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 MassSpectrometer (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”

Oligonucleotide Sequencing 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 compositionhttp://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.

Sleno L, 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