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Böttcher A, Kowerko D, Sigel RKO. Explicit analytic equations for multimolecular thermal melting curves. Biophys Chem 2015; 202:32-9. [PMID: 25910861 DOI: 10.1016/j.bpc.2015.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 03/31/2015] [Accepted: 04/01/2015] [Indexed: 11/19/2022]
Abstract
The analysis of thermal melting curves requires the knowledge of equations for the temperature dependence of the relative fraction of folded and unfolded components. To implement these equations as standard tools for curve fitting, they should be as explicit as possible. From the van't Hoff formalism it is known that the equilibrium constant and hence the folded fraction is a function of the absolute temperature, the van't Hoff transition enthalpy, and the melting temperature. The work presented here is devoted to the mathematically self-contained derivation and the listing of explicit equations for the folded fraction as a function of the thermodynamic parameters in the case of arbitrary molecularities. Part of the results are known, others are new. It is in particular shown for the first time that the folded fraction is the composition of a universal function which depends solely on the molecularity and a dimensionless function which is governed by the concrete thermodynamic regime but is independent of the molecularity. The results will prove useful for extracting the thermodynamic parameters from experimental data on the basis of regression analysis. As supporting information, open-source Matlab scripts for the computer implementation of the equations are provided.
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Affiliation(s)
- Albrecht Böttcher
- Chemnitz University of Technology, Department of Mathematics, 09107 Chemnitz, Germany.
| | - Danny Kowerko
- University of Zurich, Department of Chemistry, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
| | - Roland K O Sigel
- University of Zurich, Department of Chemistry, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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2
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Scholes CA, Millar DP, Gee ML, Smith TA. Resonance energy-transfer studies of the conformational change on the adsorption of oligonucleotides to a silica interface. J Phys Chem B 2011; 115:6329-39. [PMID: 21500794 DOI: 10.1021/jp201332w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved evanescent wave-induced fluorescence studies have been carried out on a series of fluorescently labeled oligonucleotide sequences adsorbed to a silica surface from solution. The fluorescence decay profiles of a fluorescent energy donor group undergoing resonance energy transfer to a nonemissive energy-acceptor molecule have been analyzed in terms of a distribution of donor-acceptor distances to reveal the conformational changes that occur in these oligonucleotides upon adsorption. Evanescent wave-induced time-resolved Förster resonance energy-transfer (EW-TRFRET) measurements indicate that at a high electrolyte concentration, there is localized separation of the oligonucleotide strands, and the helical structure adopts an "unraveled" conformation as a result of adsorption. This is attributed to the flexibility within the oligonucleotide at high electrolyte concentration allowing multiple segments of the oligonucleotide to have direct surface interaction. In contrast, the EW-TRFRET measurements at a lower electrolyte concentration reveal that the oligonucleotide retains its helical conformation in a localized extended state. This behavior implies that the rigidity of the oligonucleotide at this electrolyte concentration restricts direct interaction with the silica to a few segments, which correspondingly introduces kinks in the double helix conformation and results in significant oligonucleotide segmental extension into solution.
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Affiliation(s)
- Colin A Scholes
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
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Zhao Y, Zhang Y, Lv X, Liu Y, Chen M, Wang P, Liu J, Guo W. Through-bond energy transfer cassettes based on coumarin–Bodipy/distyryl Bodipy dyads with efficient energy efficiences and large pseudo-Stokes' shifts. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm12503f] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Flehr R, Kienzler A, Bannwarth W, Kumke MU. Photophysical characterization of a FRET system using tailor-made DNA oligonucleotide sequences. Bioconjug Chem 2010; 21:2347-54. [PMID: 21114283 DOI: 10.1021/bc100389k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have carried out a detailed photophysical study of the FRET D/A pair consisting of a carbostyril donor and a Ru(II)bathophenanthroline complex acceptor in double-stranded synthetic DNA. Altogether 13 different double-stranded 30 base pair DNAs showing small incremental differences in the distances between donor and acceptor were synthesized. Using the fluorescence of the donor as well as of the acceptor, D/A separations were determined and compared to those derived from a well-established model for DNA distance calculations. The model calculations and anisotropy studies revealed that the donor can nearly be seen as a free rotator allowing the application of the established FRET data evaluation.
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Affiliation(s)
- Roman Flehr
- University of Potsdam, Institute of Chemistry (Physical Chemistry), 14476 Potsdam-Golm, Germany
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Khandelwal G, Bhyravabhotla J. A phenomenological model for predicting melting temperatures of DNA sequences. PLoS One 2010; 5:e12433. [PMID: 20865157 PMCID: PMC2928768 DOI: 10.1371/journal.pone.0012433] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 08/02/2010] [Indexed: 11/29/2022] Open
Abstract
We report here a novel method for predicting melting temperatures of DNA sequences based on a molecular-level hypothesis on the phenomena underlying the thermal denaturation of DNA. The model presented here attempts to quantify the energetic components stabilizing the structure of DNA such as base pairing, stacking, and ionic environment which are partially disrupted during the process of thermal denaturation. The model gives a Pearson product-moment correlation coefficient (r) of approximately 0.98 between experimental and predicted melting temperatures for over 300 sequences of varying lengths ranging from 15-mers to genomic level and at different salt concentrations. The approach is implemented as a web tool (www.scfbio-iitd.res.in/chemgenome/Tm_predictor.jsp) for the prediction of melting temperatures of DNA sequences.
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Affiliation(s)
- Garima Khandelwal
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, India
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology Delhi, New Delhi, India
| | - Jayaram Bhyravabhotla
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, India
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology Delhi, New Delhi, India
- School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
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Lee JB, Shai AS, Campolongo MJ, Park N, Luo D. Three-Dimensional Structure and Thermal Stability Studies of DNA Nanostructures by Energy Transfer Spectroscopy. Chemphyschem 2010; 11:2081-4. [DOI: 10.1002/cphc.201000107] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Saccà B, Meyer R, Niemeyer CM. Analysis of the self-assembly of 4x4 DNA tiles by temperature-dependent FRET spectroscopy. Chemphyschem 2010; 10:3239-48. [PMID: 19859932 DOI: 10.1002/cphc.200900477] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Correct and efficient self-assembly of oligonucleotides into highly ordered superstructures essentially depends on the structural integrity and thermal stability of DNA motifs such as junctions or tiles that build up the superstructure. To investigate the assembly/disassembly process of DNA tiles, we recently described a microplate-based method employing Förster resonance energy transfer (FRET) spectroscopy, which enables the analysis of DNA superstructure formation in real time and with high throughput. This method allows thermodynamic parameters of the self-assembly process to be extracted, and we here apply it for detailed analysis of the self-assembly of five different 4x4 DNA tile motifs. To specifically investigate whether the FRET probes tethered to the DNA motifs report local thermodynamic stabilities in the immediate proximity of the chromophores, or whether the global stability of the entire motif is monitored, systematic variations of the labeling position within one tile are carried out. Combined with gel electrophoretic, UV spectroscopic, and microcalorimetric analysis, this study reveals that the FRET method mainly reports the thermodynamics of local microenvironment assembly, rather than that of the entire motif. Nonetheless, the thermodynamic data derived from FRET analysis are also influenced by the structural surroundings of the motif, and thus rapid and detailed analysis and identification of potential "weak points" within a superstructure which influence the structural integrity of a given tile design are enabled. Therefore, the microplate FRET method readily provides insights into the assembly process of complex DNA superstructures to verify and complement theoretical design approaches.
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Affiliation(s)
- Barbara Saccà
- Technische Universität Dortmund, Fakultät Chemie, Biologisch-Chemische Mikrostrukturtechnik, Otto-Hahn Str. 6, 44227 Dortmund, Germany
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Harriman A, Mallon LJ, Elliot KJ, Haefele A, Ulrich G, Ziessel R. Length Dependence for Intramolecular Energy Transfer in Three- and Four-Color Donor−Spacer−Acceptor Arrays. J Am Chem Soc 2009; 131:13375-86. [DOI: 10.1021/ja9038856] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Anthony Harriman
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom, and Laboratoire de Chimie Organique et Spectroscopies Avancées (LCOSA), Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
| | - Laura J. Mallon
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom, and Laboratoire de Chimie Organique et Spectroscopies Avancées (LCOSA), Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
| | - Kristopher J. Elliot
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom, and Laboratoire de Chimie Organique et Spectroscopies Avancées (LCOSA), Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
| | - Alexandre Haefele
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom, and Laboratoire de Chimie Organique et Spectroscopies Avancées (LCOSA), Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
| | - Gilles Ulrich
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom, and Laboratoire de Chimie Organique et Spectroscopies Avancées (LCOSA), Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
| | - Raymond Ziessel
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom, and Laboratoire de Chimie Organique et Spectroscopies Avancées (LCOSA), Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
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