ID   3L21_OPHHA              Reviewed;          73 AA.
AC   P01387;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   25-MAY-2022, entry version 95.
DE   RecName: Full=Long neurotoxin 1;
DE   AltName: Full=Neurotoxin A;
OS   Ophiophagus hannah (King cobra) (Naja hannah).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Ophiophagus.
OX   NCBI_TaxID=8665;
RN   [1]
RP   PROTEIN SEQUENCE, TOXIC DOSE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=4198767;
RA   Joubert F.J.;
RT   "Snake venom toxins the amino acid sequences of two toxins from Ophiophagus
RT   hannah (King cobra) venom.";
RL   Biochim. Biophys. Acta 317:85-98(1973).
RN   [2]
RP   IDENTIFICATION BY MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=24297900; DOI=10.1073/pnas.1314702110;
RA   Vonk F.J., Casewell N.R., Henkel C.V., Heimberg A.M., Jansen H.J.,
RA   McCleary R.J., Kerkkamp H.M., Vos R.A., Guerreiro I., Calvete J.J.,
RA   Wuster W., Woods A.E., Logan J.M., Harrison R.A., Castoe T.A.,
RA   de Koning A.P., Pollock D.D., Yandell M., Calderon D., Renjifo C.,
RA   Currier R.B., Salgado D., Pla D., Sanz L., Hyder A.S., Ribeiro J.M.,
RA   Arntzen J.W., van den Thillart G.E., Boetzer M., Pirovano W., Dirks R.P.,
RA   Spaink H.P., Duboule D., McGlinn E., Kini R.M., Richardson M.K.;
RT   "The king cobra genome reveals dynamic gene evolution and adaptation in the
RT   snake venom system.";
RL   Proc. Natl. Acad. Sci. U.S.A. 110:20651-20656(2013).
CC   -!- FUNCTION: Binds with high affinity to muscular (alpha-1/CHRNA1) and
CC       neuronal (alpha-7/CHRNA7) nicotinic acetylcholine receptor (nAChR) and
CC       inhibits acetylcholine from binding to the receptor, thereby impairing
CC       neuromuscular and neuronal transmission.
CC       {ECO:0000250|UniProtKB:P60615}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:4198767}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 0.3 mg/kg by subcutaneous injection.
CC       {ECO:0000269|PubMed:4198767}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Long-chain
CC       subfamily. Type II alpha-neurotoxin sub-subfamily. {ECO:0000305}.
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DR   PIR; A01658; N2OH1.
DR   AlphaFoldDB; P01387; -.
DR   SMR; P01387; -.
DR   TopDownProteomics; P01387; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0099106; F:ion channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   InterPro; IPR018354; Snake_toxin_con_site.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Direct protein sequencing;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Secreted; Toxin.
FT   CHAIN           1..73
FT                   /note="Long neurotoxin 1"
FT                   /id="PRO_0000093556"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250"
FT   DISULFID        14..42
FT                   /evidence="ECO:0000250"
FT   DISULFID        27..31
FT                   /evidence="ECO:0000250"
FT   DISULFID        46..57
FT                   /evidence="ECO:0000250"
FT   DISULFID        58..63
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   73 AA;  8106 MW;  1AC17E91E16C54F7 CRC64;
     TKCYVTPDVK SETCPAGQDI CYTETWCDAW CTSRGKRVDL GCAATCPIVK PGVEIKCCST
     DNCNPFPTWR KRP