Open AccessUse of double-depleted 13C and 15N culture media for analysis of whole cell bacteria by MALDI time-of-flight and Fourier transform mass spectrometry
Author(s) -
Michael J. Stump,
Jeffrey Jones,
Richard C. Fleming,
Jackson O. Lay,
Charles L. Wilkins
Publication year - 2003
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1016/s1044-0305(03)00577-4
Subject(s) - chemistry , mass spectrometry , analytical chemistry (journal) , matrix assisted laser desorption/ionization , time of flight mass spectrometry , maldi imaging , resolution (logic) , ion suppression in liquid chromatography–mass spectrometry , mass spectrum , fourier transform ion cyclotron resonance , sample preparation , fourier transform , ionization , chromatography , desorption , ion , tandem mass spectrometry , mathematical analysis , mathematics , organic chemistry , adsorption , artificial intelligence , computer science
In the present paper, results demonstrating the significant advantages of matrix-assisted laser desorption/ionization (MALDI) analysis of whole cell samples of bacteria grown on double isotopically-depleted (13C and 15N) media are presented. It is shown that several advantages accrue for MALDI with a 9.4 T Fourier transform mass spectrometer (FTMS). Of particular note, for analysis of whole cells, sample preparation is simple and chemical interference is reduced. Moreover, ion coalescence problems are minimized, and data-base identification of proteins facilitated. Furthermore, high resolution mass spectra obtained from such whole cells show significant improvement in apparent mass resolving power and mass measurement accuracy, whether time-of-flight or FTMS MALDI is used. As a consequence, it becomes possible to detect subtle details in the chemistry of the organism, such as the presence of both post-translationally modified and unmodified versions of the same proteins. This approach is also adaptable to direct assay of over-expressed proteins from Escherichia coli cultures and should facilitate studies aimed at the detection of medically important cellular biomarker proteins.