Identification of peptides from sinus gland extracts in the red swamp crayfish Procambarus clarkii by mass spectrometry

Crustacean sinus gland (SG) is a well-defined neuroendocrine organ that controls the secretion of various neuropeptides which regulate many physiological activities. The red swamp crayfish Procambarus clarkii is a decapod crustacean with both high economic and scientific importance in China. To facilitate physiological investigations of SG peptide/hormone function in this species, we have been employed tissue extract fractionation by HPLC to obtain a complete description of neuropeptidome and used Electrospray ionization-Fourier transform mass spectrometry (ESI-FTMS) to detect the peptidome present in its organ. In total, 48 peptide sequences belonging to several known neuropeptide families including crustacean cardioactive peptide, CHH precursor-related peptides (CPRPs), orcokinins and pigment dispersing hormones were identified. Among these 48 sequences, 26 are novel peptides and 22 are previously identified. Overall, the results give a stimulus for future physiological studies of SG neuropeptides in P. clarkii and other crustaceans.