1
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Benedetto A, Kearley GJ, Faraone A. Conceptual study of a new instrument for dynamic neutron scattering measurements-The modulated intensity with diffraction analysis spectrometer (MIDAS). Rev Sci Instrum 2024; 95:043901. [PMID: 38557879 DOI: 10.1063/5.0193842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
Dynamic neutron scattering probes unique nanoscale dynamics via measurement of energy exchanged between a sample and the neutrons. The two spectrometers that investigate processes with characteristic times around a nanosecond are backscattering (BS) and neutron spin-echo (NSE). We present a new method for measuring dynamics using an oscillating cosine-like energy-distribution neutron-package at the sample and measure solely the portion scattered into the elastic line. This portion corresponds to elastically scattered neutrons and, in addition, inelastic components that are scattered with a probability directly proportional to the cosine Fourier-coefficients of the exchanged-energy spectrum. The counts at the detector thus correspond to the van Hove intermediate scattering function. We denote this new method as "Fourier transform neutron scattering" (FTNS), it being broadly analogous to IR and Raman spectroscopies. Here, the realization of such a concept is investigated using an oscillating incident beam produced via a precession method and a secondary spectrometer identical to a BS instrument using crystal analyzers. The instrument is denoted "Modulated Intensity with Diffraction Analysis Spectrometer" (MIDAS). However, simpler approaches, e.g., choppers, may also be used for an FTNS instrument. The theory behind MIDAS is presented, supported by numerical calculations and in silico experiments. Finally, we present a Monte Carlo simulation to compare BS and MIDAS spectrometers. This shows that MIDAS has almost 100 times more incident flux than standard BS, but due to the better signal-to-noise ratio of BS, the final information acquisition rate gain of MIDAS is approximately a factor of 2.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
- Department of Science, University of Roma Tre, 00146 Rome, Italy
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Gordon J Kearley
- School of Physics, University College Dublin, Dublin D04 N2E5, Ireland
| | - Antonio Faraone
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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2
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Abstract
In the past 25 years, a vast family of complex organic salts known as room-temperature ionic liquids (ILs) has received increasing attention due to their potential applications. ILs are composed by an organic cation and either an organic or inorganic anion, and possess several intriguing properties such as low vapor pressure and being liquid around room temperature. Several biological studies flagged their moderate-to-high (cyto)-toxicity. Toxicity is, however, also a synonym of affinity, and this boosted a series of biophysical and chemical-physical investigations aimed at exploiting ILs in bio-nanomedicine, drug-delivery, pharmacology, and bio-nanotechnology. Several of these investigations focused on the interaction between ILs and lipid membranes, aimed at determining the microscopic mechanisms behind their interaction. This is the focus of this review work. These studies have been carried out on a variety of different lipid bilayer systems ranging from 1-lipid to 5-lipids systems, and also on cell-extracted membranes. They have been carried out at different chemical-physical conditions and by the use of a number of different approaches, including atomic force microscopy, neutron and X-ray scattering, dynamic light scattering, differential scanning calorimetry, surface quartz microbalance, nuclear magnetic resonance, confocal fluorescence microscopy, and molecular dynamics simulations. The aim of this "2023 Michèle Auger Award" review work is to provide the reader with an up-to-date overview of this fascinating research field where "ILs meet lipid bilayers (aka biomembranes)," with the aim to boost it further and expand its cross-disciplinary edges towards novel high-impact ideas/applications in pharmacology, drug delivery, biomedicine, and bio-nanotechnology.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin, Dublin, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
- Department of Science, University of Roma Tre, Rome, Italy
- Laboratory for Neutron Scattering, Paul Scherrer Institute, Villigen, Switzerland
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3
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Olson W, He R, Benedetto A, Iskratsch T, Shaitan K, Hall D. Editors' roundup: October 2022. Biophys Rev 2022; 14:1085-1091. [PMID: 36345281 PMCID: PMC9636339 DOI: 10.1007/s12551-022-01002-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2022] [Indexed: 10/17/2022] Open
Abstract
This commentary constitutes the October edition of the 'Editors' roundup'-a multi-author omnibus of personal recommendations to interesting biophysics-related articles contributed by members of the editorial boards of leading international biophysics journals. The present commentary contains contributions from Progress in Biochemistry and Biophysics (an official journal of the Biophysical Society of China), European Biophysics Journal (the official journal of the European Biophysical Societies Association), Biophysical Reviews (the official IUPAB journal), and Biophysics (an official journal of the Russian Academy of Sciences). This edition of the Editors' Roundup also contains a new section from an editor at large who has provided selections from a number of journals on a single thematic topic.
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Affiliation(s)
- Wilma Olson
- Department of Chemistry and Chemical Biology, the State University of New Jersey, Rutgers Piscataway, NB, NJ USA
- Center for Quantitative Biology, the State University of New Jersey, Rutgers Piscataway, NB, NJ USA
| | - Rongqiao He
- Basic College of Medicine, Southwest Medical University, Luzhou, 646000 Sichuan China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, University of Chinese Academy of Sciences, Beijing, 100101 China
- CAS Key Laboratory of Mental Health, Institute of Psychology, University of Chinese Academy of Sciences, Beijing, 100101 China
| | - Antonio Benedetto
- School of Physics, University College Dublin, Dublin, D04 N2E5 Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, D04 N2E5 Ireland
- Department of Science, University of Roma Tre, 00146 Rome, Italy
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Thomas Iskratsch
- School of Engineering and Material Sciences, Queen Mary University of London, London, England UK
| | - Konstantin Shaitan
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Damien Hall
- WPI Nano Life Science Institute, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa 920-1164 Japan
- Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland
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4
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Pillai VS, Kumari P, Kolagatla S, Garcia Sakai V, Rudić S, Rodriguez BJ, Rubini M, Tych KM, Benedetto A. Controlling Amyloid Fibril Properties Via Ionic Liquids: The Representative Case of Ethylammonium Nitrate and Tetramethylguanidinium Acetate on the Amyloidogenesis of Lysozyme. J Phys Chem Lett 2022; 13:7058-7064. [PMID: 35900133 PMCID: PMC9358703 DOI: 10.1021/acs.jpclett.2c01505] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein aggregation into amyloid fibrils has been observed in several pathological conditions and exploited in nanotechnology. It is also key in several biochemical processes. In this work, we show that ionic liquids (ILs), a vast class of organic electrolytes, can finely tune amyloid properties, opening a new landscape in basic science and applications. The representative case of ethylammonium nitrate (EAN) and tetramethyl-guanidinium acetate (TMGA) ILs on lysozyme is considered. First, atomic force microscopy has shown that the addition of EAN and TMGA leads to thicker and thinner amyloid fibrils of greater and lower electric potential, respectively, with diameters finely tunable by IL concentration. Optical tweezers and neutron scattering have shed light on their mechanism of action. TMGA interacts with the protein hydration layer only, making the relaxation dynamics of these water molecules faster. EAN interacts directly with the protein instead, making it mechanically unstable and slowing down its relaxation dynamics.
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Affiliation(s)
- Visakh
V. S. Pillai
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Pallavi Kumari
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Srikanth Kolagatla
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Victoria Garcia Sakai
- ISIS
Neutron and Muon Source, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot OX11 0QX, U.K.
| | - Svemir Rudić
- ISIS
Neutron and Muon Source, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot OX11 0QX, U.K.
| | - Brian J. Rodriguez
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Marina Rubini
- School
of Chemistry, University College Dublin, Dublin D04 N2E5, Ireland
| | - Katarzyna M. Tych
- Groningen
Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Antonio Benedetto
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
- Department
of Science, University of Roma Tre, 00146 Rome, Italy
- Laboratory
for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
- , ,
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5
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Pillai VV, Kumari P, Benedetto A, Gobbo D, Ballone P. Absorption of Phosphonium Cations and Dications into a Hydrated POPC Phospholipid Bilayer: A Computational Study. J Phys Chem B 2022; 126:4272-4288. [PMID: 35666883 PMCID: PMC9207913 DOI: 10.1021/acs.jpcb.2c02212] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Molecular dynamics (MD) based on an empirical force field is applied to investigate the effect of phosphonium cations ([P6,6,6,6]+) and geminal dications ([DxC10]2+) inserted at T = 300 K into the hydration layer separating planar POPC phospholipid bilayers. Up to high concentration, nearly every added cation and dication becomes absorbed into the lipid phase. Absorption takes place during several microseconds and is virtually irreversible. The neutralizing counterions ([Cl]-, in the present simulation) remain dissolved in water, giving origin to the charge separation and the strong electrostatic double layer at the water/lipid interface. Incorporation of cations and dications changes the properties of the lipid bilayer such as diffusion, viscosity, and the electrostatic pattern. At high ionic concentration, the bilayer acquires a long-wavelength standing undulation, corresponding to a change of phase from fluid planar to ripple. All these changes are potentially able to affect processes relevant in the context of cell biology. The major difference between cations and dications concerns the kinetics of absorption, which takes place nearly two times faster in the [P6,6,6,6]+ case, and for [DxC10]2+ dications displays a marked separation into two-stages, corresponding to the easy absorption of the first phosphonium head of the dication and the somewhat more activated absorption of the second phosphonium head of each dication.
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Affiliation(s)
- V. V.
S. Pillai
- School
of Physics, University College Dublin, Dublin 4, Ireland
- Conway
Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin
4, Ireland
| | - P. Kumari
- School
of Physics, University College Dublin, Dublin 4, Ireland
- Conway
Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin
4, Ireland
| | - A. Benedetto
- School
of Physics, University College Dublin, Dublin 4, Ireland
- Conway
Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin
4, Ireland
- Department
of Sciences, University of Roma Tre, I-00154 Rome, Italy
| | - D. Gobbo
- School
of Pharmaceutical Sciences and ISPSO, University
of Geneva, Rue Michel-Servet
1, CH-1211, Geneva
4, Switzerland
- Computational
and Chemical Biology, Fondazione Istituto
Italiano di Tecnologia, I-16163 Genova, Italy
| | - P. Ballone
- School
of Physics, University College Dublin, Dublin 4, Ireland
- Conway
Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin
4, Ireland
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6
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Abstract
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Lipid bilayers are
a key component of cell membranes and play a
crucial role in life and in bio-nanotechnology. As a result, controlling
their physicochemical properties holds the promise of effective therapeutic
strategies. Ionic liquids (ILs)—a vast class of complex organic
electrolytes—have shown a high degree of affinity with lipid
bilayers and can be exploited in this context. However, the chemical
physics of IL absorption and partitioning into lipid bilayers is yet
to be fully understood. This work focuses on the absorption of the
model IL [bmim][Cl] into 1,2-dimyristoyl-sn-glycero-3-phosphocholine
(DMPC) lipid bilayers across their gel, ripple, and fluid phases.
Here, by small-angle neutron scattering, we show that (i) the IL cations
are absorbed in the lipid bilayer in all its thermodynamic phases
and (ii) the amount of IL inserted into the lipid phase increased
with increasing temperature, changing from three to four IL cations
per 10 lipids with increasing temperature from 10 °C in the gel
phase to 40 °C in the liquid phase, respectively. An explicative
hypothesis, based on the entropy gain coming from the IL hydration
water, is presented to explain the observed temperature trend. The
ability to control IL absorption with temperature can be used as a
handle to tune the effect of ILs on biomembranes and can be exploited
in bio-nanotechnological applications.
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Affiliation(s)
- Antonio Benedetto
- Department of Science, University of Roma Tre, 00146 Rome, Italy.,School of Physics, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland.,Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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7
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Forero-Martinez NC, Cortes-Huerto R, Benedetto A, Ballone P. Thermoresponsive Ionic Liquid/Water Mixtures: From Nanostructuring to Phase Separation. Molecules 2022; 27:molecules27051647. [PMID: 35268747 PMCID: PMC8912101 DOI: 10.3390/molecules27051647] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/15/2022] [Accepted: 02/28/2022] [Indexed: 12/10/2022] Open
Abstract
The thermodynamics, structures, and applications of thermoresponsive systems, consisting primarily of water solutions of organic salts, are reviewed. The focus is on organic salts of low melting temperatures, belonging to the ionic liquid (IL) family. The thermo-responsiveness is represented by a temperature driven transition between a homogeneous liquid state and a biphasic state, comprising an IL-rich phase and a solvent-rich phase, divided by a relatively sharp interface. Demixing occurs either with decreasing temperatures, developing from an upper critical solution temperature (UCST), or, less often, with increasing temperatures, arising from a lower critical solution temperature (LCST). In the former case, the enthalpy and entropy of mixing are both positive, and enthalpy prevails at low T. In the latter case, the enthalpy and entropy of mixing are both negative, and entropy drives the demixing with increasing T. Experiments and computer simulations highlight the contiguity of these phase separations with the nanoscale inhomogeneity (nanostructuring), displayed by several ILs and IL solutions. Current applications in extraction, separation, and catalysis are briefly reviewed. Moreover, future applications in forward osmosis desalination, low-enthalpy thermal storage, and water harvesting from the atmosphere are discussed in more detail.
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Affiliation(s)
- Nancy C. Forero-Martinez
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 9, 55128 Mainz, Germany;
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Robinson Cortes-Huerto
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Correspondence:
| | - Antonio Benedetto
- School of Physics, University College Dublin, 94568 Dublin, Ireland; (A.B.); (P.B.)
- Conway Institute for Biomolecular and Biomedical Research, University College Dublin, 94568 Dublin, Ireland
- Department of Sciences, University of Roma Tre, 00146 Rome, Italy
| | - Pietro Ballone
- School of Physics, University College Dublin, 94568 Dublin, Ireland; (A.B.); (P.B.)
- Conway Institute for Biomolecular and Biomedical Research, University College Dublin, 94568 Dublin, Ireland
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8
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Benedetto A, Pezzolato M, Robotti E, Biasibetti E, Marengo E, Bozzetta E. Detection of dexamethasone administration in veal calves: transcriptional biomarkers validation in FFPE muscle samples. Toxicol Lett 2021. [DOI: 10.1016/s0378-4274(21)00421-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Benedetto A, Kearley GJ. Experimental demonstration of the novel "van-Hove integral method (vHI)" for measuring diffusive dynamics by elastic neutron scattering. Sci Rep 2021; 11:14093. [PMID: 34238981 PMCID: PMC8266890 DOI: 10.1038/s41598-021-93463-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/24/2021] [Indexed: 11/09/2022] Open
Abstract
Quasi-elastic neutron scattering (QENS)-based on the seminal work of Nobel Laureate Brockhouse-has been one of the major methods for studying pico-second to nano-second diffusive dynamics over the past 70 years. This is regarded as an "inelastic" method for dynamics. In contrast, we recently proposed a new neutron-scattering method for dynamics, which uses the elastic line of the scattering to access system dynamics directly in the time domain (Benedetto and Kearley in Sci Rep 9:11284, 2019). This new method has been denoted "vHI" that stands for "van Hove Integral". The reason is that, under certain conditions, the measured elastic intensity corresponds to the running-time integral of the intermediate scattering function, [Formula: see text], up to a time that is inversely proportional to the energy band-width incident on the sample. As a result, [Formula: see text] is accessed from the time derivative of the measured vHI profile. vHI has been supported by numerical and Monte-Carlo simulations, but has been difficult to validate experimentally due to the lack of a suitable instrument. Here we show that vHI works in practice, which we achieved by using a simple modification to the standard QENS backscattering spectrometer methodology. Basically, we varied the neutron-energy band-widths incident at the sample via a step-wise variation of the frequency of the monochromator Doppler-drive. This provides a measurement of the vHI profile at the detectors. The same instrument and sample were also used in standard QENS mode for comparison. The intermediate scattering functions, [Formula: see text], obtained by the two methods-vHI and QENS-are strikingly similar providing a direct experimental validation of the vHI method. Perhaps surprisingly, the counting statistics of the two methods are comparable even though the instrument used was expressly designed for QENS. This shows that the methodology modification adopted here can be used in practice to access vHI profiles at many of the backscattering spectrometers worldwide. We also show that partial integrations of the measured QENS spectrum cannot provide the vHI profile, which clarifies a common misconception. At the same time, we show a novel approach which does access [Formula: see text] from QENS spectra.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin, Dublin 4, Ireland. .,Conway Institute, University College Dublin, Dublin 4, Ireland. .,Department of Sciences, University of Roma Tre, Rome, Italy. .,Laboratory for Neutron Scattering, Paul Scherrer Institute, Villigen, Switzerland.
| | - Gordon J Kearley
- School of Physics, University College Dublin, Dublin 4, Ireland.,School of Chemistry, University College Dublin, Dublin 4, Ireland
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10
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Abstract
The elastic properties of the cellular lipid membrane play a crucial role for life. Their alteration can lead to cell malfunction, and in turn, being able to control them holds the promise of effective therapeutic and diagnostic approaches. In this context, due to their proven strong interaction with lipid bilayers, ionic liquids (ILs)-a vast class of organic electrolytes-may play an important role. This work focuses on the effect of the model imidazolium-IL [bmim][Cl] on the bending modulus of DMPC lipid vesicles, a basic model of cellular lipid membranes. Here, by combining small-angle neutron scattering and neutron spin-echo spectroscopy, we show that the IL, dispersed at low concentrations at the bilayer-water interface, (i) diffuses into the lipid region, accounting for five IL-cations for every 11 lipids, and (ii) causes an increase of the lipid bilayer bending modulus, up to 60% compared to the neat lipid bilayer at 40 °C.
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Affiliation(s)
- Pallavi Kumari
- Department of Sciences, University of Roma Tre, 00146 Rome, Italy.,School of Physics and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Antonio Faraone
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Antonio Benedetto
- Department of Sciences, University of Roma Tre, 00146 Rome, Italy.,School of Physics and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland.,Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
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11
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Gobbo D, Cavalli A, Ballone P, Benedetto A. Computational analysis of the effect of [Tea][Ms] and [Tea][H 2PO 4] ionic liquids on the structure and stability of Aβ(17-42) amyloid fibrils. Phys Chem Chem Phys 2021; 23:6695-6709. [PMID: 33710213 DOI: 10.1039/d0cp06434c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experimental studies have reported the possibility of affecting the growth/dissolution of amyloid fibres by the addition of organic salts of the room-temperature ionic-liquid family, raising the tantalizing prospect of controlling these processes under physiological conditions. The effect of [Tea][Ms] and [Tea][H2PO4] at various concentrations on the structure and stability of a simple model of Aβ42 fibrils has been investigated by computational means. Free energy computations show that both [Tea][Ms] and [Tea][H2PO4] decrease the stability of fibrils with respect to isolated peptides in solution, and the effect is significantly stronger for [Tea][Ms]. The secondary structure of fibrils is not much affected, but single peptides in solution show a marked decrease in their β-strand character and an increase in α-propensity, again especially for [Tea][Ms]. These observations, consistent with the experimental picture, can be traced to two primary effects, i.e., the difference in the ionicity of the [Tea][Ms] and [Tea][H2PO4] water solutions and the remarkable affinity of peptides for [Ms]- anions, due to the multiplicity of H-bonds.
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Affiliation(s)
- D Gobbo
- Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia, Genova, Italy.
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12
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Kumari P, Pillai VVS, Gobbo D, Ballone P, Benedetto A. The transition from salt-in-water to water-in-salt nanostructures in water solutions of organic ionic liquids relevant for biological applications. Phys Chem Chem Phys 2021; 23:944-959. [DOI: 10.1039/d0cp04959j] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Computer simulations show how nano-structural motifs in organic salts/water solutions change with salt content increasing from dilute to highly concentrated.
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Affiliation(s)
- P. Kumari
- School of Physics
- University College
- Dublin
- Ireland
- Conway Institute for Biomolecular and Biomedical Research
| | - V. V. S. Pillai
- School of Physics
- University College
- Dublin
- Ireland
- Conway Institute for Biomolecular and Biomedical Research
| | - D. Gobbo
- Computational and Chemical Biology
- Fondazione Istituto Italiano di Tecnologia
- Genova
- Italy
| | - P. Ballone
- School of Physics
- University College
- Dublin
- Ireland
- Conway Institute for Biomolecular and Biomedical Research
| | - A. Benedetto
- School of Physics
- University College
- Dublin
- Ireland
- Conway Institute for Biomolecular and Biomedical Research
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13
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Kumari P, Pillai VVS, Benedetto A. Mechanisms of action of ionic liquids on living cells: the state of the art. Biophys Rev 2020; 12:1187-1215. [PMID: 32936423 PMCID: PMC7575683 DOI: 10.1007/s12551-020-00754-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/03/2020] [Indexed: 12/13/2022] Open
Abstract
Ionic liquids (ILs) are a relatively new class of organic electrolytes composed of an organic cation and either an organic or inorganic anion, whose melting temperature falls around room-temperature. In the last 20 years, the toxicity of ILs towards cells and micro-organisms has been heavily investigated with the main aim to assess the risks associated with their potential use in (industrial) applications, and to develop strategies to design greener ILs. Toxicity, however, is synonym with affinity, and this has stimulated, in turn, a series of biophysical and chemical-physical investigations as well as few biochemical studies focused on the mechanisms of action (MoAs) of ILs, key step in the development of applications in bio-nanomedicine and bio-nanotechnology. This review has the intent to present an overview of the state of the art of the MoAs of ILs, which have been the focus of a limited number of studies but still sufficient enough to provide a first glimpse on the subject. The overall picture that emerges is quite intriguing and shows that ILs interact with cells in a variety of different mechanisms, including alteration of lipid distribution and cell membrane viscoelasticity, disruption of cell and nuclear membranes, mitochondrial permeabilization and dysfunction, generation of reactive oxygen species, chloroplast damage (in plants), alteration of transmembrane and cytoplasmatic proteins/enzyme functions, alteration of signaling pathways, and DNA fragmentation. Together with our earlier review work on the biophysics and chemical-physics of IL-cell membrane interactions (Biophys. Rev. 9:309, 2017), we hope that the present review, focused instead on the biochemical aspects, will stimulate a series of new investigations and discoveries in the still new and interdisciplinary field of "ILs, biomolecules, and cells."
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Affiliation(s)
- Pallavi Kumari
- Department of Sciences, University of Roma Tre, 00146, Rome, Italy
- School of Physics, University College Dublin, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Visakh V S Pillai
- Department of Sciences, University of Roma Tre, 00146, Rome, Italy
- School of Physics, University College Dublin, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Antonio Benedetto
- Department of Sciences, University of Roma Tre, 00146, Rome, Italy.
- School of Physics, University College Dublin, Dublin 4, Ireland.
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland.
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232, Villigen, Switzerland.
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Benedetto A. From protein and its hydration water dynamics to controlling mechano-elasticity of cellular lipid membranes and cell migration via ionic liquids. Biophys Rev 2020; 12:1111-1115. [PMID: 32940859 DOI: 10.1007/s12551-020-00755-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 12/29/2022] Open
Abstract
In this invited Commentary, as requested, I will walk the reader through my research path starting from my first works on proteins and their hydration water dynamics to my most recent activity on the use of ionic liquids (ILs) as molecular handles to control and manipulate cell membrane mechano-elasticity and cell migration. In doing so I will comment on my research activity on polymers, proteins, natural bioprotectants, phospholipid bilayers, amyloids and cells, which I have carried out by combining several different experimental and computational approaches including neutron scattering, atomic force microscopy, classical molecular dynamics and ab initio calculations, used in tandem with several biological assays and a palette of complementary techniques ranging from calorimetry to static and dynamic light scattering. In parallel to this biophysical/chemical-physical core activity, a smaller portion of my interest and effort has been-I may say always-dedicated to the development of a new neutron scattering method/spectroscopy for dynamics based on "elastic" scattering. I will comment on this instrumental side of my research as well and show its relationship with the biophysical core of my activity. The overall picture that emerges is, from my personal prospective, of a coherent 13-year research path based on curiosity and a problem-solving approach, in which the fundamental importance of inter- and trans-disciplinary approaches and collaborations is emerging on the way, forecasting a prosper and intriguing future for physics in biology and in nanomedicine and bionanotechnology applications.
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Affiliation(s)
- Antonio Benedetto
- Department of Sciences, University of Roma Tre, 00146, Rome, Italy. .,School of Physics, University College Dublin, Dublin 4, Ireland. .,Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland. .,Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232, Villigen, Switzerland.
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Benedetto A. From just physics to biophysics of biological systems. Biophys Rev 2020; 12:10.1007/s12551-020-00756-8. [PMID: 32910304 PMCID: PMC7755954 DOI: 10.1007/s12551-020-00756-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 01/06/2023] Open
Affiliation(s)
- Antonio Benedetto
- Department of Sciences, University of Roma Tre, 00146, Rome, Italy.
- School of Physics, University College Dublin, Dublin 4, Ireland.
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland.
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232, Villigen, Switzerland.
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Kumari P, Pillai VVS, Rodriguez BJ, Prencipe M, Benedetto A. Sub-Toxic Concentrations of Ionic Liquids Enhance Cell Migration by Reducing the Elasticity of the Cellular Lipid Membrane. J Phys Chem Lett 2020; 11:7327-7333. [PMID: 32794718 DOI: 10.1021/acs.jpclett.0c02149] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Cell migration is a universal and crucial mechanism for life. It is required in a series of physiological processes, in wound repair and immune response and is involved in several pathological conditions, including cancer and virus dissemination. Among the several biochemical and biophysical routes, changing cell membrane elasticity holds the promise to be a universal strategy to alter cell mobility. Due to their affinity with cell membranes, ionic liquids (ILs) may play an important role. This work focuses on the effect of subtoxic amounts of imidazolium-ILs on the migration of the model cancer cell line MDA-MB-231. Here we show that ILs are able to enhance cell mobility by reducing the elasticity of the cellular lipid membrane, and that both mobility and elasticity can be tuned by IL-concentration and IL-cation chain length. This biochemical-physical mechanism is potentially valid for all mammalian cells, and its impact in bionanomedicine and bionanotechnology is discussed.
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Affiliation(s)
- Pallavi Kumari
- School of Physics, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
- Department of Sciences, University of Roma Tre, 00146 Rome, Italy
| | - Visakh V S Pillai
- School of Physics, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Brian J Rodriguez
- School of Physics, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Maria Prencipe
- School of Biomolecular and Biomedical Science, and Conway Institute Cancer Biology and Therapeutics Laboratory, University College Dublin, Dublin 4, Ireland
| | - Antonio Benedetto
- School of Physics, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
- Department of Sciences, University of Roma Tre, 00146 Rome, Italy
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
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17
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Benedetto A, Kearley GJ. Dynamics from elastic neutron-scattering via direct measurement of the running time-integral of the van Hove distribution function. Sci Rep 2019; 9:11284. [PMID: 31375739 PMCID: PMC6677729 DOI: 10.1038/s41598-019-46835-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 07/03/2019] [Indexed: 12/03/2022] Open
Abstract
We present a new neutron-scattering approach to access the van Hove distribution function directly in the time domain, I(t), which reflects the system dynamics. Currently, I(t) is essentially determined from neutron energy-exchange. Our method consists of the straightforward measurement of the running time-integral of I(t), by computing the portion of scattered neutrons corresponding to species at rest within a time t, (conceptually elastic scattering). Previous attempts failed to recognise this connection. Starting from a theoretical standpoint, a practical realisation is assessed via numerical methods and an instrument simulation.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin, Dublin 4, Ireland. .,School of Chemistry, University College Dublin, Dublin 4, Ireland. .,Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland. .,Department of Sciences, University of Roma Tre, Rome, Italy. .,Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen, Switzerland.
| | - Gordon J Kearley
- School of Chemistry, University College Dublin, Dublin 4, Ireland
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Mora Cardozo JF, Embs JP, Benedetto A, Ballone P. Equilibrium Structure, Hydrogen Bonding, and Proton Conductivity in Half-Neutralized Diamine Ionic Liquids. J Phys Chem B 2019; 123:5608-5625. [PMID: 30875220 DOI: 10.1021/acs.jpcb.9b00890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent experiments on proton conducting ionic liquids point to half-neutralized diamine-triflate salts as promising candidates for applications in power generation and energy conversion electrochemical devices. Structural and dynamical properties of the simplest among these compounds are investigated by a combination of density functional theory (DFT) and molecular dynamics (MD) simulations based on an empirical force field. Three different cations have been considered, consisting of a pair of amine-ammonium terminations joined by a short aliphatic segment -(CH2) n- with n = 2, 3, and 4. First, the ground state structure, vibrational eigenstates, and hydrogen-bonding properties of single ions, neutral ion pairs, small neutral aggregates of up to eight ions, and molecularly thin hydrogen bonded wires have been investigated by DFT computations. Second, structural and dynamical properties of homogeneous liquid and amorphous phases are investigated by MD simulations over the temperature range of 200 ≤ T ≤ 440 K. Structure factors, radial distribution functions, diffusion coefficient, and electrical conductivity are computed and discussed, highlighting the inherent structural heterogeneity of these compounds. The core investigation, however, is the characterization of connected paths consisting of cation chains that could support proton transport via a Grotthuss-type mechanism. Since simulations are carried out using a force field of fixed bonding topology, this analysis is based on the equilibrium structure only, using geometrical criteria to identify potential paths for proton conduction. Paths of connected cations can reach a length of 80 cations and 30 Å, provided that bridging oxygen atoms from triflate anions are taken into account. The effects of water contamination at 1% weight concentration on the structure, dynamics, and paths for proton transport are discussed.
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Affiliation(s)
- Juan F Mora Cardozo
- Laboratory for Neutron Scattering and Imaging , Paul Scherrer Institute , Villigen PSI, Villigen 5232 , Switzerland
| | - J P Embs
- Laboratory for Neutron Scattering and Imaging , Paul Scherrer Institute , Villigen PSI, Villigen 5232 , Switzerland
| | - A Benedetto
- Laboratory for Neutron Scattering and Imaging , Paul Scherrer Institute , Villigen PSI, Villigen 5232 , Switzerland.,Department of Sciences , University of Roma Tre , Via della Vasca Navale 84 , 00146 Rome , Italy
| | - P Ballone
- Italian Institute of Technology , Via Morego 30 , 16163 Genova , Italy
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Benedetto A, Ballone P. Room-Temperature Ionic Liquids and Biomembranes: Setting the Stage for Applications in Pharmacology, Biomedicine, and Bionanotechnology. Langmuir 2018; 34:9579-9597. [PMID: 29510045 DOI: 10.1021/acs.langmuir.7b04361] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Empirical evidence and conceptual elaboration reveal and rationalize the remarkable affinity of organic ionic liquids for biomembranes. Cations of the so-called room-temperature ionic liquids (RTILs), in particular, are readily absorbed into the lipid fraction of biomembranes, causing a variety of observable biological effects, including generic cytotoxicity, broad antibacterial potential, and anticancer activity. Chemical physics analysis of model systems made of phospholipid bilayers, RTIL ions, and water confirm and partially explain this evidence, quantifying the mild destabilizing effect of RTILs on the structural, dynamic, and thermodynamic properties of lipids in biomembranes. Our Feature Article presents a brief introduction to these systems and to their roles in biophysics and biotechnology, summarizing recent experimental and computational results on their properties. More importantly, it highlights the many developments in pharmacology, biomedicine, and bionanotechnology expected from the current research effort on this topic. To anticipate future developments, we speculate on (i) potential applications of (magnetic) RTILs to affect and control the rheology of cells and biological tissues, of great relevance for diagnostics and (ii) the use of RTILs to improve the durability, reliability, and output of biomimetic photovoltaic devices.
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Affiliation(s)
- Antonio Benedetto
- Laboratory for Neutron Scattering , Paul Scherrer Institute , Villigen 5232 , Switzerland
- Conway Institute of Biomolecular and Biomedical Research , University College Dublin , Dublin 4 , Ireland
| | - Pietro Ballone
- Italian Institute of Technology , Via Morego 30 , 16163 Genova , Italy
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20
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Nandi PK, English NJ, Futera Z, Benedetto A. Hydrogen-bond dynamics at the bio-water interface in hydrated proteins: a molecular-dynamics study. Phys Chem Chem Phys 2018; 19:318-329. [PMID: 27905589 DOI: 10.1039/c6cp05601f] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Water is fundamental to the biochemistry of enzymes. It is well known that without a minimum amount of water, enzymes are not biologically active. Bare minimal solvation for biological function corresponds to about a single layer of water covering enzymes' surfaces. Many contradictory studies on protein-hydration-water-coupled dynamics have been published in recent decades. Following prevailing wisdom, a dynamical crossover in hydration water (at around 220 K for hydrated lysozymes) can trigger larger-amplitude motions of the protein, activating, in turn, biological functions. Here, we present a molecular-dynamics-simulation study on a solvated model protein (hen egg-white lysozyme), in which we determine, inter alia, the relaxation dynamics of the hydrogen-bond network between the protein and its hydration water molecules on a residue-per-residue basis. Hydrogen-bond breakage/formation kinetics is rather heterogeneous in temperature dependence (due to the heterogeneity of the free-energy surface), and is driven by the magnitude of thermal motions of various different protein residues which provide enough thermal energy to overcome energy barriers to rupture their respective hydrogen bonds with water. In particular, arginine residues exhibit the highest number of such hydrogen bonds at low temperatures, losing almost completely such bonding above 230 K. This suggests that hydration water's dynamical crossover, observed experimentally for hydrated lysozymes at ∼220 K, lies not at the origin of the protein residues' larger-amplitude motions, but rather arises as a consequence thereof. This highlights the need for new experimental investigations, and new interpretations to link protein dynamics to functions, in the context of key interrelationships with the solvation layer.
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Affiliation(s)
- Prithwish K Nandi
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Niall J English
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Zdenek Futera
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Antonio Benedetto
- School of Physics, University College Dublin, Belfield, Dublin 4, Ireland. and Neutron-Scattering and Imaging Laboratory, Paul Scherrer Institute, Villigen, Switzerland
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Benedetto A. High-Resolution Neutron Scattering Data Reveal the Decoupling of Proteins and Water at the Dynamical Transition. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.1176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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22
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Mora Cardozo JF, Burankova T, Embs JP, Benedetto A, Ballone P. Density Functional Computations and Molecular Dynamics Simulations of the Triethylammonium Triflate Protic Ionic Liquid. J Phys Chem B 2017; 121:11410-11423. [PMID: 29185753 DOI: 10.1021/acs.jpcb.7b10373] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Systematic molecular dynamics simulations based on an empirical force field have been carried out for samples of triethylammonium trifluoromethanesulfonate (triethylammonium triflate, [TEA][Tf]), covering a wide temperature range 200 K ≤ T ≤ 400 K and analyzing a broad set of properties, from self-diffusion and electrical conductivity to rotational relaxation and hydrogen-bond dynamics. The study is motivated by recent quasi-elastic neutron scattering and differential scanning calorimetry measurements on the same system, revealing two successive first order transitions at T ≈ 230 and 310 K (on heating), as well as an intriguing and partly unexplained variety of subdiffusive motions of the acidic proton. Simulations show a weakly discontinuous transition at T = 310 K and highlight an anomaly at T = 260 K in the rotational relaxation of ions that we identify with the simulation analogue of the experimental transition at T = 230 K. Thus, simulations help identifying the nature of the experimental transitions, confirming that the highest temperature one corresponds to melting, while the one taking place at lower T is a transition from the crystal, stable at T ≤ 260 K, to a plastic phase (260 ≤ T ≤ 310 K), in which molecules are able to rotate without diffusing. Rotations, in particular, account for the subdiffusive motion seen at intermediate T both in the experiments and in the simulation. The structure, distribution, and strength of hydrogen bonds are investigated by molecular dynamics and by density functional computations. Clustering of ions of the same sign and the effect of contamination by water at 1% wgt concentration are discussed as well.
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Affiliation(s)
- Juan F Mora Cardozo
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute , Villigen PSI, Villigen 5232, Switzerland
| | - T Burankova
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute , Villigen PSI, Villigen 5232, Switzerland
| | - J P Embs
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute , Villigen PSI, Villigen 5232, Switzerland
| | - A Benedetto
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute , Villigen PSI, Villigen 5232, Switzerland.,School of Chemistry, University College Dublin , Belfield, Dublin 4, Ireland.,School of Physics, University College Dublin , Belfield, Dublin 4, Ireland
| | - P Ballone
- Italian Institute of Technology , Via Morego 30, 16163 Genova, Italy
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Abstract
Water plays a major role in biosystems, greatly contributing to determine their structure, stability, and function. It is well known, for instance, that proteins require a minimum amount of water to be fully functional. Despite many years of intensive research, however, the detailed nature of protein-hydration water interactions is still partly unknown. The widely accepted "protein dynamical transition" scenario is based on perfect coupling between the dynamics of proteins and that of their hydration water, which has never been probed in depth experimentally. I present here high-resolution elastic neutron scattering measurements of the atomistic dynamics of lysozyme in water. The results show for the first time that the dynamics of proteins and of their hydration water are actually decoupled at low temperatures. This important result challenges the "protein dynamical transition" scenario and requires a new model to link protein dynamics to the dynamics of its hydration water.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin , Dublin 4, Ireland
- Laboratory for Neutron Scattering, Paul Scherrer Institut , Villigen, Switzerland
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Benedetto A, Galla HJ. Overview of the "Ionic Liquids meet Biomolecules" session at the 19th international IUPAB and 11th EBSA congress. Biophys Rev 2017; 9:279-281. [PMID: 28812293 DOI: 10.1007/s12551-017-0309-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 12/01/2022] Open
Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin (UCD), Dublin 4, Ireland. .,Laboratory for Neutron Scattering, Paul Scherrer Institut (PSI), Villigen, Switzerland.
| | - Hans-Joachim Galla
- Institute of Biochemistry, University of Münster, Wilhelm-Klemm-Str. 2, 48149, Münster, Germany
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Benedetto A. Comment on "X-ray Reflectivity Study of the Interaction of an Imidazolium-Based Ionic Liquid with a Soft Supported Lipid Membrane". Langmuir 2017; 33:6201-6202. [PMID: 28570822 DOI: 10.1021/acs.langmuir.7b01481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin , Dublin 4, Ireland
- Laboratory for Neutron Scattering, Paul Scherrer Institut , Villigen, Switzerland
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26
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Benedetto A. Biomolecules, Water and Room-Temperature Ionic Liquids: Challenges and Opportunities in Basic Science and Applications. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.2805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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27
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Girolami F, Spalenza V, Benedetto A, Manzini L, Badino P, Abete MC, Nebbia C. Comparative liver accumulation of dioxin-like compounds in sheep and cattle: Possible role of AhR-mediated xenobiotic metabolizing enzymes. Sci Total Environ 2016; 571:1222-1229. [PMID: 27476725 DOI: 10.1016/j.scitotenv.2016.07.150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/21/2016] [Accepted: 07/21/2016] [Indexed: 06/06/2023]
Abstract
PCDDs, PCDFs, and PCBs are persistent organic pollutants (POPs) that accumulate in animal products and may pose serious health problems. Those able to bind the aryl hydrocarbon receptor (AhR), eliciting a plethora of toxic responses, are defined dioxin-like (DL) compounds, while the remainders are called non-DL (NDL). An EFSA opinion has highlighted the tendency of ovine liver to specifically accumulate DL-compounds to a greater extent than any other farmed ruminant species. To examine the possible role in such an accumulation of xenobiotic metabolizing enzymes (XME) involved in DL-compound biotransformation, liver samples were collected from ewes and cows reared in an area known for low dioxin contamination. A related paper reported that sheep livers had about 5-fold higher DL-compound concentrations than cattle livers, while the content of the six marker NDL-PCBs did not differ between species. Specimens from the same animals were subjected to gene expression analysis for AhR, AhR nuclear translocator (ARNT) and AhR-dependent oxidative and conjugative pathways; XME protein expression and activities were also investigated. Both AhR and ARNT mRNA levels were about 2-fold lower in ovine samples and the same occurred for CYP1A1 and CYP1A2, being approximately 3- and 9-fold less expressed in sheep compared to cattle, while CYP1B1 could be detectable in cattle only. The results of the immunoblotting and catalytic activity (most notably EROD) measurements of the CYP1A family enzymes were in line with the gene expression data. By contrast, phase II enzyme expression and activities in sheep were higher (UGT1A) or similar (GSTA1, NQO1) to those recorded in cattle. The overall low expression of CYP1 family enzymes in the sheep is in line with the observed liver accumulation of DL-compounds and is expected to affect the kinetics and the dynamics of other POPs such as many polycyclic aromatic hydrocarbons, as well as of toxins (e.g. aflatoxins) or drugs (e.g. benzimidazole anthelmintics) known to be metabolized by those enzymes.
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Affiliation(s)
- F Girolami
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - V Spalenza
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - A Benedetto
- Istituto Zooprofilattico di Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, Torino, Italy.
| | - L Manzini
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - P Badino
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - M C Abete
- Istituto Zooprofilattico di Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, Torino, Italy.
| | - C Nebbia
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
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Benedetto A, Kearley GJ. Elastic Scattering Spectroscopy (ESS): an Instrument-Concept for Dynamics of Complex (Bio-) Systems From Elastic Neutron Scattering. Sci Rep 2016; 6:34266. [PMID: 27703184 PMCID: PMC5050422 DOI: 10.1038/srep34266] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/12/2016] [Indexed: 11/09/2022] Open
Abstract
A new type of neutron-scattering spectroscopy is presented that is designed specifically to measure dynamics in bio-systems that are difficult to obtain in any other way. The temporal information is largely model-free and is analogous to relaxation processes measured with dielectric spectroscopy, but provides additional spacial and geometric aspects of the underlying dynamics. Numerical simulations of the basic instrument design show the neutron beam can be highly focussed, giving efficiency gains that enable the use of small samples. Although we concentrate on continuous neutron sources, the extension to pulsed neutron sources is proposed, both requiring minimal data-treatment and being broadly analogous with dielectric spectroscopy, they will open the study of dynamics to new areas of biophysics.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin, Dublin, Ireland.,Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen, Switzerland
| | - Gordon J Kearley
- School of Materials Science and Engineering, UNSW Australia, Sydney, NSW 2052, Australia
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Brizio P, Benedetto A, Squadrone S, Curcio A, Pellegrino M, Ferrero M, Abete MC. Heavy metals and essential elements in Italian cereals. Food Additives & Contaminants: Part B 2016; 9:261-267. [DOI: 10.1080/19393210.2016.1209572] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Benedetto A, Brizio P, Guaraldo P, Stella C, Cappa C, Baioni E, Spalenza V, Nebbia C, Abete MC. Dioxins, DL-PCB and NDL-PCB accumulation profiles in livers from sheep and cattle reared in North-western Italy. Chemosphere 2016; 152:92-98. [PMID: 26963240 DOI: 10.1016/j.chemosphere.2016.02.101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 06/05/2023]
Abstract
Products of animal origin represent the main route of human exposure to dioxins and dioxin-like PCBs (DL-compounds). Recently, concerns have been raised about ovine products, particularly the liver, in which relatively high levels of DL-compounds have been reported. We surveyed ovine and bovine livers in areas with no known sources of dioxin or DL-PCB contamination, in order to assess accumulation patterns for both DL-compounds and non-DL (NDL-) PCBs. None of the ovine and bovine samples exceeded the current Maximum Limits (MLs) for DL-compounds. Liver DL-compound TEQ concentrations were up to 5-fold higher in sheep than in cows. No statistically significant differences in total NDL-PCBs levels were found. The main contributors to TEQ levels were the Penta- and Hexa-chlorinated PCDFs and PCB 126. The results confirm the increased bioaccumulation in ovine liver towards specific DL-compounds even in ewes reared in areas with no known sources of PCDD/Fs or DL-PCBs contamination.
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Affiliation(s)
- A Benedetto
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e valle D'Aosta, Torino, Italy.
| | - P Brizio
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e valle D'Aosta, Torino, Italy
| | - P Guaraldo
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e valle D'Aosta, Torino, Italy
| | - C Stella
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e valle D'Aosta, Torino, Italy
| | - C Cappa
- Dipartimento Provinciale di Torino Arpa Piemonte, Grugliasco, Italy
| | - E Baioni
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e valle D'Aosta, Torino, Italy
| | - V Spalenza
- Department of Veterinary Sciences, University of Torino, Grugliasco, Italy
| | - C Nebbia
- Department of Veterinary Sciences, University of Torino, Grugliasco, Italy
| | - M C Abete
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e valle D'Aosta, Torino, Italy
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Benedetto A, Brizio P, Squadrone S, Scanzio T, Righetti M, Gasco L, Prearo M, Abete MC. Oxidative stress related to chlorpyrifos exposure in rainbow trout: Acute and medium term effects on genetic biomarkers. Pestic Biochem Physiol 2016; 129:63-69. [PMID: 27017883 DOI: 10.1016/j.pestbp.2015.10.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 10/21/2015] [Accepted: 10/21/2015] [Indexed: 06/05/2023]
Abstract
Organophosphates (OPs) are derivatives of phosphoric acid widely used in agriculture as pesticides. Chlorpyrifos (CPF) is an OP that is extremely toxic to aquatic organisms. Rainbow trout (Oncorhynchus mykiss) is considered as a sentinel model species for ecotoxicology assessment in freshwater ecosystems. An exposure study was carried out on rainbow trout to investigate genetic responses to CPF-induced oxidative stress by Real-Time PCR, and to determine the accumulation dynamics of CPF and toxic metabolite chlorpyrifos-oxon (CPF-ox) in edible parts, by HPLC-MS/MS. Among the genes considered to be related to oxidative stress, a significant increase in HSP70 mRNA levels was observed in liver samples up to 14 days after CPF exposure (0.05 mg/L). CPF concentrations in muscle samples reach mean values of 285.25 ng/g within 96 hours of exposure, while CPF-ox concentrations were always under the limit of quantification (LOQ) of the applied method. Our findings lead us to consider HSP70 as a suitable genetic marker in rainbow trout for acute and medium-term monitoring of CPF exposure, complementary to analytical determinations.
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Affiliation(s)
- A Benedetto
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy.
| | - P Brizio
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - S Squadrone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - T Scanzio
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - M Righetti
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - L Gasco
- Dipartimento di Scienze Zootecniche Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Via Leonardo da Vinci 44, 10095 Grugliasco, Italy
| | - M Prearo
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - M C Abete
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
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Magazù S, Migliardo F, Benedetto A, La Torre R, Hennet L. Comments on: Bio-protective effects of homologous disaccharides on biological macromolecules. Eur Biophys J 2016; 45:379. [PMID: 27015818 DOI: 10.1007/s00249-016-1124-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Benedetto A. Retraction notice to “Protein dynamics by neutron scattering” [Biophysical Chemistry 182 (2013) 16-22]. Biophys Chem 2016; 209:56. [DOI: 10.1016/j.bpc.2015.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Benedetto A, Bingham RJ, Ballone P. Structure and dynamics of POPC bilayers in water solutions of room temperature ionic liquids. J Chem Phys 2015; 142:124706. [DOI: 10.1063/1.4915918] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin, Dublin 4, Ireland
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Richard J. Bingham
- York Centre for Complex Systems Analysis, University of York, York YO10 5GE, United Kingdom
| | - Pietro Ballone
- Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia (IIT), 00185 Roma, Italy
- Department of Physics, Università di Roma “La Sapienza,” 00185 Roma, Italy
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Squadrone S, Benedetto A, Brizio P, Prearo M, Abete MC. Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: can molar ratio be a predictive factor for mercury toxicity in a top predator? Chemosphere 2015; 119:24-30. [PMID: 25460744 DOI: 10.1016/j.chemosphere.2014.05.052] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 06/04/2023]
Abstract
The study of mercury and selenium bioaccumulation in fish is crucially important for evaluating the extent of contamination in freshwater environments, and the possible health risk posed for humans when the antagonistic interactions of these two elements are considered. Several factors affect the risk of mercury intake from fish consumption, including mercury levels, human consumption patterns, and sensitive populations (e.g., pregnant women, foetuses, young children and unknown genetic factors). The protective effects of selenium on mercury toxicity have been extensively publicised in recent years, particularly targeting fish consumers. In this study, mercury (Hg) and selenium (Se) concentrations were determined in the muscle of European catfish (Silurus glanis) collected from North Italian Rivers. Differences in mercury and selenium levels, as a function of size, gender and location were investigated. Hg was strongly related to length, gender and location, while Se levels are not dependent on fish size or location. The mean Se/Hg molar ratio was strongly affected by location, and significantly related to length and age. Selenium was in molar excess of mercury in all sites, with a rank order of mean Se/Hg molar ratio of the Parma River (2.55)>Po River (1.71)>Tanaro River (1.66)>Bormida River (1.36). However, in 37% of analyzed samples, Hg exceeded the maximum level set by 1881/2006/EC and 629/2008/EC in fish muscle. The molar ratio of Se/Hg was <1 only in the presence of significantly high Hg levels (>0.5mg/kg), and therefore the mean molar ratio cannot be considered as a safety criterion in top predator fish.
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Affiliation(s)
- S Squadrone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy.
| | - A Benedetto
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy
| | - P Brizio
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy
| | - M Prearo
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy
| | - M C Abete
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, via Bologna 148, 10154 Torino, Italy
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Benedetto A, Heinrich F, Gonzalez MA, Fragneto G, Watkins E, Ballone P. Correction to “Structure and Stability of Phospholipid Bilayers Hydrated by a Room-Temperature Ionic Liquid/Water Solution: A Neutron Reflectometry Study”. J Phys Chem B 2014; 118:14990. [DOI: 10.1021/jp511974t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Benedetto A, Heinrich F, Gonzalez MA, Fragneto G, Watkins E, Ballone P. Structure and Stability of Phospholipid Bilayers Hydrated by a Room-Temperature Ionic Liquid/Water Solution: A Neutron Reflectometry Study. J Phys Chem B 2014; 118:12192-206. [DOI: 10.1021/jp507631h] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Antonio Benedetto
- School
of Physics, University College Dublin−UCD, Belfield Campus, Dublin 4, Ireland
| | - Frank Heinrich
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Center
for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | | | | | - Erik Watkins
- Institute Laue-Langevin, Grenoble, France
- Lujan
Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Pietro Ballone
- Center
for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia (IIT), 00161 Roma, Italy
- Department
of Physics, Universita’ di Roma “La Sapienza”, 00185 Roma, Italy
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Benedetto A, Bodo E, Gontrani L, Ballone P, Caminiti R. Amino acid anions in organic ionic compounds. An ab initio study of selected ion pairs. J Phys Chem B 2014; 118:2471-86. [PMID: 24494698 DOI: 10.1021/jp412281n] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The combination of amino acids in their deprotonated and thus anionic form with a choline cation gives origin to a new and potentially important class of organic ionic compounds. A series of such neutral ion pairs has been investigated by first principle methods. The results reveal intriguing structural motives as well as regular patterns in the charge distribution and predict a number of vibrational and optical properties that could guide the experimental investigation of these compounds. The replacement of choline with its phosphocholine analogue causes the spontaneous reciprocal neutralization of cations and anions, taking place through the transfer of a proton between the two ions. Systems of this kind, therefore, provide a wide and easily accessible playground to probe the ionic/polar transition in organic systems, while the easy transfer of H(+) among neutral and ionic species points to their potential application as proton conductors. The analysis of the ab initio data highlights similarities as well as discrepancies from the rigid-ions force-field picture and suggests directions for the improvement of empirical models.
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Affiliation(s)
- A Benedetto
- School of Physics, University College Dublin , Dublin 4, Ireland
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Benedetto A. Retraction of the article “Protein dynamics by neutron scattering” published in Biophysical Chemistry 2013, 182, 16–22. Biophys Chem 2014; 185:108. [DOI: 10.1016/j.bpc.2013.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 12/03/2013] [Accepted: 12/03/2013] [Indexed: 10/25/2022]
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Magazù S, Migliardo F, Benedetto A, Vertessy B. Protein dynamics by neutron scattering: The protein dynamical transition and the fragile-to-strong dynamical crossover in hydrated lysozyme. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2013.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
Neutron scattering techniques represent a powerful tool for characterizing both the structure and dynamical properties of bio-systems, for example, proteins and membranes interacting with their solvents. In this paper, Elastic Neutron Scattering (ENS) data collected at the Institut Laue-Langevin (Grenoble, France) on dry and D2O hydrated lysozyme by varying hydration level are presented, and compared with previously published data on the same protein system, also with the addition of bio-protectants. The data have been collected with three different spectrometers, i.e. IN13, IN10 and IN4. This set of ENS data gives direct access to the temperature behavior of both (i) the Mean Square Displacement (MSD) and (ii) the characteristic system relaxation time. As a result, an explicative hypothesis on the relationship between the so-called "protein dynamical transition" (PDT) and the "fragile-to-strong dynamical crossover" (FSC) is formulated. Furthermore, by taking into proper account the effect of the finite instrumental energy resolution of the used spectrometers, the vibrational MSD of dry and hydrated lysozyme is calculated. The vibrational MSD of the lysozyme in the dry state resulted to be higher than the one in the hydrated state; the latter reaches the former at a temperature value of T=220K that corresponds to the temperature at which the FSC occurs. As a result, a cage effect resulting from the hydration water on the protein surface is hypothesized and subsequently linked to the FSC.
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Affiliation(s)
- Antonio Benedetto
- School of Physics, University College Dublin - UCD, Belfield Campus, Dublin 4, Ireland; School of Medical Sciences, Sydney Medical School, The University of Sydney, Anderson Stuart Building F13, Sydney, NSW 2006, Australia.
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Squadrone S, Prearo M, Gavinelli S, Pellegrino M, Tarasco R, Benedetto A, Abete M. Heavy metals inMugil cephalus(Mugilidae) from the Ligurian Sea (North-West Mediterranean, Italy). Food Additives & Contaminants: Part B 2013; 6:134-8. [DOI: 10.1080/19393210.2013.766817] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Squadrone S, Prearo M, Brizio P, Gavinelli S, Pellegrino M, Scanzio T, Guarise S, Benedetto A, Abete MC. Heavy metals distribution in muscle, liver, kidney and gill of European catfish (Silurus glanis) from Italian Rivers. Chemosphere 2013; 90:358-65. [PMID: 22901372 DOI: 10.1016/j.chemosphere.2012.07.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 06/29/2012] [Accepted: 07/12/2012] [Indexed: 05/25/2023]
Abstract
The accumulation of heavy metals in freshwaters has direct consequences to man and ecosystem. Thus, in this study, the concentrations of mercury, cadmium, lead, arsenic and chromium in organs of the predator European catfish (Silurus glanis) were investigated. Samples were collected annually in five sites covering the area of the Po River (North Italy) between 2007 and 2009. Metals were differently distributed in the various organs, the highest concentrations of Hg were found in muscle and liver, Cd in kidney, Pb in gill and liver, as in muscle, and of Cr in gill and liver. Our survey found Hg exceeding the Maximum Levels (MLs) of 0.5 ppm in 18% of samples, while Pb and Cd were lower than the MLs set by European regulations in muscle tissues (1881/2006/EC and 629/2008/EC). Hg concentrations were significantly related to sampling stations studied, according to the presence of many industrial activities in the catchment area of Bormida and Tanaro Rivers. The finding that Hg did not fit food fish legislation limits indicated that S. glanis flesh might not be utilised for human consumption. A close monitoring of metals pollution is strongly recommended especially in piscivorous fish, cause their bioaccumulation capacity.
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Affiliation(s)
- S Squadrone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle D'Aosta, Via Bologna 148, 10154 Torino, Italy.
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Pellegrino M, Brizio P, Gallina S, Tarasco R, Gavinelli S, Palmegiano P, Fioravanti F, Benedetto A, Squadrone S, Gallo G, Abete M. EXPORT OF CHEESE IN RUSSIA: THE ROLE OF IZSPLV. Ital J Food Saf 2012. [DOI: 10.4081/ijfs.2012.4.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Coffe-Bart D, Izing A, Benedetto A. Accompagnement d’une entreprise de transport urbain dans la prévention des risques. Travail collaboratif sur l’ergonomie aux postes de conduite de bus. ARCH MAL PROF ENVIRO 2012. [DOI: 10.1016/j.admp.2012.03.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Affiliation(s)
- Salvatore Magazù
- Department of Physics, University of Messina, Viale Ferdinando Stagno D’Alcontres n° 31, P.O. Box
55, 98166 S. Agata, Messina, Italy
| | - Federica Migliardo
- Department of Physics, University of Messina, Viale Ferdinando Stagno D’Alcontres n° 31, P.O. Box
55, 98166 S. Agata, Messina, Italy
| | - Antonio Benedetto
- Department of Physics, University of Messina, Viale Ferdinando Stagno D’Alcontres n° 31, P.O. Box
55, 98166 S. Agata, Messina, Italy
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Calvi A, Benedetto A, De Blasiis MR. A driving simulator study of driver performance on deceleration lanes. Accid Anal Prev 2012; 45:195-203. [PMID: 22269501 DOI: 10.1016/j.aap.2011.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 05/31/2011] [Accepted: 06/18/2011] [Indexed: 05/31/2023]
Abstract
Deceleration lanes are important because they help drivers transition from high-speed lanes to low-speed ramps. Although they are designed to allow vehicles to depart the freeway safely and efficiently, many studies report high accident rates on exit ramps with the highest percentage of crashes taking place in deceleration lanes. This paper describes the results of a driving simulator study that focused on driving performance while approaching a divergence area and decelerating during the exiting maneuver. Three different traffic scenarios were simulated to analyze the influence of traffic volume on driving performance. Thirty drivers drove in the simulator in these scenarios while data on their lateral position, speed and deceleration were collected. Our results indicate there are considerable differences between the main assumptions of models generally used to design deceleration lanes and actual driving performance. In particular, diverging drivers begin to decelerate before arriving at the deceleration lane, causing interference with the main flow. Moreover, speeds recorded at the end of the deceleration lane exceed those for which the ramp's curves are designed; this creates risky driving conditions that could explain the high crash rates found in studies of exit ramps. Finally, statistical analyses demonstrate significant influences of traffic volume on some aspects of exiting drivers' performance: lower traffic volume results in elevated exiting speed and deceleration, and diverging drivers begin to decelerate earlier along the main lane when traffic volume is low. However, speeds at the end of the deceleration lane and the site of lane changing are not significantly influenced by traffic volume.
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Affiliation(s)
- A Calvi
- University Roma Tre, Department of Sciences of Civil Engineering, via Vito Volterra 62, 00146 Rome, Italy.
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Benedetto A, Migliardo F, Magazù S. Protein Dynamics by Neutron Scattering: The Protein Dynamical Transition. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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50
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Magazù S, Migliardo F, Benedetto A. Elastic incoherent neutron scattering operating by varying instrumental energy resolution: principle, simulations, and experiments of the resolution elastic neutron scattering (RENS). Rev Sci Instrum 2011; 82:105115. [PMID: 22047337 DOI: 10.1063/1.3641870] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The main aim of this paper is to present the scientific case of the resolution elastic neutron scattering (RENS) method that is based on the collection of elastic neutron scattering intensity as a function of the instrumental energy resolution and that is able to extract information on the system dynamical properties from an elastic signal. In this framework, it is shown that in the measured elastic scattering law, as a function of the instrumental energy resolution, an inflection point occurs when the instrumental energy resolution intersects the system relaxation time, and in an equivalent way, a transition in the temperature behavior of the measured elastic scattering law occurs when the characteristic system relaxation time crosses the instrumental energy resolution time. With regard to the latter, an operative protocol to determine the system characteristic time by different elastic incoherent neutron scattering (EINS) thermal scans at different instrumental energy resolutions is also proposed. The proposed method, hence, is not primarily addressed to collect the measured elastic scattering intensity with a great accuracy, but rather relies on determining an inflection point in the measured elastic scattering law versus instrumental energy resolution. The RENS method is tested both numerically and experimentally. As far as numerical simulations are concerned, a simple model system for which the temperature behavior of the relaxation time follows an Arrhenius law, while its scattering law follows a Gaussian behavior, is considered. It is shown that the system relaxation time used as an input for the simulations coincides with the one obtained by the RENS approach. Regarding the experimental findings, due to the fact that a neutron scattering spectrometer working following the RENS method has not been constructed yet, different EINS experiments with different instrumental energy resolutions were carried out on a complex model system, i.e., dry and D(2)O hydrated lysozyme, in an extended temperature range. The resulting temperature behavior of the system relaxation time, obtained with RENS method, agrees very well with the one obtained in literature, for the same system, following the quasi-elastic neutron scattering (QENS) approach. The proposed scientific case puts into evidence the challenges of an RENS spectrometer working by varying the instrumental energy resolution; in particular, in comparison with QENS, the proposed RENS method requires a smaller amount of sample, which is an important point in dealing with biological and exotic systems; it is not affected by the use of model functions for fitting spectra as in QENS, but furnishes a direct access to relevant information.
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