HR: 13:40h
AN: B52C-01 INVITED     [PDF]
TI: Use of MALDI Mass Spectrometry for Identification of Microbes
AU: * Wilkins, C L
EM: cwilkins@uark.edu
AF: University of Arkansas, Department of Chemistry & Biochemistry, Fayetteville, AR 72701 United States
AU: Stump, M
EM: mstump@comp.uark.edu
AF: University of Arkansas, Department of Chemistry & Biochemistry, Fayetteville, AR 72701 United States
AU: Jones, J
EM: jjj11@mail.uark.edu
AF: University of Arkansas, Department of Chemistry & Biochemistry, Fayetteville, AR 72701 United States
AU: Lay, J O
EM: jlay@uark.edu
AF: University of Arkansas, Department of Chemistry & Biochemistry, Fayetteville, AR 72701 United States
AU: Fleming, R
EM: rflemin@uark.edu
AF: University of Arkansas, Department of Chemistry & Biochemistry, Fayetteville, AR 72701 United States
AB: 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. This presentation will discuss the first application of Fourier transform mass spectrometry (FTMS) to analysis of bacterial proteins directly from whole cells. In this research it is seen that accurate mass MALDI-FTMS can be used to characterize specific ribosomal proteins directly from Escherichia coli cells. Using the high-accuracy mass measurements and high resolution isotope profile data thus available it is possible to confirm posttranslational modifications proposed previously on the basis of low resolution mass measurements. In our initial work, 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. More recently, by use of carbon and nitrogen isotopically-depleted growth media additional E. coli proteins have been identified with even smaller mass measurement errors. MALDI FTMS also provided information regarding E. coli lipids in the low-mass region. Although ions with m/z values below 1000 were previously observed by FTMS of whole cells, the work to be presented was the first report of detection of ions in the 5000 to 10 000 m/z range by MALDI-FTMS using whole cells. The implications of these results for genus, species, and strain assignments of such organisms will be discussed.
DE: 1294 Instruments and techniques
SC: Biogeosciences [B]
MN: 2003 Fall Meeting