Tandem mass spectrometry functionality

Decaestecker, T.N. et al., Evaluation of automated single mass spectrometry to tandem mass spectrometry function switching for comprehensive drug profiling analysis using a quadrupole time-of-flight mass spectrometer, Rapid Commun. Mass Spectrom., 14, 1787, 2000. 

Hsieh Y. et al., 2000. Direct analysis of plasma samples for drug discovery compounds using mixed-function column liquid chromatography tandem mass spectrometry. Rapid Commun Mass Spectrom 14 1384. 

The main spectrometric identification techniques employed are gas chromatography/mass spectrometry (GC/MS) (13), liquid chromatography/tandem mass spectrometry (LC/MS(/MS)) (14), nuclear magnetic resonance (NMR) (11), and/or gas chromatography/Fourier transform infrared spectroscopy (GC/FL1R) (15). Each of these spectrometric techniques provides a spectrum that is characteristic of a chemical. MS and NMR spectra provide (detailed) structural information (like a fingerprint ), whereas an FUR spectrum provides information on functional groups. 

Capillary Electrophoresis Chemical Warfare Agents Chemical Weapons Convention Deuterated L-Alanine Triglycine Sulfate Dimethyl Ethylphosphonate Dimethyl Isopropylphosphonate Dimethyl Methylphosphonate Dimethyl Propylphosphonate Dimercaptotoluene Diffuse Reflectance Infrared Fourier Transform Functional Group Chromatograms Flame-Ionization Detector Fourier Transform Infrared Spectroscopy Gas Chromatography Gas Chromatography/Chemical Ionization/Mass Spectrometry Gas Chromatography/Chemical Ionization/Tandem Mass Spectrometry... 

Another wide application of mass spectrometry is the detection and characterization of post-translational modifications such as myristoylation, phosphorylation, disulfide bridging, etc. The detection and localization of post-transla-tional modifications has been a rapidly developing area of mass spectrometry due to the functional importance of these modifications in biological systems. An example of this was recently shown for the case of the human rhinovirus HRV14 [10]. Electron density maps from crystallography data indicated a myristoylation of VP4. Mass analysis of VP4 also indicated a mass difference of 212 Da (consistent with myristoylation of VP4). Additional experiments with proteolytic digestion and tandem mass spectrometry were able to localize the modification to the N-terminus of VP4. 

Tandem mass spectrometry (MS/MS) is a new analytical technique applied to problems in food and flavor analyses. Rapidity of analysis, a high discrimination against chemical noise, and the ability to analyze mixtures for functional groups are attributes of MS/MS that make it attractive for such problems. Sanple collection and pretreatment differ frcm methods used in GC/MS. Correct choice of an ionization method is paramount. Daughter ion MS/MS spectra are used for conpound identification via comparison with those of authentic compounds, and parent and neutral loss spectra are useful in functional group analysis. Applications to direct analysis of volatiles emitted from fruits and to spice analyses are considered. 

Collision-induced dissociation of protonated indole with Xe has been studied as a function of kinetic energy using guided ion beam tandem mass spectrometry techniques <2007MI388>. 

Recent achievements in the development of active-site directed affinity probes for proteases and other enzyme classes provide direct chemical labeling of proteases of interest in the biological system (24-27). These specific activity probes allow joint evaluation of selective protease inhibition concomitant with labeling of relevant protease enzymes for more analyses. Moreover, activity-based probes that selectively label the main protease subclasses—cysteine, serine, metallo, aspartic, and threonine—can provide advantageous chemical approaches for functional protease identification. Activity probe labeling of proteases allows direct identihcation of enzyme proteins by tandem mass spectrometry. Such chemical probes directed to cysteine proteases have been instrumental for identification of the new cathepsin L cysteine protease pathway for neuropeptide biosynthesis, as summarized in this article. 

The study of protein structure, function, quantity, and interactions during maturation and progression of disease is referred to as proteomics. Analytical approaches that use a combination of two-dimensional (2-D) gel electrophoresis for protein separation and MS analysis for protein identification followed by database searches is a widely practiced proteomics strategy.The tryptic peptides extracted from gels are analyzed by MALDI-TOF MS and microcolunm or capillary LC tandem mass spectrometry (MS/MS) techniques. Typically, the MALDI-TOF MS techniques are used to quickly identify peptide fragments and confirm the presence of known proteins. Nano-scale capillary LC/MS/MS techniques (using 50-100 pm diameter columns, operating at flow rates of 20-500 nL/min) are... 

Tandem mass spectrometry is replacing the Edman method as a sequencing tool. Due to the fact that peptides possess both basic and acid functional groups, they readily form [M + H]+ and [M - H] ions under FAB, ESI, and MALDI conditions, which can be subjected to CID to yield the partial or complete sequence of the peptide. 

Hsieh, Y Bryant, M.S. Gruela, G. Brisson, J.-M. Korfmacher, W.A. Direct Analysis of Plasma Samples for Drug Discovery Compounds Using Mixed-function Column Liquid Chromatography Tandem Mass Spectrometry, Rapid Commun. Mass Spectrom. 14, 1384-1390 (2000). 

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