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González A, Wildes AR, Mossou E, Cristiglio V, Moiroux G, Garden JL, Cuesta-López S, Theodorakopoulos N, Peyrard M. Melting transition of oriented Li-DNA fibers submerged in ethanol solutions. Biopolymers 2021; 112:e23422. [PMID: 33600618 DOI: 10.1002/bip.23422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/08/2021] [Accepted: 01/21/2021] [Indexed: 11/09/2022]
Abstract
The melting transition of Li-DNA fibers immersed in ethanol-water solutions has been studied using calorimetry and neutron diffraction techniques. The data have been analyzed using the Peyrard-Bishop-Dauxois model to determine the strengths of the intra- and inter-base pair potentials. The data and analysis show that the potentials are weaker than those for DNA in water. They become weaker still and the DNA less stable as the ethanol concentration increases but, conversely, the fibers become more compact and the distances between base pairs become more regular. The results show that the melting transition is relatively insensitive to local confinement and depends more on the interaction between the DNA and its aqueous environment.
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Affiliation(s)
- Adrián González
- Institut Laue-Langevin, Grenoble, France.,ICCRAM, University of Burgos, Burgos, Spain.,Nano and Biophysics division, Department of Physics, Chalmers University of Technology, Göteborg, Sweden
| | | | | | | | - Gaël Moiroux
- Institut Néel, CNRS, Grenoble, France.,Institut Néel, University Grenoble Alpes, Grenoble, France
| | - Jean-Luc Garden
- Institut Néel, CNRS, Grenoble, France.,Institut Néel, University Grenoble Alpes, Grenoble, France
| | - Santiago Cuesta-López
- ICCRAM, University of Burgos, Burgos, Spain.,Advanced Materials and Computational Engineering, ICAMCyL Foundation International Center for Advanced Materials and Raw Materials of Castilla y León, León, Spain
| | - Nikos Theodorakopoulos
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens, Greece.,Fachbereich Physik, Universität Konstanz, Constance, Germany
| | - Michel Peyrard
- Université de Lyon, Ecole Normale Supérieure de Lyon, Laboratoire de Physique, CNRS, UMR 5672, Lyon, France
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Krasnobaeva LA, Yakushevich LV. The Dynamic and Statistical Properties of DNA Kinks. Biophysics (Nagoya-shi) 2020. [DOI: 10.1134/s0006350920010091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Matsarskaia O, Roosen-Runge F, Lotze G, Möller J, Mariani A, Zhang F, Schreiber F. Tuning phase transitions of aqueous protein solutions by multivalent cations. Phys Chem Chem Phys 2018; 20:27214-27225. [PMID: 30351336 DOI: 10.1039/c8cp05884a] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the presence of trivalent cations, negatively charged globular proteins show a rich phase behaviour including reentrant condensation, crystallisation, clustering and lower critical solution temperature metastable liquid-liquid phase separation (LCST-LLPS). Here, we present a systematic study on how different multivalent cations can be employed to tune the interactions and the associated phase behaviour of proteins. We focus our investigations on the protein bovine serum albumin (BSA) in the presence of HoCl3, LaCl3 and YCl3. Using UV-Vis spectroscopy and small-angle X-ray scattering (SAXS), we find that the interprotein attraction induced by Ho3+ is very strong, while the one induced by La3+ is comparatively weak when comparing the data to BSA-Y3+ systems based on our previous work. Using zeta potential and isothermal titration calorimetry (ITC) measurements, we establish different binding affinities of cations to BSA with Ho3+ having the highest one. We propose that a combination of different cation features such as radius, polarisability and in particular hydration effects determine the protein-protein interaction induced by these cations. Our findings imply that subtle differences in cation properties can be a sensitive tool to fine-tune protein-protein interactions and phase behaviour in solution.
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Affiliation(s)
- Olga Matsarskaia
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
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