxin_3; 1.
DR   PROSITE; PS51863; LCN_CSAB; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Ion channel impairing toxin; Neurotoxin;
KW   Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..>20
FT                   /note="Neurotoxin BmK 18(2)"
FT                   /id="PRO_0000066754"
FT   DOMAIN          2..>20
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   NON_TER         20
SQ   SEQUENCE   20 AA;  2349 MW;  ED8707568FD0A421 CRC64;
     VRDAYIAEDY DCVYHCARDA