ID   3L2X1_OPHHA             Reviewed;          94 AA.
AC   Q2VBP8;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   10-JAN-2006, sequence version 1.
DT   25-MAY-2022, entry version 59.
DE   RecName: Full=Long neurotoxin LNTX1;
DE   Flags: Precursor;
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   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND TOXIC DOSE.
RC   TISSUE=Venom gland;
RX   PubMed=16689684; DOI=10.1042/bj20060004;
RA   Li J., Zhang H., Liu J., Xu K.;
RT   "Novel genes encoding six kinds of three-finger toxins in Ophiophagus
RT   hannah (king cobra) and function characterization of two recombinant long-
RT   chain neurotoxins.";
RL   Biochem. J. 398:233-242(2006).
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 (By similarity). Recombinant
CC       LNTX1 leads to a functional block of the muscle-type acetylcholine
CC       receptors. Has a cytotoxic activity (PubMed:16689684).
CC       {ECO:0000250|UniProtKB:P60615, ECO:0000269|PubMed:16689684}.
CC   -!- SUBUNIT: Monomer. {ECO:0000305}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 0.51 mg/kg by intravenous injection into mice.
CC       {ECO:0000269|PubMed:16689684}.
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   EMBL; DQ273567; ABB83621.1; -; mRNA.
DR   AlphaFoldDB; Q2VBP8; -.
DR   SMR; Q2VBP8; -.
DR   TopDownProteomics; Q2VBP8; -.
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   InterPro; IPR035076; Toxin/TOLIP.
DR   Pfam; PF00087; Toxin_TOLIP; 1.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 1.
PE   3: Inferred from homology;
KW   Acetylcholine receptor inhibiting toxin; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin; Secreted;
KW   Signal; Toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000250"
FT   CHAIN           22..94
FT                   /note="Long neurotoxin LNTX1"
FT                   /id="PRO_5000006477"
FT   DISULFID        24..43
FT                   /evidence="ECO:0000250"
FT   DISULFID        36..64
FT                   /evidence="ECO:0000250"
FT   DISULFID        49..53
FT                   /evidence="ECO:0000250"
FT   DISULFID        68..79
FT                   /evidence="ECO:0000250"
FT   DISULFID        80..85
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   94 AA;  10536 MW;  C505A2024C293264 CRC64;
     MKILLLTLVV VTIMCLDLGY TTKCYKTGER IISETCPPGQ DLCYMKTWCD VFCGSRGRVI
     ELGCTATCPT VKPHEQITCC STDNCNPHPK MKQR