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Tandem Mass Spectrometry. By Jonathan Haltiwanger and Teresa Leslie. What is Mass Spectrometry (MS)?. Analytical technique to determine the elemental composition of a sample Vaporization ionization electric field mass-to-charge (m/z) MS/MS- Tandem Mass Spectrometry
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Tandem Mass Spectrometry By Jonathan Haltiwanger and Teresa Leslie
What is Mass Spectrometry (MS)? • Analytical technique to determine the elemental composition of a sample • Vaporization ionization electric field mass-to-charge (m/z) • MS/MS- Tandem Mass Spectrometry • Fragment specific ions to identify resulting fragment ions • Data is used to form structure • Can find specific compounds in complex mixture http://upload.wikimedia.org/wikipedia/commons/e/eb/MS_MS.png
Components: • Q- Quadrupole mass analyzer • Filters sample ions (m/z) • TOF- Time-of-flight mass analyzer • Velocity depends on m/z • q- Radio frequency collision • B- Magnetic sector • E- Electric sector http://www.ich.ucl.ac.uk/services_and_facilities/lab_services/mass_spectrometry/images/HPLC_ESI_MS_3.gif
MODE TIME! • Precursor ion scan • Product ion scan • Neutral loss scan • Selected reaction monitoring • Fourier Transform Mass Spectrometer (FTMS)
Los Problemos! • Ionization issues • Ion suppression • Interfering compounds- “iso baric”
How does this apply to us? • Accurate Molecular Weight Measurements • Sample confirmation, purity • Reaction Monitoring • Monitor enzymes • Amino Acid Sequencing • Identification of protein using database “tag” • OligonucleotideSequencing • Post-Translation Modifications- • Glycosylation, phosphorylation, disulfide bridges • Protein Structure • Protein-protein, protein-ligand, protein-DNA
Expanding Newborn Screening • Screens for 30+ diseases • Usually rare, inherited metabolic disorders • Measures acylcarnitine and amino acid levels • Fast, accurate, cheap, and non-invasive • Star-G Project- Information on disorders • Examples: Sickle cell disease, phenylketonuria, maple syrup urine disease http://www.dshs.state.tx.us/lab/nbsHeelstick.jpg
Phenylketonuria (PKU) • Difficulty breaking down phenylalanine • Enzyme phenylalanine hydroxylase absent • Leads to mental retardation, eczema, seizures, and possibly death http://www.bmb.leeds.ac.uk/illingworth/bioc1010/image017.gif http://media.wiley.com/CurrentProtocols/HG/hg1701/hg1701-fig-0002-1-full.jpg
Realms of MS/MS • Biotechnology • Analysis of proteins, oligonucleotides • Pharmaceutical • Drug discovery, drug metabolism • Clinical • Neonatal screening, hemoglobin analysis, drug testing • Environmental • Water quality, food contamination • Geological • Oil composition http://www.astbury.leeds.ac.uk/facil/MStut/mstutorial.htm
Sources: • Mørtz E, O'Connor PB, Roepstorff P, Kelleher NL, Wood TD, McLafferty FW, Mann M (1996). "Sequence tag identification of intact proteins by matching tanden mass spectral data against sequence data bases". Proc. Natl. Acad. Sci. U.S.A. 93 (16): 8264–7. doi:10.1073/pnas.93.16.8264. PMID 8710858. • SlenoL, Volmer DA (2004). "Ion activation methods for tandem mass spectrometry". Journal of mass spectrometry : JMS 39 (10): 1091–112. doi:10.1002/jms.703. PMID 15481084. • Pictures from Wikipedia.com • Other sources are already cited