3L21_BUNCA
ID 3L21_BUNCA Reviewed; 75 AA.
AC A1IVR8; P84467;
DT 03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT 06-FEB-2007, sequence version 1.
DT 25-MAY-2022, entry version 57.
DE RecName: Full=Alpha-elapitoxin-Bc2a {ECO:0000305};
DE Short=Alpha-EPTX-Bc2a {ECO:0000305};
DE AltName: Full=Alpha-delta-Bgt-1 {ECO:0000312|EMBL:CAJ77819.1};
DE AltName: Full=Alpha/delta-bungarotoxin-1 {ECO:0000303|PubMed:30944155, ECO:0000303|Ref.2};
DE Short=Alpha/delta-BgTx-1 {ECO:0000303|PubMed:30944155};
DE Flags: Precursor; Fragment;
OS Bungarus candidus (Malayan krait).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX NCBI_TaxID=92438;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 3-75, FUNCTION, MASS
RP SPECTROMETRY, SYNTHESIS OF 3-75, TOXIC DOSE, AND 3D-STRUCTURE MODELING.
RC TISSUE=Venom;
RX PubMed=30944155; DOI=10.1042/bcj20180909;
RA Utkin Y.N., Kuch U., Kasheverov I.E., Lebedev D.S., Cederlund E.,
RA Molles B.E., Polyak I., Ivanov I.A., Prokopev N.A., Ziganshin R.H.,
RA Jornvall H., Alvelius G., Chanhome L., Warrell D.A., Mebs D., Bergman T.,
RA Tsetlin V.I.;
RT "Novel long-chain neurotoxins from Bungarus candidus distinguish the two
RT binding sites in muscle-type nicotinic acetylcholine receptors.";
RL Biochem. J. 476:1285-1302(2019).
RN [2]
RP PROTEIN SEQUENCE OF 3-75, FUNCTION, SUBCELLULAR LOCATION, AND MASS
RP SPECTROMETRY.
RC TISSUE=Venom;
RA Kuch U., Cederlund E., Molles B.E., Anvelius G., Bergman T., Chanhome L.,
RA Omori-Satoh T., Chen Y.M., Samejima Y., Warrell D.A., Mebs D.;
RT "A novel reversible long-chain neurotoxin from Malayan krait (Bungarus
RT candidus) venom with high toxicity and site-selective binding at the alpha-
RT delta subunit interface of the muscle nicotinic acetylcholine receptor.";
RL Submitted (FEB-2005) to UniProtKB.
CC -!- FUNCTION: Binds to muscular and neuronal nicotinic acetylcholine
CC receptor (nAChR) and inhibits acetylcholine from binding to the
CC receptor, thereby impairing neuromuscular and neuronal transmission
CC (Ref.2, PubMed:30944155). Reversibly blocks chick and mouse muscle
CC nicotinic acetylcholine receptors (Ref.2, PubMed:30944155). Blocks
CC muscle type nAChR with an IC(50)=30 nM, when heterologously expressed
CC in oocytes (PubMed:30944155). Also binds with high affinity to alpha-
CC 7/CHRNA7 nAChRs (PubMed:30944155). In addition, shows a weak inhibition
CC of neuronal alpha-3-beta-2/CHRNA3-CHRNB2 nAChR (IC(50)=2.9 uM)
CC (PubMed:30944155). Selectively binds to alpha-1-delta subunit interface
CC of the mouse muscle nicotinic acetylcholine receptor, with a 10-fold
CC higher affinity for the adult than for the fetal receptors (Ref.2,
CC PubMed:30944155). In vivo, when intraperitoneally injected into mice,
CC causes flaccid paralysis and respiratory distress, followed by death
CC within 2-4 hours (PubMed:30944155). {ECO:0000250|UniProtKB:P60615,
CC ECO:0000269|PubMed:30944155, ECO:0000269|Ref.2}.
CC -!- SUBUNIT: Monomer in solution, homodimer in crystal state.
CC {ECO:0000250|UniProtKB:P60615}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.2}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=8030.50; Method=Electrospray;
CC Evidence={ECO:0000269|Ref.2};
CC -!- MASS SPECTROMETRY: Mass=8031; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:30944155};
CC -!- TOXIC DOSE: LD(50) is 170-280 ug/kg by intraperitoneal injection into
CC mice. {ECO:0000269|PubMed:30944155}.
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; AM231681; CAJ77819.1; -; Genomic_DNA.
DR AlphaFoldDB; A1IVR8; -.
DR SMR; A1IVR8; -.
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 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; Signal; Toxin.
FT SIGNAL <1..2
FT /evidence="ECO:0000269|Ref.2"
FT CHAIN 3..75
FT /note="Alpha-elapitoxin-Bc2a"
FT /id="PRO_5000189420"
FT DISULFID 5..24
FT /evidence="ECO:0000250|UniProtKB:P60615"
FT DISULFID 17..45
FT /evidence="ECO:0000250|UniProtKB:P60615"
FT DISULFID 30..34
FT /evidence="ECO:0000250|UniProtKB:P60615"
FT DISULFID 49..60
FT /evidence="ECO:0000250|UniProtKB:P60615"
FT DISULFID 61..66
FT /evidence="ECO:0000250|UniProtKB:P60615"
FT NON_TER 1
FT /evidence="ECO:0000312|EMBL:CAJ77819.1"
SQ SEQUENCE 75 AA; 8306 MW; 93B6D58310B4240B CRC64;
YTLLCYKTPS PINAETCPPG ENLCYTKMWC DAWCSSRGKV IELGCAATCP SKKPYEEVTC
CSTDKCNPHP KQRPG
