Substance p

Mass spectra were acquired in positive reflector mode using Bruker ultrafleX III or ultrafleXtreme mass spectrometers (Bruker Daltonics, Bremen, Germany). Samples were mixed with 0.5 µl 2,5-Dihydroxybenzoic acid (DHB, 10 mg/ml in 20% acetonitrile, 1% FA) on the MALDI sample plate and dried using a gentle stream of hot air. External calibration was conducted using calibration mixtures containing bradykinin 1-7 , angiotensin I, angiotensin II, substance P, bombesin, ACTH clip 1-17 , ACTH clip 18-39 , somatostatin 28, insulin and ubiquitin I (Bruker Daltonics).

Mass spectra were acquired in positive linear or reflector mode using either a Voyager DE STR matrix-assisted laser desorption ionisation mass spectrometer (Applied Biosystems, Warrington, UK) or a Bruker Ultraflex mass spectrometer (Bruker Daltonic GmbH, Bremen, Germany). Samples were mixed with equal volumes of either α-Cyano-4-hydroxycinnamic acid (10 mg/ml in 70% acetonitrile, 0.1% TFA) or 2,5-Dihydroxybenzoic acid (10 mg/ml in 20% acetonitrile, 1% formic acid) on the MALDI sample plate and allowed to air-dry.
External calibration was conducted using a calibration mixture containing des-Argbradykinin, angiotensin1, Glu-fibrinopeptide B, and neurotensin (Applied Biosystems) or angiotensin I, angiotensin II, substance P, bombesin, ACTH clip 1-17 , ACTH clip 18-39 and somatostatin 28 (Bruker Daltonics). Masses are shown as average masses [M+H] + for analyses performed in linear mode and monoisotopic masses for analyses in reflector mode.