Surface activity of polypeptide toxins isolated from Anemonia sulcata

Circular dichroism spectra and surface activities are reported for toxins II and III isolated from Anemonia sulcata. Toxin II is highly surface active and as a result possesses a synergistic effect with phospholipase A2. In complete contrast, toxin III lacks detectable surface activity. The presence of sodium dodecyl sulfate (2.5 mg.ml-1) failed to trigger large conformation changes in both toxins II and III. From a comparison of the sequences of toxins II and III it is suggested that the hydrophobic region 17-27 is responsible for the surface activity of toxin II.