Matrix-assisted laser desorption/ionization quadrupole time-of-flight mass spectrometry: an elegant tool for peptidomics

Abstract

A Matrix-assisted laser desorption/ionization hybrid quadrupole orthogonal acceleration time-of-flight mass spectrometer was employed to acquire neuropeptide mass spectra, directly from neuropeptide secreting tissue deposited on the sample target, in the presence of dihydroxybenzoic acid as matrix. The cockroach corpus cardiacum served as model neuroendocrine tissue. Twelve neuropeptide ion peaks, with mass-to-charge ratio values ranging between 800 and 3,000 Da were selected for tandem mass spectrometry. All peptides below 1,600 Da could be fully sequenced; tandem mass spectrometry analysis of the remaining (three) largest peptides resulted in (limited) sequence tags, which, also due to unavailability of an appropriate neuropeptide structure database, did not allow complete structure elucidation.