ID   3L23_DENPO              Reviewed;          72 AA.
AC   P25667;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   25-MAY-2022, entry version 83.
DE   RecName: Full=Alpha-elapitoxin-Dpp2b;
DE            Short=Alpha-EPTX-Dpp2b;
DE   AltName: Full=Long neurotoxin 3;
DE   AltName: Full=Toxin VN2;
OS   Dendroaspis polylepis polylepis (Black mamba).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Dendroaspis.
OX   NCBI_TaxID=8620;
RN   [1]
RP   PROTEIN SEQUENCE, TOXIC DOSE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RA   Strydom D.J., Haylett T.;
RT   "Snake venom toxins. The amino acid sequence of toxin VN2 of Dendroaspis
RT   polylepis polylepis (black mamba).";
RL   S. Afr. J. Chem. 30:40-48(1977).
CC   -!- FUNCTION: Binds with high affinity to muscular (alpha-1/CHRNA1) and
CC       neuronal (alpha-7/CHRNA7) nicotinic acetylcholine receptor (nAChR) and
CC       inhibits acetylcholine from binding to the receptor, thereby impairing
CC       neuromuscular and neuronal transmission.
CC       {ECO:0000250|UniProtKB:P60615}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.1}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 0.4 mg/kg by subcutaneous injection.
CC       {ECO:0000269|Ref.1}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Long-chain
CC       subfamily. Type II alpha-neurotoxin sub-subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P25667; -.
DR   SMR; P25667; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   InterPro; IPR018354; Snake_toxin_con_site.
DR   InterPro; IPR035076; Toxin/TOLIP.
DR   Pfam; PF00087; Toxin_TOLIP; 1.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Direct protein sequencing;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Secreted; Toxin.
FT   CHAIN           1..72
FT                   /note="Alpha-elapitoxin-Dpp2b"
FT                   /id="PRO_0000093540"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250"
FT   DISULFID        14..42
FT                   /evidence="ECO:0000250"
FT   DISULFID        27..31
FT                   /evidence="ECO:0000250"
FT   DISULFID        46..57
FT                   /evidence="ECO:0000250"
FT   DISULFID        58..63
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   72 AA;  7939 MW;  0C5E7912833F8F59 CRC64;
     RTCNKTFSDQ SKICPPGENI CYTKTWCDAW CSRRGKIVEL GCAATCPKVK AGVGIKCCST
     DNCNLFKFGK PR