Isolation of proteinase inhibitory, toxic and hemolytic polypeptides from a sea anemone, Stoichactis sp.

Abstract

From a sea anemone, Stoichactis sp., biologically active polypeptides exhibiting toxic, hemolytic and proteinase inhibitory properties have been isolated by gel filtration and ion-exchange chromatography. For the hemolytic polypeptide a mol. wt of 10,000 was determined by gel filtration. It induces complete hemolysis of human erythrocytes at 0·86 μg/ml concentration, is free of phospholipase A activity and has ichthyotoxic activity. The toxic principle (minimum lethal dose ca. 2·3 mg/kg injected s.c. into mice, and 0·5 mg/kg for crabs, i.m. injection) has a mol. wt of about 6000 and was separated from the hemolysin and from the three proteinase inhibitors which inhibit trypsin and chymotrypsin and which are composed of 52–56 amino acid residues.