ID   SCX2_LEIHE              Reviewed;          64 AA.
AC   P59355;
DT   28-FEB-2003, integrated into UniProtKB/Swiss-Prot.
DT   28-FEB-2003, sequence version 1.
DT   03-AUG-2022, entry version 71.
DE   RecName: Full=Alpha-mammal toxin Lqh2;
DE   AltName: Full=Lqh II;
DE            Short=LqhII;
OS   Leiurus hebraeus (Deathstalker scorpion) (Leiurus quinquestriatus
OS   hebraeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Leiurus.
OX   NCBI_TaxID=6884;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AMIDATION AT ARG-64, AND TOXIC DOSE.
RC   TISSUE=Venom;
RX   PubMed=9690781; DOI=10.1016/s0041-0101(98)00080-4;
RA   Sautiere P., Cestele S., Kopeyan C., Martinage A., Drobecq H.,
RA   Doljansky Y., Gordon D.;
RT   "New toxins acting on sodium channels from the scorpion Leiurus
RT   quinquestriatus hebraeus suggest a clue to mammalian vs insect
RT   selectivity.";
RL   Toxicon 36:1141-1154(1998).
RN   [2]
RP   FUNCTION.
RX   PubMed=10678738; DOI=10.1007/s004249900181;
RA   Chen H., Gordon D., Heinemann S.H.;
RT   "Modulation of cloned skeletal muscle sodium channels by the scorpion
RT   toxins Lqh II, Lqh III, and Lqh alphaIT.";
RL   Pflugers Arch. 439:423-432(2000).
RN   [3]
RP   IDENTIFICATION BY MASS SPECTROMETRY.
RX   PubMed=16551474; DOI=10.1016/j.toxicon.2006.01.015;
RA   Nascimento D.G., Rates B., Santos D.M., Verano-Braga T., Barbosa-Silva A.,
RA   Dutra A.A.A., Biondi I., Martin-Eauclaire M.-F., De Lima M.E.,
RA   Pimenta A.M.C.;
RT   "Moving pieces in a taxonomic puzzle: venom 2D-LC/MS and data clustering
RT   analyses to infer phylogenetic relationships in some scorpions from the
RT   Buthidae family (Scorpiones).";
RL   Toxicon 47:628-639(2006).
CC   -!- FUNCTION: Alpha toxins bind voltage-independently at site-3 of sodium
CC       channels (Nav) and inhibit the inactivation of the activated channels,
CC       thereby blocking neuronal transmission. The dissociation is voltage-
CC       dependent. Is active on mammals and competes for alpha-toxins binding
CC       on both mammalian and cockroach sodium channels.
CC       {ECO:0000269|PubMed:10678738, ECO:0000269|PubMed:9690781}.
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   -!- TOXIC DOSE: LD(50) is 1.9 mg/kg by intracerebroventricular injection
CC       into mice. {ECO:0000269|PubMed:9690781}.
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; P59355; -.
DR   SMR; P59355; -.
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   GO; GO:0006952; P:defense response; IEA:InterPro.
DR   CDD; cd00107; Knot1; 1.
DR   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR   InterPro; IPR003614; Scorpion_toxin-like.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR018218; Scorpion_toxinL.
DR   InterPro; IPR002061; Scorpion_toxinL/defensin.
DR   Pfam; PF00537; Toxin_3; 1.
DR   PRINTS; PR00285; SCORPNTOXIN.
DR   SMART; SM00505; Knot1; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51863; LCN_CSAB; 1.
PE   1: Evidence at protein level;
KW   Amidation; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..64
FT                   /note="Alpha-mammal toxin Lqh2"
FT                   /evidence="ECO:0000269|PubMed:9690781"
FT                   /id="PRO_0000066783"
FT   DOMAIN          2..64
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         64
FT                   /note="Arginine amide"
FT                   /evidence="ECO:0000269|PubMed:9690781"
FT   DISULFID        12..63
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        16..36
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        22..46
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        26..48
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   64 AA;  7285 MW;  D020C85A29B7D19F CRC64;
     IKDGYIVDDV NCTYFCGRNA YCNEECTKLK GESGYCQWAS PYGNACYCYK LPDHVRTKGP
     GRCR