ID   CA1B_CONPU              Reviewed;          16 AA.
AC   P0C351;
DT   29-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT   29-MAY-2007, sequence version 1.
DT   25-MAY-2022, entry version 34.
DE   RecName: Full=Alpha-conotoxin PIB;
OS   Conus purpurascens (Purple cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Chelyconus.
OX   NCBI_TaxID=41690;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, MASS
RP   SPECTROMETRY, AMIDATION AT CYS-16, PYROGLUTAMATE FORMATION AT GLN-1,
RP   HYDROXYLATION AT PRO-3, AND SYNTHESIS.
RC   TISSUE=Venom;
RX   PubMed=17382984; DOI=10.1016/j.toxicon.2007.02.007;
RA   Lopez-Vera E., Jacobsen R.B., Ellison M., Olivera B.M., Teichert R.W.;
RT   "A novel alpha conotoxin (alpha-PIB) isolated from C. purpurascens is
RT   selective for skeletal muscle nicotinic acetylcholine receptors.";
RL   Toxicon 49:1193-1199(2007).
CC   -!- FUNCTION: Alpha-conotoxins act on postsynaptic membranes, they bind to
CC       the nicotinic acetylcholine receptors (nAChR) and thus inhibit them.
CC       This toxin causes paralysis upon intramuscular injection into goldfish
CC       and blocks both fetal (alpha-1/beta-1/delta-gamma subunits) and adult
CC       (alpha-1/beta-1/delta-epsilon subunits) subtypes of vertebrate muscle
CC       nAChRs in a dose-dependent manner. {ECO:0000269|PubMed:17382984}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:17382984}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC       {ECO:0000269|PubMed:17382984}.
CC   -!- DOMAIN: The cysteine framework is I (CC-C-C). Alpha4/4 pattern.
CC   -!- MASS SPECTROMETRY: Mass=1760.73; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:17382984};
CC   -!- SIMILARITY: Belongs to the conotoxin A superfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0C351; -.
DR   ConoServer; 38; PIB.
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; Hydroxylation;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin;
KW   Pyrrolidone carboxylic acid; Secreted; Toxin.
FT   PEPTIDE         1..16
FT                   /note="Alpha-conotoxin PIB"
FT                   /id="PRO_0000288946"
FT   MOD_RES         1
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:17382984"
FT   MOD_RES         3
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000269|PubMed:17382984"
FT   MOD_RES         16
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000269|PubMed:17382984"
FT   DISULFID        5..11
FT                   /evidence="ECO:0000250|UniProtKB:P69657"
FT   DISULFID        6..16
FT                   /evidence="ECO:0000250|UniProtKB:P69657"
SQ   SEQUENCE   16 AA;  1766 MW;  42619D9EFA10EB5C CRC64;
     QSPGCCWNPA CVKNRC