Purification and characterisation of four polypeptides with neurotoxic activity from Condylactis aurantiaca

Abstract

Four toxic polypeptides, Toxins I, II, III and IV were isolated in pure form from the sea anemone Condylactis aurantiaca (Actinaria). Toxin isolation was achieved by alcoholic extraction of the homogenised sea anemones, batchwise adsorption onto cation exchangers, gel filtration on Sephadex G-50 and G-25 and ion-exchange chromatography on SP-Sephadex and QAE-Sephadex. Toxins from Condylactis aurantiaca all contain between 49 and 51 amino acids. Their amino acid compositions were compared to those of the Anemonia sulcata toxins. The toxins were tested on the shore crab Carcinus maenas by intramusclar injection. Crabs react highly sensitively to sea anemone toxins with muscle cramps and paralysis. For Condylactis toxins LD100 ranges from 2 to 6.6 mug/kg Carcinus maenas.