Actinoporins are a family of sea anemone proteins that bind to membranes
and produce functional pores which result in cell lysis. Actinoporin vari-ants with decreased lytic activity usually show a reduced affinity for mem-branes.
Equinatoxin II is a cytolytic protein isolated from the sea anemoneActi-nia equina. It is a member of the actinoporins, a family of eukaryotic pore-forming toxins with a unique mechanism of pore formation. Equinatoxin II
is a 20 kDa cysteineless protein, with sphingomyelin-dependent activity.
Recent studies showed that the N-terminal region of the molecule requires
conformational flexibility during pore formation.
Sticholysin II is a pore-forming toxin produced by the sea anemoneSticho-dactyla helianthus. We studied its cytolytic activity on COS-7 cells. Fluor-escence spectroscopy and flow cytometry revealed that the toxin
permeabilizes cells to propidium cations in a dose-dependent and time-dependent manner.