Sea anemone neurotoxin

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Symbol = Toxin_4
Name = Anenome neurotoxin


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caption =
Pfam= PF00706
InterPro= IPR000693
SMART=
Prosite =
SCOP = 1atx
TCDB =
OPM family= 56
OPM protein= 1apf
PDB=PDB3|1apf :3-47 PDB3|1ahl :3-47 PDB3|1atx :3-44PDB3|2sh1 :2-44 PDB3|1shi :2-44 PDB3|1sh1 :2-44

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Symbol = BDS_I_II
Name = Antihypertensive protein BDS-I/II


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caption =
Pfam= PF07936
InterPro= IPR012414
SMART=
Prosite =
SCOP = 2bds
TCDB =
OPM family=56
OPM protein= 1bds
PDB=PDB3|2bds :1-43 PDB3|1bds :1-43 PDB3|1wqkA:1-41PDB3|1wxnA:1-41

Sea anemones produce many different neurotoxins with related structure and function. Proteins belonging to this family include the neurotoxins, of which there are several, including "calitoxin" and "anthopleurin". The neurotoxins bind specifically to the sodium channel, thereby delaying its inactivation during signal transduction, resulting in strong stimulation of mammalian cardiac muscle contraction. Calitoxin 1 has been found in neuromuscular preparations of crustaceans, where it increases transmitter release, causing firing of the axons. Three disulfide bonds are present in this proteincite journal |author=Norton TR |title=Cardiotonic polypeptides from Anthopleura xanthogrammica (Brandt) and A. elegantissima (Brandt) |journal=Fed. Proc. |volume=40 |issue=1 |pages=- |year=1981 |pmid=6108877] cite journal |author=Yasunobu KT, Norton TR, Reimer NS, Yasunobu CL |title=Amino acid sequence of the Anthopleura xanthogrammica heart stimulant, anthopleurin-B |journal=J. Biol. Chem. |volume=260 |issue=15 |pages=- |year=1985 |pmid=4019448] cite journal |author=Scanlon MJ, Pallaghy PK, Norton RS, Monks SA |title=Solution structure of the cardiostimulant polypeptide anthopleurin-B and comparison with anthopleurin-A |journal=Structure |volume=3 |issue=8 |pages=- |year=1995 |pmid=7582896] .

This family also includes the antihypertensive and antiviral proteins BDS-I (Uniprot|P11494) and BDS-II (Uniprot|P59084) expressed by "Anemonia sulcata". BDS-I is organised into a triple-stranded antiparallel beta-sheet, with an additional small antiparallel beta-sheet at the N-terminuscite journal |author=Clore GM, Driscoll PC, Gronenborn AM, Beress L |title=Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: a study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing |journal=Biochemistry |volume=28 |issue=5 |pages=2188–2198 |year=1989 |pmid=2566326 |doi=10.1021/bi00431a033] . Both peptides are known to specifically block the Kv3.4 potassium channel, and thus bring about a decrease in blood pressurecite journal |author=Lazdunski M, Schweitz H, Diochot S, Beress L |title=Sea anemone peptides with a specific blocking activity against the fast inactivating potassium channel Kv3.4 |journal=J. Biol. Chem. |volume=273 |issue=12 |pages=6744–6749 |year=1998 |pmid=9506974 |doi=10.1074/jbc.273.12.6744] . Moreover, they inhibit the cytopathic effects of mouse hepatitis virus strain MHV-A59 on mouse liver cells, by an unknown mechanism.

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