title: Mass spectral characterization of peptide transmitters/hormones in the nervous system and neuroendocrine organs of the American lobster Homarus americanus.
abstract: The American lobster Homarus americanus is a decapod crustacean with both high economic and scientific importance. To facilitate physiological investigations of peptide transmitter/hormone function in this species, we have used matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nanoscale liquid chromatography coupled to electrospray ionization quadrupole time-of-flight tandem mass spectrometry (nanoLC-ESI-Q-TOF MS/MS) to elucidate the peptidome present in its nervous system and neuroendocrine organs. In total, 84 peptides were identified, including 27 previously known H. americanus peptides (e.g., VYRKPPFNGSIFamide [Val(1)-SIFamide]), 23 peptides characterized previously from other decapods, but new to the American lobster (e.g., pQTFQYSRGWTNamide [Arg(7)-corazonin]), and 34 new peptides de novo sequenced/detected for the first time in this study. Of particular note are a novel B-type allatostatin (TNWNKFQGSWamide) and several novel FMRFamide-related peptides, including an unsulfated analog of sulfakinin (GGGEYDDYGHLRFamide), two myosuppressins (QDLDHVFLRFamide and pQDLDHVFLRFamide), and a collection of short neuropeptide F isoforms (e.g., DTSTPALRLRFamide and FEPSLRLRFamide). Our data also include the first detection of multiple tachykinin-related peptides in a non-brachyuran decapod, as well as the identification of potential individual-specific variants of orcokinin and orcomyotropin-related peptide. Taken collectively, our results not only expand greatly the number of known H. americanus neuropeptides, but also provide a framework for future studies on the physiological roles played by these molecules in this commercially and scientifically important species.
authors.affiliation: School of Pharmacy, University of Wisconsin, Madison, WI 53705-2222, USA.
authors.forename: Mingming
authors.initials: M
authors.lastname: Ma
authors.forename: Ruibing
authors.initials: R
authors.lastname: Chen
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Sousa
authors.forename: Eleanor K
authors.initials: EK
authors.lastname: Bors
authors.forename: Molly A
authors.initials: MA
authors.lastname: Kwiatkowski
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Goiney
authors.forename: Michael F
authors.initials: MF
authors.lastname: Goy
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Christie
authors.forename: Lingjun
authors.initials: L
authors.lastname: Li
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D019075:Electrophoresis, Capillary; D005557:Formaldehyde / Q000737:chemistry; D013058:Mass Spectrometry; D008121:Nephropidae / Q000502:physiology*; D009479:Neuropeptides / Q000032:analysis / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000032:analysis / Q000378:metabolism*; D036361:Peptide Hormones / Q000032:analysis / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D015320:Tachykinins / Q000096:biosynthesis; D053719:Tandem Mass Spectrometry
chemical_list: D009479:Neuropeptides; D018377:Neurotransmitter Agents; D036361:Peptide Hormones; D015320:Tachykinins; D005557:Formaldehyde