ID   SCX1_CENBA              Reviewed;          66 AA.
AC   C0HLR3;
DT   07-OCT-2020, integrated into UniProtKB/Swiss-Prot.
DT   07-OCT-2020, sequence version 1.
DT   03-AUG-2022, entry version 6.
DE   RecName: Full=Beta-toxin Cb1 {ECO:0000303|PubMed:32479835};
OS   Centruroides baergi (Scorpion) (Centruroides nigrovariatus baergi).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=329350 {ECO:0000303|PubMed:32479835};
RN   [1] {ECO:0000305}
RP   PROTEIN SEQUENCE, FUNCTION, ACTIVITY REGULATION, SUBCELLULAR LOCATION, MASS
RP   SPECTROMETRY, AND TOXIC DOSE.
RC   TISSUE=Venom {ECO:0000303|PubMed:32479835};
RX   PubMed=32479835; DOI=10.1016/j.toxicon.2020.05.021;
RA   Gomez-Ramirez I.V., Riano-Umbarila L., Olamendi-Portugal T.,
RA   Restano-Cassulini R., Possani L.D., Becerril B.;
RT   "Biochemical, electrophysiological and immunological characterization of
RT   the venom from Centruroides baergi, a new scorpion species of medical
RT   importance in Mexico.";
RL   Toxicon 184:10-18(2020).
CC   -!- FUNCTION: Beta toxins bind voltage-independently at site-4 of sodium
CC       channels (Nav) and reduces peak current and shifts the voltage of
CC       activation toward more negative potentials thereby affecting sodium
CC       channel activation and promoting spontaneous and repetitive firing
CC       (PubMed:32479835). Has an inhibitory effect on voltage-gated sodium
CC       channel hNav1.6/SCN8A, affecting both the activation and inactivation
CC       processes (PubMed:32479835). This toxin is active against mammals and
CC       lethal to mice (PubMed:32479835). {ECO:0000269|PubMed:32479835}.
CC   -!- ACTIVITY REGULATION: Inhibited by human antibodies scFvs 10FG2 and LR.
CC       {ECO:0000269|PubMed:32479835}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:32479835}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:32479835}.
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=7522.7; Mass_error=1; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:32479835};
CC   -!- TOXIC DOSE: LD(50) is 2.0 ug/mouse by intraperitoneal injection into
CC       mice. {ECO:0000269|PubMed:32479835}.
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; C0HLR3; -.
DR   SMR; C0HLR3; -.
DR   GO; GO:0005615; C:extracellular space; IDA:UniProtKB.
DR   GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0019871; F:sodium channel inhibitor activity; IDA:UniProtKB.
DR   GO; GO:0090729; F:toxin activity; IDA:UniProtKB.
DR   GO; GO:0006952; P:defense response; IDA:UniProtKB.
DR   GO; GO:0044493; P:envenomation resulting in negative regulation of voltage-gated sodium channel activity in another organism; IDA:UniProtKB.
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   Calcium channel impairing toxin; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   CHAIN           1..66
FT                   /note="Beta-toxin Cb1"
FT                   /id="PRO_0000450847"
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   66 AA;  7530 MW;  D8653D5B610BB5C2 CRC64;
     KEGYIVNHST GCKYECYKLG DNDYCLRECK AQYGKGAGGY CYAFGCWCTH LYEQAVVWPL
     PKKTCN