3LKB_BUNMU
ID 3LKB_BUNMU Reviewed; 87 AA.
AC P01398;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1997, sequence version 2.
DT 25-MAY-2022, entry version 118.
DE RecName: Full=Kappa-bungarotoxin {ECO:0000303|PubMed:3986193, ECO:0000303|PubMed:9020044};
DE Short=Kappa-bgt;
DE AltName: Full=Kappa-1-bungarotoxin;
DE AltName: Full=Long neurotoxin 2;
DE AltName: Full=Neuronal bungarotoxin {ECO:0000303|PubMed:1550821};
DE Short=nBgt {ECO:0000303|PubMed:1550821};
DE AltName: Full=Toxin F {ECO:0000303|PubMed:3021284};
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=9020044; DOI=10.1006/bbrc.1996.5916;
RA Chang L.-S., Lin J., Wu P.-F., Chang C.-C., Hong E.;
RT "cDNA sequence analysis and expression of kappa-bungarotoxin from Taiwan
RT banded krait.";
RL Biochem. Biophys. Res. Commun. 230:192-195(1997).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Liver;
RX PubMed=12403176; DOI=10.1023/a:1020139728292;
RA Chang L.-S., Chung C., Lin J., Hong E.;
RT "Organization and phylogenetic analysis of kappa-bungarotoxin genes from
RT Bungarus multicinctus (Taiwan banded krait).";
RL Genetica 115:213-221(2002).
RN [3]
RP PROTEIN SEQUENCE OF 22-87, FUNCTION, AND SUBCELLULAR LOCATION.
RC TISSUE=Venom;
RX PubMed=3986193; DOI=10.1021/bi00327a036;
RA Grant G.A., Chiappinelli V.A.;
RT "Kappa-bungarotoxin: complete amino acid sequence of a neuronal nicotinic
RT receptor probe.";
RL Biochemistry 24:1532-1537(1985).
RN [4]
RP PROTEIN SEQUENCE OF 22-87.
RC TISSUE=Venom;
RX PubMed=3021284; DOI=10.1016/0006-8993(86)91543-x;
RA Loring R.H., Andrews D., Lane W., Zigmond R.E.;
RT "Amino acid sequence of toxin F, a snake venom toxin that blocks neuronal
RT nicotinic receptors.";
RL Brain Res. 385:30-37(1986).
RN [5]
RP FUNCTION, AND MUTAGENESIS OF GLN-47; ARG-55 AND PRO-57.
RX PubMed=9027980; DOI=10.1016/s0041-0101(96)00110-9;
RA Chiappinelli V.A., Weaver W.R., McLane K.E., Conti-Fine B.M.,
RA Fiordalisi J.J., Grant G.A.;
RT "Binding of native kappa-neurotoxins and site-directed mutants to nicotinic
RT acetylcholine receptors.";
RL Toxicon 34:1243-1256(1996).
RN [6]
RP X-RAY CRYSTALLOGRAPHY (2.3 ANGSTROMS) OF 22-87, DISULFIDE BONDS, AND
RP SUBUNIT.
RX PubMed=7947721; DOI=10.1021/bi00248a026;
RA Dewan J.C., Grant G.A., Sacchettini J.C.;
RT "Crystal structure of kappa-bungarotoxin at 2.3-A resolution.";
RL Biochemistry 33:13147-13154(1994).
RN [7]
RP STRUCTURE BY NMR OF 22-87, DISULFIDE BONDS, AND SUBUNIT.
RX PubMed=2036359; DOI=10.1021/bi00234a010;
RA Oswald R.E., Sutcliffe M.J., Bamberger M., Loring R.H., Braswell E.,
RA Dobson C.M.;
RT "Solution structure of neuronal bungarotoxin determined by two-dimensional
RT NMR spectroscopy: sequence-specific assignments, secondary structure, and
RT dimer formation.";
RL Biochemistry 30:4901-4909(1991).
RN [8]
RP STRUCTURE BY NMR OF 22-87, AND DISULFIDE BONDS.
RX PubMed=1550821; DOI=10.1021/bi00126a017;
RA Sutcliffe M.J., Dobson C.M., Oswald R.E.;
RT "Solution structure of neuronal bungarotoxin determined by two-dimensional
RT NMR spectroscopy: calculation of tertiary structure using systematic
RT homologous model building, dynamical simulated annealing, and restrained
RT molecular dynamics.";
RL Biochemistry 31:2962-2970(1992).
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:0000269|PubMed:3986193, ECO:0000303|PubMed:9027980}.
CC -!- SUBUNIT: Homodimer (PubMed:7947721, PubMed:2036359) and heterodimer (By
CC similarity); non-covalently linked. {ECO:0000250|UniProtKB:P15816,
CC ECO:0000269|PubMed:2036359, ECO:0000269|PubMed:7947721}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:3986193}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC -!- MISCELLANEOUS: Shows very low activity towards muscle nicotinic
CC acetylcholine receptors (IC=~10 uM). {ECO:0000269|PubMed:9027980}.
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; Y08721; CAA69971.1; -; mRNA.
DR EMBL; Y11768; CAA72433.1; -; Genomic_DNA.
DR PIR; JC5383; N1KF2U.
DR PDB; 1KBA; X-ray; 2.30 A; A/B=22-87.
DR PDB; 2NBT; NMR; -; A/B=22-87.
DR PDBsum; 1KBA; -.
DR PDBsum; 2NBT; -.
DR AlphaFoldDB; P01398; -.
DR BMRB; P01398; -.
DR SMR; P01398; -.
DR EvolutionaryTrace; P01398; -.
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 3D-structure; Acetylcholine receptor inhibiting toxin;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Postsynaptic neurotoxin; Secreted; Signal; Toxin.
FT SIGNAL 1..21
FT /evidence="ECO:0000269|PubMed:3021284,
FT ECO:0000269|PubMed:3986193"
FT CHAIN 22..87
FT /note="Kappa-bungarotoxin"
FT /id="PRO_0000035410"
FT DISULFID 24..42
FT /evidence="ECO:0000269|PubMed:1550821,
FT ECO:0000269|PubMed:2036359, ECO:0000269|PubMed:7947721"
FT DISULFID 35..63
FT /evidence="ECO:0000269|PubMed:1550821,
FT ECO:0000269|PubMed:2036359, ECO:0000269|PubMed:7947721"
FT DISULFID 48..52
FT /evidence="ECO:0000269|PubMed:1550821,
FT ECO:0000269|PubMed:2036359, ECO:0000269|PubMed:7947721"
FT DISULFID 67..79
FT /evidence="ECO:0000269|PubMed:1550821,
FT ECO:0000269|PubMed:2036359, ECO:0000269|PubMed:7947721"
FT DISULFID 80..85
FT /evidence="ECO:0000269|PubMed:1550821,
FT ECO:0000269|PubMed:2036359, ECO:0000269|PubMed:7947721"
FT MUTAGEN 47
FT /note="Q->W: Little increase in inhibition of neuronal
FT receptor and 8-fold increase in inhibition of muscle
FT receptor."
FT /evidence="ECO:0000269|PubMed:9027980"
FT MUTAGEN 55
FT /note="R->A: Loss of inhibition of neuronal and muscle
FT receptors."
FT /evidence="ECO:0000269|PubMed:9027980"
FT MUTAGEN 57
FT /note="P->A: No important change in inhibition of muscle
FT and neuronal receptors."
FT /evidence="ECO:0000269|PubMed:9027980"
FT MUTAGEN 57
FT /note="P->K: 13-fold decrease in inhibition of neuronal
FT receptor, and complete loss of activity towards muscle
FT receptor."
FT /evidence="ECO:0000269|PubMed:9027980"
FT STRAND 23..26
FT /evidence="ECO:0007829|PDB:1KBA"
FT TURN 27..30
FT /evidence="ECO:0007829|PDB:1KBA"
FT STRAND 31..34
FT /evidence="ECO:0007829|PDB:1KBA"
FT STRAND 37..39
FT /evidence="ECO:0007829|PDB:2NBT"
FT STRAND 41..47
FT /evidence="ECO:0007829|PDB:1KBA"
FT HELIX 52..55
FT /evidence="ECO:0007829|PDB:1KBA"
FT STRAND 58..66
FT /evidence="ECO:0007829|PDB:1KBA"
FT STRAND 74..82
FT /evidence="ECO:0007829|PDB:1KBA"
SQ SEQUENCE 87 AA; 9566 MW; E4950E1222066FB6 CRC64;
MKTLLLTLVV VTIVCLDLGY TRTCLISPSS TPQTCPNGQD ICFLKAQCDK FCSIRGPVIE
QGCVATCPQF RSNYRSLLCC TTDNCNH
