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Kuzyk VO, Somsen GW, Haselberg R. CE-MS for Proteomics and Intact Protein Analysis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1336:51-86. [PMID: 34628627 DOI: 10.1007/978-3-030-77252-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This chapter aims to explore various parameters involved in achieving high-end capillary electrophoresis hyphenated to mass spectrometry (CE-MS) analysis of proteins, peptides, and their posttranslational modifications. The structure of the topics discussed in this book chapter is conveniently mapped on the scheme of the CE-MS system itself, starting from sample preconcentration and injection techniques and finishing with mass analyzer considerations. After going through the technical considerations, a variety of relevant applications for this analytical approach are presented, including posttranslational modifications analysis, clinical biomarker discovery, and its growing use in the biotechnological industry.
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Affiliation(s)
- Valeriia O Kuzyk
- Division of Bioanalytical Chemistry, AIMMS: Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Govert W Somsen
- Division of Bioanalytical Chemistry, AIMMS: Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Rob Haselberg
- Division of Bioanalytical Chemistry, AIMMS: Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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2
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Li T, Booker CJ, Yeung KKC. Migration behaviour of discontinuous buffers in capillary electrophoresis during protein enrichment. Analyst 2012; 137:4766-73. [DOI: 10.1039/c2an35548e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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3
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Online sample pre-concentration via dynamic pH junction in capillary and microchip electrophoresis. J Sep Sci 2011; 34:2800-21. [DOI: 10.1002/jssc.201100414] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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4
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Myoglobin-biomimetic electroactive materials made by surface molecular imprinting on silica beads and their use as ionophores in polymeric membranes for potentiometric transduction. Biosens Bioelectron 2011; 26:4760-6. [DOI: 10.1016/j.bios.2011.05.045] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 05/25/2011] [Accepted: 05/26/2011] [Indexed: 11/21/2022]
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5
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Removal of sample background buffering ions and myoglobin enrichment via a pH junction created by discontinuous buffers in capillary electrophoresis. J Chromatogr A 2011; 1218:5705-11. [DOI: 10.1016/j.chroma.2011.06.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 06/01/2011] [Accepted: 06/13/2011] [Indexed: 01/04/2023]
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6
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Pourhaghighi MR, Busnel JM, Girault HH. High-sensitive protein analysis by FESI-CE-MALDI-MS. Electrophoresis 2011; 32:1795-803. [DOI: 10.1002/elps.201100024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/07/2011] [Accepted: 03/11/2011] [Indexed: 11/06/2022]
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7
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Liu Y, Fu X, Bai Y, Zhai M, Liao Y, Liao J, Liu H. Improvement of reproducibility and sensitivity of CE analysis by using the capillary coated dynamically with carboxymethyl chitosan. Anal Bioanal Chem 2011; 399:2821-9. [DOI: 10.1007/s00216-011-4659-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/01/2011] [Accepted: 01/02/2011] [Indexed: 11/29/2022]
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8
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Chen Y, Zhang L, Cai Z, Chen G. Dynamic pH junction–sweeping for on-line focusing of dipeptides in capillary electrophoresis with laser-induced fluorescence detection. Analyst 2011; 136:1852-8. [DOI: 10.1039/c0an00744g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Analytical potential of mid-infrared detection in capillary electrophoresis and liquid chromatography: A review. Anal Chim Acta 2010; 679:31-42. [DOI: 10.1016/j.aca.2010.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 09/01/2010] [Accepted: 09/03/2010] [Indexed: 11/22/2022]
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10
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Mei J, Tian YP, He W, Xiao YX, Wei J, Feng YQ. Preparation approaches of the coated capillaries with liposomes in capillary electrophoresis. J Chromatogr A 2010; 1217:6979-86. [DOI: 10.1016/j.chroma.2010.08.062] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 08/21/2010] [Accepted: 08/24/2010] [Indexed: 11/28/2022]
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11
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Vítková K, Petr J, Maier V, Znaleziona J, Ševčík J. Study of electromigration effects on a pH boundary during the on-line electrokinetic preconcentration by capillary electrophoresis. Electrophoresis 2010; 31:2771-7. [DOI: 10.1002/elps.200900663] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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12
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Wang J, Jiang X, Sturm RM, Li L. Combining tissue extraction and off-line capillary electrophoresis matrix-assisted laser desorption/ionization Fourier transform mass spectrometry for neuropeptide analysis in individual neuronal organs using 2,5-dihydroxybenzoic acid as a multi-functional agent. J Chromatogr A 2009; 1216:8283-8. [PMID: 19473662 PMCID: PMC2783529 DOI: 10.1016/j.chroma.2009.04.085] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/25/2009] [Accepted: 04/28/2009] [Indexed: 01/20/2023]
Abstract
In this study we report an improved protocol that combines simplified sample preparation and micro-scale separation for mass spectrometric analysis of neuropeptides from individual neuroendocrine organs of crab Cancer borealis. A simple, one-step extraction method with commonly used matrix-assisted laser desorption/ionization (MALDI) matrix, 2,5-dihydroxybenzoic acid (DHB), in saturated aqueous solution, is employed for improved extraction of neuropeptides. Furthermore, a novel use of DHB as background electrolyte for capillary electrophoresis (CE) separation in the off-line coupling of CE to MALDI-Fourier transform mass spectrometric (FT-MS) detection is also explored. The new CE electrolyte exhibits full compatibility with MALDI-MS analysis of neuropeptides in that both the peptide extraction process and MALDI detection utilize DHB. In addition, enhanced resolving power and improved sensitivity are also observed for CE-MALDI-MS of peptide mixture analysis. Collectively, the use of DHB has simplified the extraction and reduced the sample loss by elimination of homogenizing, drying, and desalting processes. In the mean time, the concurrent use of DHB as CE separation buffer and subsequent MALDI matrix offers improved spectral quality by eliminating the interferences from typical CE electrolyte in MALDI detection.
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Affiliation(s)
- Junhua Wang
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - Xiaoyue Jiang
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - Robert M. Sturm
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - Lingjun Li
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
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Guo L, Qiu B, Xue L, Chen G. CE with a new electrochemiluminescent detection system for separation and detection of proteins labeled with tris(1,10-phenanthroline) ruthenium(II). Electrophoresis 2009; 30:2390-6. [DOI: 10.1002/elps.200800715] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Jurcic K, Yeung KKC. Sphingomyelins as semi-permanent capillary coatings for protein separations in CE and off-line analysis with MALDI-MS. Electrophoresis 2009; 30:1817-27. [DOI: 10.1002/elps.200800633] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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15
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Kartsova LA, Bessonova EA. Preconcentration techniques in capillary electrophoresis. JOURNAL OF ANALYTICAL CHEMISTRY 2009. [DOI: 10.1134/s1061934809040029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Liu J, Liu Z, Kang M, Liu S, Chen HY. Combination of large volume sample stacking and reversed pH junction in capillary electrophoresis for online preconcentration of glycoforms of recombinant human erythropoietin. J Sep Sci 2009; 32:422-9. [DOI: 10.1002/jssc.200800387] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Nesbitt CA, Yeung KKC. In-capillary enrichment, proteolysis and separation using capillary electrophoresis with discontinuous buffers: application on proteins with moderately acidic and basic isoelectric points. Analyst 2009; 134:65-71. [DOI: 10.1039/b812628c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Recent applications of capillary electrophoresis–mass spectrometry (CE–MS): CE performing functions beyond separation. Anal Chim Acta 2008; 627:3-24. [DOI: 10.1016/j.aca.2008.04.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 04/02/2008] [Accepted: 04/08/2008] [Indexed: 11/18/2022]
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19
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Lin CY, Liu CH, Chang HC, Tseng WL. Enrichment and separation of acidic and basic proteins using the centrifugal ultrafiltration followed by nanoparticle-filled capillary electrophoresis. Electrophoresis 2008; 29:3024-31. [DOI: 10.1002/elps.200700879] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Kim H, Lubman DM. Micro-proteome analysis using micro-chromatofocusing in intact protein separations. J Chromatogr A 2008; 1194:3-10. [PMID: 18407281 PMCID: PMC2479787 DOI: 10.1016/j.chroma.2008.03.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 03/14/2008] [Accepted: 03/18/2008] [Indexed: 01/23/2023]
Abstract
Multi-dimensional liquid-based separation is required for fractionation and mapping of complex protein mixtures from cells. A method that has been used as the first dimension in such separations is chromatofocusing (CF), which is based on generating a pH gradient on an anion exchange column. The use of pH in the first dimension is essential where pH is a fundamental property of proteins and can provide information on post-translationally modified forms of a protein. In this work, a micro-chromatofocusing technique is introduced which can separate microgram levels of proteins from cell lysates for further analysis by LC-MS/MS. It is shown that this method can analyze 10 microg of sample and detect nearly 700-800 proteins from ovarian cancer cell line lysates.
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Affiliation(s)
- Hyeyeung Kim
- Department of Chemistry, University of Michigan, 48109, Ann Arbor, MI, U.S.A
| | - David M. Lubman
- Department of Chemistry, University of Michigan, 48109, Ann Arbor, MI, U.S.A
- Department of Pathology, University of Michigan Medical Center, 48109, Ann Arbor, MI, U.S.A
- Department of Surgery, University of Michigan Medical Center, 48109, Ann Arbor, MI, U.S.A
- Comprehensive Cancer Center, University of Michigan, 48109, Ann Arbor, MI, U.S.A
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21
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Busnel JM, Lion N, Girault HH. Electrokinetic supercharging for highly efficient peptide preconcentration in capillary zone electrophoresis. Electrophoresis 2008; 29:1565-72. [DOI: 10.1002/elps.200700643] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Lucy CA, MacDonald AM, Gulcev MD. Non-covalent capillary coatings for protein separations in capillary electrophoresis. J Chromatogr A 2008; 1184:81-105. [DOI: 10.1016/j.chroma.2007.10.114] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2007] [Revised: 10/25/2007] [Accepted: 10/31/2007] [Indexed: 11/27/2022]
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23
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Simpson SL, Quirino JP, Terabe S. On-line sample preconcentration in capillary electrophoresis. J Chromatogr A 2008; 1184:504-41. [DOI: 10.1016/j.chroma.2007.11.001] [Citation(s) in RCA: 269] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 10/30/2007] [Accepted: 11/01/2007] [Indexed: 02/06/2023]
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24
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Nesbitt CA, Jurcic K, Yeung KKC. Nanoliter-volume protein enrichment, tryptic digestion, and partial separation based on isoelectric points by CE for MALDI mass spectral analysis. Electrophoresis 2008; 29:466-74. [DOI: 10.1002/elps.200700339] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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25
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Abstract
The article brings a comprehensive survey of recent developments and applications of high-performance capillary electromigration methods, zone electrophoresis, ITP, IEF, affinity electrophoresis, EKC, and electrochromatography, to analysis, preparation, and physicochemical characterization of peptides. New approaches to the theoretical description and experimental verification of electromigration behavior of peptides and to methodology of their separations, such as sample preparation, adsorption suppression, and detection, are presented. Novel developments in individual CE and CEC modes are shown and several types of their applications to peptide analysis are presented: conventional qualitative and quantitative analysis, purity control, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of CE and CEC techniques to provide important physicochemical characteristics of peptides are demonstrated.
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Affiliation(s)
- Václav Kasicka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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26
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Ptolemy AS, Britz-McKibbin P. New advances in on-line sample preconcentration by capillary electrophoresis using dynamic pH junction. Analyst 2008; 133:1643-8. [DOI: 10.1039/b808236g] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Chen Y, Guo Z, Wang X, Qiu C. Sample preparation. J Chromatogr A 2007; 1184:191-219. [PMID: 17991475 DOI: 10.1016/j.chroma.2007.10.026] [Citation(s) in RCA: 252] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 10/08/2007] [Accepted: 10/10/2007] [Indexed: 11/17/2022]
Abstract
A panorama of sample preparation methods has been composed from 481 references, with a highlight of some promising methods fast developed during recent years and a somewhat brief introduction on most of the well-developed methods. All the samples were commonly referred to molecular composition, being extendable to particles including cells but not to organs, tissues and larger bodies. Some criteria to evaluate or validate a sample preparation method were proposed for reference. Strategy for integration of several methods to prepare complicated protein samples for proteomic studies was illustrated and discussed.
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Affiliation(s)
- Yi Chen
- Beijing National Laboratory of Molecular Science, Laboratory of Analytical Chemistry for Life Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
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28
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Horáková J, Petr J, Maier V, Tesarová E, Veis L, Armstrong DW, Gas B, Sevcík J. On-line preconcentration of weak electrolytes by electrokinetic accumulation in CE: Experiment and simulation. Electrophoresis 2007; 28:1540-7. [PMID: 17447246 DOI: 10.1002/elps.200600681] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A new on-line preconcentration technique was developed that makes possible to determine nanomolar concentrations of weak acidic analytes in CE. The method consists of long-running electrokinetic sample injection and stacking (electrokinetic immobilization) of the analytes at a boundary of two electrolytes with different pH values (pH 9.5 and 2.5) and consequent mobilization of the stacked uncharged analytes in a micellar system (containing SDS micelles). Several factors including buffer concentration, pH, applied voltage, time of preconcentration, and SDS concentration were tested to optimize the analysis method. An about 4600-fold increase of the sample concentration (in comparison with the standard CZE) can be achieved during the preconcentration step. Two preservatives applied in food industry -- benzoic acid and sorbic acid were used as model samples. The applicability of the proposed method in food analysis was demonstrated by determination of nanomolar concentrations of benzoic acid in sunflower oil. An extended version of the computer program Simul was used for modeling both the preconcentration and mobilization processes taking place in the capillary.
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Affiliation(s)
- Jana Horáková
- Department of Analytical Chemistry, Palacký University, Trída Svobody, Olomouc, Czech Republic
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29
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Imami K, Monton MRN, Ishihama Y, Terabe S. Simple on-line sample preconcentration technique for peptides based on dynamic pH junction in capillary electrophoresis–mass spectrometry. J Chromatogr A 2007; 1148:250-5. [PMID: 17382949 DOI: 10.1016/j.chroma.2007.03.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 02/07/2007] [Accepted: 03/05/2007] [Indexed: 11/29/2022]
Abstract
We report an on-line sample preconcentration technique based on dynamic pH junction in capillary electrophoresis-mass spectrometry (CE-MS). For peptide analysis, the samples were dissolved in a solution with higher pH than the background solution (BGS), and were injected into the capillary as a long plug. The pH difference between the sample matrix and BGS caused changes in analytes' mobilities during electrophoresis, resulting in narrowing of their bands at the boundary. Around 550-1000-fold sensitivity enhancement could be achieved in terms of peak intensity without degrading peak shape and resolution. This technique is easy to perform and will be useful for peptide mass fingerprinting in protein analysis.
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Affiliation(s)
- Koshi Imami
- Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan.
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30
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Breadmore MC. Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips. Electrophoresis 2007; 28:254-81. [PMID: 17149782 DOI: 10.1002/elps.200600463] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Poor sensitivity is considered to be one of the major limitations of electrophoretic separation methods, particularly when compared to traditional liquid chromatographic techniques. To address this issue, various in-line preconcentration techniques have been developed over the past 15 years, ranging in power and complexity, and there are now a number of well understood approaches routinely capable of providing a 10,000- to 100,000-fold increase in sensitivity, as well as several that can be pushed above a million. Furthermore, these have been achieved with particularly troublesome and often difficult samples, such as those having high salinity from a biological or environmental origin. This review will discuss the most common methods for improving the sensitivity of CE, CEC and microchip version of these, with particular attention to those approaches developed over the last five years.
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Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
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Malá Z, Krivánková L, Gebauer P, Bocek P. Contemporary sample stacking in CE: A sophisticated tool based on simple principles. Electrophoresis 2007; 28:243-53. [PMID: 17136738 DOI: 10.1002/elps.200600397] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sample stacking is a general term for methods in CE which are used for on-line concentration of diluted analytes. During the stacking process, analytes present at low concentrations in a long injected sample zone are concentrated into a short zone (stack). The stacked analytes are then separated and individual zones are detected. Thus stacking provides better separation efficiency and detection sensitivity. Many papers have been published on stacking till now, various procedures have been described, and, many names have been proposed for stacking procedures utilizing the same principles. This contribution brings an easy and unified view on stacking, describes the basic principles utilized, makes a list of recognized operational principles and brings an overview of principal current procedures. Further, it surveys selected recent practical applications ordered according to their operational principles and includes the terms, nicknames, and acronyms used for these actual stacking procedures. This contribution may help both newcomers and experts in the field of CE to orient themselves in the already quite complex topic of sample stacking.
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Affiliation(s)
- Zdena Malá
- Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Brno, Czech Republic
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32
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Quintás G, Nuñez E, Vellekoop M, Lendl B. On-line monitoring of pH junctions in capillary electrophoresis using Fourier transform infrared spectrometry. Anal Bioanal Chem 2006; 387:287-92. [PMID: 17131109 DOI: 10.1007/s00216-006-0944-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 09/25/2006] [Accepted: 10/12/2006] [Indexed: 10/23/2022]
Abstract
Fourier transform mid-infrared spectroscopic detection is proposed as an on-line detection technique for the study of on-line preconcentration processes in capillary electrophoresis (CE). The molecule-specific information contained in mid-IR spectra can be used to directly determine the chemical compositions of individual zones and their boundaries. This paper reports on pH junctions employed in myoglobin analysis. On-line mid-IR detection allowed the shape of the sample peak to be monitored as well as the chemical compositions of the surrounding zones. From this information it was possible to obtain detailed insights into the actual chemical compositions of the individual zones governing the efficiency of the preconcentration technique applied. The principle of measurement outlined here can therefore also be regarded as a promising one for investigating other on-line preconcentration techniques, like stacking, sweeping, and pH junction-sweeping among others.
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Affiliation(s)
- Guillermo Quintás
- Institute for Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060, Vienna, Austria
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33
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Jurcic K, Nesbitt CA, Yeung KKC. Characterization of discontinuous buffer junctions using pH indicators in capillary electrophoresis for protein preconcentration. J Chromatogr A 2006; 1134:317-25. [PMID: 17022988 DOI: 10.1016/j.chroma.2006.09.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 08/31/2006] [Accepted: 09/04/2006] [Indexed: 11/19/2022]
Abstract
An effective sample preconcentration technique for proteins and peptides was recently developed using capillary electrophoresis (CE) with discontinuous buffers [C.A. Nesbitt, J.T.-M. Lo, K.K.-C. Yeung, J. Chromatogr. A 1073 (2005) 175]. Two buffers of different pH created a junction to trap the sample molecules at their isoelectric points and resulted in over 1000-fold preconcentration for myoglobin within 30 min. To study the formation of pH junctions in CE, a pH indicator, bromothymol blue, is used in this work to reveal the pH changes at the discontinuous buffer boundary. Bromothymol blue (BTB) exhibits a drastic change in its visible absorption spectrum (300-600 nm) going from the acidic to basic pH conditions, and is therefore ideal for visualizing the changes in pH at the junctions created by various buffer combinations. Preconcentration of myoglobin was performed in discontinuous buffers containing BTB. Major differences in the BTB absorption profiles were identified from buffer systems that differ significantly in preconcentration performance, which in turn, allowed for the identification of ideal buffers for sample preconcentration. Up to 2000-fold preconcentrations of myoglobin were achieved in the buffer systems studied in this work. In addition, the role of the electroosmotic flow (EOF) on the preconcentration performance was investigated. A low EOF was found to be desirable, as the pH junction could stay longer in the capillary for accumulation of proteins. The pH junction also displayed characteristics to resist bandbroadening. Potential laminar flow resulted from the mismatched residual EOFs under the two pH conditions within the discontinuous buffers appeared to have minimal effect on the preconcentration. In fact, external applied pressure can be used to control the migration of the pH junction without compromising the protein preconcentration.
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Affiliation(s)
- Kristina Jurcic
- Department of Chemistry, The University of Western Ontario, London, Ont., Canada
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34
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Huang YF, Huang CC, Hu CC, Chang HT. Capillary electrophoresis-based separation techniques for the analysis of proteins. Electrophoresis 2006; 27:3503-22. [PMID: 16927348 DOI: 10.1002/elps.200600100] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
CE offers the advantages of high speed, great efficiency, as well as the requirement of minimum amounts of sample and buffer for the analysis of proteins. In this review, we summarize the CE-based techniques coupled with absorption, LIF, and MS detection systems for the analysis of proteins mostly within the past 5 years. The basic principle of each technique and its advantages and disadvantages for protein analysis are discussed in brief. Advanced CE techniques, including on-column concentration techniques and high-efficiency multidimensional separation techniques, for high-throughput protein profiling of complex biological samples and/or of single cells are emphasized. Although the developed techniques provide improved peak capacity, they have not become practical tools for proteomics, mainly because of poor reproducibility, low-sample lading capacity, and low throughput due to ineffective interfaces between two separation dimensions and that between separation and MS systems. In order to identify the complexities and dynamics of the proteomes expressed by cells, tissues, or organisms, techniques providing improved analytical sensitivity, throughput, and dynamic ranges are still demanded.
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Affiliation(s)
- Yu-Fen Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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Yu CJ, Tseng WL. Online concentration and separation of basic proteins using a cationic polyelectrolyte in the presence of reversed electroosmotic flow. Electrophoresis 2006; 27:3569-77. [PMID: 16915567 DOI: 10.1002/elps.200600121] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We report an online concentration and separation method for basic proteins using poly(diallyldimethylammonium chloride) (PDDA) solutions in the presence of reversed EOF. Using a capillary dynamically coated with 2% PDDA containing 0.1 M NaCl and filled with 1.2% PDDA under neutral conditions (10 mM phosphate, pH 7.0), we have demonstrated the separation of six basic proteins with peak efficiencies ranging from 175 000 to 616 000 plates/m and RSDs of migration time less than 0.4%. Additionally, high-speed separation of six basic proteins (<7 min) was achieved using a short capillary filled with 0.6% PDDA solutions. Under injection of the large-volume sample (210 nL), the LODs at S/N of 3 for basic proteins are down to nanomolar range. For example, the LOD for lysozyme is 1.2 nM, which is a 260-fold sensitivity enhancement compared with conventional injection method. The proposed method has been applied to the stacking of lysozyme in human saliva samples. Without any pretreatment, we also demonstrated the capability of this method to detect low amounts of peptide samples through the stacking of tryptic peptide of myoglobin. The experimental results indicate that our proposed method has great potential for use in clinical diagnosis and proteomics applications.
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Affiliation(s)
- Cheng-Ju Yu
- Department of Chemistry, National SunYat-sen University, Kaohsiung, Taiwan
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Monton MRN, Terabe S. Sample enrichment techniques in capillary electrophoresis: Focus on peptides and proteins. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 841:88-95. [PMID: 16716769 DOI: 10.1016/j.jchromb.2006.04.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 04/17/2006] [Accepted: 04/20/2006] [Indexed: 01/03/2023]
Abstract
Compared to chromatography-based techniques, the concentration limits of detection (CLOD) associated with capillary electrophoresis are worse, and these have largely precluded their use in many practical applications. To overcome this limitation, researchers from various disciplines have exerted tremendous efforts toward developing strategies for increasing the concentration sensitivities of capillary electrophoresis (CE) systems, via the so-called sample enrichment techniques. This review highlights selected developments and advances in this area as applied to the analyses of proteins and peptides in the last 5 years.
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Affiliation(s)
- Maria Rowena N Monton
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0017, Japan
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Zhang H, Hunter GK, Goldberg HA, Lajoie GA, Yeung KKC. An integrated procedure of selective injection, sample stacking and fractionation of phosphopeptides for MALDI MS analysis. Anal Chim Acta 2006; 581:268-80. [PMID: 17386453 DOI: 10.1016/j.aca.2006.08.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 08/09/2006] [Accepted: 08/10/2006] [Indexed: 10/24/2022]
Abstract
Protein phosphorylation is one of the most important post-translational modifications (PTM), however, the detection of phosphorylation in proteins using mass spectrometry (MS) remains challenging. This is because many phosphorylated proteins are only present in low abundance, and the ionization of the phosphorylated components in MS is very inefficient compared to the non-phosphorylated counterparts. Recently, we have reported a selective injection technique that can separate phosphopeptides from non-phosphorylated peptides due to the differences in their isoelectric points (pI) [1]. Phosphorylated peptides from alpha-casein were clearly observed at low femtomole level using MALDI MS. In this work, further developments on selective injection of phosphopeptides are presented to enhance its capability in handling higher sample complexity. The approach is to integrate selective injection with a sample stacking technique used in capillary electrophoresis to enrich the sample concentration, followed by electrophoresis to fractionate the components in preparation for MALDI MS analysis. The effectiveness of the selective injection and stacking was evaluated quantitatively using a synthetic phosphopeptide as sample, with an enrichment factor of up to 600 being recorded. Next, a tryptic digest of alpha-casein was used to evaluate the separation and fractionation of peptides for MALDI MS analysis. The elution order of phosphopeptides essentially followed the order of decreasing number of phosphates on the peptides. Finally, to illustrate the applicability, the integrated procedure was applied to evaluate the phosphorylation of a highly phosphorylated protein, osteopontin. Up to 41 phosphopeptides were observed, which allowed us to examine the phosphorylation of all 29 possible sites previously reported [2]. A high level of heterogeneity in the phosphorylation of OPN was evident by the multiple-forms of variable phosphorylation detected for a large number of peptides.
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Affiliation(s)
- Haixia Zhang
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
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Kraly J, Fazal MA, Schoenherr RM, Bonn R, Harwood MM, Turner E, Jones M, Dovichi NJ. Bioanalytical Applications of Capillary Electrophoresis. Anal Chem 2006; 78:4097-110. [PMID: 16771542 DOI: 10.1021/ac060704c] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James Kraly
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
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Kasicka V. Recent developments in capillary electrophoresis and capillary electrochromatography of peptides. Electrophoresis 2006; 27:142-75. [PMID: 16307429 DOI: 10.1002/elps.200500527] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The article gives a comprehensive review on the recent developments in the applications of high-performance capillary electromigration methods, zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography, to analysis, preparation, and physicochemical characterization of peptides. The article presents new approaches to the theoretical description and experimental verification of electromigration behavior of peptides, covers the methodological aspects of capillary electroseparations of peptides, such as rational selection of separation conditions, sample preparation, suppression of peptide adsorption, new developments in individual separation modes, and new designs of detection systems. Several types of applications of capillary electromigration methods to peptide analysis are presented: conventional qualitative and quantitative analysis, purity control, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of capillary electromigration techniques to provide important physicochemical characteristics of peptides are demonstrated.
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Affiliation(s)
- Václav Kasicka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Abstract
This review article with 304 references describes recent developments in CE of proteins, and covers the two years since the previous review (Hutterer, K., Dolník, V., Electrophoresis 2003, 24, 3998-4012) through Spring 2005. It covers topics related to CE of proteins, including modeling of the electrophoretic migration of proteins, sample pretreatment, wall coatings, improving separation, various forms of detection, special electrophoretic techniques such as affinity CE, CIEF, and applications of CE to the analysis of proteins in real-world samples including human body fluids, food and agricultural samples, protein pharmaceuticals, and recombinant protein preparations.
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Breadmore MC, Mosher RA, Thormann W. High-Resolution Computer Simulations of Stacking of Weak Bases Using a Transient pH Boundary in Capillary Electrophoresis. 1. Concept and Impact of Sample Ionic Strength. Anal Chem 2005; 78:538-46. [PMID: 16408937 DOI: 10.1021/ac051420f] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamics of focusing weak bases using a transient pH boundary was examined via high-resolution computer simulation software. Emphasis was placed on the mechanism and impact that the presence of salt, namely, NaCl, has on the ability to focus weak bases. A series of weak bases with mobilities ranging from 5 x 10(-9) to 30 x 10(-9) m2/V x s and pKa values between 3.0 and 7.5 were examined using a combination of 65.6 mM formic acid, pH 2.85, for the separation electrolyte, and 65.6 mM formic acid, pH 8.60, for the sample matrix. Simulation data show that it is possible to focus weak bases with a pKa value similar to that of the separation electrolyte, but it is restricted to weak bases having an electrophoretic mobility of 20 x 10(-9) m2/V x s or quicker. This mobility range can be extended by the addition of NaCl, with 50 mM NaCl allowing stacking of weak bases down to a mobility of 15 x 10(-9) m2/V x s and 100 mM extending the range to 10 x 10(-9) m2/V x s. The addition of NaCl does not adversely influence focusing of more mobile bases, but does prolong the existence of the transient pH boundary. This allows analytes to migrate extensively through the capillary as a single focused band around the transient pH boundary until the boundary is dissipated. This reduces the length of capillary that is available for separation and, in extreme cases, causes multiple analytes to be detected as a single highly efficient peak.
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Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, G.P.O. Box 252-75, Hobart, Tasmania 7001, Australia.
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