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Marie A, Georgescauld F, Johnson KR, Ray S, Engen JR, Ivanov AR. Native Capillary Electrophoresis-Mass Spectrometry of Near 1 MDa Non-Covalent GroEL/GroES/Substrate Protein Complexes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306824. [PMID: 38191978 PMCID: PMC10953559 DOI: 10.1002/advs.202306824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/21/2023] [Indexed: 01/10/2024]
Abstract
Protein complexes are essential for proteins' folding and biological function. Currently, native analysis of large multimeric protein complexes remains challenging. Structural biology techniques are time-consuming and often cannot monitor the proteins' dynamics in solution. Here, a capillary electrophoresis-mass spectrometry (CE-MS) method is reported to characterize, under near-physiological conditions, the conformational rearrangements of ∽1 MDa GroEL upon complexation with binding partners involved in a protein folding cycle. The developed CE-MS method is fast (30 min per run), highly sensitive (low-amol level), and requires ∽10 000-fold fewer samples compared to biochemical/biophysical techniques. The method successfully separates GroEL14 (∽800 kDa), GroEL7 (∽400 kDa), GroES7 (∽73 kDa), and NanA4 (∽130 kDa) oligomers. The non-covalent binding of natural substrate proteins with GroEL14 can be detected and quantified. The technique allows monitoring of GroEL14 conformational changes upon complexation with (ATPγS)4-14 and GroES7 (∽876 kDa). Native CE-pseudo-MS3 analyses of wild-type (WT) GroEL and two GroEL mutants result in up to 60% sequence coverage and highlight subtle structural differences between WT and mutated GroEL. The presented results demonstrate the superior CE-MS performance for multimeric complexes' characterization versus direct infusion ESI-MS. This study shows the CE-MS potential to provide information on binding stoichiometry and kinetics for various protein complexes.
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Affiliation(s)
- Anne‐Lise Marie
- Barnett Institute of Chemical and Biological AnalysisDepartment of Chemistry and Chemical BiologyNortheastern University360 Huntington AvenueBostonMA02115USA
| | - Florian Georgescauld
- Barnett Institute of Chemical and Biological AnalysisDepartment of Chemistry and Chemical BiologyNortheastern University360 Huntington AvenueBostonMA02115USA
| | - Kendall R. Johnson
- Barnett Institute of Chemical and Biological AnalysisDepartment of Chemistry and Chemical BiologyNortheastern University360 Huntington AvenueBostonMA02115USA
| | - Somak Ray
- Barnett Institute of Chemical and Biological AnalysisDepartment of Chemistry and Chemical BiologyNortheastern University360 Huntington AvenueBostonMA02115USA
| | - John R. Engen
- Barnett Institute of Chemical and Biological AnalysisDepartment of Chemistry and Chemical BiologyNortheastern University360 Huntington AvenueBostonMA02115USA
| | - Alexander R. Ivanov
- Barnett Institute of Chemical and Biological AnalysisDepartment of Chemistry and Chemical BiologyNortheastern University360 Huntington AvenueBostonMA02115USA
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Su J, Sun T, Wang Y, Shen Y. Conformational Dynamics of Glucagon-like Peptide-2 with Different Electric Field. Polymers (Basel) 2022; 14:polym14132722. [PMID: 35808767 PMCID: PMC9269336 DOI: 10.3390/polym14132722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 11/28/2022] Open
Abstract
Molecular dynamics (MD) simulation was used to study the influence of electric field on Glucagon-like Peptide-2 (GLP-2). Different electric field strengths (0 V/nm ≤ E ≤ 1 V/nm) were mainly carried out on GLP-2. The structural changes in GLP-2 were analyzed by the Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), Radius of Gyration (Rg), Solvent Accessible Surface Area (SASA), Secondary Structure and the number of hydrogen bonds. The stable α—helix structure of GLP-2 was unwound and transformed into an unstable Turn and Coil structure since the stability of the GLP-2 protein structure was reduced under the electric field. Our results show that the degree of unwinding of the GLP-2 structure was not linearly related to the electric field intensity. E = 0.5 V/nm was a special point where the degree of unwinding of the GLP-2 structure reached the maximum at this electric field strength. Under a weak electric field, E < 0.5 V/nm, the secondary structure of GLP-2 becomes loose, and the entropy of the chain increases. When E reaches a certain value (E > 0.5 V/nm), the electric force of the charged residues reaches equilibrium, along the z-direction. Considering the confinement of moving along another direction, the residue is less free. Thus, entropy decreases and enthalpy increases, which enhance the interaction of adjacent residues. It is of benefit to recover hydrogen bonds in the middle region of the protein. These investigations, about the effect of an electric field on the structure of GLP-2, can provide some theoretical basis for the biological function of GLP-2 in vivo.
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Affiliation(s)
| | - Tingting Sun
- Correspondence: (T.S.); (Y.W.); Tel.: +86-571-8507-0705 (T.S. & Y.W.)
| | - Yan Wang
- Correspondence: (T.S.); (Y.W.); Tel.: +86-571-8507-0705 (T.S. & Y.W.)
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3
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Yu F, Yuan Z, Zhang D, Liu Y, Zhao Q, Wang H. High-affinity and undissociated capillary electrophoresis for DNA strand exchange analysis. Chem Commun (Camb) 2020; 56:7403-7406. [PMID: 32514506 DOI: 10.1039/d0cc02844d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
By identification of a super-stable protein-DNA-affinity system, we developed a free-solution capillary electrophoresis approach for rapid and sensitive detection of fundamentally important DNA strand exchange reactions mediated by recombinases. We further extended this assay for identification of hyper-recombinases generated from bioengineering and detection of single DNA mismatches caused by replication error.
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Affiliation(s)
- Fangzhi Yu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18 Shuangqing Road, Beijing 100085, P. R. China.
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Leng W, Evans K, Roper MG. A microfluidic platform integrating pressure-driven and electroosmotic-driven flow with inline filters for affinity separations. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2019; 11:5768-5775. [PMID: 31983930 PMCID: PMC6980329 DOI: 10.1039/c9ay01758e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Pancreatic islets of Langerhans release glucagon to maintain blood glucose levels, and release of this peptide is dysregulated in diabetes mellitus. Although the importance of proper secretion of this peptide has been shown, no measurement of its release at the single islet level has been reported. In previous work, a non-competitive assay for glucagon was developed with a 6 pM limit of detection, low enough to measure from a single islet. To incorporate this method in an online assay, a microfluidic system with several distinct features was developed. To maintain appropriate flow rates in the presence of the high concentration of salt that was required for the assay, a piezo-actuated pressure transducer with in-line flow sensors was used to drive sample flow through 80 × 50 μm (width × depth) channels, while electroosmotic flow was used to gate the sample away from 15 × 5 μm separation channel. Flow rates tested with this system were 50 - 200 nL min-1 with relative standard deviations (RSDs) ranging from 1 - 4 %. Use of the pressure-driven flow was found to increase the amount of clogs in the system, so a method to incorporate in-line filters into the channels was developed. A total of 4 low resistance, in-line microfabricated filters were evaluated, with all designs prolonging the operation time of the microfluidic device to more than 4 hours without clogs observed. Use of this system enabled highly reproducible injections (3-6% RSD). During initial incorporation of the noncompetitive assay for glucagon, it was determined that Joule heating was problematic and temperature measurements revealed the separation channel increased to more than 50°C during operation. A 3D-printed manifold was used to hold a Peltier cooler in place on the microfluidic device which produced a 2.6-fold improvement in the amount of the noncovalent glucagon complex that was detected compared to without cooling. These features are expected to be useful for not only long-term monitoring of the glucagon release from islets of Langerhans, but has the potential to be applied to a number of other microfluidic separation-based assays as well.
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Affiliation(s)
- Weijia Leng
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Dittmer Building, Tallahassee, FL 32306, USA
| | - Kimberly Evans
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Dittmer Building, Tallahassee, FL 32306, USA
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Dittmer Building, Tallahassee, FL 32306, USA
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Nowak PM, Śpiewak K, Woźniakiewicz M, Kościelniak P. Minimizing the impact of Joule heating as a prerequisite for the reliable analysis of metal‐protein complexes by capillary electrophoresis. J Chromatogr A 2017; 1495:83-87. [DOI: 10.1016/j.chroma.2017.03.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/14/2017] [Accepted: 03/16/2017] [Indexed: 11/29/2022]
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6
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Li Z, Wang Q, Yang X, Wang K, Du S, Zhang H, Gao L, Zheng Y, Nie W. Evaluating the Effect of Lidocaine on the Interactions of C-reactive Protein with Its Aptamer and Antibody by Dynamic Force Spectroscopy. Anal Chem 2017; 89:3370-3377. [PMID: 28231708 DOI: 10.1021/acs.analchem.6b03960] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Effects of medicine on the biomolecular interaction have been given extensive attention in biochemistry and biomedicine because of the complexity of the environment in vivo and the increasing opportunity of exposure to medicine. Herein, the effect of lidocaine on the interactions of C-reactive protein (CRP) with its aptamer and antibody under different temperature was investigated through dynamic force spectroscopy (DFS). The results revealed that lidocaine could reduce the binding probabilities and binding affinities of the CRP-aptamer and the CRP-antibody. An interesting discovery was that lidocaine had differential influences on the dynamic force spectra of the CRP-aptamer and the CRP-antibody. The energy landscape of the CRP-aptamer turned from two activation barriers to one after the treatment of lidocaine, while the one activation barrier in energy landscape of the CRP-antibody almost remained unchanged. In addition, similar results were obtained for 25 and 37 °C. In accordance with the result of molecular docking, the reduction of binding probabilities might be due to the binding of lidocaine on CRP. Additionally, the alteration of the dissociation pathway of the CRP-aptamer and the change of binding affinities might be caused by the conformational change of CRP, which was verified through synchronous fluorescence spectroscopy. Furthermore, differential effects of lidocaine on the interactions of CRP-aptamer and CRP-antibody might be attributed to the different dissociation processes and binding sites of the CRP-aptamer and the CRP-antibody and different structures of the aptamer and the antibody. This work indicated that DFS provided information for further research and comprehensive applications of biomolecular interaction, especially in the design of biosensors in complex systems.
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Affiliation(s)
- Zhiping Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Qing Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Xiaohai Yang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Kemin Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Shasha Du
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Hua Zhang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Lei Gao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Yan Zheng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
| | - Wenyan Nie
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, P. R. China
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Kanoatov M, Mehrabanfar S, Krylov SN. Systematic Approach to Optimization of Experimental Conditions in Nonequilibrium Capillary Electrophoresis of Equilibrium Mixtures. Anal Chem 2016; 88:9300-8. [DOI: 10.1021/acs.analchem.6b02882] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mirzo Kanoatov
- Department of Chemistry and
Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Sina Mehrabanfar
- Department of Chemistry and
Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Sergey N. Krylov
- Department of Chemistry and
Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
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8
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Möller FM, Kieß M, Braun D. Photochemical Microscale Electrophoresis Allows Fast Quantification of Biomolecule Binding. J Am Chem Soc 2016; 138:5363-70. [PMID: 27042755 DOI: 10.1021/jacs.6b01756] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intricate spatiotemporal patterns emerge when chemical reactions couple to physical transport. We induce electrophoretic transport by a confined photochemical reaction and use it to infer the binding strength of a second, biomolecular binding reaction under physiological conditions. To this end, we use the photoactive compound 2-nitrobenzaldehyde, which releases a proton upon 375 nm irradiation. The charged photoproducts locally perturb electroneutrality due to differential diffusion, giving rise to an electric potential Φ in the 100 μV range on the micrometer scale. Electrophoresis of biomolecules in this field is counterbalanced by back-diffusion within seconds. The biomolecule concentration is measured by fluorescence and settles proportionally to exp(-μ/D Φ). Typically, binding alters either the diffusion coefficient D or the electrophoretic mobility μ. Hence, the local biomolecule fluorescence directly reflects the binding state. A fit to the law of mass action reveals the dissociation constant of the binding reaction. We apply this approach to quantify the binding of the aptamer TBA15 to its protein target human-α-thrombin and to probe the hybridization of DNA. Dissociation constants in the nanomolar regime were determined and match both results in literature and in control experiments using microscale thermophoresis. As our approach is all-optical, isothermal and requires only nanoliter volumes at nanomolar concentrations, it will allow for the fast screening of biomolecule binding in low volume multiwell formats.
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Affiliation(s)
- Friederike M Möller
- Systems Biophysics, Physics Department, Nanosystems Initiative Munich and Center for NanoScience, Ludwig-Maximilians-Universität München , Amalienstraße 54, 80799 München, Germany
| | - Michael Kieß
- Systems Biophysics, Physics Department, Nanosystems Initiative Munich and Center for NanoScience, Ludwig-Maximilians-Universität München , Amalienstraße 54, 80799 München, Germany
| | - Dieter Braun
- Systems Biophysics, Physics Department, Nanosystems Initiative Munich and Center for NanoScience, Ludwig-Maximilians-Universität München , Amalienstraße 54, 80799 München, Germany
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9
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Mukhitov N, Yi L, Schrell AM, Roper MG. Optimization of a microfluidic electrophoretic immunoassay using a Peltier cooler. J Chromatogr A 2014; 1367:154-60. [PMID: 25263064 DOI: 10.1016/j.chroma.2014.09.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 09/12/2014] [Accepted: 09/16/2014] [Indexed: 01/06/2023]
Abstract
Successful analysis of electrophoretic affinity assays depends strongly on the preservation of the affinity complex during separations. Elevated separation temperatures due to Joule heating promotes complex dissociation leading to a reduction in sensitivity. Affinity assays performed in glass microfluidic devices may be especially prone to this problem due to poor heat dissipation due to the low thermal conductivity of glass and the large amount of bulk material surrounding separation channels. To address this limitation, a method to cool a glass microfluidic chip for performing an affinity assay for insulin was achieved by a Peltier cooler localized over the separation channel. The Peltier cooler allowed for rapid stabilization of temperatures, with 21°C the lowest temperature that was possible to use without producing detrimental thermal gradients throughout the device. The introduction of cooling improved the preservation of the affinity complex, with even passive cooling of the separation channel improving the amount of complex observed by 2-fold. Additionally, the capability to thermostabilize the separation channel allowed for utilization of higher separation voltages than what was possible without temperature control. Kinetic CE analysis was utilized as a diagnostic of the affinity assay and indicated that optimal conditions were at the highest separation voltage, 6 kV, and the lowest separation temperature, 21°C, leading to 3.4% dissociation of the complex peak during the separation. These optimum conditions were used to generate a calibration curve and produced 1 nM limits of detection, representing a 10-fold improvement over non-thermostated conditions. This methodology of cooling glass microfluidic devices for performing robust and high sensitivity affinity assays on microfluidic systems should be amenable in a number of applications.
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Affiliation(s)
- Nikita Mukhitov
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States
| | - Lian Yi
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States
| | - Adrian M Schrell
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Dittmer Building, Tallahassee, FL 32306, United States.
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Elsheshiny AAA, Ashcroft AE, Harris SA. A comparison of the electromechanical properties of structurally diverse proteins by molecular dynamics simulation. J Biomol Struct Dyn 2013; 32:1734-41. [PMID: 24028659 DOI: 10.1080/07391102.2013.833864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Proteins are subjected to electric fields both within the cell and during routine biochemical analysis. We have used atomistic molecular dynamics simulations to study conformational changes within three structurally diverse proteins subjected to high electric fields. At electric fields in excess of .5 V/nm, major structural changes were observed in all three proteins due to charge redistribution within the biomolecule. However, the electromechanical resilience was found to be highly dependent on the protein secondary structure, with α-helices showing a particularly high susceptibility to deformation by the applied electric field.
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11
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Matzke AJM, Matzke M. Membrane "potential-omics": toward voltage imaging at the cell population level in roots of living plants. FRONTIERS IN PLANT SCIENCE 2013; 4:311. [PMID: 23964285 PMCID: PMC3734365 DOI: 10.3389/fpls.2013.00311] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 07/24/2013] [Indexed: 05/18/2023]
Abstract
Genetically encoded voltage-sensitive fluorescent proteins (VSFPs) are being used in neurobiology as non-invasive tools to study synchronous electrical activities in specific groups of nerve cells. Here we discuss our efforts to adapt this "light-based electrophysiology" for use in plant systems. We describe the production of transgenic plants engineered to express different versions of VSFPs that are targeted to the plasma membrane and internal membranes of root cells. The aim is to optically record concurrent changes in plasma membrane potential in populations of cells and at multiple membrane systems within single cells in response to various stimuli in living plants. Such coordinated electrical changes may globally orchestrate cell behavior to elicit successful reactions of the root as a whole to varying and unpredictable environments. Findings from membrane "potential-omics" can eventually be fused with data sets from other "omics" approaches to forge the integrated and comprehensive understanding that underpins the concept of systems biology.
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12
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Starzyk A, Cieplak M. Proteins in the electric field near the surface of mica. J Chem Phys 2013; 139:045102. [DOI: 10.1063/1.4813854] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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13
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Musheev MU, Kanoatov M, Krylov SN. Non-uniform velocity of homogeneous DNA in a uniform electric field: consequence of electric-field-induced slow dissociation of highly stable DNA-counterion complexes. J Am Chem Soc 2013; 135:8041-6. [PMID: 23646889 DOI: 10.1021/ja402257x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Identical molecules move with identical velocities when placed in a uniform electric field within a uniform electrolyte. Here we report that homogeneous DNA does not obey this fundamental rule. While most DNA moves with similar velocities, a fraction of DNA moves with velocities that vary within a multiple-fold range. The size of this irregular fraction increases several orders of magnitude when exogenous counterions are added to DNA. The irregular fraction decreases several orders of magnitude when DNA counterions are removed by dialysis against deionized water in the presence of a strong electric field (0.6 kV/cm). Dialysis without the field is ineffective in decreasing the size of irregular fraction. These results suggest that (i) DNA can form very stable complexes with counterions, (ii) these complexes can be dissociated by an electric field, and (iii) the observed non-uniform velocity of DNA is caused by electric-field-induced slow dissociation of these stable complexes. Our findings help to better understand a fundamental property of DNA: its interaction with counterions. In addition, these findings suggest a practical way of making electromigration of DNA more uniform: removal of strongly bound DNA counterions by electro-dialysis against deionized water.
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Affiliation(s)
- Michael U Musheev
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
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