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.