ID   PA2AA_ACAAN             Reviewed;          27 AA.
AC   P86523;
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 P-elapitoxin-Aa1a alpha chain;
DE            Short=P-EPTX-Aa1a alpha chain {ECO:0000303|PubMed:20361942};
DE            Short=svPLA2;
DE            EC=3.1.1.4;
DE   AltName: Full=Phosphatidylcholine 2-acylhydrolase {ECO:0000250|UniProtKB:P00608};
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, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL
RP   PROPERTIES, SUBUNIT, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, AND MASS
RP   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: presynaptic neurotoxin. Inhibits nerve-evoked
CC       twitch contractions but not responses to cholinergic agonists
CC       acetylcholine and carbachol and to depolarizing agonist KCl. Causes a
CC       fade in tetanic contractions. Displays a triphasic mode of action with
CC       depression, enhancement and blockade of neurotransmission. Does not
CC       display myotoxic activity such as changes in baseline muscle tension or
CC       inhibition of directly stimulated muscle twitches. All subunits are
CC       necessary for maximum toxicity. {ECO:0000269|PubMed:20361942}.
CC   -!- FUNCTION: Monomer: Snake venom phospholipase A2 (PLA2) alpha chain that
CC       has enzymatic activity. PLA2 catalyzes the calcium-dependent hydrolysis
CC       of the 2-acyl groups in 3-sn-phosphoglycerides.
CC       {ECO:0000269|PubMed:20361942}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1-acyl-sn-
CC         glycero-3-phosphocholine + a fatty acid + H(+); Xref=Rhea:RHEA:15801,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:28868,
CC         ChEBI:CHEBI:57643, ChEBI:CHEBI:58168; EC=3.1.1.4;
CC         Evidence={ECO:0000255|PROSITE-ProRule:PRU10035, ECO:0000255|PROSITE-
CC         ProRule:PRU10036, ECO:0000269|PubMed:20361942};
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250};
CC       Note=Binds 1 Ca(2+) ion. {ECO:0000250};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         Vmax=211 umol/min/mg enzyme {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=13809; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:20361942};
CC   -!- MISCELLANEOUS: Preincubation of this protein with monovalent antivenom
CC       or suramin prevents or delays toxicity, respectively. Antivenom fails
CC       to reverse neurotoxicity when applied at point of 90% neuromuscular
CC       blockade. Treatment of this protein with 4-bromophenacyl bromide
CC       drastically reduces enzymatic activity and toxicity, presumably by
CC       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; P86523; -.
DR   SMR; P86523; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0004623; F:phospholipase A2 activity; IEA:UniProtKB-EC.
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:UniProtKB-KW.
DR   GO; GO:0006644; P:phospholipid metabolic process; IEA:InterPro.
DR   InterPro; IPR036444; PLipase_A2_dom_sf.
DR   SUPFAM; SSF48619; SSF48619; 1.
PE   1: Evidence at protein level;
KW   Calcium; Direct protein sequencing; Disulfide bond; Hydrolase;
KW   Lipid degradation; Lipid metabolism; Metal-binding; Neurotoxin;
KW   Presynaptic neurotoxin; Secreted; Toxin.
FT   CHAIN           1..>27
FT                   /note="Phospholipase A2 P-elapitoxin-Aa1a alpha chain"
FT                   /id="PRO_0000395307"
FT   DISULFID        11..?
FT                   /evidence="ECO:0000250|UniProtKB:P00608"
FT   DISULFID        27..?
FT                   /evidence="ECO:0000250|UniProtKB:P00608"
FT   NON_TER         27
FT                   /evidence="ECO:0000303|PubMed:20361942"
SQ   SEQUENCE   27 AA;  3272 MW;  CF17044C5B8D32E8 CRC64;
     NLLQFGFMIR CANKRRRPVW PYEESGC