ID   3S12_NAJNA              Reviewed;          62 AA.
AC   C0HM08;
DT   03-AUG-2022, integrated into UniProtKB/Swiss-Prot.
DT   03-AUG-2022, sequence version 1.
DT   03-AUG-2022, entry version 1.
DE   RecName: Full=Alpha-elapitoxin-Nn2a {ECO:0000303|PubMed:35418867};
DE   AltName: Full=Short neurotoxin 2 {ECO:0000305};
DE   AltName: Full=Short-chain alpha-neurotoxin Nn2a {ECO:0000303|PubMed:35418867};
OS   Naja naja (Indian cobra).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Naja.
OX   NCBI_TaxID=35670;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RX   PubMed=35418867; DOI=10.3389/fphar.2022.815079;
RA   Huynh T.M., Silva A., Isbister G.K., Hodgson W.C.;
RT   "Isolation and Characterization of Two Postsynaptic Neurotoxins From Indian
RT   Cobra (Naja Naja) Venom.";
RL   Front. Pharmacol. 13:815079-815079(2022).
CC   -!- FUNCTION: Nicotinic acetylcholine receptor antagonist
CC       (PubMed:35418867). Binds to muscle nicotinic acetylcholine receptor
CC       (nAChR) and inhibits acetylcholine from binding to the receptor,
CC       thereby impairing neuromuscular transmission (PubMed:35418867).
CC       Produces peripheral paralysis by blocking neuromuscular transmission at
CC       the postsynaptic site (PubMed:35418867). Induces concentration-
CC       dependent inhibition of indirect twitches and abolishes contractile
CC       responses of tissues to exogenous acetylcholine and carbachol, in the
CC       chick biventer cervicis nerve-muscle preparation at 100-300 nM (in
CC       vitro) (PubMed:35418867). Prior incubation of tissues with Indian
CC       polyvalent antivenom (1 ml/0.6 mg) prevents the neurotoxic effects at
CC       100 nM (in vitro) (PubMed:35418867). Addition of Indian polyvalent
CC       antivenom (1 ml/0.6 mg) at the t90 time point does not reverse the
CC       neurotoxic effects (in vitro) (PubMed:35418867). Displays non-
CC       competitive antagonism of concentration-response curves to carbachol,
CC       with a pA2 of 8.01 (in vitro) (PubMed:35418867).
CC       {ECO:0000269|PubMed:35418867}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:35418867}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- MASS SPECTROMETRY: Mass=7020; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:35418867};
CC   -!- MISCELLANEOUS: Constitutes approximately 1% of the whole venom protein
CC       content. {ECO:0000269|PubMed:35418867}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type I alpha-neurotoxin sub-subfamily. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   Proteomes; UP000694559; Unplaced.
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; Reference proteome; Secreted; Toxin.
FT   CHAIN           1..62
FT                   /note="Alpha-elapitoxin-Nn2a"
FT                   /id="PRO_0000456213"
FT   DISULFID        3..24
FT                   /evidence="ECO:0000250|UniProtKB:P80958"
FT   DISULFID        17..41
FT                   /evidence="ECO:0000250|UniProtKB:P80958"
FT   DISULFID        43..54
FT                   /evidence="ECO:0000250|UniProtKB:P80958"
FT   DISULFID        55..60
FT                   /evidence="ECO:0000250|UniProtKB:P80958"
SQ   SEQUENCE   62 AA;  6911 MW;  CB8B1F6A40AF337A CRC64;
     LECHNQQSSQ TPTTTDCSGG ETNCYKKWWS DHRGTIIERG CGCPTVKKGI ELNCCTTDRC
     NN