3L22_BUNCA
ID 3L22_BUNCA Reviewed; 75 AA.
AC A1IVR9;
DT 03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT 06-FEB-2007, sequence version 1.
DT 25-MAY-2022, entry version 58.
DE RecName: Full=Alpha-elapitoxin-Bc2b {ECO:0000305};
DE Short=Alpha-EPTX-Bc2b {ECO:0000305};
DE AltName: Full=Alpha-delta-Bgt-2 {ECO:0000312|EMBL:CAJ77820.1};
DE AltName: Full=Alpha/delta-bungarotoxin-2 {ECO:0000303|PubMed:30944155};
DE Short=Alpha/delta-BgTx-2 {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 3-37 AND 40-71,
RP FUNCTION, AND MASS SPECTROMETRY.
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).
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 (PubMed:30944155). Blocks muscle type nAChR (PubMed:30944155). Also
CC binds with high affinity to alpha-7/CHRNA7 nAChRs (By similarity). In
CC addition, shows a weak inhibition of neuronal alpha-3-beta-2/CHRNA3-
CC CHRNB2 nAChR (By similarity). Selectively binds to alpha-1-delta
CC subunit interface of the mouse muscle nicotinic acetylcholine receptor,
CC with a 10-fold higher affinity for the adult than for the fetal
CC receptors (By similarity). In vivo, when intraperitoneally injected
CC into mice, causes flaccid paralysis and respiratory distress, followed
CC by death within 2-4 hours (By similarity).
CC {ECO:0000250|UniProtKB:A1IVR8, ECO:0000269|PubMed:30944155}.
CC -!- SUBUNIT: Monomer in solution, homodimer in crystal state.
CC {ECO:0000250|UniProtKB:P60615}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:A1IVR8}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=8143.5; Method=MALDI;
CC Evidence={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; AM231682; CAJ77820.1; -; Genomic_DNA.
DR AlphaFoldDB; A1IVR9; -.
DR SMR; A1IVR9; -.
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|PubMed:30944155"
FT CHAIN 3..75
FT /note="Alpha-elapitoxin-Bc2b"
FT /evidence="ECO:0000305|PubMed:30944155"
FT /id="PRO_5000189421"
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:CAJ77820.1"
SQ SEQUENCE 75 AA; 8418 MW; 917333D1B4F96C0B CRC64;
YTLLCYKTPI PINAETCPPG ENLCYTKMWC DIWCSSRGKV VELGCAATCP SKKPYEEVTC
CSTDKCNPHP KQRPD
