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Lupi L, Bracco B, Sassi P, Corezzi S, Morresi A, Fioretto D, Comez L, Paolantoni M. Hydration Dynamics of Model Peptides with Different Hydrophobic Character. Life (Basel) 2022; 12:life12040572. [PMID: 35455063 PMCID: PMC9031890 DOI: 10.3390/life12040572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022] Open
Abstract
The multi-scale dynamics of aqueous solutions of the hydrophilic peptide N-acetyl-glycine-methylamide (NAGMA) have been investigated through extended frequency-range depolarized light scattering (EDLS), which enables the broad-band detection of collective polarizability anisotropy fluctuations. The results have been compared to those obtained for N-acetyl-leucinemethylamide (NALMA), an amphiphilic peptide which shares with NAGMA the same polar backbone, but also contains an apolar group. Our study indicates that the two model peptides induce similar effects on the fast translational dynamics of surrounding water. Both systems slow down the mobility of solvating water molecules by a factor 6–8, with respect to the bulk. Moreover, the two peptides cause a comparable far-reaching spatial perturbation extending to more than two hydration layers in diluted conditions. The observed concentration dependence of the hydration number is explained considering the random superposition of different hydration shells, while no indication of solute aggregation phenomena has been found. The results indicate that the effect on the dynamics of water solvating the amphiphilic peptide is dominated by the hydrophilic backbone. The minor impact of the hydrophobic moiety on hydration features is consistent with structural findings derived by Fourier transform infrared (FTIR) measurements, performed in attenuated total reflectance (ATR) configuration. Additionally, we give evidence that, for both systems, the relaxation mode in the GHz frequency range probed by EDLS is related to solute rotational dynamics. The rotation of NALMA occurs at higher timescales, with respect to the rotation of NAGMA; both processes are significantly slower than the structural dynamics of hydration water, suggesting that solute and solvent motions are uncoupled. Finally, our results do not indicate the presence of super-slow water (relaxation times in the order of tens of picoseconds) around the peptides investigated.
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Affiliation(s)
- Laura Lupi
- Dipartimento di Matematica e Fisica, Università Roma Tre, 00146 Rome, Italy;
| | - Brenda Bracco
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy; (B.B.); (P.S.); (A.M.)
| | - Paola Sassi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy; (B.B.); (P.S.); (A.M.)
| | - Silvia Corezzi
- Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia, Italy; (S.C.); (D.F.)
| | - Assunta Morresi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy; (B.B.); (P.S.); (A.M.)
| | - Daniele Fioretto
- Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia, Italy; (S.C.); (D.F.)
- IOM-CNR c/o Department of Physics and Geology, Università degli Studi di Perugia, 060123 Perugia, Italy
| | - Lucia Comez
- IOM-CNR c/o Department of Physics and Geology, Università degli Studi di Perugia, 060123 Perugia, Italy
- Correspondence: (L.C.); (M.P.)
| | - Marco Paolantoni
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy; (B.B.); (P.S.); (A.M.)
- Correspondence: (L.C.); (M.P.)
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Camisasca G, De Marzio M, Gallo P. Effect of trehalose on protein cryoprotection: Insights into the mechanism of slowing down of hydration water. J Chem Phys 2021; 153:224503. [PMID: 33317300 DOI: 10.1063/5.0033526] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study, with molecular dynamics simulations, a lysozyme protein immersed in a water-trehalose solution upon cooling. The aim is to understand the cryoprotectant role played by this disaccharide through the modifications that it induces on the slow dynamics of protein hydration water with its presence. The α-relaxation shows a fragile to strong crossover about 20° higher than that in the bulk water phase and 15° higher than that in lysozyme hydration water without trehalose. The protein hydration water without trehalose was found to show a second slower relaxation exhibiting a strong to strong crossover coupled with the protein dynamical transition. This slower relaxation time importantly appears enormously slowed down in our cryoprotectant solution. On the other hand, this long-relaxation in the presence of trehalose is also connected with a stronger damping of the protein structural fluctuations than that found when the protein is in contact with the pure hydration water. Therefore, this appears to be the mechanism through which trehalose manifests its cryoprotecting function.
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Affiliation(s)
- Gaia Camisasca
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | - Margherita De Marzio
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | - Paola Gallo
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
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Iorio A, Camisasca G, Gallo P. Slow dynamics of hydration water and the trehalose dynamical transition. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.088] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Physico-chemical properties of aqueous drug solutions: From the basic thermodynamics to the advanced experimental and simulation results. Int J Pharm 2018; 540:65-77. [PMID: 29412151 DOI: 10.1016/j.ijpharm.2018.01.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/22/2018] [Accepted: 01/22/2018] [Indexed: 11/20/2022]
Abstract
The physical chemical properties of aqueous solutions of model compounds are illustrated in relation to hydration and solubility issues by using three perspectives: thermodynamic, spectroscopic and molecular dynamics simulations. The thermodynamic survey of the fundamental backgrounds of concentration dependence and experimental solubility results show some peculiar behavior of aqueous solutions with several types of similar solutes. Secondly, the use of a variety of experimental spectroscopic devices, operating under different experimental conditions of dimension and frequency, has produced a large amount of structural and dynamic data on aqueous solutions showing the richness of the information produced, depending on where and how the experiment is carried out. Finally, the use of molecular dynamics computational work is presented to highlight how the different types of solute functional groups and surface topologies organize adjacent water molecules differently. The highly valuable contribution of computer simulation studies in providing molecular explanations for experimental deductions, either of a thermodynamic or spectroscopic nature, is shown to have changed the current knowledge of many aqueous solution processes. While this paper is intended to provide a collective view on the latest literature results, still the presentation aims at a tutorial explanation of the potentials of the three methodologies in the field of aqueous solutions of pharmaceutical molecules.
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Camisasca G, De Marzio M, Corradini D, Gallo P. Two structural relaxations in protein hydration water and their dynamic crossovers. J Chem Phys 2016; 145:044503. [DOI: 10.1063/1.4959286] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Comez L, Paolantoni M, Sassi P, Corezzi S, Morresi A, Fioretto D. Molecular properties of aqueous solutions: a focus on the collective dynamics of hydration water. SOFT MATTER 2016; 12:5501-5514. [PMID: 27280176 DOI: 10.1039/c5sm03119b] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
When a solute is dissolved in water, their mutual interactions determine the molecular properties of the solute on one hand, and the structure and dynamics of the surrounding water particles (the so-called hydration water) on the other. The very existence of soft matter and its peculiar properties are largely due to the wide variety of possible water-solute interactions. In this context, water is not an inert medium but rather an active component, and hydration water plays a crucial role in determining the structure, stability, dynamics, and function of matter. This review focuses on the collective dynamics of hydration water in terms of retardation with respect to the bulk, and of the number of molecules whose dynamics is perturbed. Since water environments are in a dynamic equilibrium, with molecules continuously exchanging from around the solute towards the bulk and vice versa, we examine the ability of different techniques to measure the water dynamics on the basis of the explored time scales and exchange rates. Special emphasis is given to the collective dynamics probed by extended depolarized light scattering and we discuss whether and to what extent the results obtained in aqueous solutions of small molecules can be extrapolated to the case of large biomacromolecules. In fact, recent experiments performed on solutions of increasing complexity clearly indicate that a reductionist approach is not adequate to describe their collective dynamics. We conclude this review by presenting current ideas that are being developed to describe the dynamics of water interacting with macromolecules.
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Affiliation(s)
- L Comez
- IOM-CNR c/o Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
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Comez L, Paolantoni M, Corezzi S, Lupi L, Sassi P, Morresi A, Fioretto D. Aqueous solvation of amphiphilic molecules by extended depolarized light scattering: the case of trimethylamine-N-oxide. Phys Chem Chem Phys 2016; 18:8881-9. [PMID: 26958663 DOI: 10.1039/c5cp04357c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrophilic and hydrophobic interactions strongly affect the solvation dynamics of biomolecules. To understand their role, small model systems are generally employed to simplify the investigations. In this study the amphiphile trimethylamine N-oxide (TMAO) is chosen as an exemplar, and studied by means of extended frequency range depolarized light scattering (EDLS) experiments as a function of solute concentration. This technique proves to be a suitable tool for investigating different aspects of aqueous solvation, being able at the same time to provide information about relaxation processes and vibrational modes of solvent and solute. In the case study of TMAO, we find that the relaxation dynamics of hydration water is moderately retarded compared to the bulk, and the perturbation induced by the solute on surrounding water is confined to the first hydration shell. The results highlight the hydrophobic character of TMAO in its interaction with water. The number of molecules taking part in the solvation process decreases as the solute concentration increases, following a trend consistent with the hydration water-sharing model, and suggesting that aggregation between solute molecules is negligible. Finally, the analysis of the resonant modes in the THz region and the comparison with the corresponding results obtained for the isosteric molecule tert-butyl alcohol (TBA) allow us to provide new insights into the different solvating properties of these two biologically relevant molecules.
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Affiliation(s)
- L Comez
- IOM-CNR c/o Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy. and Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
| | - M Paolantoni
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy
| | - S Corezzi
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
| | - L Lupi
- Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, USA
| | - P Sassi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy
| | - A Morresi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy
| | - D Fioretto
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy
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Comez L, Paolantoni M, Lupi L, Sassi P, Corezzi S, Morresi A, Fioretto D. Hydrophobic Hydration in Water–tert-Butyl Alcohol Solutions by Extended Depolarized Light Scattering. J Phys Chem B 2014; 119:9236-43. [DOI: 10.1021/jp509854a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- L. Comez
- IOM-CNR
c/o Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
- Dipartimento
di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
| | - M. Paolantoni
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce
di Sotto 8, I-06123 Perugia, Italy
| | - L. Lupi
- Department
of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - P. Sassi
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce
di Sotto 8, I-06123 Perugia, Italy
| | - S. Corezzi
- Dipartimento
di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
| | - A. Morresi
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce
di Sotto 8, I-06123 Perugia, Italy
| | - D. Fioretto
- Dipartimento
di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
- Centro
di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy
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