Author/Editor		Anderluh, Gregor; Maček, Peter
Title		Cytolytic peptide and protein toxins from sea anemones (Anthozoa: Actiniaria)
Type		članek
Source		Toxicon
Vol. and No.		Letnik 40
Publication year		2002
Volume		str. 111-24
Language		eng
Abstract		More than 32 species of sea anemones have been reported to produce lethal cytolytic peptides and proteins. Based on their primary structure and functional properties, cytolysins have been classified into four polypeptide groups. Group I consists of 5-8 kDa peptides, represented by those from the sea anemones Tealia felina and Radianthus macrodactylus. These peptides form pores in phosphatidylcholine containing membranes. The most numerous is group II comprising 20 kDa basic proteins, actinoporins, isolated from several genera of the fam. Actiniidae and Stichodactylidae. Equinatoxins, sticholysins, and magnificalysins from Actinia equina, Stichodactyla helianthus, and Heteractis magnifica, respectively, have been studied mostly. They associate typically with sphingomyelin containing membranes and create cation-selective pores. The crystal structure of equinatoxin II has been determined at 1.9 A resolution. Lethal 30-40 kDa cytolytic phospholipases AZ from Aiptasia paldida (fam. Aiptasiidae) and a similar cytolysin, which is devoid of enzymatic activity, from Urticina piscivora, form group III. A thiol-activated cytolysin, metridiolysin, with a mass of 80 kDa from Metridium senile (fam. Metridiidae) is a single representative of the fourth family. Its activity is inhibited by cholesterol or phosphatides. Biological, structure-function, and pharmacological characteristics of these cytolysins are reviewed.
Descriptors		SEA ANEMONES CNIDARIAN VENOMS CYTOTOXINS HEMOLYSINS PORINS