title: Identification of neuropeptides from brains of larval Manduca sexta and Lacanobia oleracea using MALDI-TOF mass spectrometry and post-source decay.
abstract: The occurrence of neuropeptides in the brain of larvae of the tobacco hawkmoth, Manduca sexta, and tomato moth, Lacanobia oleracea, was investigated using matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry (MS) and post-source decay (PSD). Methanolic extracts of 100 brains separated by reversed-phase high performance liquid chromatography yielded numerous ion peaks, some of which were common to both species. In M. sexta six [M+H](+) ions were in agreement with peptides previously structurally characterised from M. sexta (FLRF-amides I, II and III, M. sexta allatostatin, CAP(2b) and myoinhibitory peptide VI), whereas a further five corresponded to other known lepidopteran peptides (cydiastatins 3 and 4, helicostatins 1 and 6 and helicokinin II). Of these the identities of FLRF-amide I, cydiastatins 3 and 4 and CAP(2b) were confirmed by PSD analysis. Fourteen [M+H](+) ions corresponding to known lepidopteran peptides (FLRF-amide I, cydiastatins 2, 3 and 4, helicostatins 1, 5, 6, 7 and 9, CCAP, CAP(2b), M. sexta allatostatin and myoinhibitory peptide VI) were measured in L. oleracea brain extracts. From this insect, cydiastatins 3 and 4, helicostatin 5 and FLRF-amide I were identified by PSD. These peptides had not previously been structurally characterised from L. oleracea.
authors.affiliation: Central Science Laboratory, Sand Hutton, YO41 1LZ, York, UK. n.audsley@csl.gov.uk
authors.forename: Neil
authors.initials: N
authors.lastname: Audsley
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Weaver
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D019476:Insect Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D007814:Larva / Q000737:chemistry*; D007915:Lepidoptera / Q000737:chemistry*; D018402:Manduca / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009479:Neuropeptides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D010455:Peptides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D019476:Insect Proteins; D009479:Neuropeptides; D010455:Peptides; C071432:allatostatin protein, Manduca sexta; D011761:Pyrrolidonecarboxylic Acid