A NOVEL GUT TETRADECAPEPTIDE ISOLATED FROM THE EARTHWORM, EISENIA-FOETIDA

A novel bioactive tetradecapeptide, GFKDGAADRISHGFamide, was isolated from the gut of the oligochaete annelid, Eisenia foetida, using the is olated anterior gut (crop-gizzard) as a bioassay system. A highly homo logous peptide, GFRDGSADRISHCFamide, was also purified from the whole body of another species of earthworm, Pheretima vittata. These peptide s were termed Eisenia tetradecapeptide (ETP) and Pheretima tetradecape ptide (PTP), respectively. Both the peptides showed a potent excitator y action on spontaneous contractions of the anterior gut with a thresh old as low as 10(-10)-10(-9) M. These peptides were significantly homo logous to molluscan tetradecapeptides and, to a lesser extent, to arth ropodan tridecapeptides that have been reported to date. All these pep tides seem to be evolutionally related to each other.