ID   CDKB_CONVX              Reviewed;          95 AA.
AC   P0C1W6; C4PWC2;
DT   19-SEP-2006, integrated into UniProtKB/Swiss-Prot.
DT   07-OCT-2020, sequence version 3.
DT   25-MAY-2022, entry version 42.
DE   RecName: Full=Alpha-conotoxin VxXXB {ECO:0000303|PubMed:19275168};
DE   AltName: Full=Vx20.2 {ECO:0000312|EMBL:CAX51120.1};
DE   AltName: Full=VxXIIB {ECO:0000303|PubMed:16790424};
DE   Contains:
DE     RecName: Full=Alpha-conotoxin [des-Gly95]VxXXB;
DE   Flags: Precursor;
OS   Conus vexillum (Flag cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Rhizoconus.
OX   NCBI_TaxID=89431;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom duct;
RX   PubMed=19275168; DOI=10.1021/bi9000326;
RA   Loughnan M.L., Nicke A., Lawrence N., Lewis R.J.;
RT   "Novel alpha D-conopeptides and their precursors identified by cDNA cloning
RT   define the D-conotoxin superfamily.";
RL   Biochemistry 48:3717-3729(2009).
RN   [2]
RP   PROTEIN SEQUENCE OF 46-95, HYDROXYLATION AT PRO-59; PRO-75 AND PRO-94,
RP   GAMMA-CARBOXYGLUTAMATION AT GLU-48 AND GLU-50, AMIDATION AT PRO-94, MASS
RP   SPECTROMETRY, SUBUNIT, FUNCTION, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=16790424; DOI=10.1074/jbc.m603703200;
RA   Loughnan M., Nicke A., Jones A., Schroeder C.I., Nevin S.T., Adams D.J.,
RA   Alewood P.F., Lewis R.J.;
RT   "Identification of a novel class of nicotinic receptor antagonists: dimeric
RT   conotoxins VxXIIA, VxXIIB and VxXIIC from Conus vexillum.";
RL   J. Biol. Chem. 281:24745-24755(2006).
CC   -!- FUNCTION: Alpha-conotoxins act on postsynaptic membranes, they bind to
CC       the nicotinic acetylcholine receptors (nAChR) and thus inhibit them.
CC       This toxin specifically blocks mammalian neuronal nAChR of the alpha-
CC       7/CHRNA7 (IC(50)=0.4 nM), alpha-3-beta-2/CHRNA3-CHRNB2 (IC(50)=8.4 nM)
CC       and alpha-4-beta-2/CHRNA4-CHRNB2 (IC(50)=228 nM) subtypes. VxXXB
CC       inhibits alpha-7/CHRNA7, alpha-3-beta-2/CHRNA3-CHRNB2 and alpha-4-beta-
CC       2/CHRNA4-CHRNB2 nAChR subtypes more efficiently than VxXXA and VxXXC.
CC       {ECO:0000269|PubMed:16790424}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000269|PubMed:16790424}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16790424}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC       {ECO:0000305|PubMed:16790424}.
CC   -!- DOMAIN: The cysteine framework is XX (C-CC-C-CC-C-C-C-C).
CC       {ECO:0000305}.
CC   -!- PTM: Contains 4 disulfide bonds. {ECO:0000305}.
CC   -!- MASS SPECTROMETRY: [Alpha-conotoxin VxXXB]: Mass=5741.4;
CC       Method=Electrospray; Evidence={ECO:0000269|PubMed:16790424};
CC   -!- MISCELLANEOUS: [desGly-95]VxXXB is a minor form.
CC   -!- SIMILARITY: Belongs to the conotoxin D superfamily. {ECO:0000305}.
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DR   EMBL; FN178634; CAX51120.1; -; mRNA.
DR   AlphaFoldDB; P0C1W6; -.
DR   SMR; P0C1W6; -.
DR   ConoServer; 1685; VxXXB.
DR   ConoServer; 3631; VxXXB precursor.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0035792; C:host cell postsynaptic membrane; IEA:UniProtKB-KW.
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.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Amidation;
KW   Direct protein sequencing; Disulfide bond; Gamma-carboxyglutamic acid;
KW   Hydroxylation; Ion channel impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000255"
FT   PROPEP          25..45
FT                   /evidence="ECO:0000269|PubMed:16790424"
FT                   /id="PRO_0000391783"
FT   CHAIN           46..95
FT                   /note="Alpha-conotoxin VxXXB"
FT                   /evidence="ECO:0000269|PubMed:16790424"
FT                   /id="PRO_0000249794"
FT   CHAIN           46..94
FT                   /note="Alpha-conotoxin [des-Gly95]VxXXB"
FT                   /evidence="ECO:0000269|PubMed:16790424"
FT                   /id="PRO_0000249795"
FT   MOD_RES         48
FT                   /note="4-carboxyglutamate"
FT                   /evidence="ECO:0000269|PubMed:16790424"
FT   MOD_RES         50
FT                   /note="4-carboxyglutamate"
FT                   /evidence="ECO:0000269|PubMed:16790424"
FT   MOD_RES         59
FT                   /note="4-hydroxyproline; partial"
FT                   /evidence="ECO:0000269|PubMed:16790424"
FT   MOD_RES         75
FT                   /note="4-hydroxyproline; partial"
FT                   /evidence="ECO:0000305|PubMed:16790424"
FT   MOD_RES         94
FT                   /note="4-hydroxyproline; partial"
FT                   /evidence="ECO:0000305|PubMed:16790424"
FT   MOD_RES         94
FT                   /note="Proline amide; in form [desGly-95]VxXXB"
FT                   /evidence="ECO:0000305|PubMed:16790424"
FT   CONFLICT        91
FT                   /note="C -> R (in Ref. 1; CAX51120)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   95 AA;  10545 MW;  7BFDFFF55CA36322 CRC64;
     MPKLAVVLLV LLILPLSYFD AAGGQAVQGD WRGNRLARDL QRGGRDDESE CIINTRDSPW
     GRCCRTRMCG SMCCPRNGCT CVYHWRRGHG CSCPG