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Biomarker discovery by automatic annotation of N-glycan species in MALDI-TOF-TOF spectra Chuan-Yih, Yu 2010-4-8 Capstone Advisor: Prof. Haixu Tang
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Introduction Post-Translation Modification (PTM) –Nitrosylation –Phosphorylation –Glycosolation 50% of all eukaryotic proteins are glycosylated 1 1.Apweiler, R., H. Hermjakob, and N. Sharon, On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database. Biochim Biophys Acta, 1999. 1473(1): p. 4-8
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Glycoprotein Protein glycosylation –N-linked glycosylation Core structure – 2 GlcNac + 3 Man Asn-X-Ser or Asn-X-Thr, X can be any but Pro Glycosylation before folding –O-linked glycosylation Core structures Serine or Threonine Glycosylation after folding
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Monosaccharides Building blocks Diverse linage Three types N-linked glycan –High mannose –Complex –Hybrid 412 combinations ->7,000 structures 1 Graphs: Varki, A., Essentials of glycobiology. 2nd ed. 2009, Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory Press. xxix, 784 p NameMolecular formula/ Structure Mannose (Man)C 6 H 12 O 6 Galactose (Gal)C 6 H 12 O 6 Fucose (Fuc)C 6 H 12 O 5 GlcNacC 8 H 15 NO 6 NeuNACC 11 H 19 NO 9 NeuNGCC 11 H 19 NO 10 1.Krambeck, F.J. and M.J. Betenbaugh, A mathematical model of N-linked glycosylation. Biotechnol Bioeng, 2005. 92(6): p. 711-28.
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Mass Spectrometry Wright scale of molecular Ion Source –Electrospray ionization (ESI) –Matrix-assisted laser desorption/ionization (MALDI) Mass Analyzer –Time of flight (TOF) –Quadrupole –Fourier transform mass spectrometry (FTMS) Detector –Charge induced or the current produced
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MALDI-TOF-TOF Graph:MALDI-TOF Mass Analysis. (2008, 11 16). Retrieved May 2, 2009, from The Protein Facility of the Iowa State University Office of Biotechnology www.protein.iastate.edu/maldi.html www.protein.iastate.edu/maldi.html
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Problem Isotope pattern overlap –Permethylated, Add Sodium 2 GlcNac + 9 Man = 2,396.18 7 GlcNac + 3 Man = 2,397.22 High-throughput glycans screening –Find significant differences between groups of sample Graphs: Isotope Pattern Calculator v4.0 http://yanjunhua.tripod.com/pattern.htmhttp://yanjunhua.tripod.com/pattern.htm http://en.wikipedia.org/wiki/Carbon
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Major Features Glycans profile correlation –Report scores for non-overlap and overlap profile –Glycans examination Glycan profiling comparison –Report significant glycan between groups –Glycans biomarker discovery
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Glycans Profile Correlation For each glycan combination –412 different glycan combinations –Generate a theoretical isotope pattern –Calculate the correlation for following cases Glycans Glycans + Glycans, linear combination applied Glycans + Unknown, linear combination applied Mercury algorithm 1 1.Rockwood, A., S. Van Orden, and R. Smith, Rapid Calculation of Isotope Distributions. Analytical Chemistry, 1995. 67: p. 2699-2704.
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Three Cases Experiment spectrum Glycans αβ α β Unknown Score
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Glycan Profiling Comparison Multiple spectra comparison Biomarker discovery –Given spectrum with several conditions –Find distinct glycans between samples Graph: Ressom, H.W., et al., Analysis of MALDI-TOF mass spectrometry data for discovery of peptide and glycan biomarkers of hepatocellular carcinoma. J Proteome Res, 2008. 7(2): p. 603-10. HCC: Hepatocellular Carcinoma ( Cancer of liver) CLD: Chronic liver disease
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Concept Health spectra (H 1, H 2, H 3 …H k ) Disease spectra (D 1, D 2, D 3 …D k ) Remove the least significant component. Repeat until all the score above threshold. 1.Hastie, T., et al., 'Gene shaving' as a method for identifying distinct sets of genes with similar expression patterns. Genome Biol, 2000. 1(2): p. RESEARCH0003 70% identical with a cutoff at 0.5
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Multi N-Glycan Software Requirement –.net framework 2.0 using C# –C++ runtime –R –Thermo Scientific Xcalibur Input –Spectrum Plain text (Peak list) mzXML 1 RAW ( instrument raw file) –Glycans list CSV file 1.Pedrioli, P., et al., A Common Open Representation of Mass Spectrometry Data and its Application in a Proteomics Research Environment. Nature Biotechnology, 2004. 22(11): p. 1459-1466.
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Software Interface
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Html result export Biomarker discovery setting
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Result Filtered out Can’t find the glycan structure in CFG database
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Result
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Future Works Test on more clinical samples Verify the correlation between glycan modification with disease Perform these tasks on O-linked glycan
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References Apweiler, R., H. Hermjakob, and N. Sharon, On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database. Biochim Biophys Acta, 1999. 1473(1): p. 4-8. Hastie, T., et al., ‘Gene shaving’ as a method for identifying distinct sets of genes with similar expression patterns. Genome Biol, 2000. 1(2): p. RESEARCH0003. Krambeck, F.J. and M.J. Betenbaugh, A mathematical model of N-linked glycosylation. Biotechnol Bioeng, 2005. 92(6): p. 711-28. Pedrioli, P., et al., A Common Open Representation of Mass Spectrometry Data and its Application in a Proteomics Research Environment. Nature Biotechnology, 2004. 22(11): p. 1459-1466. Ressom, H.W., et al., Analysis of MALDI-TOF mass spectrometry data for discovery of peptide and glycan biomarkers of hepatocellular carcinoma. J Proteome Res, 2008. 7(2): p. 603-10. Rockwood, A., S. Van Orden, and R. Smith, Rapid Calculation of Isotope Distributions. Analytical Chemistry, 1995. 67: p. 2699-2704. Tang, Z., et al., Identification of N-glycan serum markers associated with hepatocellular carcinoma from mass spectrometry data. J Proteome Res, 2010. 9(1): p. 104-12. Varki, A., Essentials of glycobiology. 2nd ed. 2009, Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory Press. xxix, 784 p.
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Acknowledge Advisor: Prof. Haixu Tang Co-worker: Anoop Mayampurath Collaborator: Yehia Mechref, Department of Chemistry This work will present in 26 th May, 58 th ASMS Conference Salt Lake City, Utah and submit to the Bioinformatics Application Notes.
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Thank You
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