Identification of protein biomarkers in the pyrolysis electron ionization high-resolution mass spectrum of Brucella neotomae

Pyrolysis electron ionization high resolution mass spectrometry (Py-El-HR-MS) has been previously used to identify the source of lipid, carbohydrate and nucleic acid peaks from whole bacterial cells and standards. Py-El-HR-MS has proven to be a powerful technique for examining biomarker ions in a complex mixture, since most nominal pyrolysis mass spectral peaks are composed of several contributing species. Empirical formula from high-resolution MS data generated from Brucella neotomae, amino acids and proteins for a series of Py-low-resolution mass spectral peaks (m/z 67, 76, 79, 89, 93, 95, 103, 105, 115, 117, 129, and 131) have been calculated. These peaks had been previously found to be statistically important in chemically distinguishing various bacteria. Mechanisms for the formation of pyrolysis and/or electron ionization fragments from the bacterial proteins are presented for ions that were common to the amino acids, protein standards and the bacterial data. (C) 2005 Elsevier B.V. All rights reserved.