title: Investigation of MALDI-TOF and FT-MS techniques for analysis of Escherichia coli whole cells.
abstract: Recently, it has been demonstrated that bacteria can be characterized using whole cells and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). However, identification of specific bacterial proteins usually requires analysis of cellular fractions or purified extracts. Here, the first application of Fourier transform mass spectrometry (FTMS) to analysis of bacterial proteins directly from whole cells is reported. It is shown that accurate mass MALDI-FTMS can be used to characterize specific ribosomal proteins directly from Escherichia coli cells. High-accuracy mass measurements and high-resolution isotope profile data confirm posttranslational modifications proposed previously on the basis of low-resolution mass measurements. Seven ribosomal proteins from E. coli whole cells were observed with errors of less than 27 ppm. This was accomplished directly from whole cells without fractionation, concentration, or overt overexpression of characteristic cellular proteins. MALDI-FTMS also provided information regarding E. coli lipids in the low-mass region. Although ions with m/z values below 1000 have been observed by FTMS of whole cells, this represents the first report of detection of ions in the 5000 to 10,000 m/z range by MALDI-FTMS using whole cells.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Jones
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Stump
authors.forename: Richard C
authors.initials: RC
authors.lastname: Fleming
authors.forename: Jackson O
authors.initials: JO
authors.lastname: Lay
authors.forename: Charles L
authors.initials: CL
authors.lastname: Wilkins
mesh_terms: D004926:Escherichia coli / Q000166:cytology*; D029968:Escherichia coli Proteins / Q000032:analysis*; D005583:Fourier Analysis; D008055:Lipids / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D012269:Ribosomal Proteins / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D029968:Escherichia coli Proteins; D008055:Lipids; D012269:Ribosomal Proteins