1
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Graziano G. Structural Order in the Hydration Shell of Nonpolar Groups versus that in Bulk Water. Chemphyschem 2024:e202400102. [PMID: 38923744 DOI: 10.1002/cphc.202400102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/08/2024] [Indexed: 06/28/2024]
Abstract
The poor solubility of nonpolar compounds in water around room temperature is governed by a large and negative entropy change, whose molecular cause is still debated. Since the Frank and Evans original proposal in 1945, the large and negative entropy change is usually attributed to the formation of ordered structures in the hydration shell of nonpolar groups. However, the existence of such ordered structures has never been proven. The present study is aimed at providing available structural results and thermodynamic arguments disproving the existence of ordered structures in the hydration shell of nonpolar groups.
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Affiliation(s)
- Giuseppe Graziano
- Dipartimento di Scienze e Tecnologie, Università del Sannio, Via Francesco de Sanctis, snc, 82100, Benevento, Italy
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2
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König B, Pezzotti S, Ramos S, Schwaab G, Havenith M. Real-time measure of solvation free energy changes upon liquid-liquid phase separation of α-elastin. Biophys J 2024; 123:1367-1375. [PMID: 37515326 PMCID: PMC11163292 DOI: 10.1016/j.bpj.2023.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/16/2023] [Accepted: 07/26/2023] [Indexed: 07/30/2023] Open
Abstract
Biological condensates are known to retain a large fraction of water to remain in a liquid and reversible state. Local solvation contributions from water hydrating hydrophilic and hydrophobic protein surfaces were proposed to play a prominent role for the formation of condensates through liquid-liquid phase separation (LLPS). However, although the total free energy is accessible by calorimetry, the partial solvent contributions to the free energy changes upon LLPS remained experimentally inaccessible so far. Here, we show that the recently developed THz calorimetry approach allows to quantify local hydration enthalpy and entropy changes upon LLPS of α-elastin in real time, directly from experimental THz spectroscopy data. We find that hydrophobic solvation dominates the entropic solvation term, whereas hydrophilic solvation mainly contributes to the enthalpy. Both terms are in the order of hundreds of kJ/mol, which is more than one order of magnitude larger than the total free energy changes at play during LLPS. However, since we show that entropy/enthalpy mostly compensates, a small entropy/enthalpy imbalance is sufficient to tune LLPS. Theoretically, a balance was proposed before. Here we present experimental evidence based on our spectroscopic approach. We finally show that LLPS can be steered by inducing small changes of solvation entropy/enthalpy compensation via concentration or temperature in α-elastin.
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Affiliation(s)
- Benedikt König
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum, Germany
| | - Simone Pezzotti
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum, Germany
| | - Sashary Ramos
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum, Germany
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum, Germany.
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3
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Mukherjee S, Ramos S, Pezzotti S, Kalarikkal A, Prass TM, Galazzo L, Gendreizig D, Barbosa N, Bordignon E, Havenith M, Schäfer LV. Entropy Tug-of-War Determines Solvent Effects in the Liquid-Liquid Phase Separation of a Globular Protein. J Phys Chem Lett 2024; 15:4047-4055. [PMID: 38580324 PMCID: PMC11033941 DOI: 10.1021/acs.jpclett.3c03421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/15/2024] [Accepted: 03/19/2024] [Indexed: 04/07/2024]
Abstract
Liquid-liquid phase separation (LLPS) plays a key role in the compartmentalization of cells via the formation of biomolecular condensates. Here, we combined atomistic molecular dynamics (MD) simulations and terahertz (THz) spectroscopy to determine the solvent entropy contribution to the formation of condensates of the human eye lens protein γD-Crystallin. The MD simulations reveal an entropy tug-of-war between water molecules that are released from the protein droplets and those that are retained within the condensates, two categories of water molecules that were also assigned spectroscopically. A recently developed THz-calorimetry method enables quantitative comparison of the experimental and computational entropy changes of the released water molecules. The strong correlation mutually validates the two approaches and opens the way to a detailed atomic-level understanding of the different driving forces underlying the LLPS.
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Affiliation(s)
- Saumyak Mukherjee
- Center
for Theoretical Chemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Sashary Ramos
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Simone Pezzotti
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Abhishek Kalarikkal
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Tobias M. Prass
- Center
for Theoretical Chemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Laura Galazzo
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Dominik Gendreizig
- Department
of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland
| | - Natercia Barbosa
- Department
of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland
| | - Enrica Bordignon
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
- Department
of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland
| | - Martina Havenith
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Lars V. Schäfer
- Center
for Theoretical Chemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
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4
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Mahanta DD, Brown DR, Webber T, Pezzotti S, Schwaab G, Han S, Shell MS, Havenith M. Bridging the Gap in Cryopreservation Mechanism: Unraveling the Interplay between Structure, Dynamics, and Thermodynamics in Cryoprotectant Aqueous Solutions. J Phys Chem B 2024; 128:3720-3731. [PMID: 38584393 DOI: 10.1021/acs.jpcb.4c00264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Cryoprotectants play a crucial role in preserving biological material, ensuring their viability during storage and facilitating crucial applications such as the conservation of medical compounds, tissues, and organs for transplantation. However, the precise mechanism by which cryoprotectants modulate the thermodynamic properties of water to impede the formation and growth of ice crystals, thus preventing long-term damage, remains elusive. This is evident in the use of empirically optimized recipes for mixtures that typically contain DMSO, glycerol, and various sugar constituents. Here, we use terahertz calorimetry, Overhauser nuclear polarization, and molecular dynamics simulations to show that DMSO exhibits a robust structuring effect on water around its methyl groups, reaching a maximum at a DMSO mole fraction of XDMSO = 0.33. In contrast, glycerol exerts a smaller water-structuring effect, even at higher concentrations (Scheme 1). These results potentially suggest that the wrapped water around DMSO's methyl group, which can be evicted upon ligand binding, may render DMSO a more surface-active cryoprotectant than glycerol, while glycerol may participate more as a viscogen that acts on the entire sample. These findings shed light on the molecular intricacies of cryoprotectant solvation behavior and have potentially significant implications for optimizing cryopreservation protocols.
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Affiliation(s)
- Debasish Das Mahanta
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
- Department of Physics, Technische Universität (TU) Dortmund, Dortmund 44227, Germany
| | - Dennis Robinson Brown
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Thomas Webber
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Simone Pezzotti
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
| | - Songi Han
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-9510, United States
| | - M Scott Shell
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
- Department of Physics, Technische Universität (TU) Dortmund, Dortmund 44227, Germany
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5
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Tao YH, Schulke S, Schwaab G, Nealon GL, Pezzotti S, Hodgetts SI, Harvey AR, Havenith M, Wallace VP. Hydration water drives the self-assembly of guanosine monophosphate. Biophys J 2024; 123:931-939. [PMID: 38454599 PMCID: PMC11052693 DOI: 10.1016/j.bpj.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/04/2024] [Accepted: 03/04/2024] [Indexed: 03/09/2024] Open
Abstract
Guanosine monophosphate (GMP) is a nucleotide that can self-assemble in aqueous solution under certain conditions. An understanding of the process at the molecular level is an essential step to comprehend the involvement of DNA substructures in transcription and replication, as well as their relationship to genetic diseases such as cancer. We present the temperature-dependent terahertz (1.5-12 THz, 50-400 cm-1) absorptivity spectra of aqueous Na2 GMP solution in comparison with the aqueous solutions of other RNA nucleotides. Distinct absorption features were observed in the spectrum of GMP, which we attribute to the intramolecular modes of the self-assemblies (i.e., G-complexes) that, at 1 M, start to form at 313 K and below. Changes in broad-band features of the terahertz spectrum were also observed, which we associate with the release of hydration water in the temperature-dependent formation of guanine quadruplexes. Using a state-of-the-art THz calorimetry approach correlating spectroscopic to thermodynamic changes, we propose a molecular mechanism of hydrophilic hydration driving GMP self-assembly as a function of temperature. The free energy contribution of hydrophilic hydration is shown as a decisive factor in guanine-quadruplex formation. Our findings spotlight the role of hydration in the formation of macromolecular structures and suggest the potential of hydration tuning for regulating DNA transcription and replication.
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Affiliation(s)
- Yu Heng Tao
- Department of Physics, The University of Western Australia, Crawley, WA, Australia
| | - Simon Schulke
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Gerhard Schwaab
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Gareth L Nealon
- School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia; Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Crawley, WA, Australia
| | - Simone Pezzotti
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Stuart I Hodgetts
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia; Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Alan R Harvey
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia; Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.
| | - Vincent P Wallace
- Department of Physics, The University of Western Australia, Crawley, WA, Australia.
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6
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Kumar D, Kuijken PF, van de Poel T, Neumann K, Galimberti DR. Revealing the Unique Role of Water in the Formation of Benzothiazoles: an Experimental and Computational Study. Chemistry 2024; 30:e202302596. [PMID: 37812133 DOI: 10.1002/chem.202302596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/05/2023] [Accepted: 10/07/2023] [Indexed: 10/10/2023]
Abstract
We present here a joint experimental and computational study on the formation of benzothiazoles. Our investigation reveals a green protocol for accessing benzothiazoles from acyl chlorides using either water alongside a reducing agent as the reaction medium or in combination with stoichiometric amounts of a weak acid, instead of the harsh conditions and catalysts previously reported. Specifically, we show that a protic solvent, particularly water, enables the formation of 2-substituted benzothiazoles from N-acyl 1,2-aminothiophenols already at room temperature, without the need for strong acids or metal catalysts. DFT Molecular Dynamics simulations coupled with advanced enhanced sampling techniques provide a clear understanding of the catalytic role of water. We demonstrate how bulk water - due to its extended network of hydrogen bonds and an efficient Grotthuss mechanism - provides a reaction path that strongly reduces the reaction barriers compared to aprotic environments, namely more than 80 kJ/mol for the first reaction step and 250 kJ/mol for the second. Finally, we discuss the influence of different aliphatic and aromatic substituents with varying electronic properties on chemical reactivity. Besides providing in-depth mechanistic insights, we believe that our findings pave the way for a greener route toward an important class of bioactive molecules.
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Affiliation(s)
- Dipanshu Kumar
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Peter F Kuijken
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Tjerk van de Poel
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Kevin Neumann
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Daria Ruth Galimberti
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
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7
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Pyne S, Pyne P, Mitra RK. The explicit role of interfacial hydration during polyethylene glycol induced lipid fusion: a THz spectroscopic investigation. Phys Chem Chem Phys 2023; 25:31326-31334. [PMID: 37960951 DOI: 10.1039/d3cp04868c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
While the phenomenon of excipient mediated membrane fusion has been studied widely, the inherent role of interfacial hydration involved in the process has mostly remained unaddressed. Here we report the experimental validation of the fact that PEG-induced membrane fusion is associated with the dehydration of the membrane(s). We explore the explicit hydration behavior at three different lipids (DOPC, POPC and DPPC) membranes with different aliphatic tails as they undergo fusogenic transition in the presence of PEG of average molecular weight of 4000 using THz-FTIR spectroscopy in the frequency window of 1.5-13.5 THz. Dynamic light scattering and electron microscopic measurements confirm the formation of different intermediate steps of the liposomes during the fusion process: bilayer aggregation, destabilization and finally lipid fusion. We observe that membrane hydration follows a systematic trend with the lipid specificity as the fusion process sets in.
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Affiliation(s)
- Sumana Pyne
- Department of Chemical and Biological Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
| | - Partha Pyne
- Department of Chemical and Biological Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
| | - Rajib Kumar Mitra
- Department of Chemical and Biological Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
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8
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Ockelmann T, Hoberg C, Buchmann A, Novelli F, Havenith M. Energy Dissipation into the Solvent during Proton Transfer Occurs via Acoustic Phonons. J Phys Chem B 2023; 127:9560-9565. [PMID: 37879121 DOI: 10.1021/acs.jpcb.3c04874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
In photochemistry, rapid energy dissipation into the solvent is mandatory to prevent radiation damages. By optical pump THz spectroscopy, we are able to follow the details of the energy dissipation mechanism upon photoexcitation of the photoacid to the hydrogen-bonded network of water: Based on the frequency maps subsequent to photoexcitation, we propose that energy transfer takes place via propagation of an acoustic phonon. The dissipation into the solvent can be rationalized by an initial first hydration shell response followed by energy dissipation via an acoustic phonon. Surprisingly, for the first 10 ps, the propagation in the water network can be described by a wave packet with a constant group velocity, indicating a long-range correlation. After 300 ps, thermalization in the liquid jet is reached and the THz spectrum reflects a Boltzmann population, corresponding a temperature increase of ΔT = 0.5 °C.
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Affiliation(s)
- Thorsten Ockelmann
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany
| | - Claudius Hoberg
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany
| | - Adrian Buchmann
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany
| | - Fabio Novelli
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany
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9
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Bag S, Pezzotti S, Das Mahanta D, Schulke S, Schwaab G, Havenith M. From Local Hydration Motifs in Aqueous Acetic Acid Solutions to Macroscopic Mixing Thermodynamics: A Quantitative Connection from THz-Calorimetry. J Phys Chem B 2023; 127:9204-9210. [PMID: 37843511 DOI: 10.1021/acs.jpcb.3c06328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
We report the results of THz measurements (30-440 cm-1) of aqueous acetic acid solutions over the full mixing range (XAcAc = 0-1). We recorded spectroscopic observables as a function of the acetic acid concentration in the frequency range of the intermolecular stretch at 150 cm-1 and of the librational modes at 350-440 cm-1. This allowed us to unravel changes in hydrophobic and hydrophilic hydration motifs, respectively. By means of a novel THz-calorimetry approach, we quantitatively correlated these changes in local hydration motifs to excess mixing entropy and enthalpy. We find that ΔHmix is determined by both hydrophobic and hydrophilic solvation contributions. In contrast, ΔSmix is governed by hydrophobic cavity formation. Our results further suggest that acetic acid-water mixtures are systems at the edge of phase separation due to endothermic contributions from both hydrophilic and hydrophobic solvation in a large portion of the miscibility range. Our work establishes a quantitative relationship between the balance of local hydrophobic and hydrophilic solvation motifs and the macroscopic mixing thermodynamic properties.
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Affiliation(s)
- Sampad Bag
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
| | - Simone Pezzotti
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
| | - Debasish Das Mahanta
- Department of Physics, Gandhi Institute of Technology and Management (GITAM), Bengaluru, Karnataka 561203, India
| | - Simon Schulke
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany
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10
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Ramos S, Kamps J, Pezzotti S, Winklhofer KF, Tatzelt J, Havenith M. Hydration makes a difference! How to tune protein complexes between liquid-liquid and liquid-solid phase separation. Phys Chem Chem Phys 2023; 25:28063-28069. [PMID: 37840355 DOI: 10.1039/d3cp03299j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Understanding how protein rich condensates formed upon liquid-liquid phase separation (LLPS) evolve into solid aggregates is of fundamental importance for several medical applications, since these are suspected to be hot-spots for many neurotoxic diseases. This requires developing experimental approaches to observe in real-time both LLPS and liquid-solid phase separation (LSPS), and to unravel the delicate balance of protein and water interactions dictating the free energy differences between the two. We present a vibrational THz spectroscopy approach that allows doing so from the point of view of hydration water. We focus on a cellular prion protein of high medical relevance, which we can drive to undergo either LLPS or LSPS with few mutations. We find that it is a subtle balance of hydrophobic and hydrophilic solvation contributions that allows tuning between LLPS and LSPS. Hydrophobic hydration provides an entropic driving force to phase separation, through the release of hydration water into the bulk. Water hydrating hydrophilic groups provides an enthalpic driving force to keep the condensates in a liquid state. As a result, when we modify the protein by a few mutations to be less hydrophilic, we shift from LLPS to LSPS. This molecular understanding paves the way for a rational design of proteins.
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Affiliation(s)
- Sashary Ramos
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.
| | - Janine Kamps
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Simone Pezzotti
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.
| | - Konstanze F Winklhofer
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr Unviersity Bochum, Bochum, Germany
| | - Jörg Tatzelt
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.
- Department of Physics, TU Dortmund, Dortmund, Germany
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11
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Pyne P, Pyne S, Mitra RK. Sugar Molecules Inhibit Insulin Aggregation: A Decisive Role Being Played by the Protein Solvation Energetics. J Phys Chem B 2023; 127:8825-8832. [PMID: 37816171 DOI: 10.1021/acs.jpcb.3c04765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
Insulin plays vital roles in controlling blood sugar level in the human body. However, it sometimes aggregates during the storage, and its efficacy (on the treatment of diabetes II disease) reduces significantly. So, understanding the insulin aggregation could help in long-term storage. Here we investigate the amyloid growth of human insulin protein in the presence of sugar molecules and observe that glucose and sucrose delay the insulin aggregation, the effect being systematically sugar dependent. We then investigate protein hydration during the aggregation process using terahertz spectroscopy, as the hydration plays a pioneering role in maintaining biological systems. Our study infers that the water network changes systematically with protein conformations and solvation entropy-enthalpy balance plays a decisive role in the aggregation process.
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Affiliation(s)
- Partha Pyne
- Department of Chemical & Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector-III, Salt Lake, Kolkata 700106, India
| | - Sumana Pyne
- Department of Chemical & Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector-III, Salt Lake, Kolkata 700106, India
| | - Rajib Kumar Mitra
- Department of Chemical & Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector-III, Salt Lake, Kolkata 700106, India
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12
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Majumdar BB, Pyne P, Mitra RK, Das Mahanta D. Impact of hydrophobicity on local solvation structures and its connection with the global solubilization thermodynamics of amphiphilic molecules. Phys Chem Chem Phys 2023; 25:27161-27169. [PMID: 37789695 DOI: 10.1039/d3cp02741d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The relationship between the local solvation structures and global thermodynamics, specifically in the case of amphiphilic molecules, is a complex phenomenon and is not yet fully understood. With the prior knowledge that local solvation structures can impose a significant impact on the overall solvation process, we here combine THz spectroscopic analysis with MD simulations to investigate the impact of the altered hydrophobicity and polarity of amphiphilic solute molecules on the local solvation configurations. We use two water soluble alcohols: ethanol (EtOH) and its fluorinated counterpart, 2,2,2-trifluoroethanol (TFE), as model solutes. Our study is aimed to determine the relative abundance of different hydrogen bonded conformers and to establish a correlation between the spectral signatures (as obtained from THz spectroscopic measurements) and microscopic solute-solvent interactions associated with the local solvation structures (as obtained from MD simulations). Finally, we estimate the possible energetic parameters associated with the alcohol solubilization process. We found that while both the alcohols are completely water soluble, they receive a contrasting solvation energy share in terms of entropy and enthalpy. We understand that these findings are not limited to the specific system studied here but can be broadly extrapolated to other amphiphilic aqueous solutions.
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Affiliation(s)
- Bibhab Bandhu Majumdar
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India.
| | - Partha Pyne
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India.
| | - Rajib Kumar Mitra
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India.
| | - Debasish Das Mahanta
- Department of Chemistry, The University of Texas at Austin, 105 E 24th 4 Street, Austin, TX 78712, USA.
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13
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Chakraborty S, Bhattacharya I, Mitra RK. Solvation Plays a Key Role in Antioxidant-Mediated Attenuation of Elevated Creatinine Level: An In Vitro Spectroscopic Investigation. J Phys Chem B 2023; 127:8576-8585. [PMID: 37769128 DOI: 10.1021/acs.jpcb.3c05334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
An elevated level of creatinine (CRN) is a mark of kidney ailment, and prolonged retention of such condition could lead to renal failure, associated with severe ischemia. Antioxidants are clinically known to excrete CRN from the body through urine, thereby reducing its level in blood. The molecular mechanism of such an exclusion process is still illusive. As the excretion channel is urine, solvation of the solute is expected to play a pivotal role. Here, we report a detailed time-domain and frequency-domain terahertz (THz) spectroscopic investigation to understand the solvation of CRN in the presence of two model antioxidants, mostly used to treat elevated CRN level: N-Acetyl-l-cysteine (NAC) and ascorbic acid (ASC). FTIR spectroscopy in the mid-infrared region and UV absorption spectroscopy measurements coupled with quantum chemical calculations [at the B3LYP/6-311G++(d,p) level] reveal that both NAC and ASC form HBonded complexes with CRN and rapidly undergo a barrier-less proton transfer process to form creatinium ions. THz measurements provide explicit evidence of the formation of highly solvated complexes compared with bare CRN, which eventually enables its excretion through urine. These observations could provide a foundation for designing more beneficial drugs to resolve kidney diseases..
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Affiliation(s)
- Subhadip Chakraborty
- Department of Chemical and Biological Sciences, S.N. Bose National Centre for Basic Sciences; Block-JD; Sector-III; Salt Lake, Kolkata 700106, India
| | - Indrani Bhattacharya
- Department of Chemical and Biological Sciences, S.N. Bose National Centre for Basic Sciences; Block-JD; Sector-III; Salt Lake, Kolkata 700106, India
| | - Rajib Kumar Mitra
- Department of Chemical and Biological Sciences, S.N. Bose National Centre for Basic Sciences; Block-JD; Sector-III; Salt Lake, Kolkata 700106, India
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14
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Das Mahanta D, Brown DR, Pezzotti S, Han S, Schwaab G, Shell MS, Havenith M. Local solvation structures govern the mixing thermodynamics of glycerol-water solutions. Chem Sci 2023; 14:7381-7392. [PMID: 37416713 PMCID: PMC10321518 DOI: 10.1039/d3sc00517h] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023] Open
Abstract
Glycerol is a major cryoprotective agent and is widely used to promote protein stabilization. By a combined experimental and theoretical study, we show that global thermodynamic mixing properties of glycerol and water are dictated by local solvation motifs. We identify three hydration water populations, i.e., bulk water, bound water (water hydrogen bonded to the hydrophilic groups of glycerol) and cavity wrap water (water hydrating the hydrophobic moieties). Here, we show that for glycerol experimental observables in the THz regime allow quantification of the abundance of bound water and its partial contribution to the mixing thermodynamics. Specifically, we uncover a 1 : 1 connection between the population of bound waters and the mixing enthalpy, which is further corroborated by the simulation results. Therefore, the changes in global thermodynamic quantity - mixing enthalpy - are rationalized at the molecular level in terms of changes in the local hydrophilic hydration population as a function of glycerol mole fraction in the full miscibility range. This offers opportunities to rationally design polyol water, as well as other aqueous mixtures to optimize technological applications by tuning mixing enthalpy and entropy based on spectroscopic screening.
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Affiliation(s)
- Debasish Das Mahanta
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
- Department of Physics, Technische Universität Dortmund 44227 Dortmund Germany
| | - Dennis Robinson Brown
- Department of Chemical Engineering, University of California Santa Barbara California 93106-5080 USA
| | - Simone Pezzotti
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Songi Han
- Department of Chemical Engineering, University of California Santa Barbara California 93106-5080 USA
- Department of Chemistry and Biochemistry, University of California Santa Barbara California 93106-9510 USA
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
| | - M Scott Shell
- Department of Chemical Engineering, University of California Santa Barbara California 93106-5080 USA
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum 44780 Bochum Germany
- Department of Physics, Technische Universität Dortmund 44227 Dortmund Germany
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15
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Yang L, Guo S, Liao C, Hou C, Jiang S, Li J, Ma X, Shi L, Ye L, He X. Spatial Layouts of Low-Entropy Hydration Shells Guide Protein Binding. GLOBAL CHALLENGES (HOBOKEN, NJ) 2023; 7:2300022. [PMID: 37483413 PMCID: PMC10362119 DOI: 10.1002/gch2.202300022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/29/2023] [Indexed: 07/25/2023]
Abstract
Protein-protein binding enables orderly biological self-organization and is therefore considered a miracle of nature. Protein‒protein binding is driven by electrostatic forces, hydrogen bonding, van der Waals force, and hydrophobic interactions. Among these physical forces, only hydrophobic interactions can be considered long-range intermolecular attractions between proteins due to the electrostatic shielding of surrounding water molecules. Low-entropy hydration shells around proteins drive hydrophobic attraction among them that essentially coordinate protein‒protein binding. Here, an innovative method is developed for identifying low-entropy regions of hydration shells of proteins by screening off pseudohydrophilic groups on protein surfaces and revealing that large low-entropy regions of the hydration shells typically cover the binding sites of individual proteins. According to an analysis of determined protein complex structures, shape matching between a large low-entropy hydration shell region of a protein and that of its partner at the binding sites is revealed as a universal law. Protein‒protein binding is thus found to be mainly guided by hydrophobic collapse between the shape-matched low-entropy hydration shells that is verified by bioinformatics analyses of hundreds of structures of protein complexes, which cover four test systems. A simple algorithm is proposed to accurately predict protein binding sites.
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Affiliation(s)
- Lin Yang
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
- School of AerospaceMechanical and Mechatronic EngineeringThe University of SydneyNSW2006Australia
| | - Shuai Guo
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Chenchen Liao
- School of Electronics and Information EngineeringHarbin Institute of TechnologyHarbin150080P. R. China
| | - Chengyu Hou
- School of Electronics and Information EngineeringHarbin Institute of TechnologyHarbin150080P. R. China
| | - Shenda Jiang
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Jiacheng Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Xiaoliang Ma
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Liping Shi
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Lin Ye
- School of System Design and Intelligent ManufacturingSouthern University of Science and TechnologyShenzhen518055P. R. China
| | - Xiaodong He
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
- Shenzhen STRONG Advanced Materials Research Institute Co., LtdShenzhen518035P. R. China
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16
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DeStefano A, Nguyen M, Fredrickson GH, Han S, Segalman RA. Design of Soft Material Surfaces with Rationally Tuned Water Diffusivity. ACS CENTRAL SCIENCE 2023; 9:1019-1024. [PMID: 37252353 PMCID: PMC10214527 DOI: 10.1021/acscentsci.3c00208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Indexed: 05/31/2023]
Abstract
Water structure and dynamics can be key modulators of adsorption, separations, and reactions at soft material interfaces, but systematically tuning water environments in an aqueous, accessible, and functionalizable material platform has been elusive. This work leverages variations in excluded volume to control and measure water diffusivity as a function of position within polymeric micelles using Overhauser dynamic nuclear polarization spectroscopy. Specifically, a versatile materials platform consisting of sequence-defined polypeptoids simultaneously offers a route to controlling the functional group position and a unique opportunity to generate a water diffusivity gradient extending away from the polymer micelle core. These results demonstrate an avenue not only to rationally design the chemical and structural properties of polymer surfaces but also to design and tune the local water dynamics that, in turn, can adjust the local activity for solutes.
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Affiliation(s)
- Audra
J. DeStefano
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - My Nguyen
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Glenn H. Fredrickson
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Materials
Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Department
of Materials, University of California, Santa Barbara, California 93106, United States
| | - Songi Han
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Department
of Chemistry and Biochemistry, University
of California, Santa Barbara, California 93106, United States
| | - Rachel A. Segalman
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Materials
Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Department
of Materials, University of California, Santa Barbara, California 93106, United States
- Department
of Chemistry and Biochemistry, University
of California, Santa Barbara, California 93106, United States
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17
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Light, Water, and Melatonin: The Synergistic Regulation of Phase Separation in Dementia. Int J Mol Sci 2023; 24:ijms24065835. [PMID: 36982909 PMCID: PMC10054283 DOI: 10.3390/ijms24065835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
The swift rise in acceptance of molecular principles defining phase separation by a broad array of scientific disciplines is shadowed by increasing discoveries linking phase separation to pathological aggregations associated with numerous neurodegenerative disorders, including Alzheimer’s disease, that contribute to dementia. Phase separation is powered by multivalent macromolecular interactions. Importantly, the release of water molecules from protein hydration shells into bulk creates entropic gains that promote phase separation and the subsequent generation of insoluble cytotoxic aggregates that drive healthy brain cells into diseased states. Higher viscosity in interfacial waters and limited hydration in interiors of biomolecular condensates facilitate phase separation. Light, water, and melatonin constitute an ancient synergy that ensures adequate protein hydration to prevent aberrant phase separation. The 670 nm visible red wavelength found in sunlight and employed in photobiomodulation reduces interfacial and mitochondrial matrix viscosity to enhance ATP production via increasing ATP synthase motor efficiency. Melatonin is a potent antioxidant that lowers viscosity to increase ATP by scavenging excess reactive oxygen species and free radicals. Reduced viscosity by light and melatonin elevates the availability of free water molecules that allow melatonin to adopt favorable conformations that enhance intrinsic features, including binding interactions with adenosine that reinforces the adenosine moiety effect of ATP responsible for preventing water removal that causes hydrophobic collapse and aggregation in phase separation. Precise recalibration of interspecies melatonin dosages that account for differences in metabolic rates and bioavailability will ensure the efficacious reinstatement of the once-powerful ancient synergy between light, water, and melatonin in a modern world.
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18
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Lazaric A, Pattni V, Fuegner K, Ben-Naim A, Heyden M. Solvation free energy arithmetic for small organic molecules. J Comput Chem 2023; 44:1263-1277. [PMID: 36866644 DOI: 10.1002/jcc.27081] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 11/21/2022] [Accepted: 12/29/2022] [Indexed: 03/04/2023]
Abstract
Solvent-mediated interactions contribute to ligand binding affinities in computational drug design and provide a challenge for theoretical predictions. In this study, we analyze the solvation free energy of benzene derivatives in water to guide the development of predictive models for solvation free energies and solvent-mediated interactions. We use a spatially resolved analysis of local solvation free energy contributions and define solvation free energy arithmetic, which enable us to construct additive models to describe the solvation of complex compounds. The substituents analyzed in this study are carboxyl and nitro-groups due to their similar sterical requirements but distinct interactions with water. We find that nonadditive solvation free energy contributions are primarily attributed to electrostatics, which are qualitatively reproduced with computationally efficient continuum models. This suggests a promising route for the development of efficient and accurate models for the solvation of complex molecules with varying substitution patterns using solvation arithmetic.
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Affiliation(s)
- Aleksandar Lazaric
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
| | - Viren Pattni
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
| | - Kaprao Fuegner
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
| | - Arieh Ben-Naim
- Department of Physical Chemistry, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
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19
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Abstract
The photo-induced radiolysis of water is an elementary reaction in biology and chemistry, forming solvated electrons, OH radicals, and hydronium cations on fast time scales. Here, we use an optical-pump terahertz-probe spectroscopy setup to trigger the photoionization of water molecules with optical laser pulses at ~400 nm and then time-resolve the transient solvent response with broadband terahertz (THz) fields with a ~90 fs time resolution. We observe three distinct spectral responses. The first is a positive broadband mode that can be attributed to an initial diffuse, delocalized electron with a radius of (22 ± 1) Å, which is short lived (<200 fs) because the absorption is blue-shifting outside of the THz range. The second emerging spectroscopic signature with a lifetime of about 150 ps is attributed to an intermolecular mode associated with a mass rearrangement of solvent molecules due to charge separation of radicals and hydronium cations. After 0.2 ps, we observe a long-lasting THz signature with depleted intensity at 110 cm-1 that is well reproduced by ab initio molecular dynamics. We interpret this negative band at 110 cm-1 as the solvent cage characterized by a weakening of the hydrogen bond network in the first and second hydration shells of the cavity occupied by the localized electron.
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20
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Pezzotti S, König B, Ramos S, Schwaab G, Havenith M. Liquid-Liquid Phase Separation? Ask the Water! J Phys Chem Lett 2023; 14:1556-1563. [PMID: 36745512 DOI: 10.1021/acs.jpclett.2c02697] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Water is more than an inert spectator during liquid-liquid phase separation (LLPS), the reversible compartmentalization of protein solutions into a protein-rich and a dilute phase. We show that LLPS is driven by changes in hydration entropy and enthalpy. Tuning LLPS by adjusting experimental parameters, e.g., addition of co-solutes, is a major goal for biological and medical applications. This requires a general model to quantify thermodynamic driving forces. Here, we develop such a model based on the measured amplitudes of characteristic THz-features of two hydration populations: "Cavity-wrap" water hydrating hydrophobic patches is released during LLPS leading to an increase in entropy. "Bound" water hydrating hydrophilic patches is retained since it is enthalpically favorable. We introduce a THz-phase diagram mapping these spectroscopic/thermodynamic changes. This provides not only a precise understanding of hydrophobic and hydrophilic hydration driving forces as a function of temperature and concentration but also a rational means to tune LLPS.
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Affiliation(s)
- Simone Pezzotti
- Department of Physical Chemistry II, Ruhr University Bochum, 44801Bochum, Germany
| | - Benedikt König
- Department of Physical Chemistry II, Ruhr University Bochum, 44801Bochum, Germany
| | - Sashary Ramos
- Department of Physical Chemistry II, Ruhr University Bochum, 44801Bochum, Germany
| | - Gerhard Schwaab
- Department of Physical Chemistry II, Ruhr University Bochum, 44801Bochum, Germany
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, 44801Bochum, Germany
- Department of Physics, Technische Universität Dortmund, 44227Dortmund, Germany
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21
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Masaya TW, Goulay F. A Molecular Dynamic Study of the Effects of Surface Partitioning on the OH Radical Interactions with Solutes in Multicomponent Aqueous Aerosols. J Phys Chem A 2023; 127:751-764. [PMID: 36639126 DOI: 10.1021/acs.jpca.2c07419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The surface-bulk partitioning of small saccharide and amide molecules in aqueous droplets was investigated using molecular dynamics. The air-particle interface was modeled using a 80 Å cubic water box containing a series of organic molecules and surrounded by gaseous OH radicals. The properties of the organic solutes within the interface and the water bulk were examined at a molecular level using density profiles and radial pair distribution functions. Molecules containing only polar functional groups such as urea and glucose are found predominantly in the water bulk, forming an exclusion layer near the water surface. Substitution of a single polar group by an alkyl group in sugars and amides leads to the migration of the molecule toward the interface. Within the first 2 nm from the water surface, surface-active solutes lose their rotational freedom and adopt a preferred orientation with the alkyl group pointing toward the surface. The different packing within the interface leads to different solvation shell structures and enhanced interaction between the organic molecules and absorbed OH radicals. The simulations provide quantitative information about the dimension, composition, and organization of the air-water interface as well as about the nonreactive interaction of the OH radicals with the organic solutes. It suggests that increased concentrations, preferred orientations, and decreased solvation near the air-water surface may lead to differences in reactivities between surface-active and surface-inactive molecules. The results are important to explain how heterogeneous oxidation mechanisms and kinetics within interfaces may differ from those of the bulk.
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Affiliation(s)
- Tadini Wenyika Masaya
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Fabien Goulay
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
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22
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Poudel H, Leitner DM. Locating dynamic contributions to allostery via determining rates of vibrational energy transfer. J Chem Phys 2023; 158:015101. [PMID: 36610954 DOI: 10.1063/5.0132089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Determining rates of energy transfer across non-covalent contacts for different states of a protein can provide information about dynamic and associated entropy changes during transitions between states. We investigate the relationship between rates of energy transfer across polar and nonpolar contacts and contact dynamics for the β2-adrenergic receptor, a rhodopsin-like G-protein coupled receptor, in an antagonist-bound inactive state and agonist-bound active state. From structures sampled during molecular dynamics (MD) simulations, we find the active state to have, on average, a lower packing density, corresponding to generally more flexibility and greater entropy than the inactive state. Energy exchange networks (EENs) are computed for the inactive and active states from the results of the MD simulations. From the EENs, changes in the rates of energy transfer across polar and nonpolar contacts are found for contacts that remain largely intact during activation. Change in dynamics of the contact, and entropy associated with the dynamics, can be estimated from the change in rates of energy transfer across the contacts. Measurement of change in the rates of energy transfer before and after the transition between states thereby provides information about dynamic contributions to activation and allostery.
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Affiliation(s)
- Humanath Poudel
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA
| | - David M Leitner
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA
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23
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Crescenzi O, Graziano G. A quantum chemical study on the hydration energetics of trimethylamine N-oxide, its protonated form and tert-butanol. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Galimberti DR. Vibrational Circular Dichroism from DFT Molecular Dynamics: The AWV Method. J Chem Theory Comput 2022; 18:6217-6230. [PMID: 36112978 PMCID: PMC9558311 DOI: 10.1021/acs.jctc.2c00736] [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] [Indexed: 11/29/2022]
Abstract
![]()
The paper illustrates the Activity Weighted Velocities
(AWV) methodology
to compute Vibrational Circular Dichroism (VCD) anharmonic spectra
from Density Functional Theory (DFT) molecular dynamics. AWV calculates
the spectra by the Fourier Transform of the time correlation functions
of velocities, weighted by specific observables: the Atomic Polar
Tensors (APTs) and the Atomic Axial Tensors (AATs). Indeed, AWV shows
to correctly reproduce the experimental spectra for systems in the
gas and liquid phases, both in the case of weakly and strongly interacting
systems. The comparison with the experimental spectra is striking
especially in the fingerprint region, as demonstrated by the three
benchmark systems discussed: (1S)-Fenchone in the
gas phase, (S)-(−)-Propylene oxide in the
liquid phase, and (R)-(−)-2-butanol in the
liquid phase. The time evolution of APTs and AATs can be adequately
described by a linear combination of the tensors of a small set of
appropriate reference structures, strongly reducing the computational
cost without compromising accuracy. Additionally, AWV allows the partition
of the spectral signal in its molecular components without any expensive
postprocessing and any localization of the charge density or the wave
function.
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Affiliation(s)
- Daria Ruth Galimberti
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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25
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Pyne S, Pyne P, Mitra RK. Addition of cholesterol alters the hydration at the surface of model lipids: a spectroscopic investigation. Phys Chem Chem Phys 2022; 24:20381-20389. [PMID: 35983752 DOI: 10.1039/d2cp01905a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cholesterol is known to modify the phase behavior of model lipid membranes as it makes phospholipid bilayers more structured. Simulation results have shown that the addition of cholesterol allows more bulk-like water to protrude into phospholipid interfaces. However, such claims have not yet been verified experimentally. We have investigated the alteration in the hydrogen bond network structure of water at the surface of two model phospholipids DOPC and DOPG as cholesterol is added into these using ATR-FTIR spectroscopy in the FIR-THz region. Our measurements and analysis led us to probe the collective H-bond network explicitly at the lipid surface. A detailed principal component analysis of the measured data concludes that the water-water H-bond vibration dynamics gets slower at the lipid surface as compared to bulk water, the effect being more prominent in the case of the charged phospholipid, DOPG. However, as cholesterol is added and more bulk-like water protrudes into the liposome interface, the H-bond vibration gets weaker and correspondingly the dynamics gets accelerated.
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Affiliation(s)
- Sumana Pyne
- Department of Chemical Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
| | - Partha Pyne
- Department of Chemical Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
| | - Rajib Kumar Mitra
- Department of Chemical Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
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26
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Pezzotti S, Sebastiani F, van Dam EP, Ramos S, Conti Nibali V, Schwaab G, Havenith M. Spectroscopic Fingerprints of Cavity Formation and Solute Insertion as a Measure of Hydration Entropic Loss and Enthalpic Gain. Angew Chem Int Ed Engl 2022; 61:e202203893. [PMID: 35500074 PMCID: PMC9401576 DOI: 10.1002/anie.202203893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Indexed: 11/09/2022]
Abstract
Hydration free energies are dictated by a subtle balance of hydrophobic and hydrophilic interactions. We present here a spectroscopic approach, which gives direct access to the two main contributions: Using THz-spectroscopy to probe the frequency range of the intermolecular stretch (150-200 cm-1 ) and the hindered rotations (450-600 cm-1 ), the local contributions due to cavity formation and hydrophilic interactions can be traced back. We show that via THz calorimetry these fingerprints can be correlated 1 : 1 with the group specific solvation entropy and enthalpy. This allows to deduce separately the hydrophobic (i.e. cavity formation) and hydrophilic contributions to thermodynamics, as shown for hydrated alcohols as a case study. Accompanying molecular dynamics simulations quantitatively support our experimental results. In the future our approach will allow to dissect hydration contributions in inhomogeneous mixtures and under non-equilibrium conditions.
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Affiliation(s)
- Simone Pezzotti
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Federico Sebastiani
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.,Current affiliation: Department of Chemistry "U. Schiff", University of Florence, I-50019, Sesto Fiorentino, FI, Italy
| | - Eliane P van Dam
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Sashary Ramos
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Valeria Conti Nibali
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.,Current affiliation: Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra (MIFT), Università di Messina, 98166, Messina, Italy
| | - Gerhard Schwaab
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, Bochum, Germany.,Department of Physics, Technische Universität Dortmund, 44227, Dortmund, Germany
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27
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Nishida K, Anada T, Tanaka M. Roles of interfacial water states on advanced biomedical material design. Adv Drug Deliv Rev 2022; 186:114310. [PMID: 35487283 DOI: 10.1016/j.addr.2022.114310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 12/15/2022]
Abstract
When biomedical materials come into contact with body fluids, the first reaction that occurs on the material surface is hydration; proteins are then adsorbed and denatured on the hydrated material surface. The amount and degree of denaturation of adsorbed proteins affect subsequent cell behavior, including cell adhesion, migration, proliferation, and differentiation. Biomolecules are important for understanding the interactions and biological reactions of biomedical materials to elucidate the role of hydration in biomedical materials and their interaction partners. Analysis of the water states of hydrated materials is complicated and remains controversial; however, knowledge about interfacial water is useful for the design and development of advanced biomaterials. Herein, we summarize recent findings on the hydration of synthetic polymers, supramolecular materials, inorganic materials, proteins, and lipid membranes. Furthermore, we present recent advances in our understanding of the classification of interfacial water and advanced polymer biomaterials, based on the intermediate water concept.
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Affiliation(s)
- Kei Nishida
- Institute for Materials Chemistry and Engineering Kyushu university, 744 Motooka, Nishi-ku Fukuoka 819-0395, Japan; Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Japan(1)
| | - Takahisa Anada
- Institute for Materials Chemistry and Engineering Kyushu university, 744 Motooka, Nishi-ku Fukuoka 819-0395, Japan
| | - Masaru Tanaka
- Institute for Materials Chemistry and Engineering Kyushu university, 744 Motooka, Nishi-ku Fukuoka 819-0395, Japan.
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28
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Pyne S, Pyne P, Kumar Mitra R. The inner hydration in surfactant/cholesterol vesicles differs from the outer one: a spectroscopic investigation. Chemphyschem 2022; 23:e202200337. [PMID: 35775165 DOI: 10.1002/cphc.202200337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/21/2022] [Indexed: 11/07/2022]
Abstract
Vesicles contain two aqueous regions: inner core and outer-to-bulk . It has remained an open question whether hydration behaviour in the inner core differs from the outer-to-bulk region, mostly owning to the inability of the conventional spectroscopic techniques to deconvolute the contribution from these two regions. We, using THz-FTIR spectroscopy (1.5-13.5 THz) experimentally probe the inner hydration of three differently charged surfactant/cholesterol vesicles composed of SDS, CTAB and Brij 30. Both dynamic light scattering (DLS) and atomic force microscopy (AFM) measurements affirm the transition from micelles to vesicles as cholesterol is added into surfactant solutions. FTIR measurements show that hydration behaviour changes significantly as micelles are converted into vesicles, the change been exclusively caused due to the formation of an inner core . Our measurements on the hydrogen bond stretch and librational motion of the inner hydration show distinct features compared to the overall hydration, which in turn is found to be surfactant type and cholesterol concentration dependent.
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Affiliation(s)
- Sumana Pyne
- Department of Chemical Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
| | - Partha Pyne
- Department of Chemical Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
| | - Rajib Kumar Mitra
- Department of Chemical Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
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29
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Pezzotti S, Sebastiani F, Dam EP, Ramos S, Conti Nibali V, Schwaab G, Havenith M. Spectroscopic Fingerprints of Cavity Formation and Solute Insertion as a Measure of Hydration Entropic Loss and Enthalpic Gain. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Simone Pezzotti
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
| | - Federico Sebastiani
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
- Current affiliation: Department of Chemistry “U. Schiff” University of Florence I-50019 Sesto Fiorentino FI Italy
| | - Eliane P. Dam
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
| | - Sashary Ramos
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
| | - Valeria Conti Nibali
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
- Current affiliation: Dipartimento di Scienze Matematiche e Informatiche Scienze Fisiche e Scienze della Terra (MIFT) Università di Messina 98166 Messina Italy
| | - Gerhard Schwaab
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
| | - Martina Havenith
- Department of Physical Chemistry II Ruhr University Bochum Bochum Germany
- Department of Physics Technische Universität Dortmund 44227 Dortmund Germany
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30
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MAREKHA B, Hunger J. A single methyl group drastically changes urea's hydration dynamics. J Chem Phys 2022; 156:164504. [DOI: 10.1063/5.0085461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The amphiphilicity and denaturation efficiency of urea can be tuned via alkylation. Although the interaction of alkylureas with water and proteins has been studied in detail, the hydration of 1-methylurea has remained elusive, precluding the isolation of the effect of an individual methyl group. Here, we study water dynamics in the hydration shell of 1-methylurea (1-MU) using infrared absorption and ultrafast infrared spectroscopies. We find that 1-MU hardly affects the hydrogen-bond distribution of water as probed by the OD stretching vibration of HOD molecules. Polarization resolved infrared pump-probe experiments reveal that 1-MU slows down the rotational dynamics of up to 3 water molecules in its hydration shell. Comparison to earlier results for other alkylureas suggests that further alkylation does not necessarily slow down the rotational dynamics of additional water molecules. Two-dimensional infrared experiments show that 1-MU markedly slows down the hydrogen-bond fluctuation dynamics of water, yet similar to what has been found for urea and dimethylureas. Remarkably, (alkyl-) ureas that share a similar effect on water's hydrogen-bond fluctuation dynamics share a similar (modest) protein denaturation tendency. As such, not only the hydrophobicity but also hydration of hydrophilic fragments of alkylureas may be relevant to explain their function towards biomolecules.
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Affiliation(s)
- Bogdan MAREKHA
- Max-Planck-Institute for Medical Research Department of Biomolecular Mechanisms, Germany
| | - Johannes Hunger
- Molecular Spectroscopy, Max Planck Institute for Polymer Research, Germany
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31
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Pyne P, Mitra RK. Excipients Do Regulate Phase Separation in Lysozyme and Thus Also Its Hydration. J Phys Chem Lett 2022; 13:931-938. [PMID: 35050625 DOI: 10.1021/acs.jpclett.1c03449] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
While the liquid-liquid phase separation (LLPS) process in proteins has been studied in great detail, it has not been widely explored how the associated protein hydration changes during the process and how crucial its role is in the process itself. In this contribution, we experimentally explore the alteration of lysozyme hydration during its LLPS process using attenuated total reflection (ATR)-FTIR spectroscopy in the THz frequency region (1.5-21 THz). Additionally, we explore the role of excipients (l-arginine, sucrose, bovine albumin (BSA), and ubiquitin (Ubi)) in regulating the process and found that, while sucrose stabilizes the LLPS, BSA inhibits it. The effect of Arg in the LLPS is subtle, and that of Ubi is concentration dependent. We made a detailed analysis of the hydration profile of Lys in the presence of these excipients and observe that a change in hydration in terms of H-bond making/breaking is a definite signature regulating the process.
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Affiliation(s)
- Partha Pyne
- Department of Chemical, Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
| | - Rajib Kumar Mitra
- Department of Chemical, Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
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32
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Hande V, Chakrabarty S. Size-Dependent Order-Disorder Crossover in Hydrophobic Hydration: Comparison between Spherical Solutes and Linear Alcohols. ACS OMEGA 2022; 7:2671-2678. [PMID: 35097265 PMCID: PMC8793046 DOI: 10.1021/acsomega.1c05064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/31/2021] [Indexed: 05/03/2023]
Abstract
Theory and computer simulation studies have predicted that water molecules around hydrophobic molecules should undergo an order-disorder transition with increasing solute size around a 1 nm length scale. Some theories predict the formation of a clathrate-like ordered structure around smaller hydrophobic solutes (<1 nm) and the formation of disordered vapor-liquid interfaces around larger solutes (>1 nm) and surfaces. Experimental validation of these predictions has often been elusive and contradictory. High-resolution Raman spectroscopy has detected that water around small hydrophobic solutes shows a signature similar to that of bulk water at lower temperature (increased ordering and a stronger hydrogen-bonded network). Similarly, water around larger solutes shows an increasing population of dangling OH bonds very similar to higher temperature bulk water. Thus, the solute size dependence of the structure and dynamics of water around hydrophobic molecules seems to have an analogy with the temperature dependence in bulk water. In this work, using atomistic classical molecular dynamics (MD) simulations, we have systematically investigated this aspect and characterized this interesting analogy. Structural order parameters including the tetrahedral order parameter (Q), hydrogen bond distribution, and vibrational power spectrum highlight this similarity. However, in contrast to the experimental observations, we do not observe any length-dependent crossover for linear hydrophobic alcohols (n-alkanols) using classical MD simulations. This is in agreement with earlier findings that linear alkane chains do not demonstrate the length-dependent order-disorder transition due to the presence of a sub-nanometer length scale along the cross section of the chain. Moreover, the collapsed state of linear hydrocarbon chains is not significantly populated for smaller chains (number of carbons below 20). In the context of our computational results, we raise several pertinent questions related to the sensitivity of various structural and dynamical parameters toward capturing these complex phenomena of hydrophobic hydration.
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Affiliation(s)
- Vrushali Hande
- Physical
and Materials Chemistry Division, CSIR-National
Chemical Laboratory, Pune, Maharashtra 411008, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Suman Chakrabarty
- Department
of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata 700 106, India
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33
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Moon H, Collanton RP, Monroe JI, Casey TM, Shell MS, Han S, Scott SL. Evidence for Entropically Controlled Interfacial Hydration in Mesoporous Organosilicas. J Am Chem Soc 2022; 144:1766-1777. [PMID: 35041412 DOI: 10.1021/jacs.1c11342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
At aqueous interfaces, the distribution and dynamics of adsorbates are modulated by the behavior of interfacial water. Hydration of a hydrophobic surface can store entropy via the ordering of interfacial water, which contributes to the Gibbs energy of solute binding. However, there is little experimental evidence for the existence of such entropic reservoirs, and virtually no precedent for their rational design in systems involving extended interfaces. In this study, two series of mesoporous silicas were modified in distinct ways: (1) progressively deeper thermal dehydroxylation, via condensation of surface silanols, and (2) increasing incorporation of nonpolar organic linkers into the silica framework. Both approaches result in decreasing average surface polarity, manifested in a blue-shift in the fluorescence of an adsorbed dye. For the inorganic silicas, hydrogen-bonding of water becomes less extensive as the number of surface silanols decreases. Overhauser dynamic nuclear polarization (ODNP) relaxometry indicates enhanced surface water diffusivity, reflecting a loss of enthalpic hydration. In contrast, organosilicas show a monotonic decrease in surface water diffusivity with decreasing polarity, reflecting enhanced hydrophobic hydration. Molecular dynamics simulations predict increased tetrahedrality of interfacial water for the organosilicas, implying increased ordering near the nm-size organic domains (relative to inorganic silicas, which necessarily lack such domains). These findings validate the prediction that hydrophobic hydration at interfaces is controlled by the microscopic length scale of the hydrophobic regions. They further suggest that the hydration thermodynamics of structurally heterogeneous silica surfaces can be tuned to promote adsorption, which in turn tunes the selectivity in catalytic reactions.
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Affiliation(s)
- Hyunjin Moon
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Ryan P Collanton
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Jacob I Monroe
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Thomas M Casey
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510, United States
| | - M Scott Shell
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Songi Han
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States.,Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510, United States
| | - Susannah L Scott
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States.,Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510, United States
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34
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Stripping away ion hydration shells in electrical double-layer formation: Water networks matter. Proc Natl Acad Sci U S A 2021; 118:2108568118. [PMID: 34782461 PMCID: PMC8617503 DOI: 10.1073/pnas.2108568118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2021] [Indexed: 11/24/2022] Open
Abstract
For centuries the double layer at the solid/electrolyte interface has been a central concept in electrochemistry. Today, it is still crucial for virtually all renewable energy storage and conversion technologies. Here, the double-layer formation is probed by THz spectroscopy with ultrabright synchrotron light as a source. Our results capture the molecular details of double-layer formation at positively/negatively charged Au electrodes for an NaCl electrolyte. We reveal a contrasting response applying positive versus negative bias, which is dictated by the interfacial water network and rationalized by accompanying molecular dynamics simulations and electronic-structure calculations. While Na+ is directly attracted toward the negatively charged electrode, stripping of the Cl− hydration shell is observed only at larger potential values. The double layer at the solid/electrolyte interface is a key concept in electrochemistry. Here, we present an experimental study combined with simulations, which provides a molecular picture of the double-layer formation under applied voltage. By THz spectroscopy we are able to follow the stripping away of the cation/anion hydration shells for an NaCl electrolyte at the Au surface when decreasing/increasing the bias potential. While Na+ is attracted toward the electrode at the smallest applied negative potentials, stripping of the Cl− hydration shell is observed only at higher potential values. These phenomena are directly measured by THz spectroscopy with ultrabright synchrotron light as a source and rationalized by accompanying molecular dynamics simulations and electronic-structure calculations.
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35
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Gaigeot MP. Some opinions on MD-based vibrational spectroscopy of gas phase molecules and their assembly: An overview of what has been achieved and where to go. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 260:119864. [PMID: 34052762 DOI: 10.1016/j.saa.2021.119864] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 04/13/2021] [Accepted: 04/18/2021] [Indexed: 06/12/2023]
Abstract
We hereby review molecular dynamics simulations for anharmonic gas phase spectroscopy and provide some of our opinions of where the field is heading. With these new directions, the theoretical IR/Raman spectroscopy of large (bio)-molecular systems will be more easily achievable over longer time-scale MD trajectories for an increase in accuracy of the MD-IR and MD-Raman calculated spectra. With the new directions presented here, the high throughput 'decoding' of experimental IR/Raman spectra into 3D-structures should thus be possible, hence advancing e.g. the field of MS-IR for structural characterization by spectroscopy. We also review the assignment of vibrational spectra in terms of anharmonic molecular modes from the MD trajectories, and especially introduce our recent developments based on Graph Theory algorithms. Graph Theory algorithmic is also introduced in this review for the identification of the molecular 3D-structures sampled over MD trajectories.
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Affiliation(s)
- Marie-Pierre Gaigeot
- Université Paris-Saclay, Univ Evry, CNRS, LAMBE UMR8587, 91025 Evry-Courcouronnes, France.
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36
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Ma CY, Pezzotti S, Schwaab G, Gebala M, Herschlag D, Havenith M. Cation enrichment in the ion atmosphere is promoted by local hydration of DNA. Phys Chem Chem Phys 2021; 23:23203-23213. [PMID: 34622888 PMCID: PMC8797164 DOI: 10.1039/d1cp01963e] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrostatic interactions are central to the structure and function of nucleic acids, including their folding, condensation, and interaction with proteins and other charged molecules. These interactions are profoundly affected by ions surrounding nucleic acids, the constituents of the so-called ion atmosphere. Here, we report precise Fourier Transform-Terahertz/Far-Infrared (FT-THz/FIR) measurements in the frequency range 30-500 cm-1 for a 24-bp DNA solvated in a series of alkali halide (NaCl, NaF, KCl, CsCl, and CsF) electrolyte solutions which are sensitive to changes in the ion atmosphere. Cation excess in the ion atmosphere is detected experimentally by observation of cation modes of Na+, K+, and Cs+ in the frequency range between 70-90 cm-1. Based on MD simulations, we propose that the magnitude of cation excess (which is salt specific) depends on the ability of the electrolyte to perturb the water network at the DNA interface: In the NaF atmosphere, the ions reduce the strength of interactions between water and the DNA more than in case of a NaCl electrolyte. Here, we explicitly take into account the solvent contribution to the chemical potential in the ion atmosphere: A decrease in the number of bound water molecules in the hydration layer of DNA is correlated with enhanced density fluctuations, which decrease the free energy cost of ion-hydration, thus promoting further ion accumulation within the DNA atmosphere. We propose that taking into account the local solvation is crucial for understanding the ion atmosphere.
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Affiliation(s)
- Chun Yu Ma
- Department of Physical Chemistry II, Ruhr-University Bochum, 44780 Bochum, Germany.
| | - Simone Pezzotti
- Department of Physical Chemistry II, Ruhr-University Bochum, 44780 Bochum, Germany.
| | - Gerhard Schwaab
- Department of Physical Chemistry II, Ruhr-University Bochum, 44780 Bochum, Germany.
| | - Magdalena Gebala
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Daniel Herschlag
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr-University Bochum, 44780 Bochum, Germany.
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37
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Pal S, Chattopadhyay A. Hydration Dynamics in Biological Membranes: Emerging Applications of Terahertz Spectroscopy. J Phys Chem Lett 2021; 12:9697-9709. [PMID: 34590862 DOI: 10.1021/acs.jpclett.1c02576] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Water drives the spontaneous self-assembly of lipids and proteins into quasi two-dimensional biological membranes that act as catalytic scaffolds for numerous processes central to life. However, the functional relevance of hydration in membrane biology is only beginning to be addressed, predominantly because of challenges associated with direct measurements of hydration microstructure and dynamics in a biological milieu. Our recent work on the novel interplay of membrane electrostatics and crowding in shaping membrane hydration dynamics utilizing terahertz (THz) spectroscopy represents an important step in this context. In this Perspective, we provide a glimpse into the ever-broadening functional landscape of hydration dynamics in biological membranes in the backdrop of the unique physical chemistry of water molecules. We further highlight the immense (and largely untapped) potential of the THz toolbox in addressing contemporary problems in membrane biology, while emphasizing the adaptability of the analytical framework reported recently by us to such studies.
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Affiliation(s)
- Sreetama Pal
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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38
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39
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Adams E, Pezzotti S, Ahlers J, Rüttermann M, Levin M, Goldenzweig A, Peleg Y, Fleishman SJ, Sagi I, Havenith M. Local Mutations Can Serve as a Game Changer for Global Protein Solvent Interaction. JACS AU 2021; 1:1076-1085. [PMID: 34337607 PMCID: PMC8317155 DOI: 10.1021/jacsau.1c00155] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Indexed: 05/15/2023]
Abstract
Although it is well-known that limited local mutations of enzymes, such as matrix metalloproteinases (MMPs), may change enzyme activity by orders of magnitude as well as its stability, the completely rational design of proteins is still challenging. These local changes alter the electrostatic potential and thus local electrostatic fields, which impacts the dynamics of water molecules close the protein surface. Here we show by a combined computational design, experimental, and molecular dynamics (MD) study that local mutations have not only a local but also a global effect on the solvent: In the specific case of the matrix metalloprotease MMP14, we found that the nature of local mutations, coupled with surface morphology, have the ability to influence large patches of the water hydrogen-bonding network at the protein surface, which is correlated with stability. The solvent contribution can be experimentally probed via terahertz (THz) spectroscopy, thus opening the door to the exciting perspective of rational protein design in which a systematic tuning of hydration water properties allows manipulation of protein stability and enzymatic activity.
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Affiliation(s)
- Ellen
M. Adams
- Lehrstuhl
für Physkalische Chemie II, Ruhr
Universität Bochum, 44801 Bochum, Germany
| | - Simone Pezzotti
- Lehrstuhl
für Physkalische Chemie II, Ruhr
Universität Bochum, 44801 Bochum, Germany
| | - Jonas Ahlers
- Lehrstuhl
für Physkalische Chemie II, Ruhr
Universität Bochum, 44801 Bochum, Germany
| | - Maximilian Rüttermann
- Lehrstuhl
für Physkalische Chemie II, Ruhr
Universität Bochum, 44801 Bochum, Germany
| | - Maxim Levin
- Department
of Biological Regulation, Weizmann Institute
of Science, Rehovot 7610001, Israel
| | - Adi Goldenzweig
- Department
of Biomolecular Sciences, Weizmann Institute
of Science, Rehovot 7610001, Israel
| | - Yoav Peleg
- Structural
Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sarel J. Fleishman
- Department
of Biomolecular Sciences, Weizmann Institute
of Science, Rehovot 7610001, Israel
| | - Irit Sagi
- Department
of Biological Regulation, Weizmann Institute
of Science, Rehovot 7610001, Israel
| | - Martina Havenith
- Lehrstuhl
für Physkalische Chemie II, Ruhr
Universität Bochum, 44801 Bochum, Germany
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40
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Kolling I, Hölzl C, Imoto S, Alfarano SR, Vondracek H, Knake L, Sebastiani F, Novelli F, Hoberg C, Brubach JB, Roy P, Forbert H, Schwaab G, Marx D, Havenith M. Aqueous TMAO solution under high hydrostatic pressure. Phys Chem Chem Phys 2021; 23:11355-11365. [PMID: 33972970 DOI: 10.1039/d1cp00703c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Trimethylamine N-oxide (TMAO) is a well known osmolyte in nature, which is used by deep sea fish to stabilize proteins against High Hydrostatic Pressure (HHP). We present a combined ab initio molecular dynamics, force field molecular dynamics, and THz absorption study of TMAO in water up to 12 kbar to decipher its solvation properties upon extreme compression. On the hydrophilic oxygen side of TMAO, AIMD simulations at 1 bar and 10 kbar predict a change of the coordination number from a dominating TMAO·(H2O)3 complex at ambient conditions towards an increased population of a TMAO·(H2O)4 complex at HHP conditions. This increase of the TMAO-oxygen coordination number goes in line with a weakening of the local hydrogen bond network, spectroscopic shifts and intensity changes of the corresponding intermolecular THz bands. Using a pressure-dependent HHP force field, FFMD simulations predict a significant increase of hydrophobic hydration from 1 bar up to 4-5 kbar, which levels off at higher pressures up to 10 kbar. THz spectroscopic data reveal two important pressure regimes with spectroscopic inflection points of the dominant intermolecular modes: The first regime (1.5-2 kbar) is barely recognizable in the simulation data. However, it relates well with the observation that the apparent molar volume of solvated TMAO is nearly constant in the biologically relevant pressure range up to 1 kbar as found in the deepest habitats on Earth in the ocean. The second inflection point around 4-5 kbar is related to the amount of hydrophobic hydration as predicted by the FFMD simulations. In particular, the blueshift of the intramolecular CNC bending mode of TMAO at about 390 cm-1 is the spectroscopic signature of increasingly pronounced pressure-induced changes in the solvation shell of TMAO. Thus, the CNC bend can serve as local pressure sensor in the multi-kbar pressure regime.
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Affiliation(s)
- Inga Kolling
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany.
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41
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Pezzotti S, Serva A, Sebastiani F, Brigiano FS, Galimberti DR, Potier L, Alfarano S, Schwaab G, Havenith M, Gaigeot MP. Molecular Fingerprints of Hydrophobicity at Aqueous Interfaces from Theory and Vibrational Spectroscopies. J Phys Chem Lett 2021; 12:3827-3836. [PMID: 33852317 PMCID: PMC9004482 DOI: 10.1021/acs.jpclett.1c00257] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/09/2021] [Indexed: 05/28/2023]
Abstract
Hydrophobicity/hydrophilicity of aqueous interfaces at the molecular level results from a subtle balance in the water-water and water-surface interactions. This is characterized here via density functional theory-molecular dynamics (DFT-MD) coupled with vibrational sum frequency generation (SFG) and THz-IR absorption spectroscopies. We show that water at the interface with a series of weakly interacting materials is organized into a two-dimensional hydrogen-bonded network (2D-HB-network), which is also found above some macroscopically hydrophilic silica and alumina surfaces. These results are rationalized through a descriptor that measures the number of "vertical" and "horizontal" hydrogen bonds formed by interfacial water, quantifying the competition between water-surface and water-water interactions. The 2D-HB-network is directly revealed by THz-IR absorption spectroscopy, while the competition of water-water and water-surface interactions is quantified from SFG markers. The combination of SFG and THz-IR spectroscopies is thus found to be a compelling tool to characterize the finest details of molecular hydrophobicity at aqueous interfaces.
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Affiliation(s)
- Simone Pezzotti
- Université
Paris-Saclay, Univ Evry, CNRS, LAMBE
UMR8587, 91025 Evry-Courcouronnes, France
| | - Alessandra Serva
- Université
Paris-Saclay, Univ Evry, CNRS, LAMBE
UMR8587, 91025 Evry-Courcouronnes, France
| | - Federico Sebastiani
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44801 Bochum, Germany
| | - Flavio Siro Brigiano
- Université
Paris-Saclay, Univ Evry, CNRS, LAMBE
UMR8587, 91025 Evry-Courcouronnes, France
| | - Daria Ruth Galimberti
- Université
Paris-Saclay, Univ Evry, CNRS, LAMBE
UMR8587, 91025 Evry-Courcouronnes, France
| | - Louis Potier
- Université
Paris-Saclay, Univ Evry, CNRS, LAMBE
UMR8587, 91025 Evry-Courcouronnes, France
| | - Serena Alfarano
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44801 Bochum, Germany
| | - Gerhard Schwaab
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44801 Bochum, Germany
| | - Martina Havenith
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44801 Bochum, Germany
| | - Marie-Pierre Gaigeot
- Université
Paris-Saclay, Univ Evry, CNRS, LAMBE
UMR8587, 91025 Evry-Courcouronnes, France
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42
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Ahlers J, Adams EM, Bader V, Pezzotti S, Winklhofer KF, Tatzelt J, Havenith M. The key role of solvent in condensation: Mapping water in liquid-liquid phase-separated FUS. Biophys J 2021; 120:1266-1275. [PMID: 33515602 PMCID: PMC8059208 DOI: 10.1016/j.bpj.2021.01.019] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/21/2020] [Accepted: 01/19/2021] [Indexed: 01/09/2023] Open
Abstract
Formation of biomolecular condensates through liquid-liquid phase separation (LLPS) has emerged as a pervasive principle in cell biology, allowing compartmentalization and spatiotemporal regulation of dynamic cellular processes. Proteins that form condensates under physiological conditions often contain intrinsically disordered regions with low-complexity domains. Among them, the RNA-binding proteins FUS and TDP-43 have been a focus of intense investigation because aberrant condensation and aggregation of these proteins is linked to neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal dementia. LLPS occurs when protein-rich condensates form surrounded by a dilute aqueous solution. LLPS is per se entropically unfavorable. Energetically favorable multivalent protein-protein interactions are one important aspect to offset entropic costs. Another proposed aspect is the release of entropically unfavorable preordered hydration water into the bulk. We used attenuated total reflection spectroscopy in the terahertz frequency range to characterize the changes in the hydrogen bonding network accompanying the FUS enrichment in liquid-liquid phase-separated droplets to provide experimental evidence for the key role of the solvent as a thermodynamic driving force. The FUS concentration inside LLPS droplets was determined to be increased to 2.0 mM independent of the initial protein concentration (5 or 10 μM solutions) by fluorescence measurements. With terahertz spectroscopy, we revealed a dewetting of hydrophobic side chains in phase-separated FUS. Thus, the release of entropically unfavorable water populations into the bulk goes hand in hand with enthalpically favorable protein-protein interaction. Both changes are energetically favorable, and our study shows that both contribute to the thermodynamic driving force in phase separation.
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Affiliation(s)
- Jonas Ahlers
- Department Physical Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Ellen M Adams
- Department Physical Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Verian Bader
- Department Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Simone Pezzotti
- Department Physical Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Konstanze F Winklhofer
- Department Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Jörg Tatzelt
- Department Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Martina Havenith
- Department Physical Chemistry, Ruhr-University Bochum, Bochum, Germany.
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Size dependence of hydrophobic hydration at electrified gold/water interfaces. Proc Natl Acad Sci U S A 2021; 118:2023867118. [PMID: 33876767 DOI: 10.1073/pnas.2023867118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hydrophobic hydration at metal/water interfaces actively contributes to the energetics of electrochemical reactions, e.g. [Formula: see text] and [Formula: see text] reduction, where small hydrophobic molecules are involved. In this work, constant applied potential molecular dynamics is employed to study hydrophobic hydration at a gold/water interface. We propose an adaptation of the Lum-Chandler-Weeks (LCW) theory to describe the free energy of hydrophobic hydration at the interface as a function of solute size and applied voltage. Based on this model we are able to predict the free energy cost of cavity formation at the interface directly from the free energy cost in the bulk plus an interface-dependent correction term. The interfacial water network contributes significantly to the free energy, yielding a preference for outer-sphere adsorption at the gold surface for ideal hydrophobes. We predict an accumulation of small hydrophobic solutes of sizes comparable to CO or [Formula: see text], while the free energy cost to hydrate larger hydrophobes, above 2.5-Å radius, is shown to be greater at the interface than in the bulk. Interestingly, the transition from the volume dominated to the surface dominated regimes predicted by the LCW theory in the bulk is also found to take place for hydrophobes at the Au/water interface but occurs at smaller cavity radii. By applying the adapted LCW theory to a simple model addition reaction, we illustrate some implications of our findings for electrochemical reactions.
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Priyadarsini A, Mallik BS. Insignificant Effect of Temperature on the Structure and Angular Jumps of Water near a Hydrophobic Cation. ACS OMEGA 2021; 6:8356-8364. [PMID: 33817496 PMCID: PMC8015100 DOI: 10.1021/acsomega.1c00091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/15/2021] [Indexed: 05/12/2023]
Abstract
The ambiguity in the behavior of water molecules around hydrophobic solutes is a matter of interest for many studies. Motivated by the earlier results on the dynamics of water molecules around tetramethylammonium (TMA) cation, we present the effect of temperature on the structure and angular jumps of water due to hydrophobicity using first principles molecular dynamics simulations. The average intermolecular distance between the central oxygen and four nearest neighbors is found to be the highest for water molecules in the solvation shell of TMA at 400 K, followed by the same at 330 K. The hydrogen bond (HB) donor-acceptor count, HB per water molecule, and tetrahedral order parameter suggests the loss of tetrahedrality in the solvation shell. Elevated temperature affects the tetrahedral parameter in local regions. The HB jump mechanism is studied for methyl hydrogen and water molecules in the solvation shell. Observations hint at the presence of dangling water molecules in the vicinity of the hydrophobic cation, and no evidence is found for the enhanced structural ordering of nearby water molecules.
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Pyne P, Samanta N, Gohil H, Prabhu SS, Mitra RK. Alteration of water absorption in the THz region traces the onset of fibrillation in proteins. Chem Commun (Camb) 2021; 57:998-1001. [PMID: 33399590 DOI: 10.1039/d0cc06500e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using terahertz spectroscopy, we established the alteration of the collective hydration of water during the fibrillation process (native → intermediate → fibril) of a model protein bovine serum albumin. This label-free study concludes that water dynamics change systematically with protein conformational changes as it experiences a hydrophobic environment during the initial protein unfolding process, followed by the release of bound water during oligomerization and finally the hydrophobic interior of the fibril.
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Affiliation(s)
- Partha Pyne
- Department of Chemical, Biological & Macro-Molecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences, Block-JD; Sector-III; Salt Lake, Kolkata-700106, India.
| | - Nirnay Samanta
- Department of Chemical, Biological & Macro-Molecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences, Block-JD; Sector-III; Salt Lake, Kolkata-700106, India. and Institute for Physical and Theoretical Chemistry, TU Braunschweig, 38106 Braunschweig, Germany
| | - Himanshu Gohil
- Department of Condensed Matter Physics And Material Science, Tata Institute of Fundamental Research, Homi Bhahba Road, Colaba, Mumbai-400005, India.
| | - S S Prabhu
- Department of Condensed Matter Physics And Material Science, Tata Institute of Fundamental Research, Homi Bhahba Road, Colaba, Mumbai-400005, India.
| | - Rajib Kumar Mitra
- Department of Chemical, Biological & Macro-Molecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences, Block-JD; Sector-III; Salt Lake, Kolkata-700106, India.
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An isolated water droplet in the aqueous solution of a supramolecular tetrahedral cage. Proc Natl Acad Sci U S A 2020; 117:32954-32961. [PMID: 33318176 PMCID: PMC7777103 DOI: 10.1073/pnas.2012545117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Water under nanoconfinement at ambient conditions has exhibited low-dimensional ice formation and liquid-solid phase transitions, but with structural and dynamical signatures that map onto known regions of water's phase diagram. Using terahertz (THz) absorption spectroscopy and ab initio molecular dynamics, we have investigated the ambient water confined in a supramolecular tetrahedral assembly, and determined that a dynamically distinct network of 9 ± 1 water molecules is present within the nanocavity of the host. The low-frequency absorption spectrum and theoretical analysis of the water in the Ga4L6 12- host demonstrate that the structure and dynamics of the encapsulated droplet is distinct from any known phase of water. A further inference is that the release of the highly unusual encapsulated water droplet creates a strong thermodynamic driver for the high-affinity binding of guests in aqueous solution for the Ga4L6 12- supramolecular construct.
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