3LK2_BUNMU
ID 3LK2_BUNMU Reviewed; 87 AA.
AC P15816;
DT 01-APR-1990, integrated into UniProtKB/Swiss-Prot.
DT 01-APR-1990, sequence version 1.
DT 25-MAY-2022, entry version 102.
DE RecName: Full=Kappa-2-bungarotoxin {ECO:0000303|PubMed:2322821};
DE AltName: Full=Kappa-neurotoxin CB1 {ECO:0000303|PubMed:2315018};
DE Flags: Precursor;
OS Bungarus multicinctus (Many-banded krait).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX NCBI_TaxID=8616;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=2315018; DOI=10.1093/nar/18.4.1050;
RA Danse J.-M., Garnier J.-M.;
RT "cDNA deduced amino-acid sequences of two novel kappa-neurotoxins from
RT Bungarus multicinctus.";
RL Nucleic Acids Res. 18:1050-1050(1990).
RN [2]
RP PROTEIN SEQUENCE OF 23-67, FUNCTION, AND SUBCELLULAR LOCATION.
RX PubMed=2322821; DOI=10.1016/0006-8993(90)90548-p;
RA Chiappinelli V.A., Wolf K.M., Grant G.A., Chen S.-J.;
RT "Kappa 2-bungarotoxin and kappa 3-bungarotoxin: two new neuronal nicotinic
RT receptor antagonists isolated from the venom of Bungarus multicinctus.";
RL Brain Res. 509:237-248(1990).
CC -!- FUNCTION: Postsynaptic neurotoxin that binds and inhibits neuronal
CC nicotinic acetylcholine receptors (nAChR) with high affinity
CC (IC(50)<100 nM). Is a selective, and slowly reversible antagonist of
CC alpha-3/CHRNA3-containing and some alpha-4/CHRNA4-containing AChRs.
CC {ECO:0000250|UniProtKB:P01398, ECO:0000269|PubMed:2322821}.
CC -!- SUBUNIT: Homodimer and heterodimer with kappa 3-bungarotoxin; non-
CC covalently linked. {ECO:0000269|PubMed:2322821}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:2322821}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the snake three-finger toxin family. Long-chain
CC subfamily. Kappa-neurotoxin sub-subfamily. {ECO:0000305}.
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DR EMBL; X51412; CAA35774.1; -; mRNA.
DR PIR; A60549; A60549.
DR PIR; S08399; S08399.
DR AlphaFoldDB; P15816; -.
DR SMR; P15816; -.
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; Signal; Toxin.
FT SIGNAL 1..21
FT CHAIN 22..87
FT /note="Kappa-2-bungarotoxin"
FT /id="PRO_0000035411"
FT DISULFID 24..42
FT /evidence="ECO:0000250|UniProtKB:P01398"
FT DISULFID 35..63
FT /evidence="ECO:0000250|UniProtKB:P01398"
FT DISULFID 48..52
FT /evidence="ECO:0000250|UniProtKB:P01398"
FT DISULFID 67..79
FT /evidence="ECO:0000250|UniProtKB:P01398"
FT DISULFID 80..85
FT /evidence="ECO:0000250|UniProtKB:P01398"
SQ SEQUENCE 87 AA; 9517 MW; 87326EAE8B5B1A49 CRC64;
MKTLLLTLVV VTIVCLDLGY TKTCLKTPSS TPQTCPQGQD ICFLKVSCEQ FCPIRGPVIE
QGCAATCPEF RSNDRSLLCC TTDNCNH
