ID   SCX5_LEIQU              Reviewed;          64 AA.
AC   P01481;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   03-AUG-2022, entry version 97.
DE   RecName: Full=Alpha-mammal toxin Lqq5;
DE   AltName: Full=Lqq V;
DE   AltName: Full=Neurotoxin V;
OS   Leiurus quinquestriatus quinquestriatus (Egyptian scorpion) (Deathstalker
OS   scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Leiurus.
OX   NCBI_TaxID=6885;
RN   [1]
RP   PROTEIN SEQUENCE, AND AMIDATION AT ASN-64.
RC   TISSUE=Venom;
RX   PubMed=658402; DOI=10.1016/0014-5793(78)80521-3;
RA   Kopeyan C., Martinez G., Rochat H.;
RT   "Amino acid sequence of neurotoxin V from the scorpion Leiurus
RT   quinquestriatus quinquestriatus.";
RL   FEBS Lett. 89:54-58(1978).
RN   [2]
RP   FUNCTION.
RX   PubMed=8212041; DOI=10.1016/0041-0101(93)90261-g;
RA   Borneman J., Hahin R.;
RT   "Purification of protein toxins from Leiurus quinquestriatus hebraeus that
RT   modify Na channels.";
RL   Toxicon 31:1019-1038(1993).
RN   [3]
RP   FUNCTION, AND TOXIC DOSE.
RX   PubMed=8626486; DOI=10.1074/jbc.271.14.8034;
RA   Gordon D., Martin-Eauclaire M.-F., Cestele S., Kopeyan C., Carlier E.,
RA   Khalifa R.B., Pelhate M., Rochat H.;
RT   "Scorpion toxins affecting sodium current inactivation bind to distinct
RT   homologous receptor sites on rat brain and insect sodium channels.";
RL   J. Biol. Chem. 271:8034-8045(1996).
RN   [4]
RP   PHOSPHOLIPID-BINDING ACTIVITY.
RX   PubMed=15632158; DOI=10.1074/jbc.m412552200;
RA   Smith J.J., Alphy S., Seibert A.L., Blumenthal K.M.;
RT   "Differential phospholipid binding by site 3 and site 4 toxins.
RT   Implications for structural variability between voltage-sensitive sodium
RT   channel domains.";
RL   J. Biol. Chem. 280:11127-11133(2005).
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. Is active on mammals and bind
CC       with high affinity to rat brain synaptosome. Does not display
CC       phospholipid-binding activity. {ECO:0000269|PubMed:8212041,
CC       ECO:0000269|PubMed:8626486}.
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 125 ng/kg (2.5 ng/mouse) by
CC       intracerebroventricular injection into mice, 3.4 pmol/g by subcutaneous
CC       injection in mouse and 2317 pmol/g in Blattella germanica.
CC       {ECO:0000269|PubMed:8626486}.
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   PIR; A01741; NTSR5L.
DR   AlphaFoldDB; P01481; -.
DR   SMR; P01481; -.
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 Lqq5"
FT                   /id="PRO_0000066782"
FT   DOMAIN          2..64
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         64
FT                   /note="Asparagine amide"
FT                   /evidence="ECO:0000269|PubMed:658402"
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;  7301 MW;  3D139791CE53DD36 CRC64;
     LKDGYIVDDK NCTFFCGRNA YCNDECKKKG GESGYCQWAS PYGNACWCYK LPDRVSIKEK
     GRCN