Macek_1982_Toxicon_20_181

Three lethal and hemolytic toxins, caritoxin I, II and III were isolated from the sea anemone Actinia cari. Following controlled autolysis, tentacles were strained through a nylon sieve and thus a crude extract was obtained. The toxins were further purified by Sephadex G-75 gel chromatography. All three toxins which were eluted at the same peak, were separated by ion-exchange chromatography on CM-cellulose. Disc-PAGE revealed electrophoretic homogeneity of caritoxin II. Caritoxin I was obtained in pure form following rechromatography on CM-cellulose. Purified toxins were stable in the pH range 3 - 8. The preliminary determined molecular weight of the toxins was 20 - 25000 daltons. All three toxins are basic proteins. Isoelectric point of caritoxin I was determined as 10.7. The isolated toxins are lethal (LD 5o of caritoxin I is 22 microgram/kg mice, i.v.) and indicate high hemolytic activity with a pH optimum between 8 and 9. Sphingomyelin specifically and irreversibly inhibits the hemolytic activity of caritoxins as well as some other sea anemone cytolytic toxins.