THE ROLE OF IONIC-STRENGTH ON THE ENHANCEMENT OF THE HEMOLYTIC-ACTIVITY OF STICHOLYSIN-I, A CYTOLYSIN FROM STICHODACTYLA-HELIANTHUS

Sticholysin I (St I) is a potent cytolytic polypeptide purified from t he Caribbean sea anemone Stichodactyla helianthus. The hemolytic activ ity of sticholysin is potentiated by its preincubation at high ionic s trengths. In the present work the mechanism of the potentiating action of the medium ionic strength on the toxin hemolytic capacity is inves tigated. It is suggested that preincubation with high saline concentra tion induces a transition of St I to a more relaxed conformation that facilitates the lytic process. (C) 1998 Elsevier Science Ltd. All righ ts reserved.