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Takayanagi T, Mine M, Mizuguchi H. Capillary Electrophoresis/Dynamic Frontal Analysis for the Enzyme Assay of 4-Nitrophenyl Phosphate with Alkaline Phosphatase. ANAL SCI 2020; 36:829-834. [PMID: 31956161 DOI: 10.2116/analsci.19p471] [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] [Indexed: 11/23/2022]
Abstract
A substrate of 4-nitrophenyl phosphate was enzymatically hydrolyzed by alkaline phosphatase (ALP) in a capillary tube, while an injected zone of the substrate was electrophoretically migrating in the separation buffer containing the enzyme by capillary electrophoresis (CE). During CE migration of the substrate from the start time of the electrophoresis to the detection time of the substrate, the substrate was continuously hydrolyzed by ALP to form a product of 4-nitrophenolate, and a plateau signal of 4-nitrophenolate was detected as a result of the zero-order kinetic reaction. The height of the plateau signal was directly related to the reaction rate, and it was used for the determination of a Michaelis-Menten constant through Lineweaver-Burk plots. Since the plateau signal is attributed to the dynamic formation of the product by the enzymatic reaction in CE, this analysis method is named as capillary electrophoresis/dynamic frontal analysis (CE/DFA). In CE/DFA, the CE separation is included on detecting the plateau signal, and the hydrolysis product before the sample injection is resolved from the dynamically and continuously formed product. The inhibition of the enzyme with the product is also eliminated in CE/DFA by the CE separation.
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Affiliation(s)
- Toshio Takayanagi
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University
| | - Masanori Mine
- Graduate School of Advanced Technology and Science, Tokushima University
| | - Hitoshi Mizuguchi
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University
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2
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Zhang C, Woolfork AG, Suh K, Ovbude S, Bi C, Elzoeiry M, Hage DS. Clinical and pharmaceutical applications of affinity ligands in capillary electrophoresis: A review. J Pharm Biomed Anal 2019; 177:112882. [PMID: 31542417 DOI: 10.1016/j.jpba.2019.112882] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 01/14/2023]
Abstract
Affinity capillary electrophoresis (ACE) is a separation technique that combines a biologically-related binding agent with the separating power and efficiency of capillary electrophoresis. This review will examine several classes of binding agents that have been used in ACE and applications that have been described for the resulting methods in clinical or pharmaceutical analysis. Binding agents that will be considered are antibodies, aptamers, lectins, serum proteins, carbohydrates, and enzymes. This review will also describe the various formats in which each type of binding agent has been used in CE, including both homogeneous and heterogeneous methods. Specific areas of applications that will be considered are CE-based immunoassays, glycoprotein/glycan separations, chiral separations, and biointeraction studies. The general principles and formats of ACE for each of these applications will be examined, along with the potential advantages or limitations of these methods.
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Affiliation(s)
- Chenhua Zhang
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA
| | - Ashley G Woolfork
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA
| | - Kyungah Suh
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA
| | - Susan Ovbude
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA
| | - Cong Bi
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA
| | - Marawan Elzoeiry
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA
| | - David S Hage
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304, USA.
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Gattu S, Crihfield CL, Lu G, Bwanali L, Veltri LM, Holland LA. Advances in enzyme substrate analysis with capillary electrophoresis. Methods 2018; 146:93-106. [PMID: 29499329 PMCID: PMC6098732 DOI: 10.1016/j.ymeth.2018.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/01/2018] [Accepted: 02/05/2018] [Indexed: 02/06/2023] Open
Abstract
Capillary electrophoresis provides a rapid, cost-effective platform for enzyme and substrate characterization. The high resolution achievable by capillary electrophoresis enables the analysis of substrates and products that are indistinguishable by spectroscopic techniques alone, while the small volume requirement enables analysis of enzymes or substrates in limited supply. Furthermore, the compatibility of capillary electrophoresis with various detectors makes it suitable for KM determinations ranging from nanomolar to millimolar concentrations. Capillary electrophoresis fundamentals are discussed with an emphasis on the separation mechanisms relevant to evaluate sets of substrate and product that are charged, neutral, and even chiral. The basic principles of Michaelis-Menten determinations are reviewed and the process of translating capillary electrophoresis electropherograms into a Michaelis-Menten curve is outlined. The conditions that must be optimized in order to couple off-line and on-line enzyme reactions with capillary electrophoresis separations, such as incubation time, buffer pH and ionic strength, and temperature, are examined to provide insight into how the techniques can be best utilized. The application of capillary electrophoresis to quantify enzyme inhibition, in the form of KI or IC50 is detailed. The concept and implementation of the immobilized enzyme reactor is described as a means to increase enzyme stability and reusability, as well as a powerful tool for screening enzyme substrates and inhibitors. Emerging techniques focused on applying capillary electrophoresis as a rapid assay to obtain structural identification or sequence information about a substrate and in-line digestions of peptides and proteins coupled to mass spectrometry analyses are highlighted.
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Affiliation(s)
- Srikanth Gattu
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States
| | - Cassandra L Crihfield
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States
| | - Grace Lu
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States
| | - Lloyd Bwanali
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States
| | - Lindsay M Veltri
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States
| | - Lisa A Holland
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, United States.
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Riasová P, Doubková D, Pincová L, Jung O, Polášek M, Jáč P. Development of micellar electrokinetic chromatography method for the determination of three defined impurities in indomethacin. Electrophoresis 2018; 39:2550-2557. [DOI: 10.1002/elps.201800080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Petra Riasová
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové; Charles University; Czech Republic
| | - Dagmar Doubková
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové; Charles University; Czech Republic
| | - Lucie Pincová
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové; Charles University; Czech Republic
| | - Ondřej Jung
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové; Charles University; Czech Republic
| | - Miroslav Polášek
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové; Charles University; Czech Republic
| | - Pavel Jáč
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové; Charles University; Czech Republic
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Advances in the Use of Cyclodextrins as Chiral Selectors in Capillary Electrokinetic Chromatography: Fundamentals and Applications. Chromatographia 2016. [DOI: 10.1007/s10337-016-3167-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Zhu Q, El-Mergawy RG, Zhou Y, Chen C, Heinemann SH, Schönherr R, Robaa D, Sippl W, Scriba GKE. Stereospecific capillary electrophoresis assays using pentapeptide substrates for the study of Aspergillus nidulans methionine sulfoxide reductase A and mutant enzymes. Electrophoresis 2016; 37:2083-90. [PMID: 27145186 DOI: 10.1002/elps.201600181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 04/27/2016] [Accepted: 04/27/2016] [Indexed: 12/18/2022]
Abstract
Stereospecific capillary electrophoresis-based methods for the analysis of methionine sulfoxide [Met(O)]-containing pentapeptides were developed in order to investigate the reduction of Met(O)-containing peptide substrates by recombinant Aspergillus nidulans methionine sulfoxide reductase A (MsrA) as well as enzymes carrying mutations in position Glu99 and Asp134. The separation of the diastereomers of the N-acetylated, C-terminally 2,4-dinitrophenyl (Dnp)-labeled pentapeptides ac-Lys-Phe-Met(O)-Lys-Lys-Dnp, ac-Lys-Asp-Met(O)-Asn-Lys-Dnp and ac-Lys-Asn-Met(O)-Asp-Lys-Dnp was achieved in 50 mM Tris-HCl buffers containing sulfated β-CD in fused-silica capillaries, while the diastereomer separation of ac-Lys-Asp-Met(O)-Asp-Lys-Dnp was achieved by sulfated β-CD-mediated MEKC. The methods were validated with regard to range, linearity, accuracy, limits of detection and quantitation as well as precision. Subsequently, the substrates were incubated with wild-type MsrA and three mutants in the presence of dithiothreitol as reductant. Wild-type MsrA displayed the highest activity towards all substrates compared to the mutants. Substitution of Glu99 by Gln resulted in the mutant with the lowest activity towards all substrates except for ac-Lys-Asn-Met(O)-Asp-Lys-Dnp, while replacement Asn for Asp134 lead to a higher activity towards ac-Lys-Asp-Met(O)-Asn-Lys-Dnp compared with the Glu99 mutant. The mutant with Glu instead of Asp134 was the most active among the mutant enzymes. Molecular modeling indicated that the conserved Glu99 residue is buried in the Met-S-(O) groove, which might contribute to the correct placing of substrates and, consequently, to the catalytic activity of MsrA, while Asp134 did not form hydrogen bonds with the substrates but only within the enzyme.
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Affiliation(s)
- Qingfu Zhu
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Rabab G El-Mergawy
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Yuzhen Zhou
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Chunyang Chen
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
| | - Stefan H Heinemann
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Roland Schönherr
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Dina Robaa
- Department of Medicinal Chemistry, University of Halle, Halle, Germany
| | - Wolfgang Sippl
- Department of Medicinal Chemistry, University of Halle, Halle, Germany
| | - Gerhard K E Scriba
- Department of Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany
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Kašička V. Recent developments in capillary and microchip electroseparations of peptides (2013-middle 2015). Electrophoresis 2015; 37:162-88. [DOI: 10.1002/elps.201500329] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Revised: 08/25/2015] [Accepted: 08/25/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Václav Kašička
- Institute of Organic Chemistry and Biochemistry, v.v.i; The Czech Academy of Sciences; Prague Czech Republic
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Tajik S, Taher MA, Beitollahi H, Hosseinzadeh R, Ranjbar M. Preparation, Characterization and Electrochemical Application of ZnS/ZnAl2S4Nanocomposite for Voltammetric Determination of Methionine and Tryptophan Using Modified Carbon Paste Electrode. ELECTROANAL 2015. [DOI: 10.1002/elan.201500423] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Achilli C, Ciana A, Minetti G. The discovery of methionine sulfoxide reductase enzymes: An historical account and future perspectives. Biofactors 2015; 41:135-52. [PMID: 25963551 DOI: 10.1002/biof.1214] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/19/2015] [Indexed: 01/26/2023]
Abstract
L-Methionine (L-Met) is the only sulphur-containing proteinogenic amino acid together with cysteine. Its importance is highlighted by it being the initiator amino acid for protein synthesis in all known living organisms. L-Met, free or inserted into proteins, is sensitive to oxidation of its sulfide moiety, with formation of L-Met sulfoxide. The sulfoxide could not be inserted into proteins, and the oxidation of L-Met in proteins often leads to the loss of biological activity of the affected molecule. Key discoveries revealed the existence, in rats, of a metabolic pathway for the reduction of free L-Met sulfoxide and, later, in Escherichia coli, of the enzymatic reduction of L-Met sulfoxide inserted in proteins. Upon oxidation, the sulphur atom becomes a new stereogenic center, and two stable diastereoisomers of L-Met sulfoxide exist. A fundamental discovery revealed the existence of two unrelated families of enzymes, MsrA and MsrB, whose members display opposite stereospecificity of reduction for the two sulfoxides. The importance of Msrs is additionally emphasized by the discovery that one of the only 25 selenoproteins expressed in humans is a Msr. The milestones on the road that led to the discovery and characterization of this group of antioxidant enzymes are recounted in this review.
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Affiliation(s)
- Cesare Achilli
- Laboratories of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Annarita Ciana
- Laboratories of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Giampaolo Minetti
- Laboratories of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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Zhu Q, Heinemann SH, Schönherr R, Scriba GKE. Capillary electrophoresis separation of peptide diastereomers that contain methionine sulfoxide by dual cyclodextrin-crown ether systems. J Sep Sci 2014; 37:3548-54. [PMID: 25216019 DOI: 10.1002/jssc.201400825] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/03/2014] [Accepted: 09/04/2014] [Indexed: 12/12/2022]
Abstract
A dual-selector system employing achiral crown ethers in combination with cyclodextrins has been developed for the separation of peptide diastereomers that contain methionine sulfoxide. The combinations of the crown ethers 15-crown-5, 18-crown-6, Kryptofix® 21 and Kryptofix® 22 and β-cyclodextrin, carboxymethyl-β-cyclodextrin, and sulfated β-cyclodextrin were screened at pH 2.5 and pH 8.0 using a 40/50.2 cm, 50 μm id fused-silica capillary and a separation voltage of 25 kV. No diastereomer separation was observed in the sole presence of crown ethers, while only sulfated β-cyclodextrin was able to resolve some peptide diastereomers at pH 8.0. Depending on the amino acid sequence of the peptide and the applied cyclodextrin, the addition of crown ethers, especially the Krpytofix® diaza-crown ethers, resulted in significantly enhanced chiral recognition. Keeping one selector of the dual system constant, increasing concentrations of the second selector resulted in increased peak resolution and analyte migration time for peptide-crown ether-cyclodextrin combinations. The simultaneous diastereomer separation of three structurally related peptides was achieved using the dual selector system.
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Affiliation(s)
- Qingfu Zhu
- Department of Pharmaceutical/Medicinal Chemistry, Friedrich Schiller University Jena, Jena, Germany
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