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Direct characterization of overproduced proteins by native mass spectrometry

Abstract

Proteins derived by recombinant technologies must be characterized to ensure quality, consistency and optimal production. These properties are usually assayed following purification procedures that are time consuming and labor intensive. Here, we describe a native mass spectrometry (MS) approach, direct-MS, for rapid characterization of intact overexpressed proteins immediately from crude samples. In this protocol, we discuss the multiple applications of the method and outline the necessary steps required for sample preparation, data collection and interpretation of results. We begin with the sample preparation workflows, which are relevant for recombinant proteins produced within bacteria, those analyzed straight from crude cell lysate, and secreted proteins generated in eukaryotic expression systems that are assessed directly from the growth culture medium. We continue with the mass acquisition steps that enable immediate definition of properties such as expressibility, solubility, assembly state, folding, overall structure, stability, post-translational modifications and associations with biomolecules. We demonstrate the applicability of the method by presenting the characterization of a computationally designed toxin–antitoxin heterodimer, activity and protein-interaction determination of a regulatory protein and detailed glycosylation analysis of a designed intact antibody. Overall, we describe a simple and rapid protocol that is relevant to both prokaryotic and eukaryotic expression systems and can be carried out on multiple mass spectrometers, such as Orbitrap and quadrupole time-of-flight (QTOF)-based mass spectroscopy platforms, that enable intact protein detection. The procedure takes from 30 min to several hours, from sample collection to data acquisition, depending on the depth of MS analysis.

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Fig. 1: An overview of the direct-MS workflow for analysis of recombinant proteins from crude samples.
Fig. 2: Types of common glycosylations and their masses.
Fig. 3: Analysis of proteins in crude samples from prokaryotic and eukaryotic expression systems.
Fig. 4: Crude samples may require dilution for efficient MS measurements.
Fig. 5: The detection limit of a protein in crude samples is ~1 µM.
Fig. 6: Direct-MS analysis of a secreted antibody unravels its multiple co-existing forms.
Fig. 7: The effect of induction time and culture volume on the analysis of recombinant proteins in crude samples.
Fig. 8: Effect of ionic strength on the spectra of a recombinant antibody.
Fig. 9: Ion mobility measurements and representative mass spectra from purified and crude samples of HSA.
Fig. 10: Effects of ammonium acetate concentration and collision energy on the spectra of the protein phosphotriesterase (PTE).
Fig. 11: Effect of resolution on the measured spectra of CBM3a.
Fig. 12: Pairwise interactions of strength and sequence mapping can be performed in crude samples.
Fig. 13: Determining RAB1A activity and interactions in crude lysates by native MS.
Fig. 14: Detailed analysis of antibody glycosylation.

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Data availability

The datasets generated during the current study are available from the corresponding author upon reasonable request.

References

  1. Adrio, J. L. & Demain, A. L. Microbial enzymes: tools for biotechnological processes. Biomolecules 4, 117–139 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  2. Carter, P. J. Introduction to current and future protein therapeutics: a protein engineering perspective. Exp. Cell Res. 317, 1261–1269 (2011).

    Article  CAS  PubMed  Google Scholar 

  3. Gainza-Cirauqui, P. & Correia, B. E. Computational protein design-the next generation tool to expand synthetic biology applications. Curr. Opin. Biotechnol. 52, 145–152 (2018).

    Article  CAS  PubMed  Google Scholar 

  4. Assenberg, R., Wan, P. T., Geisse, S. & Mayr, L. M. Advances in recombinant protein expression for use in pharmaceutical research. Curr. Opin. Struct. Biol. 23, 393–402 (2013).

    Article  CAS  PubMed  Google Scholar 

  5. Holtzhauer, M. Basic Methods for the Biochemical Lab (Springer, 2006).

  6. Miles, A. J. & Wallace, B. A. Biophysical Characterization of Proteins in Developing Biopharmaceuticals (Elsevier, 2015).

  7. Kay, L. E. NMR studies of protein structure and dynamics. J. Magn. Reson. 173, 193–207 (2005).

    Article  CAS  PubMed  Google Scholar 

  8. Ben-Nissan, G. et al. Rapid characterization of secreted recombinant proteins by native mass spectrometry. Commun. Biol. 1, 213 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  9. Cveticanin, J. et al. Estimating interprotein pairwise interaction energies in cell lysates from a single native mass spectrum. Anal. Chem. 90, 10090–10094 (2018).

    Article  CAS  PubMed  Google Scholar 

  10. Gan, J. et al. Native mass spectrometry of recombinant proteins from crude cell lysates. Anal. Chem. 89, 4398–4404 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Ghaemmaghami, S. & Oas, T. G. Quantitative protein stability measurement in vivo. Nat. Struct. Biol. 8, 879–882 (2001).

    Article  CAS  PubMed  Google Scholar 

  12. Larsen, M. R., Trelle, M. B., Thingholm, T. E. & Jensen, O. N. Analysis of posttranslational modifications of proteins by tandem mass spectrometry. Biotechniques 40, 790–798 (2006).

    Article  CAS  PubMed  Google Scholar 

  13. Eyers, C. E. & Gaskel, S. J. Mass Spectrometry to Identify Posttranslational Function and Types of Posttranslational Modifications (John Wiley & Sons, 2008).

  14. Christensen, D. G. et al. Mechanisms, detection, and relevance of protein acetylation in prokaryotes. mBio 10, e02708-18 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  15. St-Denis, N. & Gingras, A. C. Mass spectrometric tools for systematic analysis of protein phosphorylation. Prog. Mol. Biol. Transl. Sci. 106, 3–32 (2012).

    Article  CAS  PubMed  Google Scholar 

  16. Zhou, Q. & Qiu, H. the mechanistic impact of N-glycosylation on stability, pharmacokinetics, and immunogenicity of therapeutic proteins. J. Pharm. Sci. 108, 1366–1377 (2019).

    Article  CAS  PubMed  Google Scholar 

  17. Hernandez, H. & Robinson, C. V. Determining the stoichiometry and interactions of macromolecular assemblies from mass spectrometry. Nat. Protoc. 2, 715–726 (2007).

    Article  CAS  PubMed  Google Scholar 

  18. Wu, L. & Han, D. K. Overcoming the dynamic range problem in mass spectrometry-based shotgun proteomics. Expert Rev. Proteom. 3, 611–619 (2006).

    Article  CAS  Google Scholar 

  19. Rose, R. J., Damoc, E., Denisov, E., Makarov, A. & Heck, A. J. High-sensitivity Orbitrap mass analysis of intact macromolecular assemblies. Nat. Methods 9, 1084–1086 (2012).

    Article  CAS  PubMed  Google Scholar 

  20. Chernushevich, I. V. & Thomson, B. A. Collisional cooling of large ions in electrospray mass spectrometry. Anal. Chem. 76, 1754–1760 (2004).

    Article  CAS  PubMed  Google Scholar 

  21. Giles, K. et al. Applications of a travelling wave-based radio-frequency-only stacked ring ion guide. Rapid Commun. Mass Spectrom. 18, 2401–2414 (2004).

    Article  CAS  PubMed  Google Scholar 

  22. Rosano, G. L. & Ceccarelli, E. A. Recombinant protein expression in Escherichia coli: advances and challenges. Front. Microbiol. 5, 172 (2014).

    PubMed  PubMed Central  Google Scholar 

  23. Dumont, J., Euwart, D., Mei, B., Estes, S. & Kshirsagar, R. Human cell lines for biopharmaceutical manufacturing: history, status, and future perspectives. Crit. Rev. Biotechnol. 36, 1110–1122 (2016).

    Article  CAS  PubMed  Google Scholar 

  24. Kebarle, P. & Verkerk, U. H. Electrospray: from ions in solution to ions in the gas phase, what we know now. Mass Spectrom. Rev. 28, 898–917 (2009).

    Article  CAS  PubMed  Google Scholar 

  25. Cech, N. B. & Enke, C. G. Practical implications of some recent studies in electrospray ionization fundamentals. Mass Spectrom. Rev. 20, 362–387 (2001).

    Article  CAS  PubMed  Google Scholar 

  26. Menetret, J. F. et al. Ribosome binding of a single copy of the SecY complex: implications for protein translocation. Mol. Cell 28, 1083–1092 (2007).

    Article  CAS  PubMed  Google Scholar 

  27. Flick, T. G., Cassou, C. A., Chang, T. M. & Williams, E. R. Solution additives that desalt protein ions in native mass spectrometry. Anal. Chem. 84, 7511–7517 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Hashimoto, K. & Panchenko, A. R. Mechanisms of protein oligomerization, the critical role of insertions and deletions in maintaining different oligomeric states. Proc. Natl Acad. Sci. USA 107, 20352–20357 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Dixit, S. M., Polasky, D. A. & Ruotolo, B. T. Collision induced unfolding of isolated proteins in the gas phase: past, present, and future. Curr. Opin. Chem. Biol. 42, 93–100 (2018).

    Article  CAS  PubMed  Google Scholar 

  30. Ruotolo, B. T., Benesch, J. L. P., Sandercock, A. M., Hyung, S.-J. & Robinson, C. V. Ion mobility–mass spectrometry analysis of large protein complexes. Nat. Protoc. 3, 1139–1152 (2008).

    Article  CAS  PubMed  Google Scholar 

  31. Toby, T. K. et al. A comprehensive pipeline for translational top-down proteomics from a single blood draw. Nat. Protoc. 14, 119–152 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. van de Waterbeemd, M. et al. Dissecting ribosomal particles throughout the kingdoms of life using advanced hybrid mass spectrometry methods. Nat. Commun. 9, 2493 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  33. Kaltashov, I. A. & Mohimen, A. Estimates of protein surface areas in solution by electrospray ionization mass spectrometry. Anal. Chem. 77, 5370–5379 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Sokolovski, M. et al. Measuring inter-protein pairwise interaction energies from a single native mass spectrum by double-mutant cycle analysis. Nat. Commun. 8, 212 (2017).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  35. Chorev, D. S. et al. Protein assemblies ejected directly from native membranes yield complexes for mass spectrometry. Science 362, 829–834 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Ben-Nissan, G. et al. Triple-stage mass spectrometry unravels the heterogeneity of an endogenous protein complex. Anal. Chem. 89, 4708–4715 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Allison, T. M. et al. Quantifying the stabilizing effects of protein-ligand interactions in the gas phase. Nat. Commun. 6, 8551 (2015).

    Article  CAS  PubMed  Google Scholar 

  38. Marzahn, M. R. et al. Higher-order oligomerization promotes localization of SPOP to liquid nuclear speckles. EMBO J. 35, 1254–1275 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Xing, G., Zhang, J., Chen, Y. & Zhao, Y. Identification of four novel types of in vitro protein modifications. J. Proteome Res. 7, 4603–4608 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Francis, G. L. Albumin and mammalian cell culture: implications for biotechnology applications. Cytotechnology 62, 1–16 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Darfler, F. J. A protein-free medium for the growth of hybridomas and other cells of the immune system. Vitr. Cell Dev. Biol. 26, 769–778 (1990).

    Article  CAS  Google Scholar 

  42. Valdés, R., González, M., Geada, D. & Fernández, E. Assessment of a protein-free medium performance in dfferent cell culture vessels using mouse hybridomas to produce monoclonal antibodies. Pharm. Anal. Acta 3, 155 (2012).

    Article  CAS  Google Scholar 

  43. Kirshenbaum, N., Michaelevski, I. & Sharon, M. Analyzing large protein complexes by structural mass spectrometry. J. Vis. Exp. 2010, 1954 (2010).

    Google Scholar 

  44. Lossl, P., Snijder, J. & Heck, A. J. Boundaries of mass resolution in native mass spectrometry. J. Am. Soc. Mass Spectrom. 25, 906–917 (2014).

    Article  PubMed  CAS  Google Scholar 

  45. Netzer, R. et al. Ultrahigh specificity in a network of computationally designed protein-interaction pairs. Nat. Commun. 9, 5286 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  46. Walsh, G. Biopharmaceutical benchmarks 2018. Nat. Biotechnol. 36, 1136–1145 (2018).

    Article  CAS  PubMed  Google Scholar 

  47. Tiller, K. E. & Tessier, P. M. Advances in antibody design. Annu. Rev. Biomed. Eng. 17, 191–216 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Liu, H. et al. In vitro and in vivo modifications of recombinant and human IgG antibodies. mAbs 6, 1145–1154 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  49. Qiu, H. et al. Engineering an anti-CD52 antibody for enhanced deamidation stability. mAbs 11, 1266-1275 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Jung, S. Y. et al. Complications in the assignment of 14 and 28 Da mass shift detected by mass spectrometry as in vivo methylation from endogenous proteins. Anal. Chem. 80, 1721–1729 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Afjehi-Sadat, L. & Garcia, B. A. Comprehending dynamic protein methylation with mass spectrometry. Curr. Opin. Chem. Biol. 17, 12–19 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Brown, C. W. et al. Large-scale analysis of post-translational modifications in E. coli under glucose-limiting conditions. BMC Genomics 18, 301 (2017).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  53. Raftery, M. J. Determination of oxidative protein modifications using mass spectrometry. Redox Rep. 19, 140–147 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Wingfield, P. T. N-terminal methionine processing. Curr. Protoc. Protein Sci. 88, 6.14.11–16.14.13 (2017).

    Article  CAS  Google Scholar 

  55. Lorence, A. Recombinant Gene Expression (Humana Press, 2012).

  56. Liu, H. & May, K. Disulfide bond structures of IgG molecules: structural variations, chemical modifications and possible impacts to stability and biological function. mAbs 4, 17–23 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Maverakis, E. et al. Glycans in the immune system and The Altered Glycan Theory of Autoimmunity: a critical review. J. Autoimmun. 57, 1–13 (2015).

    Article  CAS  PubMed  Google Scholar 

  58. Manneberg, M., Friedlein, A., Kurth, H., Lahm, H. W. & Fountoulakis, M. Structural analysis and localization of the carbohydrate moieties of a soluble human interferon gamma receptor produced in baculovirus-infected insect cells. Protein Sci. 3, 30–38 (1994).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Morelle, W. & Michalski, J. C. Analysis of protein glycosylation by mass spectrometry. Nat. Protoc. 2, 1585–1602 (2007).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

We thank E. Morag and E. Bayer, for providing us with the pPICK9 plasmid for CBM3a expression, and Y. Peleg, for providing the pPICK9 plasmid for HSA expression. We are grateful to O. Kersonsky and S. Fleishman for providing us with the plasmid for the expression of MBP-PTE. We also thank S. Warszawski, A. Katz, R. Diskin and S. J. Fleishman, for providing us with the growth media containing secreted antibodies, and R. Diskin, H. Cohen-Dvashi, M. Yona and T. Unger, for providing us with the growth media containing the secreted TfR1. We are also grateful for the support of a Starting Grant from the European Research Council (ERC) (Horizon 2020/ERC grant agreement no. 636752) and for Israel Science Foundation (ISF) grant 300/17. M.S. is the Aharon and Ephraim Katzir Memorial Professorial Chair.

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S.V., G.B.-N. and M.S. designed the experiments. S.V. and G.B.-N performed the experiments. S.V., G.B.-N. and M.S. analyzed the data. M.S., G.B.-N. and S.V. wrote and edited the manuscript.

Corresponding author

Correspondence to Michal Sharon.

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Peer review information Nature Protocols thanks Michael Landreh and other anonymous reviewer(s) for their contribution to the peer review of this work.

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Key reference using this protocol

Gan, J. et al. Anal. Chem. 89, 4398–4404 (2017): https://doi.org/10.1021/acs.analchem.7b00398

Key data used in this protocol

Ben-Nissan, G. et al. Commun. Biol. 1, 213 (2018): https://doi.org/10.1038/s42003-018-0231-3

Cveticanin, J. et al. Anal. Chem. 90, 10090–10094 (2018): https://doi.org/10.1021/acs.analchem.8b02349

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Vimer, S., Ben-Nissan, G. & Sharon, M. Direct characterization of overproduced proteins by native mass spectrometry. Nat Protoc 15, 236–265 (2020). https://doi.org/10.1038/s41596-019-0233-8

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