Complete Protein Characterization Using Top-Down Mass Spectrometry and Ultraviolet Photodissociation
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The top-down approach to proteomics offers compelling advantages due to the potential to provide complete characterization of protein sequence and post-translational modifications. Here we describe the implementation of 193 nm ultraviolet photodissociation (UVPD) in an Orbitrap mass spectrometer for characterization of intact proteins. Near-complete fragmentation of proteins up to 29 kDa is achieved with UVPD including the unambiguous localization of a single residue mutation and several protein modifications on Pin1 (Q13526), a protein implicated in the development of Alzheimer's disease and in cancer pathogenesis. The 5 ns, high-energy activation afforded by UVPD exhibits far less precursor ion-charge state dependence than conventional collision- and electron-based dissociation methods.
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UVPD preserves labile modifications and, unlike ECD and ETD, is charge state independent.
“Ultraviolet photodissociation (UVPD) also preserves labile modification, but unlike ECD and ETD, it is charge state independent [20].”
From Top-down proteomics: challenges, innovations, and applications in basic and clinical research (2020) · cites this paper as [20]
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Cites
Peptide and protein sequence analysis by electron transfer dissociation mass spectrometry
Syka, J. E. P., Coon, J. J., Schroeder, M. J., Shabanowitz, J., & Hunt, D. F. (2004) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0402700101 · Cited by 2,370 · see citing works
Electron Capture Dissociation of Multiply Charged Protein Cations. A Nonergodic Process
Zubarev, R. A., Kelleher, N. L., & McLafferty, F. W. (1998) · Journal of the American Chemical Society · doi:10.1021/ja973478k · Cited by 1,881 · see citing works
Self-citationA human peptidyl–prolyl isomerase essential for regulation of mitosis
Lu, K. P., Hanes, S. D., & Hunter, T. (1996) · Nature · doi:10.1038/380544a0 · Cited by 908 · see citing works
Infrared Multiphoton Dissociation of Large Multiply Charged Ions for Biomolecule Sequencing
Little, D. P., Speir, J. P., Senko, M. W., O’Connor, P. B., & McLafferty, F. W. (1994) · Analytical Chemistry · doi:10.1021/ac00090a004 · Cited by 754 · see citing works
The prolyl isomerase PIN1: a pivotal new twist in phosphorylation signalling and disease
Lu, K. P., & Zhou, X. Z. (2007) · Nature Reviews Molecular Cell Biology · doi:10.1038/nrm2261 · Cited by 682 · see citing works
Top Down versus Bottom Up Protein Characterization by Tandem High-Resolution Mass Spectrometry
Kelleher, N. L., Lin, H., Valaskovic, G. A., Aaserud, D. J., Fridriksson, E. K., & McLafferty, F. W. (1999) · Journal of the American Chemical Society · doi:10.1021/ja973655h · Cited by 606 · see citing works
Self-citationButterfield, D. A., Poon, H. F., St. Clair, D., Keller, J. N., Pierce, W. M., Klein, J. B., & Markesbery, W. R. (2006) · Neurobiology of Disease · doi:10.1016/j.nbd.2005.11.002 · Cited by 377 · see citing works
Michalski, A., Damoc, E., Lange, O., Denisov, E., Nolting, D., Müller, M., Viner, R., Schwartz, J., Remes, P., Belford, M., et al. (2012) · Molecular & Cellular Proteomics · doi:10.1074/mcp.o111.013698 · Cited by 373 · see citing works
Activated Ion Electron Capture Dissociation for Mass Spectral Sequencing of Larger (42 kDa) Proteins
Horn, D. M., Ge, Y. P., & McLafferty, F. W. (2000) · Analytical Chemistry · doi:10.1021/ac000494i · Cited by 333 · see citing works
Extending Top-Down Mass Spectrometry to Proteins with Masses Greater Than 200 Kilodaltons
Han, X., Jin, M., Breuker, K., & McLafferty, F. W. (2006) · Science · doi:10.1126/science.1128868 · Cited by 328 · see citing works
Jez, J. M., Ferrer, J.-L., Bowman, M. E., et al. (2000) · Biochemistry · doi:10.1021/bi991489f · Cited by 299 · see citing works
Nakamura, K., Greenwood, A., Binder, L. I., Bigio, E. H., Denial, S., Nicholson, L. K., Zhou, X. Z., & Lu, K. P. (2012) · Cell · doi:10.1016/j.cell.2012.02.016 · Cited by 255 · see citing works
Rukhsana Sultana, A., Debra Boyd-kimball, A., Poon, H. F., Cai, J., Pierce, W. M. J., Klein, J. B., Markesbery, W. R., Zhou, X. Z., Lu, K. P., & Butterfield, D. A. (2005) · Neurobiology of Aging · doi:10.1016/j.neurobiolaging.2005.05.005 · Cited by 255 · see citing works
Håkansson, K., Chalmers, M. J., Quinn, J. P., McFarland, M. A., Hendrickson, C. L., & Marshall, A. G. (2003) · Analytical Chemistry · doi:10.1021/ac030015q · Cited by 246 · see citing works
Ultraviolet photofragmentation of biomolecular ions
Reilly, J. P. (2009) · Mass Spectrometry Reviews · doi:10.1002/mas.20214 · Cited by 228 · see citing works
Gu, C., Tsaprailis, G., Breci, L. A., et al. (2000) · Analytical Chemistry · doi:10.1021/ac000555c · Cited by 196 · see citing works
Loo, J. A., Edmonds, C. G., & Smith, R. (1991) · Analytical Chemistry · doi:10.1021/ac00021a018 · Cited by 189 · see citing works
Top‐down MS, a powerful complement to the high capabilities of proteolysis proteomics
McLafferty, F. W., Breuker, K., Jin, M., Han, X., Infusini, G., Jiang, H., Kong, X., & Begley, T. P. (2007) · FEBS Journal · doi:10.1111/j.1742-4658.2007.06147.x · Cited by 187 · see citing works
Probing Proline Effect in CID of Protonated Peptides
Vaisar, T., & Urban, J. (1996) · Journal of Mass Spectrometry · doi:10.1002/(sici)1096-9888(199610)31:10 · Cited by 168 · see citing works
Bowers, W. D., Delbert, S. S., Hunter, R. L., et al. (1984) · Journal of the American Chemical Society · doi:10.1021/ja00335a094 · Cited by 144 · see citing works
The pros and cons of peptide-centric proteomics
Duncan, M. W., Aebersold, R. H., & Caprioli, R. M. (2010) · Nature Biotechnology · doi:10.1038/nbt0710-659 · Cited by 142 · see citing works
Structural Basis for High-Affinity Peptide Inhibition of Human Pin1
Zhang, Y., Daum, S., Wildemann, D., et al. (2007) · ACS Chemical Biology · doi:10.1021/cb7000044 · Cited by 138 · see citing works
Self-citationAutomated assignment of charge states from resolved isotopic peaks for multiply charged ions
Senko, M. W., Beu, S. C., & McLafferty, F. W. (1995) · Journal of the American Society for Mass Spectrometry · doi:10.1016/1044-0305(94)00091-d · Cited by 119 · see citing works
Ultrafast Ultraviolet Photodissociation at 193 nm and its Applicability to Proteomic Workflows
Madsen, J. A., Boutz, D. R., & Brodbelt, J. S. (2010) · Journal of Proteome Research · doi:10.1021/pr100515x · Cited by 114 · see citing works
Self-citation193 nm photodissociation of larger multiply-charged biomolecules
Guan, Z., Kelleher, N. L., O’Connor, P. B., Aaserud, D. J., Little, D. P., & McLafferty, F. W. (1996) · International Journal of Mass Spectrometry and Ion Processes · doi:10.1016/s0168-1176(96)04399-6 · Cited by 113 · see citing works
Self-citationAdvancements in Top-Down Proteomics
Zhou, H., Ning, Z., Starr, A. E., Abu‐Farha, M., & Figeys, D. (2011) · Analytical Chemistry · doi:10.1021/ac202882y · Cited by 94 · see citing works
Capriotti, A. L., Cavaliere, C., Foglia, P., Samperi, R., & Laganà, A. (2011) · Journal of Chromatography A · doi:10.1016/j.chroma.2011.05.094 · Cited by 91 · see citing works
Williams, E. R., Furlong, J. J. P., & McLafferty, F. W. (1990) · Journal of the American Society for Mass Spectrometry · doi:10.1016/1044-0305(90)85003-5 · Cited by 91 · see citing works
Peptide photodissociation at 157 nm in a linear ion trap mass spectrometer
Kim, T., Thompson, M. S., & Reilly, J. P. (2005) · Rapid Communications in Mass Spectrometry · doi:10.1002/rcm.1969 · Cited by 87 · see citing works
Rukhsana Sultana, A., & Butterfield, D. A. (2012) · Journal of Alzheimer s Disease · doi:10.3233/jad-2012-129018 · Cited by 83 · see citing works
Peptide sequence analysis by laser photodissociation Fourier transform mass spectrometry
Hunt, D. F., Shabanowitz, J., & Yates, J. R. (1987) · Journal of the Chemical Society Chemical Communications · doi:10.1039/c39870000548 · Cited by 79 · see citing works
Sze, S. K., Ge, Y., Oh, H. B., & McLafferty, F. W. (2003) · Analytical Chemistry · doi:10.1021/ac020446t · Cited by 72 · see citing works
Ledvina, A. R., Beauchene, N. A., McAlister, G. C., Syka, J. E. P., Schwartz, J. C., Griep‐Raming, J., Westphall, M. S., & Coon, J. J. (2010) · Analytical Chemistry · doi:10.1021/ac1020358 · Cited by 71 · see citing works
Self-citationFactors that impact the vacuum ultraviolet photofragmentation of peptide ions
Thompson, M. S., Cui, W., & Reilly, J. P. (2007) · Journal of the American Society for Mass Spectrometry · doi:10.1016/j.jasms.2007.04.015 · Cited by 64 · see citing works
Morgan, J. W., & Russell, D. H. (2006) · Journal of the American Society for Mass Spectrometry · doi:10.1016/j.jasms.2006.02.004 · Cited by 44 · see citing works
Implementing Photodissociation in an Orbitrap Mass Spectrometer
Vasicek, L. A., Ledvina, A. R., Shaw, J., Griep‐Raming, J., Westphall, M. S., Coon, J. J., & Brodbelt, J. S. (2011) · Journal of the American Society for Mass Spectrometry · doi:10.1007/s13361-011-0119-7 · Cited by 41 · see citing works
Self-citationXu, G. G., Zhang, Y., Mercedes-Camacho, A. Y., et al. (2011) · Biochemistry · doi:10.1021/bi201055c · Cited by 38 · see citing works
Self-citationRaspopov, S. A., El-Faramawy, A., Thomson, B. A., et al. (2006) · Analytical Chemistry · doi:10.1021/ac052248i · Cited by 38 · see citing works
Moon, J. H., Shin, Y. S., Jung, H. S., et al. (2007) · Rapid Communications in Mass Spectrometry · doi:10.1002/rcm.2855 · Cited by 36 · see citing works
Yoon, S. H., Chung, Y. J., & Kim, M. S. (2008) · Journal of the American Society for Mass Spectrometry · doi:10.1016/j.jasms.2008.02.003 · Cited by 20 · see citing works
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- [35]Ping Lu K Hanes SD Hunter T Nature 1996 380 544 547 8606777
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Progress in Top-Down Proteomics and the Analysis of Proteoforms
Toby, T. K., Fornelli, L., & Kelleher, N. L. (2016) · Annual Review of Analytical Chemistry · doi:10.1146/annurev-anchem-071015-041550 · Cited by 576 · see citing works
Self-citationHigh-Resolution Native Mass Spectrometry
Tamara, S., den Boer, M. A., & Heck, A. J. R. (2022) · Chemical Reviews · doi:10.1021/acs.chemrev.1c00212 · Cited by 511 · see citing works
Best practices and benchmarks for intact protein analysis for top-down mass spectrometry
Donnelly, D. P., Rawlins, C. M., DeHart, C. J., Fornelli, L., Schachner, L. F., Lin, Z., Lippens, J. L., Aluri, K. C., Sarin, R., Chen, B., et al. (2019) · Nature Methods · doi:10.1038/s41592-019-0457-0 · Cited by 377 · see citing works
Self-citationHendrickson, C. L., Quinn, J. P., Kaiser, N. K., Smith, D. F., Blakney, G. T., Chen, T., Marshall, A. G., Weisbrod, C. R., & Beu, S. C. (2015) · Journal of the American Society for Mass Spectrometry · doi:10.1007/s13361-015-1182-2 · Cited by 278 · see citing works
ProSight Lite: Graphical software to analyze top‐down mass spectrometry data
Fellers, R. T., Greer, J. B., Early, B. P., Yu, X., LeDuc, R. D., Kelleher, N. L., & Thomas, P. M. (2015) · PROTEOMICS · doi:10.1002/pmic.201400313 · Cited by 247 · see citing works
Self-citationThe diverse and expanding role of mass spectrometry in structural and molecular biology
Lössl, P., van de Waterbeemd, M., & Heck, A. J. (2016) · The EMBO Journal · doi:10.15252/embj.201694818 · Cited by 222 · see citing works
Top‐down proteomics in health and disease: Challenges and opportunities
Gregorich, Z. R., & Ge, Y. (2014) · PROTEOMICS · doi:10.1002/pmic.201300432 · Cited by 217 · see citing works
Top-Down Proteomics: Ready for Prime Time?
Chen, B., Brown, K. A., Lin, Z., & Ge, Y. (2018) · Analytical Chemistry · doi:10.1021/acs.analchem.7b04747 · Cited by 210 · see citing works
Belov, M. E., Damoc, E., Denisov, E., Compton, P. D., Horning, S., Makarov, A. A., & Kelleher, N. L. (2013) · Analytical Chemistry · doi:10.1021/ac4029328 · Cited by 175 · see citing works
Self-citationFornelli, L., Srzentić, K., Huguet, R., Mullen, C., Sharma, S., Zabrouskov, V., Fellers, R. T., Durbin, K. R., Compton, P. D., & Kelleher, N. L. (2018) · Analytical Chemistry · doi:10.1021/acs.analchem.8b00984 · Cited by 150 · see citing works
Self-citationTop-down proteomics: challenges, innovations, and applications in basic and clinical research
Brown, K. A., Melby, J. A., Roberts, D. S., & Ge, Y. (2020) · Expert Review of Proteomics · doi:10.1080/14789450.2020.1855982 · Cited by 152 · see citing works
McCool, E. N., Lubeckyj, R. A., Shen, X., Chen, D., Kou, Q., Liu, X., & Sun, L. (2018) · Analytical Chemistry · doi:10.1021/acs.analchem.8b00693 · Cited by 117 · see citing works
Top-down Proteomics: Technology Advancements and Applications to Heart Diseases
Cai, W., Tucholski, T. M., Gregorich, Z. R., & Ge, Y. (2016) · Expert Review of Proteomics · doi:10.1080/14789450.2016.1209414 · Cited by 99 · see citing works
Cleland, T. P., DeHart, C. J., Fellers, R. T., VanNispen, A. J., Greer, J. B., LeDuc, R. D., Parker, W. R., Thomas, P. M., Kelleher, N. L., & Brodbelt, J. S. (2017) · Journal of Proteome Research · doi:10.1021/acs.jproteome.7b00043 · Cited by 96 · see citing works
Self-citationAnderson, L. C., DeHart, C. J., Kaiser, N. K., Fellers, R. T., Smith, D. F., Greer, J. B., LeDuc, R. D., Blakney, G. T., Thomas, P. M., Kelleher, N. L., et al. (2017) · Journal of Proteome Research · doi:10.1021/acs.jproteome.6b00696 · Cited by 94 · see citing works
Self-citationFornelli, L., Durbin, K. R., Fellers, R. T., Early, B. P., Greer, J. B., LeDuc, R. D., Compton, P. D., & Kelleher, N. L. (2017) · Journal of Proteome Research · doi:10.1021/acs.jproteome.6b00698 · Cited by 88 · see citing works
Self-citationTakemori, A., Butcher, D. S., Harman, V. M., Brownridge, P., Shima, K., Higo, D., Ishizaki, J., Hasegawa, H., Suzuki, J., Yamashita, M., et al. (2020) · Journal of Proteome Research · doi:10.1021/acs.jproteome.0c00303 · Cited by 90 · see citing works
LeDuc, R. D., Fellers, R. T., Early, B. P., Greer, J. B., Thomas, P. M., & Kelleher, N. L. (2014) · Journal of Proteome Research · doi:10.1021/pr401277r · Cited by 85 · see citing works
Self-citationShen, X., Kou, Q., Guo, R., Yang, Z., Chen, D., Liu, X., Hong, H., & Sun, L. (2018) · Analytical Chemistry · doi:10.1021/acs.analchem.8b02725 · Cited by 78 · see citing works
Han, X., Wang, Y., Aslanian, A., Bern, M., Lavallée-Adam, M., & Yates, J. R. (2014) · Analytical Chemistry · doi:10.1021/ac503439n · Cited by 77 · see citing works
Proteomics in heart failure: top-down or bottom-up?
Gregorich, Z. R., Chang, Y.-H., & Ge, Y. (2014) · Pflügers Archiv - European Journal of Physiology · doi:10.1007/s00424-014-1471-9 · Cited by 69 · see citing works
Shen, Y., Tolić, N., Piehowski, P. D., Shukla, A. K., Kim, S., Zhao, R., Qu, Y., Robinson, E., Smith, R. D., & Paša-Tolić, L. (2017) · Journal of Chromatography A · doi:10.1016/j.chroma.2017.01.008 · Cited by 63 · see citing works
Zhou, M., Uwugiaren, N., Williams, S. M., Moore, R. J., Zhao, R., Goodlett, D., Dapic, I., Paša-Tolić, L., & Zhu, Y. (2020) · Analytical Chemistry · doi:10.1021/acs.analchem.0c00467 · Cited by 62 · see citing works
Gargano, A. F. G., Shaw, J. B., Zhou, M., Wilkins, C. S., Fillmore, T. L., Moore, R. J., Somsen, G. W., & Paša-Tolić, L. (2018) · Journal of Proteome Research · doi:10.1021/acs.jproteome.8b00458 · Cited by 53 · see citing works
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Greisch, J.-F., Tamara, S., Scheltema, R. A., Maxwell, H. W. R., Fagerlund, R. D., Fineran, P. C., Tetter, S., Hilvert, D., & Heck, A. J. R. (2019) · Chemical Science · doi:10.1039/c9sc01857c · Cited by 47 · see citing works
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Gargano, A. F. G., Roca, L. S., Fellers, R. T., Bocxe, M., Domínguez-Vega, E., & Somsen, G. W. (2018) · Analytical Chemistry · doi:10.1021/acs.analchem.8b00382 · Cited by 52 · see citing works
Self-citationRiley, N. M., Sikora, J. W., Seckler, H. S., Greer, J. B., Fellers, R. T., LeDuc, R. D., Westphall, M. S., Thomas, P. M., Kelleher, N. L., & Coon, J. J. (2018) · Analytical Chemistry · doi:10.1021/acs.analchem.8b01638 · Cited by 43 · see citing works
Self-citationChen, B., Hwang, L., Ochowicz, W., Lin, Z., Guardado-Alvarez, T. M., Cai, W., Xiu, L., Dani, K., Colah, C., Jin, S., et al. (2017) · Chemical Science · doi:10.1039/c6sc05435h · Cited by 43 · see citing works
Anderson, L. C., English, A. M., Wang, W.-H., Bai, D. L., Shabanowitz, J., & Hunt, D. F. (2015) · International Journal of Mass Spectrometry · doi:10.1016/j.ijms.2014.06.023 · Cited by 37 · see citing works
Sipe, S. N., Patrick, J. W., Laganowsky, A., & Brodbelt, J. S. (2020) · Analytical Chemistry · doi:10.1021/acs.analchem.9b03689 · Cited by 39 · see citing works
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Chen, B., Lin, Z., Zhu, Y., Jin, Y., Larson, E., Xu, Q., Fu, C., Zhang, Z., Zhang, Q., Pritts, W. A., et al. (2019) · Analytical Chemistry · doi:10.1021/acs.analchem.9b02194 · Cited by 38 · see citing works
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Kachuk, C., & Doucette, A. A. (2018) · Journal of Proteomics · doi:10.1016/j.jprot.2017.03.002 · Cited by 39 · see citing works
McIlwain, S. J., Wu, Z., Wetzel, M., Belongia, D., Jin, Y., Wenger, K., Ong, I. M., & Ge, Y. (2020) · Journal of the American Society for Mass Spectrometry · doi:10.1021/jasms.0c00035 · Cited by 27 · see citing works
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McCool, E. N., Lubeckyj, R., Shen, X., Kou, Q., Liu, X., & Sun, L. (2018) · Journal of Visualized Experiments · doi:10.3791/58644 · Cited by 26 · see citing works
Crittenden, C. M., Novelli, E. T., Mehaffey, M. R., Xu, G. N., Giles, D. H., Fies, W. A., Dalby, K. N., Webb, L. J., & Brodbelt, J. S. (2020) · Journal of the American Society for Mass Spectrometry · doi:10.1021/jasms.0c00066 · Cited by 24 · see citing works
Self-citationRubin, E. J., O'Brien, J. P., Ivanov, P. L., Brodbelt, J. S., & Trent, M. S. (2014) · Molecular Microbiology · doi:10.1111/mmi.12501 · Cited by 21 · see citing works
Self-citation
- Authors
- Shaw, J. B., Li, W., Holden, D. D., Zhang, Y., Griep-Raming, J., Fellers, R. T., Early, B. P., Thomas, P. M., Kelleher, N. L., & Brodbelt, J. S.
- Affiliations
- The University of Texas at Austin (US)
- Thermo Fisher Scientific GmbH, 28199 Bremen, Germany
- Northwestern University (US)
- Corresponding author
- Brodbelt, Jennifer S.
- Venue
- Journal of the American Chemical Society
- Publisher
- American Chemical Society (ACS)
- Published
- 2013-06-04
- Volume
- 135
- Issue
- 34
- Pages
- 12646-12651
- ISSN
- 0002-7863 (ISSN-L)
- 1520-5126
- PMC
- PMC3757099
- OpenAlex
- W1969050666
- Cited by
- 371
- References
- 40
- Citations by year
- 2026: 21 · 2025: 11 · 2024: 24 · 2023: 27 · 2022: 24 · 2021: 25 · 2020: 31 · 2019: 29 · 2018: 35 · 2017: 42 · 2016: 29 · 2015: 27 · 2014: 34 · 2013: 10
- FWCI
- 14.98
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Journal of the American Chemical Society (publishedVersion)
- PubMed (publishedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Institute of General Medical Sciences (R01GM067193, GM 067193)
- Topics
- Physical Sciences › Chemistry › Spectroscopy › Mass Spectrometry Techniques and Applications
- Physical Sciences › Chemistry › Spectroscopy › Advanced Proteomics Techniques and Applications
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Metabolomics and Mass Spectrometry Studies
- Keywords
- top-down proteomics, ultraviolet photodissociation, protein fragmentation, post-translational modification, Pin1, site-directed mutagenesis, 193 nm photodissociation, charge state dependence, Alzheimer's disease
- MeSH terms
- NIMA-Interacting Peptidylprolyl Isomerase, Humans, Models, Molecular, Mass Spectrometry, Ultraviolet Rays, Peptidylprolyl Isomerase, Proteomics, Photochemical Processes
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