ID   CKNB_CONIM              Reviewed;          73 AA.
AC   D0PX85; A0A125S9E3;
DT   16-MAY-2012, integrated into UniProtKB/Swiss-Prot.
DT   15-DEC-2009, sequence version 1.
DT   25-MAY-2022, entry version 22.
DE   RecName: Full=Conotoxin im23b {ECO:0000303|PubMed:22399292};
DE   AltName: Full=Conopeptide im009 {ECO:0000303|PubMed:30893765, ECO:0000312|EMBL:AME17667.1};
DE   AltName: Full=Im23.2 {ECO:0000303|PubMed:22399292};
DE   AltName: Full=U1-CTX-Ci1b;
DE   Flags: Precursor;
OS   Conus imperialis (Imperial cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Stephanoconus.
OX   NCBI_TaxID=35631;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PARTIAL PROTEIN SEQUENCE, FUNCTION, DISULFIDE
RP   BONDS, MASS SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom, and Venom duct;
RX   PubMed=22399292; DOI=10.1074/jbc.m111.334615;
RA   Ye M., Khoo K.K., Xu S., Zhou M., Boonyalai N., Perugini M.A., Shao X.,
RA   Chi C., Galea C.A., Wang C., Norton R.S.;
RT   "A helical conotoxin from Conus imperialis has a novel cysteine framework
RT   and defines a new superfamily.";
RL   J. Biol. Chem. 287:14973-14983(2012).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA], IDENTIFICATION BY MASS SPECTROMETRY, AND
RP   SUBCELLULAR LOCATION.
RC   TISSUE=Venom, and Venom duct;
RX   PubMed=30893765; DOI=10.3390/md17030177;
RA   Jin A.H., Dutertre S., Dutt M., Lavergne V., Jones A., Lewis R.J.,
RA   Alewood P.F.;
RT   "Transcriptomic-proteomic correlation in the predation-evoked venom of the
RT   cone snail, Conus imperialis.";
RL   Mar. Drugs 17:0-0(2019).
CC   -!- FUNCTION: Neurotoxin that induces excitatory symptoms in mice following
CC       intracranial administration. No symptoms are observed after
CC       intraperitoneal and intravenous (tail vein) injections.
CC       {ECO:0000269|PubMed:22399292}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:22399292,
CC       ECO:0000269|PubMed:30893765}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC       {ECO:0000305|PubMed:22399292, ECO:0000305|PubMed:30893765}.
CC   -!- DOMAIN: The cysteine framework is XXIII (C-C-C-CC-C). {ECO:0000305}.
CC   -!- MASS SPECTROMETRY: Mass=4874.0; Method=Unknown;
CC       Evidence={ECO:0000269|PubMed:22399292};
CC   -!- MISCELLANEOUS: Does not affect (up to 50 uM) the Nav1.7/SCN9A channel,
CC       Drosophila Shaker channel and rat KCa1.1/KCNMA1 channel expressed in
CC       HEK293 cell, as well as on whole cell current of neurons from neonatal
CC       rat hippocampus and prefrontal cortex. In addition, no detectable
CC       effect is observed on either action potential amplitude and duration or
CC       Na(+) and Ca(2+) current amplitude and kinetics when im23a is tested on
CC       action potentials and depolarization-activated Na(+) and Ca(2+)
CC       currents in rat DRG neurons (PubMed:22399292).
CC       {ECO:0000305|PubMed:22399292}.
CC   -!- SIMILARITY: Belongs to the conotoxin K superfamily. {ECO:0000305}.
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DR   EMBL; FJ375239; ACQ65999.1; -; mRNA.
DR   EMBL; KT377403; AME17667.1; -; mRNA.
DR   AlphaFoldDB; D0PX85; -.
DR   SMR; D0PX85; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Cleavage on pair of basic residues; Direct protein sequencing;
KW   Disulfide bond; Neurotoxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000255"
FT   PROPEP          23..28
FT                   /evidence="ECO:0000305|PubMed:22399292"
FT                   /id="PRO_0000417033"
FT   CHAIN           31..73
FT                   /note="Conotoxin im23b"
FT                   /evidence="ECO:0000269|PubMed:22399292"
FT                   /id="PRO_5000825650"
FT   DISULFID        34..41
FT                   /evidence="ECO:0000250|UniProtKB:D0PX84"
FT   DISULFID        45..55
FT                   /evidence="ECO:0000250|UniProtKB:D0PX84"
FT   DISULFID        56..71
FT                   /evidence="ECO:0000250|UniProtKB:D0PX84"
SQ   SEQUENCE   73 AA;  8091 MW;  C61962220B1065B2 CRC64;
     MIMRMTLTLF VLVVMTAASA SGDALTEAKR IPYCGQTGAE CYSWCIKQDL SKDWCCDFVK
     TIARLPPAHI CSQ