Purification, characterization and cDNA cloning of two natterin-like toxins from the skin secretion of oriental catfish Plotosus lineatus

► The oriental catfish Plotosus lineatus contains toxins in the skin secretion. ► Two proteinaceous toxins (toxins I and II) were purified from P. linearus. ► Toxins I and II exhibit lethal, edema-forming and nociceptive activities. ► The amino acid sequences of toxins I and II were elucidated by cDNA cloning. ► Toxins I and II are homologous with fish natterin-like proteins.