3NO4_BUNCA
ID 3NO4_BUNCA Reviewed; 87 AA.
AC P81783;
DT 30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-MAR-2004, sequence version 2.
DT 25-MAY-2022, entry version 100.
DE RecName: Full=Candoxin {ECO:0000303|PubMed:11884390};
DE Flags: Precursor;
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 [MRNA].
RC TISSUE=Venom gland;
RA Tsai I.H., Hsu H.Y., Wang Y.M.;
RT "Comparative genomics and characterization of novel neurotoxins in the
RT venom of Bungarus candidus (Malayan banded krait).";
RL Submitted (AUG-2002) to the EMBL/GenBank/DDBJ databases.
RN [2]
RP PROTEIN SEQUENCE OF 22-87, FUNCTION, MASS SPECTROMETRY, AND SUBCELLULAR
RP LOCATION.
RC TISSUE=Venom;
RX PubMed=11884390; DOI=10.1074/jbc.m111152200;
RA Nirthanan S., Charpantier E., Gopalakrishnakone P., Gwee M.C.E.,
RA Khoo H.-E., Cheah L.-S., Bertrand D., Kini R.M.;
RT "Candoxin, a novel toxin from Bungarus candidus, is a reversible antagonist
RT of muscle (alphabetagammadelta) but a poorly reversible antagonist of
RT neuronal alpha 7 nicotinic acetylcholine receptors.";
RL J. Biol. Chem. 277:17811-17820(2002).
RN [3]
RP PHARMACOLOGICAL CHARACTERIZATION.
RX PubMed=12813007; DOI=10.1038/sj.bjp.0705299;
RA Nirthanan S., Charpantier E., Gopalakrishnakone P., Gwee M.C.E., Khoo H.E.,
RA Cheah L.S., Kini R.M., Bertrand D.;
RT "Neuromuscular effects of candoxin, a novel toxin from the venom of the
RT Malayan krait (Bungarus candidus).";
RL Br. J. Pharmacol. 139:832-844(2003).
RN [4]
RP X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 22-87, AND DISULFIDE BONDS.
RX PubMed=12595733; DOI=10.1107/s0907444903001094;
RA Paaventhan P., Joseph J.S., Nirthanan S., Rajaseger G.,
RA Gopalakrishnakone P., Kini M.R., Kolatkar P.R.;
RT "Crystallization and preliminary X-ray analysis of candoxin, a novel
RT reversible neurotoxin from the Malayan krait Bungarus candidus.";
RL Acta Crystallogr. D 59:584-586(2003).
CC -!- FUNCTION: Binds and inhibits muscular and neuronal nicotinic
CC acetylcholine receptors (nAChR). Is a reversible antagonist of muscle
CC nAChR (alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE)
CC (IC(50)=10 nM) and a potent and poorly reversible antagonist of the
CC neuronal alpha-7/CHRNA7 nAChR (IC(50)=50 nM). May exhibit differential
CC affinities for the two binding sites on the muscle nAChR.
CC {ECO:0000269|PubMed:11884390}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:11884390}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:11884390}.
CC -!- MASS SPECTROMETRY: Mass=7334.69; Mass_error=0.26; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:11884390};
CC -!- SIMILARITY: Belongs to the snake three-finger toxin family. Ancestral
CC subfamily. Orphan group IV sub-subfamily. {ECO:0000305}.
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DR EMBL; AY142323; AAN16112.1; -; mRNA.
DR PDB; 1JGK; NMR; -; A=22-87.
DR PDBsum; 1JGK; -.
DR AlphaFoldDB; P81783; -.
DR BMRB; P81783; -.
DR SMR; P81783; -.
DR EvolutionaryTrace; P81783; -.
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 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:11884390"
FT CHAIN 22..87
FT /note="Candoxin"
FT /evidence="ECO:0000269|PubMed:11884390"
FT /id="PRO_0000035417"
FT DISULFID 24..47
FT /evidence="ECO:0000269|PubMed:12595733,
FT ECO:0000312|PDB:1JGK"
FT DISULFID 27..32
FT /evidence="ECO:0000269|PubMed:12595733,
FT ECO:0000312|PDB:1JGK"
FT DISULFID 40..64
FT /evidence="ECO:0000269|PubMed:12595733,
FT ECO:0000312|PDB:1JGK"
FT DISULFID 68..80
FT /evidence="ECO:0000269|PubMed:12595733,
FT ECO:0000312|PDB:1JGK"
FT DISULFID 81..86
FT /evidence="ECO:0000269|PubMed:12595733,
FT ECO:0000312|PDB:1JGK"
FT STRAND 23..26
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 36..39
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 42..44
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 46..52
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 59..61
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 64..66
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 72..74
FT /evidence="ECO:0007829|PDB:1JGK"
FT STRAND 77..81
FT /evidence="ECO:0007829|PDB:1JGK"
SQ SEQUENCE 87 AA; 9635 MW; 57D07EC7243B4D53 CRC64;
MKTLLLTLVV VTIVCLDLGY TMKCKICNFD TCRAGELKVC ASGEKYCFKE SWREARGTRI
ERGCAATCPK GSVYGLYVLC CTTDDCN
