According to a handful of papers published more than forty years ago, sea anemone Metridium senile contains cytolytic protein that is inhibited by cholesterol. Similarly, sea anemone Alicia mirabilis contains cytolytic protein which is probably the cause of several stings upon the contact with the anemone, as described in several medical reports. Both proteins are putative members of MACPF/CDC superfamily. In our research, we managed to partly purify both proteins and to determine some of their biophysical characteristics. Both proteins have molecular masses of approximately 55 kDa and are thermally labile with Tm at 65 °C. Optimal pH values for haemolysis are 5,5 (Metridium) and 7,0 (Alicia) while pH 8,0 proved to be inhibitory for both. Experiments with artificial lipid vesicles did not show strong biding specificity for used lipids. Additionally, we acquired N-terminal amino acid sequence for both proteins and cDNA sequence of cytolytic protein from M. senile.
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