SCX8_CENNO
ID SCX8_CENNO Reviewed; 67 AA.
AC Q9TWL0;
DT 16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT 14-DEC-2011, sequence version 2.
DT 03-AUG-2022, entry version 70.
DE RecName: Full=Beta-toxin Cn8 {ECO:0000303|PubMed:22200496};
DE Short=Toxin 8 {ECO:0000303|PubMed:7706233};
DE AltName: Full=Toxin II-13.4 {ECO:0000303|PubMed:22200496};
OS Centruroides noxius (Mexican scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX NCBI_TaxID=6878;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, 3D-STRUCTURE MODELING, AND MASS SPECTROMETRY.
RC TISSUE=Venom;
RX PubMed=22200496; DOI=10.1016/j.toxicon.2011.12.003;
RA Schiavon E., Pedraza-Escalona M., Gurrola G.B., Olamendi-Portugal T.,
RA Corzo G., Wanke E., Possani L.D.;
RT "Negative-shift activation, current reduction and resurgent currents
RT induced by beta-toxins from Centruroides scorpions in sodium channels.";
RL Toxicon 59:283-293(2012).
RN [2]
RP PROTEIN SEQUENCE, AND MASS SPECTROMETRY.
RC TISSUE=Venom;
RA Schiavon E., Pedraza-Escalona M., Gurrola G.B., Olamendi-Portugal T.,
RA Possani L.D.;
RT "Negative-shift activation, partial blockage and resurgent currents induced
RT by beta-toxins from Centruroides scorpions in Nav channels.";
RL Submitted (SEP-2011) to UniProtKB.
RN [3]
RP PROTEIN SEQUENCE OF 1-62, FUNCTION, AND SUBCELLULAR LOCATION.
RC TISSUE=Venom;
RX PubMed=7706233; DOI=10.1093/oxfordjournals.jbchem.a124691;
RA Valdivia H.H., Martin B.M., Ramirez A.N., Fletcher P.L. Jr., Possani L.D.;
RT "Isolation and pharmacological characterization of four novel Na+ channel-
RT blocking toxins from the scorpion Centruroides noxius Hoffmann.";
RL J. Biochem. 116:1383-1391(1994).
CC -!- FUNCTION: Beta toxin that binds site-4 of sodium channels (Nav),
CC reduces peak current (observed on Nav1.6/SCN8A (IC(50)=67.7 nM),
CC Nav1.1/SCN1A, Nav1.2/SCN2A, Nav1.3/SCN3A (weak), Nav1.4/SCN4A, and
CC Nav1.5/SCN5A), shifts the voltage of activation toward more negative
CC potentials (observed on Nav1.6, Nav1.1, Nav1.2, and Nav1.4 (weak)), and
CC induces resurgent currents at negative voltages following brief and
CC strong depolarizations (observed on Nav1.6, Nav1.1 (weak), Nav1.2
CC (weak), and Nav1.3 (weak)) (PubMed:22200496).
CC {ECO:0000269|PubMed:22200496, ECO:0000269|PubMed:7706233}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:7706233}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:7706233}.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=7626.0; Mass_error=1; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:22200496, ECO:0000269|Ref.2};
CC -!- MISCELLANEOUS: Does not show inhibition of peak current on Nav1.7 (at
CC 140 nM). {ECO:0000269|PubMed:22200496}.
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR AlphaFoldDB; Q9TWL0; -.
DR SMR; Q9TWL0; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006952; P:defense response; IEA:InterPro.
DR Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR003614; Scorpion_toxin-like.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR018218; Scorpion_toxinL.
DR PRINTS; PR00285; SCORPNTOXIN.
DR SMART; SM00505; Knot1; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT CHAIN 1..67
FT /note="Beta-toxin Cn8"
FT /evidence="ECO:0000269|PubMed:22200496"
FT /id="PRO_0000066769"
FT DOMAIN 1..66
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 12..65
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 16..41
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 25..46
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 29..48
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ SEQUENCE 67 AA; 7634 MW; 81073D6D4DEC2678 CRC64;
KEGYIVNYYT GCKFACAKLG DNDYCLRECK ARYGKGAGGY CYAFGCWCTH LYEQAVVWPL
PKKKCRA
