Isolation of two neuropeptides in the AKH/RPCH-family from horseflies (Diptera).

Two neuropeptides (DCCI and DCCII) in the adipokinetic/red pigment concentrating hormone-family have been isolated and purified from the corpora cardiaca of horseflies (Diptera : Tabanidae). Both peptides were purified by a sequence of three reversed phase-high performance liquid chromatographic steps. Amino acid analysis of the purified peptides indicated the following composition for DCCI: Glx(l), Gly(1), Leu(1), Phe(1), Pro(1), Thr(2) and for DCCII: Glx(1), Gly(2), Leu(1), Phe(1), Pro(1), Thr(2), and Tyr(1). Photodiode array ultraviolet spectroscopy indicated the presence of tryptophan in both DCCI and II. Both DCCI and II had red pigment concentrating hormone activity in the crab, Uca pugilator.