High-accuracy mass measurement

The Use of High-Accuracy Mass Measurements in Combination with LC-MS for the Structure Determination of Drug Metabolites... 

The Use of Cone-Voltage Fragmentation in Conjunction with High-Accuracy Mass Measurements and LC-MS for Metabolite Identification... 

Chaif, B. T., and S. B. H. Kent, Weighing naked proteins Practical, high-accuracy mass measurement of peptides and proteins. Science 257 1885-1893, 1992. Proteins with molecular masses of as much as 100 kd or more can be analyzed at picomole sensitivities to give simple mass spectra corresponding to the intact molecule. This development has allowed unprecedented accuracy in the determination of protein molecular weights. 

Chait, B. T. and Kent, S. B. (1992) Weighing naked proteins practical, high-accuracy mass measurement of peptides and proteins. Science 257, 1885-1894. 

Identification and structural characterization of an unknown class of substrates for FAAH. (A) By high-resolution mass spectrometry, the high-accuracy mass measurements of a compound of this class gives an exact mass of 446.3310 that corresponds to a molecular formula of C24H48N04S. (B) By MS/MS analysis, the structure of this compound is assigned as the C24 0 fatty acyl amide of taurine (NAT). Reproduced from Saghatelian A., Trauger S.A., Want E.J., Hawkins E.G., Siuzdak G. and Cravatt B.F., Biochemistry, 43,14332-14339, 2004, with permission. 

Y. Shen, E.F. Stiittmatter, R. Zhang, T.O. Metz, R.J. Moore, F. Li, H.R. Udseth, R.D. Smith, K.K. Unger, D. Kumar, D. Lubda, Making broad proteome protein measurements in 1-5 min using highspeed RPLC separations and high-accuracy mass measurements. Anal. Chem., 77 (2005) 7763. 

Chait, B., and Kent, S. (1992). Weighing Naked Proteins Practical, High-accuracy Mass Measurement of Peptides and Proteins, Science 257 1885-1894. 

The diameter of the laser beam used to probe the sample surface typically determines the effective spatial resolution of a measurement performed in microprobe mode. Obviously, the laser beam diameter can be reduced by focusing the beam to smaller dimensions. However, as the laser beam diameter is reduced, it illuminates a smaller area, fewer molecules of each analyte are present within the probe beam, and so fewer molecules are ionized at each location. Therefore, smallest diameter beams are rarely practical because the amount of analyte that can be desorbed and ionized from a smaller sample area is not sufficient for detection and high-accuracy mass measurement. Consequently, the laser probe diameter for the analyses of proteins and peptides usually is larger than 10 xm. 

Following gradient purification of virions, LC/MS/MS was used to identify the components of the HCMV virion [6]. The results were verified by coupling high-accuracy mass measurements with LC and FT-ICR (Fourier transform ion cyclotron resonance) MS. Fifty-nine proteins were identified including 12 proteins encoded by known HCMV ORFs not previously known to reside in virions. The classes of proteins identified included capsid proteins, tegument proteins, glycoproteins, and 12 proteins involved in DNA replication and transcription. Additionally, 12 more viral polypeptides were identified that had not been previously characterized [6]. 

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