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Zhang Y, Hu Y, Xie B, Yang G, Yin Z, Wu H. Hoffmeister Effect Optimized Hydrogel Electrodes with Enhanced Electrical and Mechanical Properties for Nerve Conduction Studies. RESEARCH (WASHINGTON, D.C.) 2024; 7:0453. [PMID: 39145116 PMCID: PMC11322598 DOI: 10.34133/research.0453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/24/2024] [Indexed: 08/16/2024]
Abstract
Flexible epidermal electrodes hold substantial promise in realizing human electrophysiological information collections. Conventional electrodes exhibit certain limitations, including the requirement of skin pretreatment, reliance on external object-assisted fixation, and a propensity of dehydration, which severely hinder their applications in medical diagnosis. To tackle those issues, we developed a hydrogel electrode with both transcutaneous stimulation and neural signal acquisition functions. The electrode consists of a composite conductive layer (CCL) and adhesive conductive hydrogel (ACH). The CCL is designed as a laminated structure with high conductivity and charge storage capacity (CSC). Based on the optimization of Hoffmeister effect, the ACH demonstrates excellent electrical (resistivity of 3.56 Ω·m), mechanical (tensile limit of 1,650%), and adhesion properties (peeling energy of 0.28 J). The utilization of ACH as electrode/skin interface can reduce skin contact impedance and noise interference and enhance the CSC and charge injection capacity of electrodes. As a proof of concept, peripheral nerve conduction studies were performed on human volunteers to evaluate the as-fabricated hydrogel electrodes. Compared with the commercial electrodes, our hydrogel electrodes achieved better signal continuity and lower distortion, higher signal-to-noise ratio (~35 dB), and lower stimulation voltages (up to 27% lower), which can improve the safety and comfort of nerve conduction studies.
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Affiliation(s)
| | | | | | | | - Zhouping Yin
- Flexible Electronics Research Center, State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering,
Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hao Wu
- Flexible Electronics Research Center, State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering,
Huazhong University of Science and Technology, Wuhan 430074, China
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2
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Bhat B, Pahari S, Kwon JSI, Akbulut MES. Stimuli-responsive viscosity modifiers. Adv Colloid Interface Sci 2023; 321:103025. [PMID: 37871381 DOI: 10.1016/j.cis.2023.103025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 09/01/2023] [Accepted: 10/10/2023] [Indexed: 10/25/2023]
Abstract
Stimuli responsive viscosity modifiers entail an important class of materials which allow for smart material formation utilizing various stimuli for switching such as pH, temperature, light and salinity. They have seen applications in the biomedical space including tissue engineering and drug delivery, wherein stimuli responsive hydrogels and polymeric vessels have been extensively applied. Applications have also been seen in other domains like the energy sector and automobile industry, in technologies such as enhanced oil recovery. The chemistry and microstructural arrangements of the aqueous morphologies of dissolved materials are usually sensitive to the aforementioned stimuli which subsequently results in rheological sensitivity as well. Herein, we overview different structures capable of viscosity modification as well as go over the rheological theory associated with classical systems studied in literature. A detailed analysis allows us to explore correlations between commonly discussed models such as molecular packing parameter, tube reptation and stress relaxation with structural and rheological changes. We then present five primary mechanisms corresponding to stimuli responsive viscosity modification: (i) packing parameter modification via functional group conditioning and (ii) via dynamic bond formation, (iii) mesh formation by interlinking of network nodes, (iv) viscosity modification by chain conformation changes and (v) viscosity modification by particle jamming. We also overview several recent examples from literature that employ the concepts discussed to create novel classes of intriguing stimuli responsive structures and their corresponding rheological properties. Furthermore, we also explore systems that are responsive to multiple stimuli which can provide enhanced functionality and versatility by providing multi-level and precise actuation. Such systems have been used for programmed site-specific drug delivery.
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Affiliation(s)
- Bhargavi Bhat
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Silabrata Pahari
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Joseph Sang-Il Kwon
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA; Texas A&M Energy Institute, College Station, TX 77843, USA
| | - Mustafa E S Akbulut
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA; Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA; Texas A&M Energy Institute, College Station, TX 77843, USA.
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3
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Lin X, Wang X, Cui H, Rao P, Meng Y, Ouyang G, Guo H. Hydrogels with ultra-highly additive adjustable toughness under quasi-isochoric conditions. MATERIALS HORIZONS 2023; 10:993-1004. [PMID: 36651348 DOI: 10.1039/d2mh01451c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Bioinspired smart hydrogels with additive-switchable mechanical properties have been attracting increasing attention in recent years. However, most existing hydrogel systems suffer from limited stiffening amplitude and dramatic volume change upon response to environmental triggers. Herein, we propose a novel strategy to prepare additive-responsive hydrogels with ultra-highly adjustable toughness under quasi-isochoric conditions. The key point lies in tuning the softening transition temperature of the hydrogels with non-covalent interactions between the polymer networks and additives, shifting the hydrogels from glassy to rubbery states. As a proof of concept, a variety of glassy hydrogels are prepared and exposed to additives to trigger responsive performances. Young's modulus of the same hydrogel demonstrates up to 36 000 times ultra-broad-range tunability, ranging from 0.0042 to 150 MPa in response to different additives. Meanwhile, negligible volume changes occur, keeping the hydrogels in quasi-isochoric conditions. Interestingly, the mechanical behaviors of the hydrogels manifest remarkable dependence on the additive type and concentration since both the Hofmeister effect and hydrophobicity of the additives play pivotal roles according to mechanism investigations. Furthermore, the regulation with additives reveals satisfactory reversibility and universality. Taken together, this simple and effective approach provides a novel strategy to fabricate hydrogels with highly tunable toughness for versatile applications, including spatially patterned conductive gels and anti-icing coatings.
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Affiliation(s)
- Xinxing Lin
- School of Chemical Engineering and Technology, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen University, Zhuhai, 519082, China.
| | - Xiaolin Wang
- School of Pharmacy, Macau University of Science and Technology, Taipa, 999078, Macao
| | - Hongyuan Cui
- School of Chemical Engineering and Technology, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen University, Zhuhai, 519082, China.
| | - Ping Rao
- State Key Laboratory of Fluid Power & Mechatronic System, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027, China
| | - Yuezhong Meng
- The Key Laboratory of Low-Carbon Chemistry & Energy Conservation of Guangdong Province/State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China
| | - Gangfeng Ouyang
- School of Chemical Engineering and Technology, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen University, Zhuhai, 519082, China.
| | - Hui Guo
- School of Chemical Engineering and Technology, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen University, Zhuhai, 519082, China.
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4
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Effect of Sulfate, Citrate, and Tartrate Anions on the Liquid-Liquid Equilibrium Behavior of Water + Surfactant. Processes (Basel) 2022. [DOI: 10.3390/pr10102023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Cloud point extraction is a versatile method aimed at separating compounds from complex mixtures and arouses great technological interest, particularly among the biochemical industries. However, one must have deep knowledge of the liquid–liquid equilibrium behavior of systems to properly use the method. Thus, we used thermodynamic parameters to evaluate the effect of citrate, sulfate, and tartrate anions on the phase separation of water + Triton X-114® mixtures at 283.2 K, 293.2 K, and 303.2 K. In these systems, increasing the temperature and the anion molar fraction expanded the biphasic region in the following order: C6H5O73-> SO42- > C4H4O62−. Unlike other studies based on the Hofmeister series, the Gibbs free energy of micellization correlated the anion effect on the biphasic region with the spontaneity of the micelle formation. The water molecules structured around these anions were evaluated according to the shell volume of the immobilized water by electrostriction, volume of water around the hydration shell, Gibbs free energy of hydration, and Gibbs free energy of electrostriction (ΔGel12). The citrate anion presented a higher ΔGel12 of −1781.49 kJ mol−1, due to the larger number of electrons around it. In addition, the partition coefficient of the surfactant in the two liquid phases revealed a linear dependence upon the anion mole fractions by following the previous anion sequence and temperature in the phase separation.
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5
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Wei W, Chen X, Wang X. Nanopore Sensing Technique for Studying the Hofmeister Effect. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200921. [PMID: 35484475 DOI: 10.1002/smll.202200921] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/22/2022] [Indexed: 06/14/2023]
Abstract
The nanopore sensing technique is an emerging method of detecting single molecules, and extensive research has gone into various fields, including nanopore sequencing and other applications of single-molecule studies. Recently, several researchers have explored the specific ion effects in nanopore channels, enabling a unique understanding of the Hofmeister effect at the single-molecule level. Herein, the recent advances of using nanopore sensing techniques are reviewed to study the Hofmeister effect and the physicochemical mechanism of this process is attempted. The challenges and goals are also discussed for the future in this field.
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Affiliation(s)
- Weichen Wei
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Xiaojuan Chen
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Xuejiao Wang
- Fujian Provincial University Engineering Research Center of Industrial Biocatalysis, College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, China
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6
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Laurent H, Baker DL, Soper AK, Ries ME, Dougan L. Bridging Structure, Dynamics, and Thermodynamics: An Example Study on Aqueous Potassium Halides. J Phys Chem B 2021; 125:12774-12786. [PMID: 34757756 DOI: 10.1021/acs.jpcb.1c06728] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aqueous salt systems are ubiquitous in all areas of life. The ions in these solutions impose important structural and dynamic perturbations to water. In this study, we employ a combined neutron scattering, nuclear magnetic resonance, and computational modeling approach to deconstruct ion-specific perturbations to water structure and dynamics and shed light on the molecular origins of bulk thermodynamic properties of the solutions. Our approach uses the atomistic scale resolution offered to us by neutron scattering and computational modeling to investigate how the properties of particular short-ranged microenvironments within aqueous systems can be related to bulk properties of the system. We find that by considering only the water molecules in the first hydration shell of the ions that the enthalpy of hydration can be determined. We also quantify the range over which ions perturb water structure by calculating the average enthalpic interaction between a central halide anion and the surrounding water molecules as a function of distance and find that the favorable anion-water enthalpic interactions only extend to ∼4 Å. We further validate this by showing that ions induce structure in their solvating water molecules by examining the distribution of dipole angles in the first hydration shell of the ions but that this perturbation does not extend into the bulk water. We then use these structural findings to justify mathematical models that allow us to examine perturbations to rotational and diffusive dynamics in the first hydration shell around the potassium halide ions from NMR measurements. This shows that as one moves down the halide series from fluorine to iodine, and ionic charge density is therefore reduced, that the enthalpy of hydration becomes less negative. The first hydration shell also becomes less well structured, and rotational and diffusive motions of the hydrating water molecules are increased. This reduction in structure and increase in dynamics are likely the origin of the previously observed increased entropy of hydration as one moves down the halide series. These results also suggest that simple monovalent potassium halide ions induce mostly local perturbations to water structure and dynamics.
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Affiliation(s)
- Harrison Laurent
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Daniel L Baker
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Alan K Soper
- ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Michael E Ries
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Lorna Dougan
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K.,Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
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7
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Zeng Y, Jia Y, Yan T, Zhuang W. Binary structure and dynamics of the hydrogen bonds in the hydration shells of ions. Phys Chem Chem Phys 2021; 23:11400-11410. [PMID: 33949400 DOI: 10.1039/d0cp06397e] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ion-specific effects of cations (Li+, Na+, K+, Mg2+, Ca2+) and anions (F-, Cl-) on the hydrogen bond structure and dynamics of the coordination waters in the hydration shells have been studied using molecular dynamics simulations. Our simulations indicate that the hydrogen bonds between the first and second hydration shell waters show binary structural and dynamic properties. The hydrogen bond with a first shell water as the donor (HD) is strengthened, while those with a first shell water as the acceptor (HA) are weakened. For a hydrated anion, this binary effect reverses, but is less significant. This ion-specific binary effect correlates with the size and the valence of the ion, and is more significant for the strong kosmotropic ions of high charge density.
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Affiliation(s)
- Yonghui Zeng
- Institute of New Energy Material Chemistry, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Yunzhe Jia
- Institute of New Energy Material Chemistry, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Tianying Yan
- Institute of New Energy Material Chemistry, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Wei Zhuang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
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8
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Yuan L, Kong Y, Leng W, Wang Y, Jin W, Gao R. L-glutamic acid affects myosin aggregation and the physical properties of bighead carp (Aristichthys nobilis) surimi gels. FOOD BIOSCI 2021. [DOI: 10.1016/j.fbio.2021.100886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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9
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Mokhtari J, Nourisefat M, Zamiri B, Fotouhi L, Zarnani AH, Moosavi-Movahedi AA, Karimian K. Novel Method for the Isolation of Proteins and Small Target Molecules from Biological and Aqueous Media by Salt-Assisted Phase Transformation of Their PEGylated Recognition Counterparts. ACS OMEGA 2021; 6:7585-7597. [PMID: 33778269 PMCID: PMC7992175 DOI: 10.1021/acsomega.0c06149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
An efficient and simple method for the application of PEGylated affinity ligands in precipitative isolation of protein target molecules (TMs) from a biological fluid such as blood serum or small target molecules from an aqueous medium is presented for the first time. This approach is based on the high binding specificity of PEGylated recognition molecules (PEG-RMs) to their TMs and the unique physicochemical properties of PEG that result in their salt-assisted phase transformation. Addition of PEG-RM to blood serum results in the formation of an RM-specific macromolecular complex (PEG-RM + TM → PEG-RM.TM) that undergoes facile salt-assisted phase transformation to a separable semisolid with ammonium sulfate. PEG-RM.TM is then dissociated into its components by pH reduction or an increase of ionic strength (PEG-RM.TM → PEG-RM + TM). PEG-RM is salted out to afford pure TM in solution. The same phenomenon is observed when RM or TM are small molecules. The general applicability of the method was validated by PEGylation of two proteins (protein A, sheep antihuman IgG) and a small molecule (salicylic acid) used as model RMs for the isolation of Igs, IgG, and serum albumin from blood serum. The isolated protein TMs were shown to be pure and aggregate-free by gel electrophoresis and dynamic light scattering (DLS). IgG isolated by this method was further characterized by peptide mass fingerprinting. PEGylated protein A was used to demonstrate the recyclability and scale-up potential of PEG-RM. IgG isolated by this method from blood serum of a hepatitis C-vaccinated individual was tested for its binding to sheep antihuman IgG by UV spectroscopy, and its bioactivity was ascertained by comparison of its enzyme-linked immunosorbent assay (ELISA) result to that of a blood sample from the same individual. Reciprocity of RM and TM was ascertained using PEGylated salicylic acid to obtain pure serum albumin, and PEGylated serum albumin was utilized for near-exclusive isolation of one drug from an aqueous equimolar mixture of three drugs (salicylic acid, 91%; capecitabine, 6%; and deferiprone, 3%). Advantages of this approach, including target specificity and general applicability and celerity, over other affinity methods for the isolation of proteins are discussed at a molecular level.
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Affiliation(s)
- Javad Mokhtari
- Arasto Pharmaceutical Chemicals Inc., Yousefabad, Jahanarar Avenue, 23rd St. No. 8, Tehran 1438933741, Iran
- Departments of Chemistry, Science and Research Branch, Azad University, Tehran 1477893855, Iran
| | - Maryam Nourisefat
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417466191 Iran
| | - Bita Zamiri
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417466191 Iran
| | - Leila Fotouhi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417466191 Iran
| | - Amir-Hassan Zarnani
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran 1417466191, Iran
- Reproductive Immunology Research Center, Avicenna Research Institute, ACECR, Tehran 1936773493, Iran
| | | | - Khashayar Karimian
- Arasto Pharmaceutical Chemicals Inc., Yousefabad, Jahanarar Avenue, 23rd St. No. 8, Tehran 1438933741, Iran
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417466191 Iran
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10
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Garcia Garcia C, Patkar SS, Jovic N, Mittal J, Kiick KL. Alteration of Microstructure in Biopolymeric Hydrogels via Compositional Modification of Resilin-Like Polypeptides. ACS Biomater Sci Eng 2021; 7:4244-4257. [DOI: 10.1021/acsbiomaterials.0c01543] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Cristobal Garcia Garcia
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Sai S. Patkar
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Nina Jovic
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Jeetain Mittal
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Kristi L. Kiick
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
- Delaware Biotechnology Institute, Newark, Delaware 19716, United States
- Biomedical Engineering, University of Delaware, Newark, Delaware 19176, United States
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11
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Acharyya A, Mukherjee D, Gai F. Assessing the Effect of Hofmeister Anions on the Hydrogen-Bonding Strength of Water via Nitrile Stretching Frequency Shift. J Phys Chem B 2020; 124:11783-11792. [PMID: 33346656 DOI: 10.1021/acs.jpcb.0c06299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The temperature dependence of the peak frequency (νmax) of the C≡N stretching vibrational spectrum of a hydrogen-bonded C≡N species is known to be a qualitative measure of its hydrogen-bonding strength. Herein, we show that within a two-state framework, this dependence can be analyzed in a more quantitative manner to yield the enthalpy and entropy changes (ΔHHB and ΔSHB) for the corresponding hydrogen-bonding interactions. Using this method, we examine the effect of ten common anions on the strength of the hydrogen-bond(s) formed between water and the C≡N group of an unnatural amino acid, p-cyanophenylalanine (PheCN). We find that based on the ΔHHB values, these anions can be arranged in the following order: HPO42- > OAc- > F- > SO42- ≈ Cl- ≈ (H2O) ≈ ClO4- ≈ NO3- > Br- > SCN- ≈ I-, which differs from the corresponding Hofmeister series. Because PheCN has a relatively small size, the finding that anions having very different charge densities (e.g., SO42- and ClO4-) act similarly suggests that this ranking order is likely the result of specific ion effects. Since proteins contain different backbone and side-chain units, our results highlight the need to assess their individual contributions toward the overall Hofmeister effect in order to achieve a microscopic understanding of how ions affect the physical and chemical properties of such macromolecules. In addition, the analytical method described in the present study is applicable for analyzing the spectral evolution of any vibrational spectra composed of two highly overlapping bands.
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Affiliation(s)
- Arusha Acharyya
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Debopreeti Mukherjee
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Feng Gai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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12
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Laurent H, Soper AK, Dougan L. Trimethylamine N-oxide (TMAO) resists the compression of water structure by magnesium perchlorate: terrestrial kosmotrope vs. Martian chaotrope. Phys Chem Chem Phys 2020; 22:4924-4937. [PMID: 32091074 DOI: 10.1039/c9cp06324b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Neutron diffraction and computational modelling provide insight into water structure.
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Affiliation(s)
| | - Alan K. Soper
- ISIS Facility
- STFC Rutherford Appleton Laboratory
- Didcot
- UK
| | - Lorna Dougan
- Department of Physics and Astronomy
- University of Leeds
- Leeds
- UK
- Astbury Centre for Structural and Molecular Biology
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13
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Maurer M, Oostenbrink C. Water in protein hydration and ligand recognition. J Mol Recognit 2019; 32:e2810. [PMID: 31456282 PMCID: PMC6899928 DOI: 10.1002/jmr.2810] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/16/2022]
Abstract
This review describes selected basics of water in biomolecular recognition. We focus on a qualitative understanding of the most important physical aspects, how these change in magnitude between bulk water and protein environment, and how the roles that water plays for proteins arise from them. These roles include mechanical support, thermal coupling, dielectric screening, mass and charge transport, and the competition with a ligand for the occupation of a binding site. The presence or absence of water has ramifications that range from the thermodynamic binding signature of a single ligand up to cellular survival. The large inhomogeneity in water density, polarity and mobility around a solute is hard to assess in experiment. This is a source of many difficulties in the solvation of protein models and computational studies that attempt to elucidate or predict ligand recognition. The influence of water in a protein binding site on the experimental enthalpic and entropic signature of ligand binding is still a point of much debate. The strong water‐water interaction in enthalpic terms is counteracted by a water molecule's high mobility in entropic terms. The complete arrest of a water molecule's mobility sets a limit on the entropic contribution of a water displacement process, while the solvent environment sets limits on ligand reactivity.
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Affiliation(s)
- Manuela Maurer
- Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Chris Oostenbrink
- Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Vienna, Austria
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14
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Reynolds JG. Salt Solubilities in Aqueous Solutions of NaNO 3, NaNO 2, NaCl, and NaOH: A Hofmeister-like Series for Understanding Alkaline Nuclear Waste. ACS OMEGA 2018; 3:15149-15157. [PMID: 30555997 PMCID: PMC6289547 DOI: 10.1021/acsomega.8b02052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/29/2018] [Indexed: 06/09/2023]
Abstract
Nonelectrolyte solubility in electrolyte solutions follow the Hofmeister series, but the applicability of the series to salt solubility has been less appreciated. This study, using solubility data for thirteen sodium-bearing salts, shows that salts are consistently salted out by electrolytes important to alkaline nuclear waste in the order NaOH > NaCl > NaNO2 > NaNO3 at 298.15 K, which is the same order as the Hofmeister series. Graphical presentation allowed for easy separation of the common ion effect (caused by the addition of Na+) from the salting-out effect (caused by the presence of anions) because there is a large difference between the solubility of a given salt in different background electrolytes at a common Na+ molality. The trend persists even in very high electrolyte concentrations where essentially all of the water molecules must be in the coordination sphere of an ion, which means that the effect of electrolytes on "bulk water" is not the cause of the trend. These specific interactions more likely result from the sharing of water molecules between ions, augmented by differences in ion-pairing of the electrolytes. The Hofmeister series has practical application to the management of alkaline high-level radioactive waste created at nuclear fuel reprocessing facilities, where a predictive understanding of salt solubility is essential for blending wastes of disparate compositions prior to treatment.
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15
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Ochbaum G, Davidovich-Pinhas M, Bitton R. Tuning the mechanical properties of alginate-peptide hydrogels. SOFT MATTER 2018; 14:4364-4373. [PMID: 29781028 DOI: 10.1039/c8sm00059j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Alginate, a polysaccharide that gels in the presence of divalent ions, has been used in the field of regenerative medicine to facilitate cell growth in impaired tissues by providing an artificial bio-surrounding similar to the natural extra cellular matrix (ECM). Here, we present a systematic investigation of the effect of three arginine-glycine-aspartic acid (RGD)-containing peptides, G6KRGDY, A6KRGDY and V6KRGDY, on the physical properties of alginate-peptide hydrogels. Rheology measurements showed that the storage modulus of the alginate-A6KRGDY and alginate-V6KRGDY gels is an order of magnitude higher than that of the alginate-G6KRGDY gel. Small angle X-ray scattering (SAXS) measurements suggest that the difference in the mechanical properties of the gels is due to the formation of larger peptide junction zones in addition to the ones formed by calcium ions. These findings indicate that the peptides' ability to self-assemble in aqueous solution is a significant factor in tuning the stiffness of the alginate/peptide hybrid hydrogels.
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Affiliation(s)
- Guy Ochbaum
- Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
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16
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Ferreira LA, Uversky VN, Zaslavsky BY. Effects of the Hofmeister series of sodium salts on the solvent properties of water. Phys Chem Chem Phys 2018; 19:5254-5261. [PMID: 28150000 DOI: 10.1039/c6cp08214a] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The solvent features of water (solvent dipolarity/polarizability, π*, hydrogen bond donor acidity, α, and hydrogen bond acceptor basicity, β) were examined in aqueous solutions of Na2SO4, NaF, CH3COONa, NaCl, NaBr, NaI, and NaClO4 at concentrations of each salt from 0 to 1.0 M (up to 2.0 M for NaClO4). The solvent features of water in solutions of different concentrations for each salt were found to be linearly related as π* = z + aα + bβ. The coefficients of this relationship were suggested to represent the signature of the salt effect on the solvent features of water. The normalized distances for each salt were calculated using glucose as a reference compound. These distances may be used as the relative measures of the salt-water interactions. It is demonstrated that the distances for all salts examined are interrelated with structural water entropies and static polarizabilities of anions. It is shown that the distance may be used as a measure of the relative effects of salts on precipitation of ferric oxide, excessive chemical potential of propanol in salt solutions, surface tension, and viscosity. The distance represents the relative measure of the salt effect on the solvent features of water in a salt solution. The examples presented confirm that the approach used does enable us to characterize the differences between the effects of salts in the Hofmeister series on the properties of water.
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Affiliation(s)
- L A Ferreira
- Cleveland Diagnostics, 3615 Superior Ave., Suite 4407B, Cleveland, Ohio 44114, USA.
| | - V N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - B Y Zaslavsky
- Cleveland Diagnostics, 3615 Superior Ave., Suite 4407B, Cleveland, Ohio 44114, USA.
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17
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Grasso R, Musumeci F, Gulino M, Scordino A. Exploring the behaviour of water in glycerol solutions by using delayed luminescence. PLoS One 2018; 13:e0191861. [PMID: 29377914 PMCID: PMC5788358 DOI: 10.1371/journal.pone.0191861] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 01/13/2018] [Indexed: 11/19/2022] Open
Abstract
The crucial role of water in the engine of life have encouraged many researchers in studying, both theoretically and experimentally, the possible "structure" of water. Many properties of water have been related to the interplay between two distinct and interconverting structural species, namely the low-density water (LDW) and the high-density water (HDW). Supported by the results obtained with other aqueous solutions, this paper deals with the possibility of using the ultra-weak delayed luminescence (DL) to investigate water structuring in a mixture with glycerol, characterized only by hydrogen bonds between the various molecules. Spectral and temporal characteristics of DL decays give information on the two components of the mixture, by evidencing the contribution of water at glycerol concentrations close to the values used in cryopreservation. DL results have shown a correlation with LDW clusters size as determined by other researchers on the basis of neutron diffraction experiments and computational modelling, as reported in Literature.
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Affiliation(s)
- Rosaria Grasso
- Department of Physics and Astronomy, Catania University, Catania, Italy
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy
| | - Francesco Musumeci
- Department of Physics and Astronomy, Catania University, Catania, Italy
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy
| | - Marisa Gulino
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy
- Facoltà di Ingegneria e Architettura, Università di Enna Kore, Enna, Italy
| | - Agata Scordino
- Department of Physics and Astronomy, Catania University, Catania, Italy
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy
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18
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Mokhtari J, Azarnoosh S, Karimian K. Resolution of Racemic Mixtures by Phase Transition of PEGylated Resolving Agents. ACS OMEGA 2017; 2:8717-8722. [PMID: 31457403 PMCID: PMC6645586 DOI: 10.1021/acsomega.7b01070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/22/2017] [Indexed: 05/13/2023]
Abstract
A novel, efficient, and simple method for the resolution of racemic mixtures is presented in which PEGylated resolving agents are subjected to diastereomeric complex formation in alcohols. The resulting complexes then undergo temperature-assisted phase transition, affording a precipitate that is enriched in one enantiomer and separable by filtration. In an aqueous solution, phase transition can be caused by the methods used in the precipitation of poly(ethylene glycol) (e.g., addition of ammonium sulfate). A number of racemic amines have been successfully resolved using this method. The first cycle of resolution affords the amines with an optical purity of 72-85% from their corresponding racemic mixture in good yields (78-90%). An additional cycle improved the optical purity to 87-95%. The PEGylated resolving agents can be recovered and reutilized without the loss of resolution efficiency.
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Affiliation(s)
- Javad Mokhtari
- Arasto
Pharmaceutical Chemicals Inc., Yousefabad, Jahanarar Avenue, 23rd Street No. 8, Tehran 1438933741, Iran
- Departments
of Chemistry, Science and Research Branch, Islamic Azad University, P.O. Box 14515-775, Tehran 1477893855, Iran
| | - Sahar Azarnoosh
- Departments
of Chemistry, Science and Research Branch, Islamic Azad University, P.O. Box 14515-775, Tehran 1477893855, Iran
| | - Khashayar Karimian
- Arasto
Pharmaceutical Chemicals Inc., Yousefabad, Jahanarar Avenue, 23rd Street No. 8, Tehran 1438933741, Iran
- Institute
of Biochemistry and Biophysics, University
of Tehran, P.O. Box 13145-1384, Tehran 1417466191, Iran
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19
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Tyteca E, De Vos J, Tassi M, Cook K, Liu X, Kaal E, Eeltink S. Generic approach to the method development of intact protein separations using hydrophobic interaction chromatography. J Sep Sci 2017; 41:1017-1024. [PMID: 29178450 DOI: 10.1002/jssc.201701202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/21/2017] [Accepted: 11/21/2017] [Indexed: 11/05/2022]
Abstract
We describe a liquid chromatography method development approach for the separation of intact proteins using hydrophobic interaction chromatography. First, protein retention was determined as function of the salt concentration by isocratic measurements and modeled using linear regression. The error between measured and predicted retention factors was studied while varying gradient time (between 15 and 120 min) and gradient starting conditions, and ranged between 2 and 15%. To reduce the time needed to develop optimized gradient methods for hydrophobic interaction chromatography separations, retention-time estimations were also assessed based on two gradient scouting runs, resulting in significantly improved retention-time predictions (average error < 2.5%) when varying gradient time. When starting the scouting gradient at lower salt concentrations (stronger eluent), retention time prediction became inaccurate in contrast to predictions based on isocratic runs. Application of three scouting runs and a nonlinear model, incorporating the effects of gradient duration and mobile-phase composition at the start of the gradient, provides accurate results (improved fitting compared to the linear solvent-strength model) with an average error of 1.0% and maximum deviation of -8.3%. Finally, gradient scouting runs and retention-time modeling have been applied for the optimization of a critical-pair protein isoform separation encountered in a biotechnological sample.
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Affiliation(s)
- Eva Tyteca
- Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium.,University of Liège, Gembloux Agro-BioTech, Department of Agronomy, Bio-engineering and Chemistry, Analytical Chemistry, Gembloux, Belgium
| | - Jelle De Vos
- Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium
| | - Marco Tassi
- Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium
| | - Ken Cook
- Thermo Fisher Scientific, Hemel Hempstead, United Kingdom
| | | | - Erwin Kaal
- DSM Biotechnology Center, part of DSM Food Specialties B.V., Delft, The Netherlands
| | - Sebastiaan Eeltink
- Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium
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20
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Łudzik K, Kacperska A, Kustrzepa K, Dychto R. Interactions between sodium dodecylsulphate and didodecyldimethylammonium bromides vesicles in aqueous solutions. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.05.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Bodratti AM, Sarkar B, Alexandridis P. Adsorption of poly(ethylene oxide)-containing amphiphilic polymers on solid-liquid interfaces: Fundamentals and applications. Adv Colloid Interface Sci 2017; 244:132-163. [PMID: 28069108 DOI: 10.1016/j.cis.2016.09.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 09/23/2016] [Accepted: 09/23/2016] [Indexed: 12/30/2022]
Abstract
The adsorption of amphiphilic molecules of varying size on solid-liquid interfaces modulates the properties of colloidal systems. Nonionic, poly(ethylene oxide) (PEO)-based amphiphilic molecules are particularly useful because of their graded hydrophobic-hydrophilic nature, which allows for adsorption on a wide array of solid surfaces. Their adsorption also results in other useful properties, such as responsiveness to external stimuli and solubilization of hydrophobic compounds. This review focuses on the adsorption properties of PEO-based amphiphiles, beginning with a discussion of fundamental concepts pertaining to the adsorption of macromolecules on solid-liquid interfaces, and more specifically the adsorption of PEO homopolymers. The main portion of the review highlights studies on factors affecting the adsorption and surface self-assembly of PEO-PPO-PEO block copolymers, where PPO is poly(propylene oxide). Block copolymers of this type are commercially available and of interest in several fields, due to their low toxicity and compatibility in aqueous systems. Examples of applications relevant to the interfacial behavior of PEO-PPO-PEO block copolymers are paints and coatings, detergents, filtration, and drug delivery. The methods discussed herein for manipulating the adsorption properties of PEO-PPO-PEO are emphasized for their ability to shed light on molecular interactions at interfaces. Knowledge of these interactions guides the formulation of novel materials with useful mesoscale organization and micro- and macrophase properties.
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22
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Cooper RJ, O'Brien JT, Chang TM, Williams ER. Structural and electrostatic effects at the surfaces of size- and charge-selected aqueous nanodrops. Chem Sci 2017; 8:5201-5213. [PMID: 28970907 PMCID: PMC5618692 DOI: 10.1039/c7sc00481h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/17/2017] [Indexed: 11/23/2022] Open
Abstract
The effects of ion charge, polarity and size on the surface morphology of size-selected aqueous nanodrops containing a single ion and up to 550 water molecules are investigated with infrared photodissociation (IRPD) spectroscopy and theory.
The effects of ion charge, polarity and size on the surface morphology of size-selected aqueous nanodrops containing a single ion and up to 550 water molecules are investigated with infrared photodissociation (IRPD) spectroscopy and theory. IRPD spectra of M(H2O)n where M = La3+, Ca2+, Na+, Li+, I–, SO42– and supporting molecular dynamics simulations indicate that strong interactions between multiply charged ions and water molecules can disrupt optimal hydrogen bonding (H-bonding) at the nanodrop surface. The IRPD spectra also reveal that “free” OH stretching frequencies of surface-bound water molecules are highly sensitive to the ion's identity and the OH bond's local H-bond environment. The measured frequency shifts are qualitatively reproduced by a computationally inexpensive point-charge model that shows the frequency shifts are consistent with a Stark shift from the ion's electric field. For multiply charged cations, pronounced Stark shifting is observed for clusters containing ∼100 or fewer water molecules. This is attributed to ion-induced solvent patterning that extends to the nanodrop surface, and serves as a spectroscopic signature for a cation's ability to influence the H-bond network of water located remotely from the ion. The Stark shifts measured for the larger nanodrops are extrapolated to infinite dilution to obtain the free OH stretching frequency of a surface-bound water molecule at the bulk air–water interface (3696.5–3701.0 cm–1), well within the relatively wide range of values obtained from SFG measurements. These cluster measurements also indicate that surface curvature effects can influence the free OH stretching frequency, and that even nanodrops without an ion have a surface potential that depends on cluster size.
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Affiliation(s)
- Richard J Cooper
- Department of Chemistry , University of California , Berkeley , California 94720-1460 , USA . ; Tel: +1 510 643 7161
| | - Jeremy T O'Brien
- Department of Chemistry , University of California , Berkeley , California 94720-1460 , USA . ; Tel: +1 510 643 7161
| | - Terrence M Chang
- Department of Chemistry , University of California , Berkeley , California 94720-1460 , USA . ; Tel: +1 510 643 7161
| | - Evan R Williams
- Department of Chemistry , University of California , Berkeley , California 94720-1460 , USA . ; Tel: +1 510 643 7161
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23
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Giuffrida S, Cottone G, Cordone L. The water association band as a marker of hydrogen bonds in trehalose amorphous matrices. Phys Chem Chem Phys 2017; 19:4251-4265. [DOI: 10.1039/c6cp06848k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The water association band is a suitable marker of residual water behavior in bioprotective trehalose matrices.
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Affiliation(s)
- Sergio Giuffrida
- Dipartimento di Fisica e Chimica
- Università degli Studi di Palermo
- Palermo
- Italy
| | - Grazia Cottone
- Dipartimento di Fisica e Chimica
- Università degli Studi di Palermo
- Palermo
- Italy
- School of Physics
| | - Lorenzo Cordone
- Dipartimento di Fisica e Chimica
- Università degli Studi di Palermo
- Palermo
- Italy
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24
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Some physicochemical aspects of water-soluble mineral flotation. Adv Colloid Interface Sci 2016; 235:190-200. [PMID: 27346329 DOI: 10.1016/j.cis.2016.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/19/2016] [Accepted: 06/06/2016] [Indexed: 11/22/2022]
Abstract
Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation.
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25
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Colleoni C, Esposito S, Grasso R, Gulino M, Musumeci F, Romeli D, Rosace G, Salesi G, Scordino A. Delayed luminescence induced by complex domains in water and in TEOS aqueous solutions. Phys Chem Chem Phys 2016; 18:772-80. [PMID: 26627630 DOI: 10.1039/c5cp03420e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many recent studies on water have conjectured a complex structure composed of hydrogen bonded low- and high-density domains. In this work the structure of pure water and aqueous solutions of silica gel (TEOS) has been investigated by using delayed luminescence, which has previously shown a significant increase in aqueous salt solutions where low-density domain formation is expected. Photon emission shows an Arrhenius trend with an activation energy in water-TEOS solutions larger than in pure water and salt-water solutions. Moreover, delayed photon emission decay shows an intrinsic lifetime of about 5 μs both in solutions and in pure water that, along with secondary lifetimes induced by the presence of TEOS, could be related to the formation of different domains.
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Affiliation(s)
- C Colleoni
- Dipartimento di Ingegneria e Scienze Applicate, Università di Bergamo, viale Marconi 5, Dalmine, Italy.
| | - S Esposito
- Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, via Cinthia, Naples, Italy
| | - R Grasso
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy
| | - M Gulino
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Facoltà di Ingegneria e Architettura, Università di Enna "Kore", Enna, Italy
| | - F Musumeci
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy
| | - D Romeli
- Dipartimento di Ingegneria e Scienze Applicate, Università di Bergamo, viale Marconi 5, Dalmine, Italy.
| | - G Rosace
- Dipartimento di Ingegneria e Scienze Applicate, Università di Bergamo, viale Marconi 5, Dalmine, Italy.
| | - G Salesi
- Dipartimento di Ingegneria e Scienze Applicate, Università di Bergamo, viale Marconi 5, Dalmine, Italy. and Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, Milan, Italy
| | - A Scordino
- Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy and Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy
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26
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Násztor Z, Bogár F, Dér A. The interfacial tension concept, as revealed by fluctuations. Curr Opin Colloid Interface Sci 2016. [DOI: 10.1016/j.cocis.2016.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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García-Arribas AB, Axpe E, Mujika JI, Mérida D, Busto JV, Sot J, Alonso A, Lopez X, García JÁ, Ugalde JM, Plazaola F, Goñi FM. Cholesterol-Ceramide Interactions in Phospholipid and Sphingolipid Bilayers As Observed by Positron Annihilation Lifetime Spectroscopy and Molecular Dynamics Simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5434-5444. [PMID: 27158737 DOI: 10.1021/acs.langmuir.6b00927] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Free volume voids in lipid bilayers can be measured by positron annihilation lifetime spectroscopy (PALS). This technique has been applied, together with differential scanning calorimetry and molecular dynamics (MD) simulations, to study the effects of cholesterol (Chol) and ceramide (Cer) on free volume voids in sphingomyelin (SM) or dipalmitoylphosphatidylcholine (DPPC) bilayers. Binary lipid samples with Chol were studied (DPPC:Chol 60:40, SM:Chol 60:40 mol ratio), and no phase transition was detected in the 20-60 °C range, in agreement with calorimetric data. Chol-driven liquid-ordered phase showed an intermediate free volume void size as compared to gel and fluid phases. For SM and SM:Cer (85:15 mol:mol) model membranes measured in the 20-60 °C range the gel-to-fluid phase transition could be observed with a related increase in free volume, which was more pronounced for the SM:Cer sample. MD simulations suggest a hitherto unsuspected lipid tilting in SM:Cer bilayers but not in pure SM. Ternary samples of DPPC:Cer:Chol (54:23:23) and SM:Cer:Chol (54:23:23) were measured, and a clear pattern of free volume increase was observed in the 20-60 °C because of the gel-to-fluid transition. Interestingly, MD simulations showed a tendency of Cer to change its distribution along the membrane to make room for Chol in ternary mixtures. The results suggest that the gel phase formed in these ternary mixtures is stabilized by Chol-Cer interactions.
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Affiliation(s)
- Aritz B García-Arribas
- Biofisika Institute (CSIC, UPV/EHU) , 48080, Bilbao, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48080 Bilbao, Spain
| | - Eneko Axpe
- Department of Electricity and Electronics, University of the Basque Country (UPV/EHU) , 48940 Leioa, Basque Country, Spain
| | - Jon Iñaki Mujika
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) , 20080 Donostia, Euskadi, Spain
- Donostia International Physics Center (DIPC) , 20018 Donostia, Basque Country, Spain
| | - David Mérida
- Department of Electricity and Electronics, University of the Basque Country (UPV/EHU) , 48940 Leioa, Basque Country, Spain
| | - Jon V Busto
- Biofisika Institute (CSIC, UPV/EHU) , 48080, Bilbao, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48080 Bilbao, Spain
| | - Jesús Sot
- Biofisika Institute (CSIC, UPV/EHU) , 48080, Bilbao, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48080 Bilbao, Spain
| | - Alicia Alonso
- Biofisika Institute (CSIC, UPV/EHU) , 48080, Bilbao, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48080 Bilbao, Spain
| | - Xabier Lopez
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) , 20080 Donostia, Euskadi, Spain
- Donostia International Physics Center (DIPC) , 20018 Donostia, Basque Country, Spain
| | - Jose Ángel García
- Department of Applied Physics II, University of the Basque Country (UPV/EHU) , 48940 Leioa, Basque Country, Spain
| | - Jesus M Ugalde
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) , 20080 Donostia, Euskadi, Spain
- Donostia International Physics Center (DIPC) , 20018 Donostia, Basque Country, Spain
| | - Fernando Plazaola
- Department of Electricity and Electronics, University of the Basque Country (UPV/EHU) , 48940 Leioa, Basque Country, Spain
| | - Félix M Goñi
- Biofisika Institute (CSIC, UPV/EHU) , 48080, Bilbao, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48080 Bilbao, Spain
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28
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Light TP, Corbett KM, Metrick MA, MacDonald G. Hofmeister Ion-Induced Changes in Water Structure Correlate with Changes in Solvation of an Aggregated Protein Complex. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:1360-1369. [PMID: 26760222 DOI: 10.1021/acs.langmuir.5b04489] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
RecA is a naturally aggregating Escherichia coli protein that catalyzes the strand exchange reaction utilized in DNA repair. Previous studies have shown that the presence of salts influence RecA activity, aggregation, and stability and that salts stabilize RecA in an inverse-anionic Hofmeister series. Here we utilized attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and circular dichroism (CD) to investigate how various Hofmeister salts alter the water structure and RecA solvation and aggregation. Spectroscopic studies performed in water and deuterium oxide suggest that salts alter water O-(1)H and O-(2)H stretch and bend vibrations as well as protein amide I (or I') and amide II (or II') vibrations. Anions have a much larger influence on water vibrations than cations. Water studies also show increased water-water and/or water-ion interactions in the presence of strongly hydrated SO4(2-) salts and evidence for decreased interactions with weakly hydrated Cl(-) and ClO4(-) salts. Salt-water difference infrared spectra show that kosmotropic salts are more hydrated than chaotropic salts. Interestingly, this is the opposite trend to the changes in protein solvation. Infrared spectra of RecA show that vibrations associated with protein desolvation were observed in the presence of SO4(2-) salts. Conversely, vibrations associated with protein solvation were observed in the presence of Cl(-) and ClO4(-) salts. Difference infrared studies on the dehydration of model proteins aided in identifying changes in RecA-solvent interactions. This study provides evidence that salt-induced changes in water vibrations correlate to changes in protein solvent interactions and thermal stability.
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Affiliation(s)
- Taylor P Light
- Department of Chemistry and Biochemistry, James Madison University , Harrisonburg, Virginia 22807, United States
| | - Karen M Corbett
- Department of Chemistry and Biochemistry, James Madison University , Harrisonburg, Virginia 22807, United States
| | - Michael A Metrick
- Department of Chemistry and Biochemistry, James Madison University , Harrisonburg, Virginia 22807, United States
| | - Gina MacDonald
- Department of Chemistry and Biochemistry, James Madison University , Harrisonburg, Virginia 22807, United States
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29
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Corbatón-Báguena MJ, Álvarez-Blanco S, Vincent-Vela MC, Ortega-Navarro E, Pérez-Herranz V. Application of electric fields to clean ultrafiltration membranes fouled with whey model solutions. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2015.12.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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30
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Zhao H. Protein Stabilization and Enzyme Activation in Ionic Liquids: Specific Ion Effects. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 2016; 91:25-50. [PMID: 26949281 PMCID: PMC4777319 DOI: 10.1002/jctb.4837] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/12/2015] [Indexed: 05/08/2023]
Abstract
There are still debates on whether the hydration of ions perturbs the water structure, and what is the degree of such disturbance; therefore, the origin of Hofmeister effect on protein stabilization continues being questioned. For this reason, it is suggested to use the 'specific ion effect' instead of other misleading terms such as Hofmeister effect, Hofmeister series, lyotropic effect, and lyotropic series. In this review, we firstly discuss the controversial aspect of inorganic ion effects on water structures, and several possible contributors to the specific ion effect of protein stability. Due to recent overwhelming attraction of ionic liquids (ILs) as benign solvents in many enzymatic reactions, we further evaluate the structural properties and molecular-level interactions in neat ILs and their aqueous solutions. Next, we systematically compare the specific ion effects of ILs on enzyme stability and activity, and conclude that (a) the specificity of many enzymatic systems in diluted aqueous IL solutions is roughly in line with the traditional Hofmeister series albeit some exceptions; (b) however, the specificity follows a different track in concentrated or neat ILs because other factors (such as hydrogen-bond basicity, nucelophilicity, and hydrophobicity, etc) are playing leading roles. In addition, we demonstrate some examples of biocatalytic reactions in IL systems that are guided by the empirical specificity rule.
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Affiliation(s)
- Hua Zhao
- Department of Chemistry and Forensic Science, Savannah State University, Savannah, GA 31404, USA
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Naghash A, Nezamzadeh-Ejhieh A. Comparison of the efficiency of modified clinoptilolite with HDTMA and HDP surfactants for the removal of phosphate in aqueous solutions. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2015.06.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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32
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Banipal PK, Aggarwal N, Banipal TS. Effects of phosphate-based monobasic and tribasic inorganic salts on hydration characteristics of saccharides and their derivatives. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.06.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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33
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Song W, Liu L, Liu G. Ion specificity of macromolecules in crowded environments. SOFT MATTER 2015; 11:5940-5946. [PMID: 26119620 DOI: 10.1039/c5sm01023c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Macromolecular crowding plays a significant role in the solubility and stability of biomacromolecules. In this work, the thermo-sensitive poly(N-isopropylacrylamide) (PNIPAM) has been employed as a model system to study the specific ion effects on the solubility of macromolecules in crowded environments of dextran and polyethylene glycol (PEG). Our study demonstrates that crowding agents can interact with either anions or PNIPAM chains. The chaotropic anion SCN(-) interacts with dextran but does not interact with PEG. Both Cl(-) and CH3COO(-) do not interact with dextran and PEG. On the other hand, dextran can interact with PNIPAM as a hydrogen-bond donor, whereas PEG interacts with PNIPAM as a hydrogen-bond acceptor. The salting-in effect exerted by SCN(-) on PNIPAM is weakened in the crowded environment of dextran but is strengthened in the crowded environment of PEG due to the distinct anion-crowder interactions. In parallel, the salting-out effect generated by Cl(-) and CH3COO(-) on PNIPAM is weakened by the crowding of dextran but is strengthened by the crowding of PEG because of the different macromolecule-crowder interactions. Our study reveals that the ion specificity of macromolecules is altered significantly changing from dilute solutions to crowded environments.
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Affiliation(s)
- Wangqin Song
- Department of Chemical Physics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, P. R. China 230026.
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Corbatón-Báguena MJ, Álvarez-Blanco S, Vincent-Vela MC, Lora-García J. Utilization of NaCl solutions to clean ultrafiltration membranes fouled by whey protein concentrates. Sep Purif Technol 2015. [DOI: 10.1016/j.seppur.2015.06.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dupont D, Depuydt D, Binnemans K. Overview of the effect of salts on biphasic ionic liquid/water solvent extraction systems: anion exchange, mutual solubility, and thermomorphic properties. J Phys Chem B 2015; 119:6747-57. [PMID: 25978001 DOI: 10.1021/acs.jpcb.5b02980] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hydrophobic (water-immiscible) ionic liquids (ILs) are frequently used as organic phase in solvent extraction studies. These biphasic IL/water extraction systems often also contain metal salts or mineral acids, which can significantly affect the IL trough (un)wanted anion exchange and changes in the solubility of IL in the aqueous phase. In the case of thermomorphic systems, variations in the cloud point temperature are also observed. All these effects have important repercussions on the choice of IL, suitable for a certain extraction system. In this paper, a complete overview of the implications of metal salts on biphasic IL/water systems is given. Using the Hofmeister series as a starting point, a range of intuitive prediction models are introduced, supported by experimental evidence for several hydrophobic ILs, relevant to solvent extraction. Particular emphasis is placed on the IL betainium bis(trifluoromethylsulfonyl)imide [Hbet][Tf2N]. The aim of this work is to provide a comprehensive interpretation of the observed effects of metal salts, so that it can be used to predict the effect on any given biphasic IL/water system instead of relying on case-by-case reports. These prediction tools for the impact of metal salts can be useful to optimize IL synthesis procedures, extraction systems and thermomorphic properties. Some new insights are also provided for the rational design of ILs with UCST or LCST behavior based on the choice of IL anion.
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Affiliation(s)
- David Dupont
- KU Leuven, Department of Chemistry, Molecular Design and Synthesis, Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium
| | - Daphne Depuydt
- KU Leuven, Department of Chemistry, Molecular Design and Synthesis, Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium
| | - Koen Binnemans
- KU Leuven, Department of Chemistry, Molecular Design and Synthesis, Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium
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Bielejewski M, Puszkarska A, Tritt-Goc J. Thermal Properties, Conductivity, and Spin-lattice Relaxation of Gel Electrolyte Based on Low Molecular Weight Gelator and Solution of High Temperature Ionic Liquid. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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37
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Barriga HMG, Bazin R, Templer RH, Law RV, Ces O. Buffer-induced swelling and vesicle budding in binary lipid mixtures of dioleoylphosphatidylcholine:dioleoylphosphatidylethanolamine and dioleoylphosphatidylcholine:lysophosphatidylcholine using small-angle X-ray scattering and ³¹P static NMR. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:2979-2987. [PMID: 25738977 DOI: 10.1021/la5047996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A large variety of data exists on lipid phase behavior; however, it is mostly in nonbuffered systems over nonbiological temperature ranges. We present biophysical data on lipid mixtures of dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylethanolamine (DOPE), and lysophosphatidylcholine (LysoPC) examining their behaviors in excess water and buffer systems over the temperature range 4-34 °C. These mixtures are commonly used to investigate the effects of spontaneous curvature on integral membrane proteins. Using small-angle X-ray scattering (SAXS) and (31)P NMR, we observed lamellar and vesicle phases, with the buffer causing an increase in the layer spacing. Increasing amounts of DOPE in a DOPC bilayer decreased the layer spacing of the mesophase, while the opposite trend was observed for increasing amounts of LysoPC. (31)P static NMR was used to analyze the DOPC:LysoPC samples to investigate the vesicle sizes present, with evidence of vesicle budding observed at LysoPC concentrations above 30 mol %. NMR line shapes were fitted using an adapted program accounting for the distortion of the lipids within the magnetic field. The distortion of the vesicle, because of magnetic susceptibility, varied with LysoPC content, and a discontinuity was found in both the water and buffer samples. Generally, the distortion increased with LysoPC content; however, at a ratio of DOPC:LysoPC 60:40, the sample showed a level of distortion of the vesicle similar to that of pure DOPC. This implies an increased flexibility in the membrane at this point. Commonly, the assumption is that for increasing LysoPC concentration there is a reduction in membrane tension, implying that estimations of membrane tension based on spontaneous curvature assumptions may not be accurate.
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Affiliation(s)
- Hanna M G Barriga
- †Department of Chemistry, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Richard Bazin
- ‡Pfizer Global Research and Development, Sandwich, Kent CT13 9NJ, United Kingdom
| | - Richard H Templer
- †Department of Chemistry, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Robert V Law
- †Department of Chemistry, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Oscar Ces
- †Department of Chemistry, Imperial College London, London, SW7 2AZ, United Kingdom
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38
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Ruckenstein E, Huang H. Specific ion effects on double layer forces through ion hydration. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Corbatón-Báguena MJ, Álvarez-Blanco S, Vincent-Vela MC. Salt cleaning of ultrafiltration membranes fouled by whey model solutions. Sep Purif Technol 2014. [DOI: 10.1016/j.seppur.2014.05.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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40
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Zhu X, Mason TG. Passivated gel electrophoresis of charged nanospheres by light-scattering video tracking. J Colloid Interface Sci 2014; 428:199-207. [DOI: 10.1016/j.jcis.2014.04.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 04/12/2014] [Indexed: 01/20/2023]
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41
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Banipal P, Aggarwal N, Banipal T. Study on interactions of saccharides and their derivatives with potassium phosphate monobasic (1:1 electrolyte) in aqueous solutions at different temperatures. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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42
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Rakel N, Baum M, Hubbuch J. Moving through three-dimensional phase diagrams of monoclonal antibodies. Biotechnol Prog 2014; 30:1103-13. [PMID: 25044865 DOI: 10.1002/btpr.1947] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 06/14/2014] [Indexed: 11/12/2022]
Abstract
Protein phase behavior characterization is a multivariate problem due to the high amount of influencing parameters and the diversity of the proteins. Single influences on the protein are not understood and fundamental knowledge remains to be obtained. For this purpose, a systematic screening method was developed to characterize the influence of fluid phase conditions on the phase behavior of proteins in three-dimensional phase diagrams. This approach was applied to three monoclonal antibodies to investigate influences of pH, protein and salt concentrations, with five different salts being tested. Although differences exist between the antibodies, this extensive study confirmed the general applicability of the Hofmeister series over the broad parameter range analyzed. The influence of the different salts on the aggregation (crystallization and precipitation) probability was described qualitatively using this Hofmeister series, with a differentiation between crystallization and precipitation being impossible, however.
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Affiliation(s)
- Natalie Rakel
- Biomolecular Separation Engineering, Institute of Engineering in Life Sciences, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, 76131, Karlsruhe, Germany
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43
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Ni Y, Skinner JL. Ultrafast pump-probe and 2DIR anisotropy and temperature-dependent dynamics of liquid water within the E3B model. J Chem Phys 2014; 141:024509. [DOI: 10.1063/1.4886427] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Yicun Ni
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - J. L. Skinner
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
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da Silva NR, Ferreira LA, Mikheeva LM, Teixeira JA, Zaslavsky BY. Origin of salt additive effect on solute partitioning in aqueous polyethylene glycol-8000-sodium sulfate two-phase system. J Chromatogr A 2014; 1337:3-8. [PMID: 24613040 DOI: 10.1016/j.chroma.2014.02.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/31/2014] [Accepted: 02/03/2014] [Indexed: 11/29/2022]
Abstract
Partitioning of a homologous series of dinitrophenylted (DNP-) amino acids with aliphatic side chains was examined in aqueous polyethylene glycol (PEG)-8000-sodium sulfate two-phase systems (ATPS) with the additives NaSCN, NaClO4, and NaH2PO4 at concentrations varied from 0.025M up to 0.54M. The differences between the relative hydrophobicities and electrostatic properties of the two phases in all ATPS were estimated. Partitioning of adenine, adenosine mono-, di- and tri-phosphates was also examined in all ATPSs, including those with NaCl additive. Partition coefficients for these compounds and for nonionic organic compounds previously reported [L.A. Ferreira, P. Parpot, J.A. Teixeira, L.M. Mikheeva, B.Y. Zaslavsky, J. Chromatogr. A 1220 (2012) 14.] were analyzed in terms of linear solvent regression relationship. The results obtained suggest that the effects of the salts additives are related to their influence on the water structure.
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Affiliation(s)
- Nuno R da Silva
- IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Luisa A Ferreira
- IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal; Analiza, Inc., 3615 Superior Ave., Cleveland, OH 44114, USA
| | | | - José A Teixeira
- IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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45
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The ion–lipid battle for hydration water and interfacial sites at soft-matter interfaces. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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46
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Holm R, Schönbeck C, Somprasirt P, Westh P, Mu H. A study of salt effects on the complexation between β-cyclodextrins and bile salts based on the Hofmeister series. J INCL PHENOM MACRO 2014. [DOI: 10.1007/s10847-014-0383-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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47
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Stekhanova TN, Bezsudnova EY, Mardanov AV, Gumerov VM, Artemova N, Kleymenov SY, Popov VO. Sodium chloride-induced modulation of the activity and thermal stability of short-chain oxidoreductase from the archaeon Thermococcus sibiricus. Appl Biochem Biotechnol 2013; 171:1877-89. [PMID: 24061874 DOI: 10.1007/s12010-013-0462-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 08/22/2013] [Indexed: 10/26/2022]
Abstract
Recently, we have studied properties and structural features of the thermostable halotolerant alcohol dehydrogenase from archaeon Thermococcus sibiricus (TsAdh319). In the present work, the effect of sodium chloride on activity and thermostability was explored using circular dichroism, fluorescent spectroscopy, and differential scanning calorimetry. The activity of TsAdh319 increased in the presence of NaCl and remained at the elevated level up to 4 M of NaCl. Sodium chloride at molar concentrations reduced the optimal reaction temperature, increased both Michaelis constant (K m) and k cat values for the substrates tested, decreased affinity for the coenzyme, and stoichiometry of coenzyme binding. No changes were revealed in a secondary or quaternary structure of the protein in the presence of NaCl up to 90 °C. According to differential scanning calorimetry, the irreversible unfolding started around 90 °C, the addition of NaCl decreased T m from 104.2 to 102.2 °C, and reduced ΔH from 438 to 348 kJ/mol. Kinetic studies revealed positive effect of NaCl on the TsAdh319 thermostability. The results are interpreted in regard to TsAdh319 structural data.
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Cecchi T, Marcotulli F. Chromatography and the hundred year mystery of inorganic ions at aqueous interfaces: adsorption of inorganic ions at the Porous Graphitic Carbon Aqueous Interface follows the Hofmeister series. J Chromatogr A 2013; 1314:106-14. [PMID: 24075459 DOI: 10.1016/j.chroma.2013.09.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 10/26/2022]
Abstract
Many physical phenomena are affected by the structure of water interfaces, yet it remains an active and controversial subject. A great deal of recent theoretical endeavour and computer simulations question the validity of the Onsager Samaras theory of the ion-free interface between an electrolyte solution and an hydrophobic surface. Experimental results play a crucial role in assessing the legitimacy of the theories. Experimental data are scarce, while simulation results suggest an increasing surface affinity of ions with increasing chaotropic character, in dramatic contradiction to the classical view. Chromatography is a powerful separative technique, but we originally used it as a tool to detect the adsorption of chloride electrolytes and sodium electrolytes, strongly expected to shun any dielectric boundary, onto an hydrophobic surface, and to rank ions according to their adsorbophilicities. Frontal analysis gave unequivocal experimental evidence to this unexpected phenomenon and it was used to quantify it. The infinite dilution equilibrium constants for adsorption of kosmotropes and chaotropes onto the interface were obtained and contrasted to the Jones-Dole B viscosity coefficients, that is a common quantifier of the Hofmeister effect. It is clear that (i) the more chaotropic the ion is, the more it contributes to the global adsorbophilicity of the electrolyte; (ii) the influence of the variable anion is more than twofold that of the variable cation, thereby confirming a robust observation in many other physical systems. Standard free energy of adsorption for each electrolyte was calculated and its reliability was commented upon. The central issue in this paper is the effective and ascertained adsorption of electrolytes onto an hydrophobic surface and the fact that the adsorbophilicity of an electrolyte may be inferred from its position in the Hofmeister series.
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Affiliation(s)
- Teresa Cecchi
- Accademia Delle Scienze dell'istituto di Bologna, Via Zamboni, 31, 40126 Bologna, Italy.
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49
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Volumetric, Compressibility and UV Spectral Studies on Interactions of Amino Acids with Aqueous Solutions of Potassium Dihydrogen Phosphate at Different Temperatures. J SOLUTION CHEM 2013. [DOI: 10.1007/s10953-013-9982-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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50
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Liu L, Wang T, Liu C, Lin K, Ding Y, Liu G, Zhang G. Mechanistic Insights into Amplification of Specific Ion Effect in Water–Nonaqueous Solvent Mixtures. J Phys Chem B 2013; 117:2535-44. [DOI: 10.1021/jp311841m] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Lvdan Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Tao Wang
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Chang Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Ke Lin
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Yanwei Ding
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Guangming Liu
- Department of Chemical Physics,
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei,
P. R. China 230026
| | - Guangzhao Zhang
- Faculty
of Materials Science
and Engineering, South China University of Technology, Guangzhou, P. R. China 510640
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