ID   PA2HB_ACAAN             Reviewed;          31 AA.
AC   P86524;
DT   13-JUL-2010, integrated into UniProtKB/Swiss-Prot.
DT   13-JUL-2010, sequence version 1.
DT   25-MAY-2022, entry version 26.
DE   RecName: Full=Phospholipase A2 homolog P-elapitoxin-Aa1a beta chain;
DE            Short=P-EPTX-Aa1a beta chain {ECO:0000303|PubMed:20361942};
DE            Short=svPLA2 homolog;
DE   Flags: Fragment;
OS   Acanthophis antarcticus (Common death adder).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Acanthophiinae; Acanthophis.
OX   NCBI_TaxID=8605;
RN   [1] {ECO:0000305}
RP   PROTEIN SEQUENCE, FUNCTION, SUBUNIT, SUBCELLULAR LOCATION, TISSUE
RP   SPECIFICITY, AND MASS SPECTROMETRY.
RC   STRAIN=New South Wales {ECO:0000269|PubMed:20361942};
RC   TISSUE=Venom {ECO:0000269|PubMed:20361942};
RX   PubMed=20361942; DOI=10.1016/j.bcp.2010.03.030;
RA   Blacklow B., Escoubas P., Nicholson G.M.;
RT   "Characterisation of the heterotrimeric presynaptic phospholipase A(2)
RT   neurotoxin complex from the venom of the common death adder (Acanthophis
RT   antarcticus).";
RL   Biochem. Pharmacol. 80:277-287(2010).
CC   -!- FUNCTION: Heterotrimer: Snake venom phospholipase A2 (PLA2) that has
CC       presynaptic neurotoxicity. Inhibits nerve-evoked twitch contractions
CC       but not responses to cholinergic agonists acetylcholine and carbachol
CC       and to depolarizing agonist KCl. Causes a fade in tetanic contractions.
CC       Displays a triphasic mode of action with depression, enhancement and
CC       blockade of neurotransmission. Does not display myotoxic activity such
CC       as changes in baseline muscle tension or inhibition of directly
CC       stimulated muscle twitches. All subunits are necessary for maximum
CC       toxicity. {ECO:0000269|PubMed:20361942}.
CC   -!- FUNCTION: Monomer: The beta chain has no enzymatic activity and is not
CC       toxic by itself. {ECO:0000269|PubMed:20361942}.
CC   -!- SUBUNIT: Heterotrimer of alpha, beta and gamma chains, each related to
CC       PLA2. {ECO:0000269|PubMed:20361942}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:20361942}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:20361942}.
CC   -!- MASS SPECTROMETRY: Mass=13516; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:20361942};
CC   -!- MISCELLANEOUS: Preincubation of P-elapitoxin-Aa1a with monovalent
CC       antivenom or suramin prevents or delays toxicity, respectively.
CC       Antivenom fails to reverse neurotoxicity when applied at point of 90%
CC       neuromuscular blockade. Treatment of P-elapitoxin-Aa1a with 4-
CC       bromophenacyl bromide drastically reduces enzymatic activity and
CC       toxicity, presumably by alkylating a His residue at the active site.
CC   -!- SIMILARITY: Belongs to the phospholipase A2 family. Group I subfamily.
CC       {ECO:0000255}.
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DR   AlphaFoldDB; P86524; -.
DR   SMR; P86524; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005509; F:calcium ion binding; IEA:InterPro.
DR   GO; GO:0004623; F:phospholipase A2 activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0050482; P:arachidonic acid secretion; IEA:InterPro.
DR   GO; GO:0016042; P:lipid catabolic process; IEA:InterPro.
DR   GO; GO:0006644; P:phospholipid metabolic process; IEA:InterPro.
DR   Gene3D; 1.20.90.10; -; 1.
DR   InterPro; IPR001211; PLipase_A2.
DR   InterPro; IPR036444; PLipase_A2_dom_sf.
DR   PRINTS; PR00389; PHPHLIPASEA2.
DR   SUPFAM; SSF48619; SSF48619; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Neurotoxin;
KW   Presynaptic neurotoxin; Secreted; Toxin.
FT   CHAIN           1..>31
FT                   /note="Phospholipase A2 homolog P-elapitoxin-Aa1a beta
FT                   chain"
FT                   /id="PRO_0000395308"
FT   DISULFID        11..?
FT                   /evidence="ECO:0000250|UniProtKB:P00608"
FT   DISULFID        27..?
FT                   /evidence="ECO:0000250|UniProtKB:P00608"
FT   DISULFID        29..?
FT                   /evidence="ECO:0000250|UniProtKB:P00608"
FT   NON_TER         31
FT                   /evidence="ECO:0000303|PubMed:20361942"
SQ   SEQUENCE   31 AA;  3540 MW;  FBD3DC1DC6FE1D52 CRC64;
     DLFQFGKMIE CANKGSRPSL DYMNYGCYCG K