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Štěpánová S, Kašička V. Determination of physicochemical parameters of (bio)molecules and (bio)particles by capillary electromigration methods. J Sep Sci 2024; 47:e2400174. [PMID: 38867483 DOI: 10.1002/jssc.202400174] [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: 03/06/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 06/14/2024]
Abstract
The review provides an overview of recent developments and applications of capillary electromigration (CE) methods for the determination of important physicochemical parameters of various (bio)molecules and (bio)particles. These parameters include actual and limiting (absolute) ionic mobilities, effective electrophoretic mobilities, effective charges, isoelectric points, electrokinetic potentials, hydrodynamic radii, diffusion coefficients, relative molecular masses, acidity (ionization) constants, binding constants and stoichiometry of (bio)molecular complexes, changes of Gibbs free energy, enthalpy and entropy and rate constants of chemical reactions and interactions, retention factors and partition and distribution coefficients. For the determination of these parameters, the following CE methods are employed: zone electrophoresis in a free solution or in sieving media, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography. In the individual sections, the procedures for the determination of the above parameters by the particular CE methods are described.
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Affiliation(s)
- Sille Štěpánová
- Electromigration methods, Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Václav Kašička
- Electromigration methods, Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
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2
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Fan X, Xu L, Zhang J, Wang Y, Wu Z, Sun W, Yao X, Wang X, Guan S, Shan Y. Mechanism Exploration of Amyloid-β-42 Disaggregation by Single-Chain Variable Fragments of Alzheimer's Disease Therapeutic Antibodies. Int J Mol Sci 2023; 24:ijms24098371. [PMID: 37176076 PMCID: PMC10179127 DOI: 10.3390/ijms24098371] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Alzheimer's disease (AD) is a specific neurodegenerative disease. This study adopts single-chain variable fragments (scFvs) as a potential immunotherapeutic precursor for AD. According to the remarkable effects of monoclonal antibodies, such as the depolymerization or promotion of Aβ42 efflux by Crenezumab, Solanezumab, and 12B4, it is attractive to prepare corresponding scFvs targeting amyloid-β-42 protein (Aβ42) and investigate their biological activities. Crenezumab-like scFv (scFv-C), Solanezumab-like scFv (scFv-S), and 12B4-like scFv (scFv-12B4) were designed and constructed. The thermal stabilities and binding ability to Aβ42 of scFv-C, scFv-S, and scFv-12B4 were evaluated using unfolding profile and enzyme-linked immunosorbent assay. As the results indicated that scFv-C could recognize Aβ42 monomer/oligomer and promote the disaggregation of Aβ42 fiber as determined by the Thioflavin-T assay, the potential mechanism of its interaction with Aβ42 was investigated using molecular dynamics analysis. Interactions involving hydrogen bonds and salt bonds were predicted between scFv-C and Aβ42 pentamer, suggesting the possibility of inhibiting further aggregation of Aβ42. The successfully prepared scFvs, especially scFv-C, with favorable biological activity targeting Aβ42, might be developed for a potentially efficacious clinical application for AD.
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Affiliation(s)
- Xing Fan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Lipeng Xu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Jianhao Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yidan Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Zirui Wu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Wenjing Sun
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Xin Yao
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Xu Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Shanshan Guan
- College of Biology and Food Engineering, Jilin Engineering Normal University, Changchun 130052, China
| | - Yaming Shan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
- Key Laboratory for Molecular Enzymology and Engineering, The Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China
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3
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Abstract
Antibodies and T cell receptors (TCRs) are the fundamental building blocks of adaptive immunity. Repertoire-scale functionality derives from their epitope-binding properties, just as macroscopic properties like temperature derive from microscopic molecular properties. However, most approaches to repertoire-scale measurement, including sequence diversity and entropy, are not based on antibody or TCR function in this way. Thus, they potentially overlook key features of immunological function. Here we present a framework that describes repertoires in terms of the epitope-binding properties of their constituent antibodies and TCRs, based on analysis of thousands of antibody-antigen and TCR-peptide-major-histocompatibility-complex binding interactions and over 400 high-throughput repertoires. We show that repertoires consist of loose overlapping classes of antibodies and TCRs with similar binding properties. We demonstrate the potential of this framework to distinguish specific responses vs. bystander activation in influenza vaccinees, stratify cytomegalovirus (CMV)-infected cohorts, and identify potential immunological "super-agers." Classes add a valuable dimension to the assessment of immune function.
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4
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Dutta D. Stream Broadening in Free Flow Affinity Electrophoresis. J Chromatogr A 2022; 1671:463019. [DOI: 10.1016/j.chroma.2022.463019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 11/29/2022]
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5
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Ermolenko Y, Nazarova N, Belov A, Kalistratova A, Ulyanova Y, Osipova N, Gelperina S. Potential of the capillary electrophoresis method for PLGA analysis in nano-sized drug formulations. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.103220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Opallage PM, De Silva M, Dunn RC. Dual detection high-speed capillary electrophoresis for simultaneous serum protein analysis and immunoassays. Sci Rep 2022; 12:1951. [PMID: 35121780 PMCID: PMC8817013 DOI: 10.1038/s41598-022-05956-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/17/2022] [Indexed: 11/09/2022] Open
Abstract
Serum protein electrophoresis (SPE) separates serum proteins into bands whose shape and amplitude can alert clinicians to a range of disorders. This is followed by more specific immunoassays to quantify important antigens and confirm a diagnosis. Here we develop a high-speed capillary electrophoresis (HSCE) platform capable of simultaneous SPE and immunoassay measurements. A single laser excitation source is focused into the detection zone of the capillary to measure both refractive index (SPE) and fluorescence signals (immunoassays). The refractive index signal measures characteristic SPE profiles for human serum separated in 100 mM boric acid (pH 10), 100 mM arginine (pH 11), and 20 mM CHES (pH 10). For the immunoassay, the fluorescence electropherograms reveal that CHES provides the optimal buffer for measuring the immunocomplex and separating it from the free antigen. Immunoassays in CHES yield a LOD of 23 nM and a LOQ of 70 nM for the detection of fluorescein. The high pH reduces protein adsorption but reduces antibody affinity. Preliminary studies carried out in 50 mM barbital at pH 8 show improved stability of the immunocomplex and better separation for immunoassay quantification. Further optimization will open new capabilities for measuring orthogonal diagnostic signals in seconds with HSCE.
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Affiliation(s)
- Prabhavie M Opallage
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS, 66047, USA
| | - Miyuru De Silva
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS, 66047, USA
| | - Robert C Dunn
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS, 66047, USA.
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7
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den Boer MA, Lai SH, Xue X, van Kampen MD, Bleijlevens B, Heck AJR. Comparative Analysis of Antibodies and Heavily Glycosylated Macromolecular Immune Complexes by Size-Exclusion Chromatography Multi-Angle Light Scattering, Native Charge Detection Mass Spectrometry, and Mass Photometry. Anal Chem 2021; 94:892-900. [PMID: 34939405 PMCID: PMC8771642 DOI: 10.1021/acs.analchem.1c03656] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Qualitative and quantitative mass analysis of antibodies and related macromolecular immune complexes is a prerequisite for determining their identity, binding partners, stoichiometries, and affinities. A plethora of bioanalytical technologies exist to determine such characteristics, typically based on size, interaction with functionalized surfaces, light scattering, or direct mass measurements. While these methods are highly complementary, they also exhibit unique strengths and weaknesses. Here, we benchmark mass photometry (MP), a recently introduced technology for mass measurement, against native mass spectrometry (MS) and size exclusion chromatography multi-angle light scattering (SEC-MALS). We examine samples of variable complexity, namely, IgG4Δhinge dimerizing half-bodies, IgG-RGY hexamers, heterogeneously glycosylated IgG:sEGFR antibody-antigen complexes, and finally megadalton assemblies involved in complement activation. We thereby assess the ability to determine (1) binding affinities and stoichiometries, (2) accurate masses, for extensively glycosylated species, and (3) assembly pathways of large heterogeneous immune complexes. We find that MP provides a sensitive approach for characterizing antibodies and stable assemblies, with dissociation correction enabling us to expand the measurable affinity range. In terms of mass resolution and accuracy, native MS performs the best but is occasionally hampered by artifacts induced by electrospray ionization, and its resolving power diminishes when analyzing extensively glycosylated proteins. In the latter cases, MP performs well, but single-particle charge detection MS can also be useful in this respect, measuring masses of heterogeneous assemblies even more accurately. Both methods perform well compared to SEC-MALS, still being the most established method in biopharma. Together, our data highlight the complementarity of these approaches, each having its unique strengths and weaknesses.
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Affiliation(s)
- Maurits A den Boer
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Szu-Hsueh Lai
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Xiaoguang Xue
- Genmab, Uppsalalaan 15, 3584 CT Utrecht, The Netherlands
| | | | | | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
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8
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Nasreddine R, Nehmé R. Microscale thermophoresis for studying protein-small molecule affinity: Application to hyaluronidase. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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9
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Kašička V. Recent developments in capillary and microchip electroseparations of peptides (2019-mid 2021). Electrophoresis 2021; 43:82-108. [PMID: 34632606 DOI: 10.1002/elps.202100243] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 12/19/2022]
Abstract
The review provides a comprehensive overview of developments and applications of high performance capillary and microchip electroseparation methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography) for analysis, microscale isolation, and physicochemical characterization of peptides from 2019 up to approximately the middle of 2021. Advances in the investigation of electromigration properties of peptides and in the methodology of their analysis, such as sample preparation, sorption suppression, EOF control, and detection, are presented. New developments in the individual CE and CEC methods are demonstrated and several types of their applications are shown. They include qualitative and quantitative analysis, determination in complex biomatrices, monitoring of chemical and enzymatic reactions and physicochemical changes, amino acid, sequence, and chiral analyses, and peptide mapping of proteins. In addition, micropreparative separations and determination of significant physicochemical parameters of peptides by CE and CEC methods are described.
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Affiliation(s)
- Václav Kašička
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague 6, Czechia
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10
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Soltermann F, Struwe WB, Kukura P. Label-free methods for optical in vitro characterization of protein-protein interactions. Phys Chem Chem Phys 2021; 23:16488-16500. [PMID: 34342317 PMCID: PMC8359934 DOI: 10.1039/d1cp01072g] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/23/2021] [Indexed: 12/13/2022]
Abstract
Protein-protein interactions are involved in the regulation and function of the majority of cellular processes. As a result, much effort has been aimed at the development of methodologies capable of quantifying protein-protein interactions, with label-free methods being of particular interest due to the associated simplified workflows and minimisation of label-induced perturbations. Here, we review recent advances in optical technologies providing label-free in vitro measurements of affinities and kinetics. We provide an overview and comparison of existing techniques and their principles, discussing advantages, limitations, and recent applications.
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Affiliation(s)
- Fabian Soltermann
- Physical and Theoretical Chemistry, Department of Chemistry, University of OxfordUK
| | - Weston B. Struwe
- Physical and Theoretical Chemistry, Department of Chemistry, University of OxfordUK
| | - Philipp Kukura
- Physical and Theoretical Chemistry, Department of Chemistry, University of OxfordUK
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11
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Chen Y, Zhou Y, Yin H. Recent advances in biosensor for histone acetyltransferase detection. Biosens Bioelectron 2021; 175:112880. [DOI: 10.1016/j.bios.2020.112880] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/15/2022]
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12
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Xiao J, Lu Q, Cong H, Shen Y, Yu B. Microporous poly(glycidyl methacrylate- co-ethylene glycol dimethyl acrylate) microspheres: synthesis, functionalization and applications. Polym Chem 2021. [DOI: 10.1039/d1py00834j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As a new kind of functional material, micron-sized porous polymer microspheres are a hot research topic in the field of polymer materials.
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Affiliation(s)
- Jingyuan Xiao
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Qingbiao Lu
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Hailin Cong
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
- State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China
| | - Youqing Shen
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Bing Yu
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
- State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China
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13
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Liu S, Li Z, Yu B, Wang S, Shen Y, Cong H. Recent advances on protein separation and purification methods. Adv Colloid Interface Sci 2020; 284:102254. [PMID: 32942182 DOI: 10.1016/j.cis.2020.102254] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/01/2020] [Accepted: 09/01/2020] [Indexed: 12/21/2022]
Abstract
Protein, as the material basis of vita, is the crucial undertaker of life activities, which constitutes the framework and main substance of human tissues and organs, and takes part in various forms of life activities in organisms. Separating proteins from biomaterials and studying their structures and functions are of great significance for understanding the law of life activities and clarifying the essence of life phenomena. Therefore, scientists have proposed the new concept of proteomics, in which protein separation technology plays a momentous role. It has been diffusely used in the food industry, agricultural biological research, drug development, disease mechanism, plant stress mechanism, and marine environment research. In this paper, combined with the recent research situation, the progress of protein separation technology was reviewed from the aspects of extraction, precipitation, membrane separation, chromatography, electrophoresis, molecular imprinting, microfluidic chip and so on.
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14
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Kannan P, Chen J, Su F, Guo Z, Huang Y. Faraday-Cage-Type Electrochemiluminescence Immunoassay: A Rise of Advanced Biosensing Strategy. Anal Chem 2019; 91:14792-14802. [PMID: 31692335 DOI: 10.1021/acs.analchem.9b04503] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Electrochemiluminescence immunoassays are usually carried out through "on-electrode" strategy, i.e., sandwich-type immunoassay format, the sensitivity of which is restricted by two key bottlenecks: (1) the number of signal labels is limited and (2) only a part of signal labels could participate in the electrode reaction. In this Perspective, we discuss the development of an "in-electrode" Faraday-cage-type concept-based immunocomplex immobilization strategy. The biggest difference from the traditional sandwich-type one is that the designed "in-electrode" Faraday-cage-type immunoassay uses a conductive two-dimensional (2-D) nanomaterial simultaneously coated with signal labels and a recognition component as the detection unit, which could directly overlap on the electrode surface. In such a case, electrons could flow freely from the electrode to the detection unit, the outer Helmholtz plane (OHP) of the electrode is extended, and thousands of signal labels coated on the 2-D nanomaterial are all electrochemically "effective." Thus, then, the above-mentioned bottlenecks obstructing the improvement of the sensitivity in sandwich-type immunoassay are eliminated, and as a result a much higher sensitivity of the Faraday-cage-type immunoassay can be obtained. And, the applications of the proposed versatile "in-electrode" Faraday-cage-type immunoassay have been explored in the detection of target polypeptide, protein, pathogen, and microRNA, with the detection sensitivity improved tens to hundreds of times. Finally, the outlook and challenges in the field are summarized. The rise of Faraday-cage-type electrochemiluminescence immunoassay (FCT-ECLIA)-based biosensing strategies opens new horizons for a wide range of early clinical identification and diagnostic applications.
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Affiliation(s)
- Palanisamy Kannan
- College of Biological, Chemical Sciences and Engineering , Jiaxing University , Jiaxing 314001 , People's Republic of China
| | - Jing Chen
- Division of Polymer and Composite Materials , Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Science (CAS) , Ningbo 315201 , People's Republic of China
| | - Fengmei Su
- National Engineering Research Centre for Advanced Polymer Processing Technology, Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education , Zhengzhou University , Zhengzhou 450002 , People's Republic of China
| | - Zhiyong Guo
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, State Key Laboratory Base of Novel Functional Materials and Preparation Science, School of Materials Science and Chemical Engineering , Ningbo University , Ningbo 315211 , People's Republic of China
| | - Youju Huang
- College of Materials, Chemistry and Chemical Engineering , Hangzhou Normal University , Hangzhou 311121 , People's Republic of China
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15
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Sasaki Y, Sato Y, Takahashi T, Umetsu M, Iki N. Capillary electrophoretic reactor for estimation of spontaneous dissociation rate of Trypsin-Aprotinin complex. Anal Biochem 2019; 585:113406. [PMID: 31445899 DOI: 10.1016/j.ab.2019.113406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 11/25/2022]
Abstract
A capillary electrophoretic reactor was used to analyze the dissociation kinetics of an enzyme-inhibitor complex in a homogeneous solution without immobilization. The complex consisting of trypsin (Try) and aprotinin (Apr) was used as the model. Capillary electrophoresis provided a reaction field for Try-Apr complex to dissociate through the steady removal of free Try and Apr from the Try-Apr zone. By analyzing the dependence of peak height of Try-Apr on separation time, the dissociation rate kdH was obtained as 2.73 × 10-4 s-1 (298 K) at pH 2.46. The dependence of kdH on the proton concentration (pH = 2.09-3.12) revealed a first-order dependence of kdH on [H+]; kdH = kd + k1[H+], where kd is the spontaneous dissociation rate and was 5.65 × 10-5 s-1, and k1 is the second-order rate constant and was 5.07 × 10-2 M-1 s-1. From the kd value, the half-life of the Try-Apr complex at physiological pH was determined as 3.4 h. The presence of the proton-assisted dissociation can be explained by the protonation of -COO- of the Asp residue in Try, which breaks the salt bridge with the -NH3+ group of Lys in Apr.
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Affiliation(s)
- Yumiko Sasaki
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aramaki-Aoba, Aoba, Sendai, 980-8579, Japan
| | - Yosuke Sato
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aramaki-Aoba, Aoba, Sendai, 980-8579, Japan
| | - Toru Takahashi
- Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui, 910-8507, Japan
| | - Mitsuo Umetsu
- Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki-Aoba, Aoba, Sendai, 980-8579, Japan
| | - Nobuhiko Iki
- Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aramaki-Aoba, Aoba, Sendai, 980-8579, Japan.
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16
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Kašička V. Recent developments in capillary and microchip electroseparations of peptides (2017–mid 2019). Electrophoresis 2019; 41:10-35. [DOI: 10.1002/elps.201900269] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/08/2019] [Accepted: 10/19/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Václav Kašička
- Institute of Organic Chemistry and BiochemistryCzech Academy of Sciences Prague 6 Czechia
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17
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Yu F, Zhao Q, Zhang D, Yuan Z, Wang H. Affinity Interactions by Capillary Electrophoresis: Binding, Separation, and Detection. Anal Chem 2018; 91:372-387. [PMID: 30392351 DOI: 10.1021/acs.analchem.8b04741] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fangzhi Yu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| | - Qiang Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| | - Dapeng Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China
| | - Zheng Yuan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , 100085 , China.,University of Chinese Academy of Sciences , Beijing , 100049 , China
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18
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