ID   3L21_NAJNI              Reviewed;          71 AA.
AC   P01390;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   25-MAY-2022, entry version 93.
DE   RecName: Full=Long neurotoxin 1;
DE   AltName: Full=Neurotoxin alpha {ECO:0000303|PubMed:5167022};
OS   Naja nivea (Cape cobra) (Coluber niveus).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Naja.
OX   NCBI_TaxID=8655;
RN   [1]
RP   PROTEIN SEQUENCE, TOXIC DOSE, SUBCELLULAR LOCATION, AND DISULFIDE BOND.
RC   TISSUE=Venom;
RX   PubMed=5167022; DOI=10.1016/s0021-9258(19)45897-3;
RA   Botes D.P.;
RT   "Snake venom toxins. The amino acid sequences of toxins alpha and beta from
RT   Naja nivea venom and the disulfide bonds of toxin alpha.";
RL   J. Biol. Chem. 246:7383-7391(1971).
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:5167022}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:5167022}.
CC   -!- TOXIC DOSE: LD(50) is 0.076 mg/kg by subcutaneous injection.
CC       {ECO:0000269|PubMed:5167022}.
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; A01661; N2NJ1C.
DR   AlphaFoldDB; P01390; -.
DR   SMR; P01390; -.
DR   PRIDE; P01390; -.
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..71
FT                   /note="Long neurotoxin 1"
FT                   /evidence="ECO:0000269|PubMed:5167022"
FT                   /id="PRO_0000093552"
FT   DISULFID        3..20
FT                   /evidence="ECO:0000269|PubMed:5167022"
FT   DISULFID        14..41
FT                   /evidence="ECO:0000269|PubMed:5167022"
FT   DISULFID        26..30
FT                   /evidence="ECO:0000269|PubMed:5167022"
FT   DISULFID        45..56
FT                   /evidence="ECO:0000269|PubMed:5167022"
FT   DISULFID        57..62
FT                   /evidence="ECO:0000269|PubMed:5167022"
SQ   SEQUENCE   71 AA;  7902 MW;  D11D7BC8C48602E3 CRC64;
     IRCFITPDVT SQACPDGHVC YTKMWCDNFC GMRGKRVDLG CAATCPKVKP GVNIKCCSRD
     NCNPFPTRKR S