1
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Steinbach MK, Leipert J, Matzanke T, Tholey A. Digital Microfluidics for Sample Preparation in Low-Input Proteomics. SMALL METHODS 2024:e2400495. [PMID: 39205538 DOI: 10.1002/smtd.202400495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 08/16/2024] [Indexed: 09/04/2024]
Abstract
Low-input proteomics, also referred to as micro- or nanoproteomics, has become increasingly popular as it allows one to elucidate molecular processes in rare biological materials. A major prerequisite for the analytics of minute protein amounts, e.g., derived from low cell numbers, down to single cells, is the availability of efficient sample preparation methods. Digital microfluidics (DMF), a technology allowing the handling and manipulation of low liquid volumes, has recently been shown to be a powerful and versatile tool to address the challenges in low-input proteomics. Here, an overview is provided on recent advances in proteomics sample preparation using DMF. In particular, the capability of DMF to isolate proteomes from cells and small model organisms, and to perform all necessary chemical sample preparation steps, such as protein denaturation and proteolytic digestion on-chip, are highlighted. Additionally, major prerequisites to making these steps compatible with follow-up analytical methods such as liquid chromatography-mass spectrometry will be discussed.
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Affiliation(s)
- Max K Steinbach
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105, Kiel, Germany
| | - Jan Leipert
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105, Kiel, Germany
| | - Theo Matzanke
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105, Kiel, Germany
| | - Andreas Tholey
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105, Kiel, Germany
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2
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Roberts DS, Loo JA, Tsybin YO, Liu X, Wu S, Chamot-Rooke J, Agar JN, Paša-Tolić L, Smith LM, Ge Y. Top-down proteomics. NATURE REVIEWS. METHODS PRIMERS 2024; 4:38. [PMID: 39006170 PMCID: PMC11242913 DOI: 10.1038/s43586-024-00318-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/24/2024] [Indexed: 07/16/2024]
Abstract
Proteoforms, which arise from post-translational modifications, genetic polymorphisms and RNA splice variants, play a pivotal role as drivers in biology. Understanding proteoforms is essential to unravel the intricacies of biological systems and bridge the gap between genotypes and phenotypes. By analysing whole proteins without digestion, top-down proteomics (TDP) provides a holistic view of the proteome and can decipher protein function, uncover disease mechanisms and advance precision medicine. This Primer explores TDP, including the underlying principles, recent advances and an outlook on the future. The experimental section discusses instrumentation, sample preparation, intact protein separation, tandem mass spectrometry techniques and data collection. The results section looks at how to decipher raw data, visualize intact protein spectra and unravel data analysis. Additionally, proteoform identification, characterization and quantification are summarized, alongside approaches for statistical analysis. Various applications are described, including the human proteoform project and biomedical, biopharmaceutical and clinical sciences. These are complemented by discussions on measurement reproducibility, limitations and a forward-looking perspective that outlines areas where the field can advance, including potential future applications.
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Affiliation(s)
- David S Roberts
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, Department of Biological Chemistry, University of California - Los Angeles, Los Angeles, CA, USA
| | | | - Xiaowen Liu
- Deming Department of Medicine, School of Medicine, Tulane University, New Orleans, LA, USA
| | - Si Wu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL, USA
| | | | - Jeffrey N Agar
- Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Ljiljana Paša-Tolić
- Environmental and Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
- Department of Cell and Regenerative Biology, Human Proteomics Program, University of Wisconsin - Madison, Madison, WI, USA
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3
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Takemori A, Kaulich PT, Konno R, Kawashima Y, Hamazaki Y, Hoshino A, Tholey A, Takemori N. GeLC-FAIMS-MS workflow for in-depth middle-down proteomics. Proteomics 2024; 24:e2200431. [PMID: 37548120 DOI: 10.1002/pmic.202200431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/20/2023] [Accepted: 07/20/2023] [Indexed: 08/08/2023]
Abstract
Middle-down proteomics (MDP) is an analytical approach in which protein samples are digested with proteases such as Glu-C to generate large peptides (>3 kDa) that are analyzed by mass spectrometry (MS). This method is useful for characterizing high-molecular-weight proteins that are difficult to detect by top-down proteomics (TDP), in which intact proteins are analyzed by MS. In this study, we applied GeLC-FAIMS-MS, a multidimensional separation workflow that combines gel-based prefractionation with LC-FAIMS MS, for deep MDP. Middle-down peptides generated by optimized limited Glu-C digestion conditions were first size-fractionated by polyacrylamide gel electrophoresis, followed by C4 reversed-phase liquid chromatography separation and additional ion mobility fractionation, resulting in a significant increase in peptide length detectable by MS. In addition to global analysis, the GeLC-FAIMS-MS concept can also be applied to targeted MDP, where only proteins in the desired molecular weight range are gel-fractionated and their Glu-C digestion products are analyzed, as demonstrated by targeted analysis of integrins in exosomes. In-depth MDP achieved by global and targeted GeLC-FAIMS-MS supports the exploration of proteoform information not covered by conventional TDP by increasing the number of detectable protein groups or post-translational modifications (PTMs) and improving the sequence coverage.
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Affiliation(s)
- Ayako Takemori
- Advanced Research Support Center, Institute for Promotion of Science and Technology, Ehime University, Ehime, Japan
| | - Philipp T Kaulich
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Ryo Konno
- Department of Applied Genomics, Kazusa DNA Research Institute, Chiba, Japan
| | - Yusuke Kawashima
- Department of Applied Genomics, Kazusa DNA Research Institute, Chiba, Japan
| | - Yuto Hamazaki
- School of Life Science and Technology, Tokyo Institute of Technology, Kanagawa, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Ayuko Hoshino
- School of Life Science and Technology, Tokyo Institute of Technology, Kanagawa, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Andreas Tholey
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Nobuaki Takemori
- Advanced Research Support Center, Institute for Promotion of Science and Technology, Ehime University, Ehime, Japan
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4
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Po A, Eyers CE. Top-Down Proteomics and the Challenges of True Proteoform Characterization. J Proteome Res 2023; 22:3663-3675. [PMID: 37937372 PMCID: PMC10696603 DOI: 10.1021/acs.jproteome.3c00416] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/09/2023] [Accepted: 10/20/2023] [Indexed: 11/09/2023]
Abstract
Top-down proteomics (TDP) aims to identify and profile intact protein forms (proteoforms) extracted from biological samples. True proteoform characterization requires that both the base protein sequence be defined and any mass shifts identified, ideally localizing their positions within the protein sequence. Being able to fully elucidate proteoform profiles lends insight into characterizing proteoform-unique roles, and is a crucial aspect of defining protein structure-function relationships and the specific roles of different (combinations of) protein modifications. However, defining and pinpointing protein post-translational modifications (PTMs) on intact proteins remains a challenge. Characterization of (heavily) modified proteins (>∼30 kDa) remains problematic, especially when they exist in a population of similarly modified, or kindred, proteoforms. This issue is compounded as the number of modifications increases, and thus the number of theoretical combinations. Here, we present our perspective on the challenges of analyzing kindred proteoform populations, focusing on annotation of protein modifications on an "average" protein. Furthermore, we discuss the technical requirements to obtain high quality fragmentation spectral data to robustly define site-specific PTMs, and the fact that this is tempered by the time requirements necessary to separate proteoforms in advance of mass spectrometry analysis.
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Affiliation(s)
- Allen Po
- Centre
for Proteome Research, Faculty of Health & Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K.
- Department
of Biochemistry, Cell & Systems Biology, Institute of Systems,
Molecular & Integrative Biology, Faculty of Health & Life
Sciences, University of Liverpool, Liverpool L69 7ZB, U.K.
| | - Claire E. Eyers
- Centre
for Proteome Research, Faculty of Health & Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K.
- Department
of Biochemistry, Cell & Systems Biology, Institute of Systems,
Molecular & Integrative Biology, Faculty of Health & Life
Sciences, University of Liverpool, Liverpool L69 7ZB, U.K.
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5
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Pavek JG, Frey BL, Frost DC, Gu TJ, Li L, Smith LM. Cysteine Counting via Isotopic Chemical Labeling for Intact Mass Proteoform Identifications in Tissue. Anal Chem 2023; 95:15245-15253. [PMID: 37791746 PMCID: PMC10637319 DOI: 10.1021/acs.analchem.3c02473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Top-down proteomics, the tandem mass spectrometric analysis of intact proteoforms, is the dominant method for proteoform characterization in complex mixtures. While this strategy produces detailed molecular information, it also requires extensive instrument time per mass spectrum obtained and thus compromises the depth of proteoform coverage that is accessible on liquid chromatography time scales. Such a top-down analysis is necessary for making original proteoform identifications, but once a proteoform has been confidently identified, the extensive characterization it provides may no longer be required for a subsequent identification of the same proteoform. We present a strategy to identify proteoforms in tissue samples on the basis of the combination of an intact mass determination with a measured count of the number of cysteine residues present in each proteoform. We developed and characterized a cysteine tagging chemistry suitable for the efficient and specific labeling of cysteine residues within intact proteoforms and for providing a count of the cysteine amino acids present. On simple protein mixtures, the tagging chemistry yields greater than 98% labeling of all cysteine residues, with a labeling specificity of greater than 95%. Similar results are observed on more complex samples. In a proof-of-principle study, proteoforms present in a human prostate tumor biopsy were characterized. Observed proteoforms, each characterized by an intact mass and a cysteine count, were grouped into proteoform families (groups of proteoforms originating from the same gene). We observed 2190 unique experimental proteoforms, 703 of which were grouped into 275 proteoform families.
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Affiliation(s)
- John G. Pavek
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave. Madison, WI 53706
| | - Brian L. Frey
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave. Madison, WI 53706
| | - Dustin C. Frost
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705
| | - Ting-Jia Gu
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave. Madison, WI 53706
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705
| | - Lloyd M. Smith
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave. Madison, WI 53706
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6
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Rogers HT, Roberts DS, Larson EJ, Melby JA, Rossler KJ, Carr AV, Brown KA, Ge Y. Comprehensive Characterization of Endogenous Phospholamban Proteoforms Enabled by Photocleavable Surfactant and Top-down Proteomics. Anal Chem 2023; 95:13091-13100. [PMID: 37607050 PMCID: PMC10597709 DOI: 10.1021/acs.analchem.3c01618] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Top-down mass spectrometry (MS)-based proteomics has become a powerful tool for analyzing intact proteins and their associated post-translational modifications (PTMs). In particular, membrane proteins play critical roles in cellular functions and represent the largest class of drug targets. However, the top-down MS characterization of endogenous membrane proteins remains challenging, mainly due to their intrinsic hydrophobicity and low abundance. Phospholamban (PLN) is a regulatory membrane protein located in the sarcoplasmic reticulum and is essential for regulating cardiac muscle contraction. PLN has diverse combinatorial PTMs, and their dynamic regulation has significant influence on cardiac contractility and disease. Herein, we have developed a rapid and robust top-down proteomics method enabled by a photocleavable anionic surfactant, Azo, for the extraction and comprehensive characterization of endogenous PLN from cardiac tissue. We employed a two-pronged top-down MS approach using an online reversed-phase liquid chromatography tandem MS method on a quadrupole time-of-flight MS and a direct infusion method via an ultrahigh-resolution Fourier-transform ion cyclotron resonance MS. We have comprehensively characterized the sequence and combinatorial PTMs of endogenous human cardiac PLN. We have shown the site-specific localization of phosphorylation to Ser16 and Thr17 by MS/MS for the first time and the localization of S-palmitoylation to Cys36. Moreover, we applied our method to characterize PLN in disease and reported the significant reduction of PLN phosphorylation in human failing hearts with ischemic cardiomyopathy. Taken together, we have developed a streamlined top-down targeted proteomics method for comprehensive characterization of combinatorial PTMs in PLN toward better understanding the role of PLN in cardiac contractility.
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Affiliation(s)
- Holden T. Rogers
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - David S. Roberts
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Eli J. Larson
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Jake A. Melby
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kalina J. Rossler
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Austin V. Carr
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Surgery, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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7
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Wang Q, Xu T, Fang F, Wang Q, Lundquist P, Sun L. Capillary Zone Electrophoresis-Tandem Mass Spectrometry for Top-Down Proteomics of Mouse Brain Integral Membrane Proteins. Anal Chem 2023; 95:12590-12594. [PMID: 37595263 PMCID: PMC10540247 DOI: 10.1021/acs.analchem.3c02346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023]
Abstract
Mass spectrometry (MS)-based top-down characterization of integral membrane proteins (IMPs) is crucial for understanding their functions in biological processes. However, it is technically challenging due to their low solubility in typical MS-compatible buffers. In this work, for the first time, we developed an efficient capillary zone electrophoresis (CZE)-tandem MS (MS/MS) method for the top-down proteomics (TDP) of IMPs enriched from mouse brains. Our technique employs a sample buffer containing 30% (v/v) formic acid and 60% (v/v) methanol for solubilizing IMPs and utilizes a separation buffer of 30% (v/v) acetic acid and 30% (v/v) methanol for maintaining the solubility of IMPs during CZE separation. Single-shot CZE-MS/MS identified 51 IMP proteoforms from the mouse brain sample. Coupling size exclusion chromatography (SEC) to CZE-MS/MS enabled the identification of 276 IMP proteoforms from the mouse brain sample containing 1-4 transmembrane domains. This proof-of-concept work demonstrates the high potential of CZE-MS/MS for the large-scale TDP of IMPs.
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Affiliation(s)
- Qianjie Wang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, United States
| | - Tian Xu
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Fei Fang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Qianyi Wang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Peter Lundquist
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, United States
| | - Liangliang Sun
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
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8
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Naplekov D, Jadeja S, Fučíková AM, Švec F, Sklenářová H, Lenčo J. Easy, Robust, and Repeatable Online Acid Cleavage of Proteins in Mobile Phase for Fast Quantitative LC-MS Bottom-Up Protein Analysis─Application for Ricin Detection. Anal Chem 2023; 95:12339-12348. [PMID: 37565982 PMCID: PMC10448442 DOI: 10.1021/acs.analchem.3c01772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023]
Abstract
Sample preparation involving the cleavage of proteins into peptides is the first critical step for successful bottom-up proteomics and protein analyses. Time- and labor-intensiveness are among the bottlenecks of the commonly used methods for protein sample preparation. Here, we report a fast online method for postinjection acid cleavage of proteins directly in the mobile phase typically used for LC-MS analyses in proteomics. The chemical cleavage is achieved in 0.1% formic acid within 35 s in a capillary heated to 195 °C installed upstream of the analytical column, enabling the generated peptides to be separated. The peptides generated by the optimized method covered the entire sequence except for one amino acid of trastuzumab used for the method development. The qualitative results are extraordinarily stable, even over a long period of time. Moreover, the method is also suitable for accurate and repeatable quantification. The procedure requires only one manual step, significantly decreasing sample transfer losses. To demonstrate its practical utility, we tested the method for the fast detection of ricin. Ricin can be unambiguously identified from an injection of 10 ng, and the results can be obtained within 7-8 min after receiving a suspicious sample. Because no sophisticated accessories and no additional reagents are needed, the method can be seamlessly transferred to any laboratory for high-throughput proteomic workflows.
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Affiliation(s)
- Denis
K. Naplekov
- Department
of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Siddharth Jadeja
- Department
of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Alena Myslivcová Fučíková
- Department
of Biology, Faculty of Science, University
of Hradec Králové, Hradecká 1285, 500 03 Hradec Králové, Czech Republic
| | - František Švec
- Department
of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Hana Sklenářová
- Department
of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Juraj Lenčo
- Department
of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
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9
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Kang J, Seshadri M, Cupp-Sutton KA, Wu S. Toward the analysis of functional proteoforms using mass spectrometry-based stability proteomics. FRONTIERS IN ANALYTICAL SCIENCE 2023; 3:1186623. [PMID: 39072225 PMCID: PMC11281393 DOI: 10.3389/frans.2023.1186623] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Functional proteomics aims to elucidate biological functions, mechanisms, and pathways of proteins and proteoforms at the molecular level to examine complex cellular systems and disease states. A series of stability proteomics methods have been developed to examine protein functionality by measuring the resistance of a protein to chemical or thermal denaturation or proteolysis. These methods can be applied to measure the thermal stability of thousands of proteins in complex biological samples such as cell lysate, intact cells, tissues, and other biological fluids to measure proteome stability. Stability proteomics methods have been popularly applied to observe stability shifts upon ligand binding for drug target identification. More recently, these methods have been applied to characterize the effect of structural changes in proteins such as those caused by post-translational modifications (PTMs) and mutations, which can affect protein structures or interactions and diversify protein functions. Here, we discussed the current application of a suite of stability proteomics methods, including thermal proteome profiling (TPP), stability of proteomics from rates of oxidation (SPROX), and limited proteolysis (LiP) methods, to observe PTM-induced structural changes on protein stability. We also discuss future perspectives highlighting the integration of top-down mass spectrometry and stability proteomics methods to characterize intact proteoform stability and understand the function of variable protein modifications.
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Affiliation(s)
- Ji Kang
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, United States
| | - Meena Seshadri
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, United States
| | - Kellye A. Cupp-Sutton
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, United States
| | - Si Wu
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK, United States
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10
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Rogers HT, Roberts DS, Larson EJ, Melby JA, Rossler KJ, Carr AV, Brown KA, Ge Y. Comprehensive Characterization of Endogenous Phospholamban Proteoforms Enabled by Photocleavable Surfactant and Top-down Proteomics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.12.536120. [PMID: 37090578 PMCID: PMC10120617 DOI: 10.1101/2023.04.12.536120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Top-down mass spectrometry (MS)-based proteomics has become a powerful tool for analyzing intact proteins and their associated post-translational modification (PTMs). In particular, membrane proteins play critical roles in cellular functions and represent the largest class of drug targets. However, the top-down MS characterization of endogenous membrane proteins remains challenging, mainly due to their intrinsic hydrophobicity and low abundance. Phospholamban (PLN) is a regulatory membrane protein located in the sarcoplasmic reticulum and is essential for regulating cardiac muscle contraction. PLN has diverse combinatorial PTMs and their dynamic regulation has significant influence on cardiac contractility and disease. Herein, we have developed a rapid and robust top-down proteomics method enabled by a photocleavable anionic surfactant, Azo, for the extraction and comprehensive characterization of endogenous PLN from cardiac tissue. We employed a two-pronged top-down MS approach using an online reversed-phase liquid chromatography tandem MS (LC-MS/MS) method on a quadrupole time-of-flight (Q-TOF) MS and a direct infusion method via an ultrahigh-resolution Fourier-transform ion cyclotron resonance (FTICR) MS. We have comprehensively characterized the sequence and combinatorial PTMs of endogenous human cardiac PLN. We have shown the site-specific localization of phosphorylation to Ser16 and Thr17 by MS/MS for the first time and the localization of S-palmitoylation to Cys36. Taken together, we have developed a streamlined top-down targeted proteomics method for comprehensive characterization of combinatorial PTMs in PLN toward better understanding the role of PLN in cardiac contractility.
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11
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Nickerson JL, Baghalabadi V, Rajendran SRCK, Jakubec PJ, Said H, McMillen TS, Dang Z, Doucette AA. Recent advances in top-down proteome sample processing ahead of MS analysis. MASS SPECTROMETRY REVIEWS 2023; 42:457-495. [PMID: 34047392 DOI: 10.1002/mas.21706] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/21/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
Top-down proteomics is emerging as a preferred approach to investigate biological systems, with objectives ranging from the detailed assessment of a single protein therapeutic, to the complete characterization of every possible protein including their modifications, which define the human proteoform. Given the controlling influence of protein modifications on their biological function, understanding how gene products manifest or respond to disease is most precisely achieved by characterization at the intact protein level. Top-down mass spectrometry (MS) analysis of proteins entails unique challenges associated with processing whole proteins while maintaining their integrity throughout the processes of extraction, enrichment, purification, and fractionation. Recent advances in each of these critical front-end preparation processes, including minimalistic workflows, have greatly expanded the capacity of MS for top-down proteome analysis. Acknowledging the many contributions in MS technology and sample processing, the present review aims to highlight the diverse strategies that have forged a pathway for top-down proteomics. We comprehensively discuss the evolution of front-end workflows that today facilitate optimal characterization of proteoform-driven biology, including a brief description of the clinical applications that have motivated these impactful contributions.
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Affiliation(s)
| | - Venus Baghalabadi
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Subin R C K Rajendran
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
- Verschuren Centre for Sustainability in Energy and the Environment, Sydney, Nova Scotia, Canada
| | - Philip J Jakubec
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hammam Said
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Teresa S McMillen
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ziheng Dang
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Alan A Doucette
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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12
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Lenčo J, Jadeja S, Naplekov DK, Krokhin OV, Khalikova MA, Chocholouš P, Urban J, Broeckhoven K, Nováková L, Švec F. Reversed-Phase Liquid Chromatography of Peptides for Bottom-Up Proteomics: A Tutorial. J Proteome Res 2022; 21:2846-2892. [PMID: 36355445 DOI: 10.1021/acs.jproteome.2c00407] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The performance of the current bottom-up liquid chromatography hyphenated with mass spectrometry (LC-MS) analyses has undoubtedly been fueled by spectacular progress in mass spectrometry. It is thus not surprising that the MS instrument attracts the most attention during LC-MS method development, whereas optimizing conditions for peptide separation using reversed-phase liquid chromatography (RPLC) remains somewhat in its shadow. Consequently, the wisdom of the fundaments of chromatography is slowly vanishing from some laboratories. However, the full potential of advanced MS instruments cannot be achieved without highly efficient RPLC. This is impossible to attain without understanding fundamental processes in the chromatographic system and the properties of peptides important for their chromatographic behavior. We wrote this tutorial intending to give practitioners an overview of critical aspects of peptide separation using RPLC to facilitate setting the LC parameters so that they can leverage the full capabilities of their MS instruments. After briefly introducing the gradient separation of peptides, we discuss their properties that affect the quality of LC-MS chromatograms the most. Next, we address the in-column and extra-column broadening. The last section is devoted to key parameters of LC-MS methods. We also extracted trends in practice from recent bottom-up proteomics studies and correlated them with the current knowledge on peptide RPLC separation.
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Affiliation(s)
- Juraj Lenčo
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
| | - Siddharth Jadeja
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
| | - Denis K Naplekov
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
| | - Oleg V Krokhin
- Department of Internal Medicine, Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, 799 JBRC, 715 McDermot Avenue, WinnipegR3E 3P4, Manitoba, Canada
| | - Maria A Khalikova
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
| | - Petr Chocholouš
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
| | - Jiří Urban
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00Brno, Czech Republic
| | - Ken Broeckhoven
- Department of Chemical Engineering (CHIS), Faculty of Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050Brussel, Belgium
| | - Lucie Nováková
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
| | - František Švec
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05Hradec Králové, Czech Republic
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13
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Takemori A, Kaulich PT, Cassidy L, Takemori N, Tholey A. Size-Based Proteome Fractionation through Polyacrylamide Gel Electrophoresis Combined with LC-FAIMS-MS for In-Depth Top-Down Proteomics. Anal Chem 2022; 94:12815-12821. [PMID: 36069571 DOI: 10.1021/acs.analchem.2c02777] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The combination of liquid chromatography (LC) and gas-phase separation by field-asymmetric ion mobility spectrometry (FAIMS) is a powerful proteoform separation system for top-down proteomics. Here, we present an in-depth top-down proteomics workflow, GeLC-FAIMS-MS, in which a molecular-weight-based proteome fractionation approach using SDS-polyacrylamide gel electrophoresis is performed prior to LC-FAIMS-MS. Since individual bands and their corresponding mass ranges require different compensating voltages (CVs), the MS parameters for each gel band and CV were optimized to increase the number and reliability of proteoform identifications further. We developed an easy-to-implement and inexpensive procedure combining the earlier established Passively Eluting Proteins from Polyacrylamide gels as Intact species (PEPPI) protocol with an optimized Anion-Exchange disk-assisted Sequential sample Preparation (AnExSP) method for the removal of stains and SDS. The protocol was compared with a methanol-chloroform-water (MCW)-based protein precipitation protocol. The results show that the PEPPI-AnExSP procedure is better suited for the identification of low-molecular-weight proteoforms, whereas the MCW-based protocol showed advantages for higher-molecular-weight proteoforms. Moreover, complementary results were observed with the two methods in terms of hydrophobicity and isoelectric points of the identified proteoforms. In total, 8500 proteoforms could be identified in a human proteome standard, showing the effectiveness of the gel-based sample fractionation approaches in combination with LC-FAIMS-MS.
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Affiliation(s)
- Ayako Takemori
- Advanced Research Support Center, Institute for Promotion of Science and Technology, Ehime University, Toon 790-8577, Ehime, Japan
| | - Philipp T Kaulich
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
| | - Liam Cassidy
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
| | - Nobuaki Takemori
- Advanced Research Support Center, Institute for Promotion of Science and Technology, Ehime University, Toon 790-8577, Ehime, Japan
| | - Andreas Tholey
- Systematic Proteome Research & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, 24105 Kiel, Germany
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14
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Lim GM, Kim BG, Jeong HJ. Trap column-based intact mass spectrometry for rapid and accurate evaluation of protein molecular weight. RSC Adv 2022; 12:15643-15651. [PMID: 35685704 PMCID: PMC9126647 DOI: 10.1039/d2ra00429a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/24/2022] [Indexed: 11/21/2022] Open
Abstract
The determination of the molecular weight (MW) of a protein using high-resolution mass spectrometry (MS) is a crucial tool used to confirm whether the protein was correctly expressed and adequately purified. However, a non-volatile buffer is normally used for protein purification and storage. Therefore, a pre-treatment step using ultrafiltration (UF) is required to exchange the buffer with a volatile buffer prior to the introduction of the protein sample into the MS equipment. This pre-treatment step is time-consuming. In this study, a trap column-based pre-treatment method applied in a nano-LC system was developed for rapid and convenient analysis of the MW of proteins. First, the trap column system was compared with the conventional UF treatment system and non-treatment system using bovine serum albumin. Subsequently, the trap column system was applied to analyze the MW of commercially available and lab-synthesized recombinant proteins. The intensity of the base peak and signal-to-noise ratio of the trap column-based pre-treated protein were higher than those of the UF-treated protein. Moreover, the entire automated procedure of the trap column-based system was conducted within 20 min, which confirms its use in versatile and accurate protein identification.
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Affiliation(s)
- Gyu-Min Lim
- Interdisciplinary Program for Biochemical Engineering and Biotechnology, Seoul National University Seoul 08826 South Korea
| | - Byung-Gee Kim
- Interdisciplinary Program for Biochemical Engineering and Biotechnology, Seoul National University Seoul 08826 South Korea
- Bio-MAX/N-Bio, Seoul National University Seoul 08826 South Korea
| | - Hee-Jin Jeong
- Department of Biological and Chemical Engineering, Hongik University Sejong 30016 South Korea
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15
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Zheng W, Yang P, Sun C, Zhang Y. Comprehensive comparison of sample preparation workflows for proteomics. Mol Omics 2022; 18:555-567. [DOI: 10.1039/d2mo00076h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mass spectrometry-based proteomics experiments can be subject to a large variability, which forms an obstacle to obtaining deep and accurate protein identification. Here, to obtain an optimal sample preparation workflow...
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16
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Methods for Proteomic Analyses of Mycobacteria. Methods Mol Biol 2021. [PMID: 34235669 DOI: 10.1007/978-1-0716-1460-0_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
The use of proteomic technologies to characterize and study the proteome of mycobacteria has provided important information in terms of function, diversity, protein-protein interactions, and host-pathogen interactions in Mycobacterium spp. There are many different mass spectrometry methodologies that can be applied to proteomics studies of mycobacteria and microorganisms in general. Sample processing and appropriate study design are critical to generating high-quality data regardless of the mass spectrometry method applied. Appropriate study design relies on statistical rigor and data curation using bioinformatics approaches that are widely applicable regardless of the organism or system studied. Sample processing, on the other hand, is often a niched process specific to the physiology of the organism or system under investigation. Therefore, in this chapter, we will provide protocols for processing mycobacterial protein samples for the specific application of Top-down and Bottom-up proteomic analyses.
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17
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Rossouw SC, Bendou H, Blignaut RJ, Bell L, Rigby J, Christoffels A. Evaluation of Protein Purification Techniques and Effects of Storage Duration on LC-MS/MS Analysis of Archived FFPE Human CRC Tissues. Pathol Oncol Res 2021; 27:622855. [PMID: 34257588 PMCID: PMC8262168 DOI: 10.3389/pore.2021.622855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/01/2021] [Indexed: 12/17/2022]
Abstract
To elucidate cancer pathogenesis and its mechanisms at the molecular level, the collecting and characterization of large individual patient tissue cohorts are required. Since most pathology institutes routinely preserve biopsy tissues by standardized methods of formalin fixation and paraffin embedment, these archived FFPE tissues are important collections of pathology material that include patient metadata, such as medical history and treatments. FFPE blocks can be stored under ambient conditions for decades, while retaining cellular morphology, due to modifications induced by formalin. However, the effect of long-term storage, at resource-limited institutions in developing countries, on extractable protein quantity/quality has not yet been investigated. In addition, the optimal sample preparation techniques required for accurate and reproducible results from label-free LC-MS/MS analysis across block ages remains unclear. This study investigated protein extraction efficiency of 1, 5, and 10-year old human colorectal carcinoma resection tissue and assessed three different gel-free protein purification methods for label-free LC-MS/MS analysis. A sample size of n = 17 patients per experimental group (with experiment power = 0.7 and α = 0.05, resulting in 70% confidence level) was selected. Data were evaluated in terms of protein concentration extracted, peptide/protein identifications, method reproducibility and efficiency, sample proteome integrity (due to storage time), as well as protein/peptide distribution according to biological processes, cellular components, and physicochemical properties. Data are available via ProteomeXchange with identifier PXD017198. The results indicate that the amount of protein extracted is significantly dependent on block age (p < 0.0001), with older blocks yielding less protein than newer blocks. Detergent removal plates were the most efficient and overall reproducible protein purification method with regard to number of peptide and protein identifications, followed by the MagReSyn® SP3/HILIC method (with on-bead enzymatic digestion), and lastly the acetone precipitation and formic acid resolubilization method. Overall, the results indicate that long-term storage of FFPE tissues (as measured by methionine oxidation) does not considerably interfere with retrospective proteomic analysis (p > 0.1). Block age mainly affects initial protein extraction yields and does not extensively impact on subsequent label-free LC-MS/MS analysis results.
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Affiliation(s)
- Sophia C. Rossouw
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa
| | - Hocine Bendou
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa
| | - Renette J. Blignaut
- Department of Statistics and Population Studies, University of the Western Cape, Bellville, South Africa
| | - Liam Bell
- Centre for Proteomic and Genomic Research, Observatory, Cape Town, South Africa
| | - Jonathan Rigby
- Division of Anatomical Pathology, Department of Pathology, Faculty of Health Sciences, University of Stellenbosch, National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa
| | - Alan Christoffels
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa
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18
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Brown KA, Tucholski T, Alpert AJ, Eken C, Wesemann L, Kyrvasilis A, Jin S, Ge Y. Top-Down Proteomics of Endogenous Membrane Proteins Enabled by Cloud Point Enrichment and Multidimensional Liquid Chromatography-Mass Spectrometry. Anal Chem 2020; 92:15726-15735. [PMID: 33231430 PMCID: PMC7968110 DOI: 10.1021/acs.analchem.0c02533] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Although top-down proteomics has emerged as a powerful strategy to characterize proteins in biological systems, the analysis of endogenous membrane proteins remains challenging due to their low solubility, low abundance, and the complexity of the membrane subproteome. Here, we report a simple but effective enrichment and separation strategy for top-down proteomics of endogenous membrane proteins enabled by cloud point extraction and multidimensional liquid chromatography coupled to high-resolution mass spectrometry (MS). The cloud point extraction efficiently enriched membrane proteins using a single extraction, eliminating the need for time-consuming ultracentrifugation steps. Subsequently, size-exclusion chromatography (SEC) with an MS-compatible mobile phase (59% water, 40% isopropanol, 1% formic acid) was used to remove the residual surfactant and fractionate intact proteins (6-115 kDa). The fractions were separated further by reversed-phase liquid chromatography (RPLC) coupled with MS for protein characterization. This method was applied to human embryonic kidney cells and cardiac tissue lysates to enable the identification of 188 and 124 endogenous integral membrane proteins, respectively, some with as many as 19 transmembrane domains.
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Affiliation(s)
- Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Trisha Tucholski
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Andrew J. Alpert
- PolyLC Inc., Columbia, Maryland 21045, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Christian Eken
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Lucas Wesemann
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Andreas Kyrvasilis
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
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19
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Thomas SL, Thacker JB, Schug KA, Maráková K. Sample preparation and fractionation techniques for intact proteins for mass spectrometric analysis. J Sep Sci 2020; 44:211-246. [DOI: 10.1002/jssc.202000936] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Shannon L. Thomas
- Department of Chemistry & Biochemistry The University of Texas Arlington Arlington Texas USA
| | - Jonathan B. Thacker
- Department of Chemistry & Biochemistry The University of Texas Arlington Arlington Texas USA
| | - Kevin A. Schug
- Department of Chemistry & Biochemistry The University of Texas Arlington Arlington Texas USA
| | - Katarína Maráková
- Department of Pharmaceutical Analysis and Nuclear Pharmacy Faculty of Pharmacy Comenius University in Bratislava Bratislava Slovakia
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20
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Pérez-Rodriguez S, Ramírez OT, Trujillo-Roldán MA, Valdez-Cruz NA. Comparison of protein precipitation methods for sample preparation prior to proteomic analysis of Chinese hamster ovary cell homogenates. ELECTRON J BIOTECHN 2020. [DOI: 10.1016/j.ejbt.2020.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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21
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Brown KA, Melby JA, Roberts DS, Ge Y. Top-down proteomics: challenges, innovations, and applications in basic and clinical research. Expert Rev Proteomics 2020; 17:719-733. [PMID: 33232185 PMCID: PMC7864889 DOI: 10.1080/14789450.2020.1855982] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022]
Abstract
Introduction- A better understanding of the underlying molecular mechanism of diseases is critical for developing more effective diagnostic tools and therapeutics toward precision medicine. However, many challenges remain to unravel the complex nature of diseases. Areas covered- Changes in protein isoform expression and post-translation modifications (PTMs) have gained recognition for their role in underlying disease mechanisms. Top-down mass spectrometry (MS)-based proteomics is increasingly recognized as an important method for the comprehensive characterization of proteoforms that arise from alternative splicing events and/or PTMs for basic and clinical research. Here, we review the challenges, technological innovations, and recent studies that utilize top-down proteomics to elucidate changes in the proteome with an emphasis on its use to study heart diseases. Expert opinion- Proteoform-resolved information can substantially contribute to the understanding of the molecular mechanisms underlying various diseases and for the identification of novel proteoform targets for better therapeutic development . Despite the challenges of sequencing intact proteins, top-down proteomics has enabled a wealth of information regarding protein isoform switching and changes in PTMs. Continuous developments in sample preparation, intact protein separation, and instrumentation for top-down MS have broadened its capabilities to characterize proteoforms from a range of samples on an increasingly global scale.
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Affiliation(s)
- Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Jake A. Melby
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - David S. Roberts
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin, United States
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22
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Achour B, Al-Majdoub ZM, Rostami-Hodjegan A, Barber J. Mass Spectrometry of Human Transporters. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2020; 13:223-247. [PMID: 32084322 DOI: 10.1146/annurev-anchem-091719-024553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Transporters are key to understanding how an individual will respond to a particular dose of a drug. Two patients with similar systemic concentrations may have quite different local concentrations of a drug at the required site. The transporter profile of any individual depends upon a variety of genetic and environmental factors, including genotype, age, and diet status. Robust models (virtual patients) are therefore required and these models are data hungry. Necessary data include quantitative transporter profiles at the relevant organ. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) is currently the most powerful method available for obtaining this information. Challenges include sourcing the tissue, isolating the hydrophobic membrane-embedded transporter proteins, preparing the samples for MS (including proteolytic digestion), choosing appropriate quantification methodology, and optimizing the LC-MS/MS conditions. Great progress has been made with all of these, especially within the last few years, and is discussed here.
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Affiliation(s)
- Brahim Achour
- Centre for Applied Pharmacokinetic Research, School of Health Sciences, University of Manchester, Manchester M13 9PT, United Kingdom;
| | - Zubida M Al-Majdoub
- Centre for Applied Pharmacokinetic Research, School of Health Sciences, University of Manchester, Manchester M13 9PT, United Kingdom;
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research, School of Health Sciences, University of Manchester, Manchester M13 9PT, United Kingdom;
- Certara, Princeton, New Jersey 08540, USA
| | - Jill Barber
- Centre for Applied Pharmacokinetic Research, School of Health Sciences, University of Manchester, Manchester M13 9PT, United Kingdom;
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23
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Nickerson JL, Doucette AA. Rapid and Quantitative Protein Precipitation for Proteome Analysis by Mass Spectrometry. J Proteome Res 2020; 19:2035-2042. [DOI: 10.1021/acs.jproteome.9b00867] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jessica L. Nickerson
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Alan A. Doucette
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
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24
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Shahinuzzaman ADA, Chakrabarty JK, Fang Z, Smith D, Kamal AHM, Chowdhury SM. Improved in-solution trypsin digestion method for methanol-chloroform precipitated cellular proteomics sample. J Sep Sci 2020; 43:2125-2132. [PMID: 32073721 DOI: 10.1002/jssc.201901273] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 01/08/2023]
Abstract
Methanol-chloroform based protein precipitation is an essential step in many liquid chromatography-tandem mass spectrometry-based cellular proteomics applications. However, re-solubilization of the total protein precipitate is difficult using regular in-solution digestion protocol. Sodium deoxycholate is reported as an efficient surfactant for re-solubilization of membrane fractions. In this study, we demonstrated an application combining methanol-chloroform based protein precipitations and deoxycholic acid assisted re-solubilization of pellets to evaluate the improvement of protein identifications in mass spectrometry-based bottom-up proteomics. We evaluated the modified method using an equal amount of Raw 264.7 mouse macrophage cell lysate. Detailed in-solution trypsin digestion studies were presented on methanol-chloroform precipitated samples with or without deoxycholic acid treatments and compared with popular sample digestion methods. A mass spectrometric analysis confirmed an 82% increase in protein identification in deoxycholic acid-treated samples compared to other established methods. Furthermore, liquid chromatography-tandem mass spectrometry analysis of an equal amount of proteins from methanol-chloroform precipitated, and methanol-chloroform/deoxycholic acid-treated macrophage cell lysate showed a 14% increase and 27% unique protein identifications. We believe this improved digestion method could be a complementary or alternative method for mammalian cell sample preparations where sodium dodecyl sulfate based lysis buffer is frequently used.
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Affiliation(s)
- A D A Shahinuzzaman
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
| | - Jayanta K Chakrabarty
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
| | - Zixiang Fang
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
| | - David Smith
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
| | | | - Saiful M Chowdhury
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
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25
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Lenčo J, Khalikova MA, Švec F. Dissolving Peptides in 0.1% Formic Acid Brings Risk of Artificial Formylation. J Proteome Res 2020; 19:993-999. [DOI: 10.1021/acs.jproteome.9b00823] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Juraj Lenčo
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Maria A. Khalikova
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - František Švec
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
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26
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Donnelly DP, Rawlins CM, DeHart CJ, Fornelli L, Schachner LF, Lin Z, Lippens JL, Aluri KC, Sarin R, Chen B, Lantz C, Jung W, Johnson KR, Koller A, Wolff JJ, Campuzano IDG, Auclair JR, Ivanov AR, Whitelegge JP, Paša-Tolić L, Chamot-Rooke J, Danis PO, Smith LM, Tsybin YO, Loo JA, Ge Y, Kelleher NL, Agar JN. Best practices and benchmarks for intact protein analysis for top-down mass spectrometry. Nat Methods 2019; 16:587-594. [PMID: 31249407 PMCID: PMC6719561 DOI: 10.1038/s41592-019-0457-0] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/21/2019] [Indexed: 12/31/2022]
Abstract
One gene can give rise to many functionally distinct proteoforms, each of which has a characteristic molecular mass. Top-down mass spectrometry enables the analysis of intact proteins and proteoforms. Here members of the Consortium for Top-Down Proteomics provide a decision tree that guides researchers to robust protocols for mass analysis of intact proteins (antibodies, membrane proteins and others) from mixtures of varying complexity. We also present cross-platform analytical benchmarks using a protein standard sample, to allow users to gauge their proficiency.
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Affiliation(s)
- Daniel P Donnelly
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Catherine M Rawlins
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Caroline J DeHart
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, IL, USA
| | - Luca Fornelli
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, IL, USA
| | - Luis F Schachner
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, IL, USA
| | - Ziqing Lin
- Department of Cell and Regenerative Biology, Department of Chemistry, Human Proteomics Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Jennifer L Lippens
- Amgen Research, Discovery Attribute Sciences, Amgen, Thousand Oaks, CA, USA
| | - Krishna C Aluri
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
- Alnylam Pharmaceuticals, Cambridge, MA, USA
| | - Richa Sarin
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
- Biogen, Cambridge, MA, USA
| | - Bifan Chen
- Department of Cell and Regenerative Biology, Department of Chemistry, Human Proteomics Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Carter Lantz
- Department of Chemistry and Biochemistry, Department of Biological Chemistry, and UCLA/DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Wonhyeuk Jung
- Department of Chemistry and Biochemistry, Department of Biological Chemistry, and UCLA/DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kendall R Johnson
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Antonius Koller
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | | | - Iain D G Campuzano
- Amgen Research, Discovery Attribute Sciences, Amgen, Thousand Oaks, CA, USA
| | - Jared R Auclair
- Biopharmaceutical Analysis Training Laboratory, Northeastern University, Burlington, MA, USA
| | - Alexander R Ivanov
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Julian P Whitelegge
- The Pasarow Mass Spectrometry Laboratory, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ljiljana Paša-Tolić
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Julia Chamot-Rooke
- Mass Spectrometry for Biology Unit, Institut Pasteur, USR 2000, CNRS, Paris, France
| | | | - Lloyd M Smith
- Department of Chemistry, Genome Center of Wisconsin, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Joseph A Loo
- Department of Chemistry and Biochemistry, Department of Biological Chemistry, and UCLA/DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ying Ge
- Department of Cell and Regenerative Biology, Department of Chemistry, Human Proteomics Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Neil L Kelleher
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, IL, USA
| | - Jeffrey N Agar
- Barnett Institute of Chemical and Biological Analysis and Departments of Chemistry & Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA.
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27
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Dagley LF, Infusini G, Larsen RH, Sandow JJ, Webb AI. Universal Solid-Phase Protein Preparation (USP3) for Bottom-up and Top-down Proteomics. J Proteome Res 2019; 18:2915-2924. [DOI: 10.1021/acs.jproteome.9b00217] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Laura F. Dagley
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Giuseppe Infusini
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Rune H. Larsen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jarrod J. Sandow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew I. Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
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28
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Unterlander N, Doucette AA. Membrane-Based SDS Depletion Ahead of Peptide and Protein Analysis by Mass Spectrometry. Proteomics 2018; 18:e1700025. [PMID: 29575800 DOI: 10.1002/pmic.201700025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 02/23/2018] [Indexed: 11/07/2022]
Abstract
SDS interferes with both bottom-up and top-down MS analysis, requiring removal prior to detection. Filter-aided sample preparation (FASP) is favored for bottom-up proteomics (BUP) while acetone precipitation is popular for top-down proteomics (TDP). We recently demonstrated acetone precipitation in a membrane filter cartridge. Alternatively, our automated electrophoretic device, termed transmembrane electrophoresis (TME), depletes SDS for both TDP and BUP studies. Here TME is compared to these two alternative methods of SDS depletion in both BUP and TDP workflows. To do so, a modified FASP method is described applicable to the SDS purification and recovery of intact proteins, suitable for LC/MS. All three methods reliably deplete >99.8% SDS. TME provide higher sample yields (average 90%) than FASP (55%) or acetone precipitation (57%), translating into higher total protein identifications (973 vs 877 FASP or 890 acetone) and higher spectral matches (2.5 times) per protein. In a top down workflow, each SDS-depletion method yields high-quality MS spectra for intact proteins. These results show each of these membrane-based strategies is capable of depleting SDS with high sample recovery and high spectra quality for both BUP and TDP studies.
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Affiliation(s)
- Nicole Unterlander
- Department of Chemistry, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Alan A Doucette
- Department of Chemistry, Dalhousie University, Halifax, NS, B3H 4R2, Canada
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29
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C. K. Rajendran SR, Mohan A, Khiari Z, Udenigwe CC, Mason B. Yield, physicochemical, and antioxidant properties of Atlantic salmon visceral hydrolysate: Comparison of lactic acid bacterial fermentation with Flavourzyme proteolysis and formic acid treatment. J FOOD PROCESS PRES 2018. [DOI: 10.1111/jfpp.13620] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Subin R. C. K. Rajendran
- Faculty of Agriculture; Dalhousie University; Nova Scotia Canada B2N5E3
- Verschuren Centre for Sustainability in Energy and the Environment; Cape Breton University; Nova Scotia Canada B1P6L2
| | - Aishwarya Mohan
- Verschuren Centre for Sustainability in Energy and the Environment; Cape Breton University; Nova Scotia Canada B1P6L2
| | - Zied Khiari
- Verschuren Centre for Sustainability in Energy and the Environment; Cape Breton University; Nova Scotia Canada B1P6L2
- Centre for Applied Research and Innovation, Lethbridge College; Alberta Canada T1K1L6
| | - Chibuike C. Udenigwe
- School of Nutrition Sciences, Faculty of Health Sciences; University of Ottawa; Ontario Canada K1N6N5
| | - Beth Mason
- Verschuren Centre for Sustainability in Energy and the Environment; Cape Breton University; Nova Scotia Canada B1P6L2
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30
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Kachuk C, Doucette AA. The benefits (and misfortunes) of SDS in top-down proteomics. J Proteomics 2018; 175:75-86. [DOI: 10.1016/j.jprot.2017.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/19/2017] [Accepted: 03/03/2017] [Indexed: 12/18/2022]
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31
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Unterlander N, Doucette AA. Accelerated SDS depletion from proteins by transmembrane electrophoresis: Impacts of Joule heating. Electrophoresis 2018; 39:1349-1356. [DOI: 10.1002/elps.201700410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/23/2018] [Accepted: 01/31/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Nicole Unterlander
- Department of Chemistry; Dalhousie University; Halifax Nova Scotia Canada
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32
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Eddhif B, Lange J, Guignard N, Batonneau Y, Clarhaut J, Papot S, Geffroy-Rodier C, Poinot P. Study of a novel agent for TCA precipitated proteins washing - comprehensive insights into the role of ethanol/HCl on molten globule state by multi-spectroscopic analyses. J Proteomics 2018; 173:77-88. [DOI: 10.1016/j.jprot.2017.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/10/2017] [Accepted: 11/21/2017] [Indexed: 12/14/2022]
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33
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Affiliation(s)
- Bifan Chen
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ziqing Lin
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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34
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Wang S, Xiao C, Jiang L, Ling L, Chen X, Guo X. A high sensitive and contaminant tolerant matrix for facile detection of membrane proteins by matrix-assisted laser desorption/ionization mass spectrometry. Anal Chim Acta 2017; 999:114-122. [PMID: 29254561 DOI: 10.1016/j.aca.2017.11.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 11/05/2017] [Accepted: 11/09/2017] [Indexed: 02/07/2023]
Abstract
Despite the significance of membrane proteins (MPs) in biological system is indisputable, their specific natures make them notoriously difficult to be analyzed. Particularly, the widely used Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) prefers analyses of hydrophilic cytosolic proteins and has a limited ionization efficiency towards hydrophobic MPs. Herein, a hydrophobic compound (E)-propyl α-Cyano-4-Hydroxyl Cinnamylate (CHCA-C3), a propyl-esterified derivative of α-cyano-4-hydroxycinnamic acid (CHCA), was applied as a contaminant tolerant matrix for high sensitivity MALDI-MS analyses of MPs. With CHCA-C3, the detection limits of hydrophobic peptides were 10- to 100-fold better than those using CHCA. Furthermore, high quality of spectra could be achieved in the presence of high concentration of chaotropes, salts and detergents, as well as human urinary and serum environment. Also, CHCA-C3 could generate uniform sample distribution even in the presence of contaminants. This high contaminant-resistance was revealed to be ascribed to the enhanced hydrophobicity of CHCA-C3 with a lower affinity towards hydrophilic contaminants. The application of CHCA-C3 is further demonstrated by the analysis of trypsin/CNBr digests of bacteriorhodopsin containing seven transmembrane domains (TMDs), which dramatically increased numbers of identified hydrophobic peptides in TMDs and sequence coverage (∼100%). Besides, a combined method by using CHCA-C3 with fluoride solvent and a patterned paraffin plate was established for analysis of integral MPs. We achieved a low detection limit of 10 fmol for integral bacteriorhodopsin, which could not be detected using traditional matrices such as 3,5-dimethoxy-4-hydroxycinamic acid, 2,5-dihydroxyacetophenone even at sample concentration of 10 pmol.
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Affiliation(s)
- Sheng Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Chunsheng Xiao
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Liyan Jiang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Science, Jilin University, Changchun 130012, China
| | - Ling Ling
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Xuesi Chen
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Xinhua Guo
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Science, Jilin University, Changchun 130012, China.
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35
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Li W, Petruzziello F, Zhao N, Zhao H, Ye X, Zhang X, Rainer G. Separation and identification of mouse brain tissue microproteins using top‐down method with high resolution nanocapillary liquid chromatography mass spectrometry. Proteomics 2017; 17. [DOI: 10.1002/pmic.201600419] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 05/01/2017] [Accepted: 05/12/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Wenxue Li
- Visual Cognition Laboratory Department of Medicine University of Fribourg Fribourg Switzerland
| | - Filomena Petruzziello
- Visual Cognition Laboratory Department of Medicine University of Fribourg Fribourg Switzerland
| | - Nan Zhao
- CAS Key Laboratory of Separation of Science for Analytical Chemistry Dalian Institute of Chemical Physics Chinese Academy of Science Dalian P. R. China
| | - Huiyuan Zhao
- CAS Key Laboratory of Separation of Science for Analytical Chemistry Dalian Institute of Chemical Physics Chinese Academy of Science Dalian P. R. China
| | - Xueting Ye
- Shenyang Pharmaceutical University Shenyang P. R. China
| | - Xiaozhe Zhang
- CAS Key Laboratory of Separation of Science for Analytical Chemistry Dalian Institute of Chemical Physics Chinese Academy of Science Dalian P. R. China
| | - Gregor Rainer
- Visual Cognition Laboratory Department of Medicine University of Fribourg Fribourg Switzerland
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36
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Dalgliesh AJ, Liu ZZ, Griffiths LG. Magnesium Presence Prevents Removal of Antigenic Nuclear-Associated Proteins from Bovine Pericardium for Heart Valve Engineering. Tissue Eng Part A 2017; 23:609-621. [PMID: 28178887 DOI: 10.1089/ten.tea.2016.0405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Current heart valve prostheses are associated with significant complications, including aggressive immune response, limited valve life expectancy, and inability to grow in juvenile patients. Animal derived "tissue" valves undergo glutaraldehyde fixation to mask tissue antigenicity; however, chronic immunological responses and associated calcification still commonly occur. A heart valve formed from an unfixed bovine pericardium (BP) extracellular matrix (ECM) scaffold, in which antigenic burden has been eliminated or significantly reduced, has potential to overcome deficiencies of current bioprostheses. Decellularization and antigen removal methods frequently use sequential solutions extrapolated from analytical chemistry approaches to promote solubility and removal of tissue components from resultant ECM scaffolds. However, the extent to which such prefractionation strategies may inhibit removal of antigenic tissue components has not been explored. We hypothesize that presence of magnesium in prefractionation steps causes DNA precipitation and reduces removal of nuclear-associated antigenic proteins. Keeping all variables consistent bar the addition or absence of magnesium (2 mM magnesium chloride hexahydrate), residual BP ECM scaffold antigenicity and removed antigenicity were assessed, along with residual and removed DNA content, ECM morphology, scaffold composition, and recellularization potential. Furthermore, we used proteomic methods to determine the mechanism by which magnesium presence or absence affects scaffold residual antigenicity. This study demonstrates that absence of magnesium from antigen removal solutions enhances solubility and subsequent removal of antigenic nuclear-associated proteins from BP. We therefore conclude that the primary mechanism of action for magnesium removal during antigen removal processes is avoidance of DNA precipitation, facilitating solubilization and removal of nuclear-associated antigenic proteins. Future studies are necessary to further facilitate solubility and removal of nuclear-associated antigenic proteins from xenogeneic ECM scaffolds, in addition to an in vivo assessing of the material.
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Affiliation(s)
- Ailsa J Dalgliesh
- 1 Department of Veterinary Medicine, Medicine and Epidemiology, University of California , Davis, Davis, California.,2 Department of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | - Zhi Zhao Liu
- 1 Department of Veterinary Medicine, Medicine and Epidemiology, University of California , Davis, Davis, California
| | - Leigh G Griffiths
- 1 Department of Veterinary Medicine, Medicine and Epidemiology, University of California , Davis, Davis, California.,2 Department of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
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37
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Güray MZ, Zheng S, Doucette AA. Mass Spectrometry of Intact Proteins Reveals +98 u Chemical Artifacts Following Precipitation in Acetone. J Proteome Res 2017; 16:889-897. [PMID: 28088865 DOI: 10.1021/acs.jproteome.6b00841] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein precipitation in acetone is frequently employed ahead of mass spectrometry for sample preconcentration and purification. Unfortunately, acetone is not chemically inert; mass artifacts have previously been observed on glycine-containing peptides when exposed to acetone under acidic conditions. We herein report a distinct chemical modification occurring at the level of intact proteins when incubated in acetone. This artifact manifests as one or more satellite peaks in the MS spectrum of intact protein, spaced 98 u above the mass of the unmodified protein. Other artifacts (+84, +112 u) also appear upon incubation of proteins or peptides in acetone. The reaction is pH-sensitive, being suppressed when proteins are exposed to acetone under acidic conditions. The +98 u artifact is speculated to originate through an intermediate product of aldol condensation of acetone to form diacetone alcohol and mesityl oxide. A +98 u product could originate from nucleophilic attack on mesityl oxide or through condensation with diacetone alcohol. Given the extent of modification possible upon exposure of proteins to acetone, particularly following overnight solvent exposure or incubation at room temperature, an awareness of the variables influencing this novel modification is valued by proteomics researchers who employ acetone precipitation for protein purification.
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Affiliation(s)
- Melda Z Güray
- Department of Chemistry, Dalhousie University , PO Box 15000, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Shi Zheng
- Department of Chemistry, Dalhousie University , PO Box 15000, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Alan A Doucette
- Department of Chemistry, Dalhousie University , PO Box 15000, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
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38
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Quijada JV, Schmitt ND, Salisbury JP, Auclair JR, Agar JN. Heavy Sugar and Heavy Water Create Tunable Intact Protein Mass Increases for Quantitative Mass Spectrometry in Any Feed and Organism. Anal Chem 2016; 88:11139-11146. [PMID: 27744677 DOI: 10.1021/acs.analchem.6b03234] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stable isotope labeling techniques for quantitative top-down proteomics face unique challenges. These include unpredictable mass shifts following isotope labeling, which impedes analysis of unknown proteins and complex mixtures and exponentially greater susceptibility to incomplete isotope incorporation, manifesting as broadening of labeled intact protein peaks. Like popular bottom-up isotope labeling techniques, most top-down labeling methods are restricted to defined media/feed as well as amino acid auxotrophic organisms. We present a labeling method optimized for top-down proteomics that overcomes these challenges. We demonstrated this method through the spiking of 13C-sugar or 2H-water into standard laboratory feedstocks, resulting in tunable intact protein mass increases (TIPMI). After mixing of labeled and unlabeled samples, direct comparison of light and heavy peaks allowed for the relative quantitation of intact proteins in three popular model organisms, including prokaryotic and eukaryotic microorganisms and an animal. This internal standard method proved to be more accurate than label-free quantitation in our hands. Advantages over top-down SILAC include working equally well in nutrient-rich media, conceivably expanding applicability to any organism and all classes of biomolecules, not requiring high-resolving power MS for quantitation and being relatively inexpensive.
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Affiliation(s)
- Jeniffer V Quijada
- Department of Chemistry and Chemical Biology, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States.,Barnett Institute of Chemical and Biological Analysis, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Nicholas D Schmitt
- Department of Chemistry and Chemical Biology, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States.,Barnett Institute of Chemical and Biological Analysis, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Joseph P Salisbury
- Department of Chemistry and Chemical Biology, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States.,Barnett Institute of Chemical and Biological Analysis, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Jared R Auclair
- Department of Chemistry and Chemical Biology, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States.,Barnett Institute of Chemical and Biological Analysis, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Jeffrey N Agar
- Department of Chemistry and Chemical Biology, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States.,Barnett Institute of Chemical and Biological Analysis, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States.,Department of Pharmaceutical Sciences, Northeastern University , 360 Huntington Avenue, Boston, Massachusetts 02115, United States
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39
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Vit O, Petrak J. Integral membrane proteins in proteomics. How to break open the black box? J Proteomics 2016; 153:8-20. [PMID: 27530594 DOI: 10.1016/j.jprot.2016.08.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/30/2016] [Accepted: 08/09/2016] [Indexed: 12/22/2022]
Abstract
Integral membrane proteins (IMPs) are coded by 20-30% of human genes and execute important functions - transmembrane transport, signal transduction, cell-cell communication, cell adhesion to the extracellular matrix, and many other processes. Due to their hydrophobicity, low expression and lack of trypsin cleavage sites in their transmembrane segments, IMPs have been generally under-represented in routine proteomic analyses. However, the field of membrane proteomics has changed markedly in the past decade, namely due to the introduction of filter assisted sample preparation (FASP), the establishment of cell surface capture (CSC) protocols, and the development of methods that enable analysis of the hydrophobic transmembrane segments. This review will summarize the recent developments in the field and outline the most successful strategies for the analysis of integral membrane proteins. SIGNIFICANCE Integral membrane proteins (IMPs) are attractive therapeutic targets mostly due to their many important functions. However, our knowledge of the membrane proteome is severely limited to effectively exploit their potential. This is mostly due to the lack of appropriate techniques or methods compatible with the typical features of IMPs, namely hydrophobicity, low expression and lack of trypsin cleavage sites. This review summarizes the most recent development in membrane proteomics and outlines the most successful strategies for their large-scale analysis.
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Affiliation(s)
- O Vit
- BIOCEV, First Faculty of Medicine, Charles University in Prague, Czech Republic.
| | - J Petrak
- BIOCEV, First Faculty of Medicine, Charles University in Prague, Czech Republic
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40
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Kachuk C, Faulkner M, Liu F, Doucette AA. Automated SDS Depletion for Mass Spectrometry of Intact Membrane Proteins though Transmembrane Electrophoresis. J Proteome Res 2016; 15:2634-42. [DOI: 10.1021/acs.jproteome.6b00199] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Carolyn Kachuk
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Melissa Faulkner
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Fang Liu
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Alan A. Doucette
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
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41
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Zheng S, Doucette AA. Preventing N- and O-formylation of proteins when incubated in concentrated formic acid. Proteomics 2016; 16:1059-68. [PMID: 26840995 DOI: 10.1002/pmic.201500366] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/11/2015] [Accepted: 01/26/2016] [Indexed: 12/28/2022]
Abstract
Concentrated formic acid is among the most effective solvents for protein solubilization. Unfortunately, this acid also presents a risk of inducing chemical modifications thereby limiting its use in proteomics. Previous reports have supported the esterification of serine and threonine residues (O-formylation) for peptides incubated in formic acid. However as shown here, exposure of histone H4 to 80% formic (1 h, 20(o) C) induces N-formylation of two independent lysine residues. Furthermore, incubating a mixture of Escherichia coli proteins in formic acid demonstrates a clear preference toward lysine modification over reactions at serine/threonine. N-formylation accounts for 84% of the 225 uniquely identified formylation sites. To prevent formylation, we provide a detailed investigation of reaction conditions (temperature, time, acid concentration) that define the parameters permitting the use of concentrated formic acid in a proteomics workflow for MS characterization. Proteins can be maintained in 80% formic acid for extended periods (24 h) without inducing modification, so long as the temperature is maintained at or below -20(o) C.
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Affiliation(s)
- Shi Zheng
- Department of Chemistry, Dalhousie University, Halifax, NS, Canada.,Key Laboratory of Pesticides and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, Hubei, P. R. China
| | - Alan A Doucette
- Department of Chemistry, Dalhousie University, Halifax, NS, Canada
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42
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Patrie SM. Top-Down Mass Spectrometry: Proteomics to Proteoforms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 919:171-200. [PMID: 27975217 DOI: 10.1007/978-3-319-41448-5_8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This chapter highlights many of the fundamental concepts and technologies in the field of top-down mass spectrometry (TDMS), and provides numerous examples of contributions that TD is making in biology, biophysics, and clinical investigations. TD workflows include variegated steps that may include non-specific or targeted preparative strategies, orthogonal liquid chromatography techniques, analyte ionization, mass analysis, tandem mass spectrometry (MS/MS) and informatics procedures. This diversity of experimental designs has evolved to manage the large dynamic range of protein expression and diverse physiochemical properties of proteins in proteome investigations, tackle proteoform microheterogeneity, as well as determine structure and composition of gas-phase proteins and protein assemblies.
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Affiliation(s)
- Steven M Patrie
- Computational and Systems Biology & Biomedical Engineering Graduate Programs, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
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43
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Comparison of sodium dodecyl sulfate depletion techniques for proteome analysis by mass spectrometry. J Chromatogr A 2015; 1418:158-166. [DOI: 10.1016/j.chroma.2015.09.042] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 12/12/2022]
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44
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Fang X, Qiao L, Yan G, Yang P, Liu B. Multifunctional nanoreactor for comprehensive characterization of membrane proteins based on surface functionalized mesoporous foams. Anal Chem 2015; 87:9360-7. [PMID: 26305297 DOI: 10.1021/acs.analchem.5b02135] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An integrated protocol is proposed here for efficient analysis of membrane proteins based on surface functionalized mesoporous graphene foams (MGF). The inherent hydrophobic nature of MGF and surface modification with hydrophilic chitosan (CS) make it highly suitable for the enrichment of hydrophobic membrane proteins from organic solvent, while remaining well-dispersed in aqueous solution for subsequent proteolysis. Therefore, such a multifunctional reactor ensures a facile solvent adjustment route. Furthermore, as a chitosan modified nanoporous reactor, it also provides a biocompatible nanoenvironment that can maintain the stability and activity of enzymes to realize efficient in situ digestion of the enriched membrane proteins. The concept was first proved with a standard hydrophobic membrane protein, bacteriorhodopsin, where a high number of identified peptides and amino acid sequence coverage were achieved even at extremely low protein concentration. The mesoporous reaction system was further applied to the analysis of complex real-case proteome samples, where 931 membrane proteins were identified in triplicate analyses by 2D LC-MS/MS. In contrast, with in-solution proteolysis, only 73 membrane proteins were identified from the same sample by the same 2D LC-MS/MS. The identified membrane proteins by the MGF-CS protocol include many biomarkers of the cell line. These results suggest that the multifunctional MGF-CS protocol is of great value to facilitate the comprehensive characterization of membrane proteins in the proteome research.
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Affiliation(s)
- Xiaoni Fang
- Department of Chemistry, Institutes of Biomedical Sciences and State Key Lab of Molecular Engineering of Polymers, Fudan University , Shanghai 200433, China
| | - Liang Qiao
- Department of Chemistry, Institutes of Biomedical Sciences and State Key Lab of Molecular Engineering of Polymers, Fudan University , Shanghai 200433, China
| | - Guoquan Yan
- Department of Chemistry, Institutes of Biomedical Sciences and State Key Lab of Molecular Engineering of Polymers, Fudan University , Shanghai 200433, China
| | - Pengyuan Yang
- Department of Chemistry, Institutes of Biomedical Sciences and State Key Lab of Molecular Engineering of Polymers, Fudan University , Shanghai 200433, China
| | - Baohong Liu
- Department of Chemistry, Institutes of Biomedical Sciences and State Key Lab of Molecular Engineering of Polymers, Fudan University , Shanghai 200433, China
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Kim KH, Compton PD, Tran JC, Kelleher NL. Online matrix removal platform for coupling gel-based separations to whole protein electrospray ionization mass spectrometry. J Proteome Res 2015; 14:2199-206. [PMID: 25836738 DOI: 10.1021/pr501331q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A fractionation method called gel-eluted liquid fraction entrapment electrophoresis (GELFrEE) has been used to dramatically increase the number of proteins identified in top-down proteomic workflows; however, the technique involves the use of sodium dodecyl sulfate (SDS), a surfactant that interferes with electrospray ionization. Therefore, an efficient removal of SDS is absolutely required prior to mass analysis. Traditionally, methanol/chloroform precipitation and spin columns have been used, but they lack reproducibility and are difficult to automate. Therefore, we developed an in-line matrix removal platform to enable the direct analysis of samples containing SDS and salts. Only small molecules like SDS permeate a porous membrane and are removed in a manner similar to cross-flow filtration. With this device, near-complete removal of SDS is accomplished within 5 min and proteins are subsequently mobilized into a mass spectrometer. The new platform was optimized for the analysis of GELFrEE fractions enriched for histones extracted from human HeLa cells. All four core histones and their proteoforms were detected in a single spectrum by high-resolution mass spectrometry. The new method versus protein precipitation/resuspension showed 2- to 10-fold improved signal intensities, offering a clear path forward to improve proteome coverage and the efficiency of top-down proteomics.
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Affiliation(s)
- Ki Hun Kim
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, 2145 North Sheridan Road, Evanston, Illinois 60208, United States
| | - Philip D Compton
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, 2145 North Sheridan Road, Evanston, Illinois 60208, United States
| | - John C Tran
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, 2145 North Sheridan Road, Evanston, Illinois 60208, United States
| | - Neil L Kelleher
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, 2145 North Sheridan Road, Evanston, Illinois 60208, United States
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