Purification and characterization of a novel tetradecapeptide that modulates oesophagus motility in Lymnaea stagnalis.

The isolated oesophagus of Lymnaea stagnalis was used as a bioassay preparation to identify peptides that modulate the activity of the oesophagus. Several modulatory messengers were detected from the oesophageal extract. One of these, having an excitatory action, was further purified from both the oesophagus and the central nervous system through high performance gel permeation chromatography followed by serial reversed phase high performance liquid chromatography. The purified peptide was chemically characterized through amino acid sequencing and mass spectrometry as GFRANSASRVAHGY-NH2.