STRUCTURE, LOCALIZATION, AND ACTION OF BUCCALIN-B - A BIOACTIVE PEPTIDE FROM APLYSIA

The cholinergic motor neurons for the accessory radula closer (ARC) co ntain several neuropeptides that affect muscle contractions. In the pr esent study, we have purified and sequenced a sixth ARC neuropeptide, using a combination of high pressure liquid chromatography and bioassa ys. This neuropeptide, Gly-Leu-Asp-Arg-Tyr-Gly-Phe-Val-Gly-Gly-Leu-ami de, has been named buccalin B (BUCb) because it is significantly homol ogous to the previously characterized neuropeptide buccalin A. BUCb wa s found to be two-three times more potent than buccalin A in depressin g motor neuron induced contractions.