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Jiao X, Li X, Zhang N, Yan B, Huang J, Zhao J, Zhang H, Chen W, Fan D. Solubilization of fish myofibrillar proteins in NaCl and KCl solutions: A DIA-based proteomics analysis. Food Chem 2024; 445:138662. [PMID: 38354641 DOI: 10.1016/j.foodchem.2024.138662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/20/2024] [Accepted: 01/31/2024] [Indexed: 02/16/2024]
Abstract
Understanding the basic solubilization of fish myofibrillar proteins (MPs) in common monovalent chloride solutions is crucial for muscle food processing. In this study, the differential proteomic profiles of MPs during extraction and solubilization in NaCl and KCl solutions were investigated by using advanced four-dimensional data-independent acquisition (4D DIA) quantitative proteomics for the first time. Compared to routine biochemical analysis, this could provide insights into the solubilization of muscle proteins. We ensure the consistency of the effective ionic strength of NaCl and KCl buffers by adjusting the conductivity. The results showed that NaCl extractor mainly facilitated the solubilization of cytoskeletal proteins, biochemical enzymes, and stromal proteins compared to KCl, such as tubulin, myosin-9, collagen, plectin, protein phosphatase, and cathepsin D. However, no significant difference was observed in the extraction of major sarcomeric proteins, including myosin, actin, troponin C, myosin-binding protein C, M-Protein, α-actinin-3, and tropomyosin.
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Affiliation(s)
- Xidong Jiao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Refrigeration and Conditioning Aquatic Products Processing, Ministry of Agriculture and Rural Affairs, Xiamen 361022, China
| | - Xingying Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Nana Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Refrigeration and Conditioning Aquatic Products Processing, Ministry of Agriculture and Rural Affairs, Xiamen 361022, China.
| | - Bowen Yan
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Refrigeration and Conditioning Aquatic Products Processing, Ministry of Agriculture and Rural Affairs, Xiamen 361022, China
| | - Jianlian Huang
- ANJOY FOODS GROUP CO., LTD., Xiamen 361022, China; Key Laboratory of Refrigeration and Conditioning Aquatic Products Processing, Ministry of Agriculture and Rural Affairs, Xiamen 361022, China; Engineering Technology Research Center of Refrigeration and Conditioning Aquatic Food (Liaoning Anjoy Food Co., LTD), China National Light Industry Council, Anshan 114100, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Wei Chen
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Daming Fan
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Refrigeration and Conditioning Aquatic Products Processing, Ministry of Agriculture and Rural Affairs, Xiamen 361022, China; Engineering Technology Research Center of Refrigeration and Conditioning Aquatic Food (Liaoning Anjoy Food Co., LTD), China National Light Industry Council, Anshan 114100, China.
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2
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Gibb CD, Tran TH, Gibb BC. Assessing Weak Anion Binding to Small Peptides. J Phys Chem B 2024; 128:3605-3613. [PMID: 38592238 PMCID: PMC11033870 DOI: 10.1021/acs.jpcb.4c00657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/11/2024] [Accepted: 03/22/2024] [Indexed: 04/10/2024]
Abstract
Since Hofmeister's seminal studies in the late 19th century, it has been known that salts and buffers can drastically affect the properties of peptides and proteins. These Hofmeister effects can be conceived of in terms of three distinct phenomena/mechanisms: water-salt interactions that indirectly induce the salting-out of a protein by water sequestration by the salt, and direct salt-protein interactions that can either salt-in or salt-out the protein. Unfortunately, direct salt-protein interactions responsible for Hofmeister effects are weak and difficult to quantify. As such, they are frequently construed of as being nonspecific. Nevertheless, there has been considerable effort to better specify these interactions. Here, we use pentapeptides to demonstrate the utility of the H-dimension of nuclear magnetic resonance (NMR) spectroscopy to assess anion binding using N-H signal shifts. We qualify binding using these, demonstrating the upfield shifts induced by anion association and revealing how they are much larger than the corresponding downfield shifts induced by magnetic susceptibility and other ionic strength change effects. We also qualify binding in terms of how the pattern of signal shifts changes with point mutations. In general, we find that the observed upfield shifts are small compared with those induced by anion binding to amide-based hosts, and MD simulations suggest that this is so. Thus, charge-diffuse anions associate mostly with the nonpolar regions of the peptide rather than directly interacting with the amide N-H groups. These findings reveal the utility of 1H NMR spectroscopy for qualifying affinity to peptides─even when affinity constants are very low─and serve as a benchmark for using NMR spectroscopy to study anion binding to more complex systems.
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Affiliation(s)
- Corinne
L. D. Gibb
- Department of Chemistry, Tulane University School of Science and Engineering, New Orleans, Louisiana 70118, United States
| | - Thien H. Tran
- Department of Chemistry, Tulane University School of Science and Engineering, New Orleans, Louisiana 70118, United States
| | - Bruce C. Gibb
- Department of Chemistry, Tulane University School of Science and Engineering, New Orleans, Louisiana 70118, United States
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3
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Jeong HG, Kim J, Lee S, Jo K, Yong HI, Choi YS, Jung S. Differences in pork myosin solubility and structure with various chloride salts and their property of pork gel. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2023; 65:1065-1080. [PMID: 37969338 PMCID: PMC10640935 DOI: 10.5187/jast.2023.e7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/22/2022] [Accepted: 01/14/2023] [Indexed: 11/17/2023]
Abstract
The solubility and structure of myosin and the properties of pork gel with NaCl, KCl, CaCl2, and MgCl2 were investigated. Myofibrillar proteins (MPs) with phosphate were more solubilized with NaCl than with KCl (p < 0.05). CaCl2 and MgCl2 showed lower MP solubilities than those of NaCl and KCl (p < 0.05). The α-helix content of myosin was lower in KCl, CaCl2, and MgCl2 than in NaCl (p < 0.05). The pH of pork batter decreased in the order of KCl, NaCl, MgCl2, and CaCl2 (p < 0.05). The cooking yield of the pork gel manufactured with monovalent salts was higher than that of the pork gel manufactured with divalent salts (p < 0.05). The pork gel manufactured with KCl and MgCl2 showed lower hardness than that of the pork gel manufactured with NaCl. The solubility and structure of myosin were different with the different chloride salts and those led the different quality properties of pork gel. Therefore, the results of this study can be helpful for understanding the quality properties of low-slat meat products manufactured by replacing sodium chloride with different chloride salts.
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Affiliation(s)
- Hyun Gyung Jeong
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134, Korea
| | - Jake Kim
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134, Korea
- Research Group of Food Processing, Korea
Food Research Institute, Wanju 55365, Korea
| | - Seonmin Lee
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134, Korea
| | - Kyung Jo
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134, Korea
| | - Hae In Yong
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134, Korea
| | - Yun-Sang Choi
- Research Group of Food Processing, Korea
Food Research Institute, Wanju 55365, Korea
| | - Samooel Jung
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134, Korea
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4
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Ferré G, Gomes AAS, Louet M, Damian M, Bisch PM, Saurel O, Floquet N, Milon A, Banères JL. Sodium is a negative allosteric regulator of the ghrelin receptor. Cell Rep 2023; 42:112320. [PMID: 37027306 DOI: 10.1016/j.celrep.2023.112320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 11/09/2022] [Accepted: 03/14/2023] [Indexed: 04/08/2023] Open
Abstract
The functional properties of G protein-coupled receptors (GPCRs) are intimately associated with the different components in their cellular environment. Among them, sodium ions have been proposed to play a substantial role as endogenous allosteric modulators of GPCR-mediated signaling. However, this sodium effect and the underlying mechanisms are still unclear for most GPCRs. Here, we identified sodium as a negative allosteric modulator of the ghrelin receptor GHSR (growth hormone secretagogue receptor). Combining 23Na-nuclear magnetic resonance (NMR), molecular dynamics, and mutagenesis, we provide evidence that, in GHSR, sodium binds to the allosteric site conserved in class A GPCRs. We further leveraged spectroscopic and functional assays to show that sodium binding shifts the conformational equilibrium toward the GHSR-inactive ensemble, thereby decreasing basal and agonist-induced receptor-catalyzed G protein activation. All together, these data point to sodium as an allosteric modulator of GHSR, making this ion an integral component of the ghrelin signaling machinery.
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Affiliation(s)
- Guillaume Ferré
- Institut de Pharmacologie et de Biologie Structurale IPBS, Université de Toulouse UPS, CNRS, Toulouse, France
| | - Antoniel A S Gomes
- Institut des Biomolécules Max Mousseron IBMM, UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France; Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Maxime Louet
- Institut des Biomolécules Max Mousseron IBMM, UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France
| | - Marjorie Damian
- Institut des Biomolécules Max Mousseron IBMM, UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France
| | - Paulo M Bisch
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Olivier Saurel
- Institut de Pharmacologie et de Biologie Structurale IPBS, Université de Toulouse UPS, CNRS, Toulouse, France
| | - Nicolas Floquet
- Institut des Biomolécules Max Mousseron IBMM, UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France
| | - Alain Milon
- Institut de Pharmacologie et de Biologie Structurale IPBS, Université de Toulouse UPS, CNRS, Toulouse, France.
| | - Jean-Louis Banères
- Institut des Biomolécules Max Mousseron IBMM, UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France.
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5
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El Harrar T, Gohlke H. Cumulative Millisecond-Long Sampling for a Comprehensive Energetic Evaluation of Aqueous Ionic Liquid Effects on Amino Acid Interactions. J Chem Inf Model 2023; 63:281-298. [PMID: 36520535 DOI: 10.1021/acs.jcim.2c01123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The interactions of amino acid side-chains confer diverse energetic contributions and physical properties to a protein's stability and function. Various computational tools estimate the effect of changing a given amino acid on the protein's stability based on parametrized (free) energy functions. When parametrized for the prediction of protein stability in water, such energy functions can lead to suboptimal results for other solvents, such as ionic liquids (IL), aqueous ionic liquids (aIL), or salt solutions. However, to our knowledge, no comprehensive data are available describing the energetic effects of aIL on intramolecular protein interactions. Here, we present the most comprehensive set of potential of mean force (PMF) profiles of pairwise protein-residue interactions to date, covering 50 relevant interactions in water, the two biotechnologically relevant aIL [BMIM/Cl] and [BMIM/TfO], and [Na/Cl]. These results are based on a cumulated simulation time of >1 ms. aIL and salt ions can weaken, but also strengthen, specific residue interactions by more than 3 kcal mol-1, depending on the residue pair, residue-residue configuration, participating ions, and concentration, necessitating considering such interactions specifically. These changes originate from a complex interplay of competitive or cooperative noncovalent ion-residue interactions, changes in solvent structural dynamics, or unspecific charge screening effects and occur at the contact distance but also at larger, solvent-separated distances. This data provide explanations at the atomistic and energetic levels for complex IL effects on protein stability and should help improve the prediction accuracies of computational tools that estimate protein stability based on (free) energy functions.
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Affiliation(s)
- Till El Harrar
- Institute of Biotechnology, RWTH Aachen University, 52074 Aachen, Germany.,John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Biochemistry), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
| | - Holger Gohlke
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Biochemistry), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany.,Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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6
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Melo L, Torres F, Guimarães J, Cortez M. Development of processed low-sodium Maasdam cheese. ARQ BRAS MED VET ZOO 2022. [DOI: 10.1590/1678-4162-12569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
ABSTRACT The article assesses the effect of different potassium emulsifying salts concentrations on physicochemical, colorimetric, and texture characteristics of processed cheese manufactured using Maasdam. Except for pH, physicochemical parameters remained unchanged, but the gradual substitution of sodium emulsifying salts with potassium-based salts influenced color and texture. Treatments with at least 50% potassium salts showed a reduction of at least 30% of sodium. The sodium decrease allows the product's classification as processed cheese with low-sodium content (<140mg per 56.7g serving). The data obtained present substantial information that can help the dairy industries develop newly reduced-sodium products.
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7
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Shilov IY, Lyashchenko AK. Analyzing Values of the Coefficients of Activity in Solutions of Formates of Alkali Metals, Based on Their Dielectric Properties. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422100296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Mitrinova Z, Alexandrov H, Denkov N, Tcholakova S. Effect of counter-ion on rheological properties of mixed surfactant solutions. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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9
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Sec-Dependent Secretion of Subtilase SptE in Haloarchaea Facilitates Its Proper Folding and Heterocatalytic Processing by Halolysin SptA Extracellularly. Appl Environ Microbiol 2022; 88:e0024622. [PMID: 35348390 DOI: 10.1128/aem.00246-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In response to high-salt conditions, haloarchaea export most secretory proteins through the Tat pathway in folded states; however, it is unclear why some haloarchaeal proteins are still routed to the Sec pathway. SptE is an extracellular subtilase of Natrinema sp. strain J7-2. Here, we found that SptE precursor comprises a Sec signal peptide, an N-terminal propeptide, a catalytic domain, and a long C-terminal extension (CTE) containing seven domains (C1 to C7). SptE is produced extracellularly as a mature form (M180) in strain J7-2 and a proform (ΔS) in the ΔsptA mutant strain, indicating that halolysin SptA mediates the conversion of the secreted proform into M180. The proper folding of ΔS is more efficient in the presence of NaCl than KCl. ΔS requires SptA for cleavage of the N-terminal propeptide and C-terminal C6 and C7 domains to generate M180, accompanied by the appearance of autoprocessing product M120 lacking C5. At lower salinities or elevated temperatures, M180 and M120 could be autoprocessed into M90, which comprises the catalytic and C1 domains and has a higher activity than M180. When produced in Haloferax volcanii, SptE could be secreted as a properly folded proform, but its variant (TSptE) with a Tat signal peptide does not fold properly and suffers from severe proteolysis extracellularly; meanwhile, TSptE is more inclined to aggregate intracellularly than SptE. Systematic domain deletion analysis reveals that the long CTE is an important determinant for secretion of SptE via the Sec rather than Tat pathway to prevent enzyme aggregation before secretion. IMPORTANCE While Tat-dependent haloarchaeal subtilases (halolysins) have been extensively studied, the information about Sec-dependent subtilases of haloarchaea is limited. Our results demonstrate that proper maturation of Sec-dependent subtilase SptE of Natrinema sp. strain J7-2 depends on the action of halolysin SptA from the same strain, yielding multiple hetero- and autocatalytic mature forms. Moreover, we found that the different extra- and intracellular salt types (NaCl versus KCl) of haloarchaea and the long CTE are extrinsic and intrinsic factors crucial for routing SptE to the Sec rather than Tat pathway. This study provides new clues about the secretion and adaptation mechanisms of Sec substrates in haloarchaea.
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Hervø-Hansen S, Heyda J, Lund M, Matubayasi N. Anion-cation contrast of small molecule solvation in salt solutions. Phys Chem Chem Phys 2022; 24:3238-3249. [PMID: 35044392 PMCID: PMC8809138 DOI: 10.1039/d1cp04129k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/24/2021] [Indexed: 11/21/2022]
Abstract
The contributions from anions and cations from salt are inseparable in their perturbation of molecular systems by experimental and computational methods, rendering it difficult to dissect the effects exerted by the anions and cations individually. Here we investigate the solvation of a small molecule, caffeine, and its perturbation by monovalent salts from various parts of the Hofmeister series. Using molecular dynamics and the energy-representation theory of solvation, we estimate the solvation free energy of caffeine and decompose it into the contributions from anions, cations, and water. We also decompose the contributions arising from the solute-solvent and solute-ions interactions and that from excluded volume, enabling us to pin-point the mechanism of salt. Anions and cations revealed high contrast in their perturbation of caffeine solvation, with the cations salting-in caffeine via binding to the polar ketone groups, while the anions were found to be salting-out via perturbations of water. In agreement with previous findings, the perturbation by salt is mostly anion dependent, with the magnitude of the excluded-volume effect found to be the governing mechanism. The free-energy decomposition as conducted in the present work can be useful to understand ion-specific effects and the associated Hofmeister series.
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Affiliation(s)
- Stefan Hervø-Hansen
- Division of Theoretical Chemistry, Department of Chemistry, Lund University, Lund SE 221 00, Sweden.
| | - Jan Heyda
- Department of Physical Chemistry, University of Chemistry and Technology, Prague CZ-16628, Czech Republic.
| | - Mikael Lund
- Division of Theoretical Chemistry, Department of Chemistry, Lund University, Lund SE 221 00, Sweden.
- Lund Institute for Advanced Neutron and X-ray Science (LINXS), Lund University, Lund, Sweden
| | - Nobuyuki Matubayasi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
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11
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Kav B, Strodel B. Does the inclusion of electronic polarisability lead to a better modelling of peptide aggregation? RSC Adv 2022; 12:20829-20837. [PMID: 35919139 PMCID: PMC9301629 DOI: 10.1039/d2ra01478e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 07/11/2022] [Indexed: 11/26/2022] Open
Abstract
Simulating the process of amyloid aggregation with atomic detail is a challenging task for various reasons. One of them is that it is difficult to parametrise a force field such that all protein states ranging from the folded through the unfolded to the aggregated state are represented with the same level of accuracy. Here, we test whether the consideration of electronic polarisability improves the description of the different states of Aβ16–22. Surprisingly, the CHARMM Drude polarisable force field is found to perform worse than its unpolarisable counterpart CHARMM36m. Sources for this failure of the Drude model are discussed. Simulating the process of amyloid aggregation is a hard task. We test whether the inclusion of electronic polarisability as done in CHARMM-Drude improves the modelling of Aβ16–22 aggregation and find it does not. Reasons for the failure are given.![]()
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Affiliation(s)
- Batuhan Kav
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Birgit Strodel
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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12
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Oberleithner H. Quantifying salt sensitivity. Biol Chem 2021; 402:1597-1602. [PMID: 34505462 DOI: 10.1515/hsz-2021-0206] [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: 03/28/2021] [Accepted: 07/03/2021] [Indexed: 11/15/2022]
Abstract
Inner surfaces of blood vessels and outer surfaces of erythrocytes are coated with a negatively charged protective film of proteoglycans, which serves as an effective buffer system for the positively charged sodium ions. If this protective coating is poorly developed or impaired, it loses its buffering capacity. As a consequence, the organism becomes increasingly sensitive to sodium, which in the long run leads to organ damage, especially if daily salt consumption is high. Recently, it has become possible to quantify salt sensitivity using a technically simple method - the salt blood test (SBT). Aim of this mini-review is to explain the physiological concept underlying the SBT and its potential practical relevance in the prevention of cardiovascular disease.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II, Medical Faculty, University of Münster, 48149 Münster, Germany
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14
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Tee HS, Waite D, Lear G, Handley KM. Microbial river-to-sea continuum: gradients in benthic and planktonic diversity, osmoregulation and nutrient cycling. MICROBIOME 2021; 9:190. [PMID: 34544488 PMCID: PMC8454136 DOI: 10.1186/s40168-021-01145-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/02/2021] [Indexed: 05/08/2023]
Abstract
BACKGROUND Coastal aquatic ecosystems include chemically distinct, but highly interconnected environments. Across a freshwater-to-marine transect, aquatic communities are exposed to large variations in salinity and nutrient availability as tidal cycles create periodic fluctuations in local conditions. These factors are predicted to strongly influence the resident microbial community structure and functioning, and alter the structure of aquatic food webs and biogeochemical cycles. Nevertheless, little is known about the spatial distribution of metabolic properties across salinity gradients, and no study has simultaneously surveyed the sediment and water environments. Here, we determined patterns and drivers of benthic and planktonic prokaryotic and microeukaryotic community assembly across a river and tidal lagoon system by collecting sediments and planktonic biomass at nine shallow subtidal sites in the summer. Genomic and transcriptomic analyses, alongside a suite of complementary geochemical data, were used to determine patterns in the distribution of taxa, mechanisms of salt tolerance, and nutrient cycling. RESULTS Taxonomic and metabolic profiles related to salt tolerance and nutrient cycling of the aquatic microbiome were found to decrease in similarity with increasing salinity, and distinct trends in diversity were observed between the water column and sediment. Non-saline and saline communities adopted divergent strategies for osmoregulation, with an increase in osmoregulation-related transcript expression as salinity increased in the water column due to lineage-specific adaptations to salt tolerance. Results indicated a transition from phosphate limitation in freshwater habitats to nutrient-rich conditions in the brackish zone, where distinct carbon, nitrogen and sulfur cycling processes dominated. Phosphorus acquisition-related activity was highest in the freshwater zone, along with dissimilatory nitrate reduction to ammonium in freshwater sediment. Activity associated with denitrification, sulfur metabolism and photosynthesis were instead highest in the brackish zone, where photosynthesis was dominated by distinct microeukaryotes in water (Cryptophyta) and sediment (diatoms). Despite microeukaryotes and archaea being rare relative to bacteria, results indicate that they contributed more to photosynthesis and ammonia oxidation, respectively. CONCLUSIONS Our study demonstrates clear freshwater-saline and sediment-water ecosystem boundaries in an interconnected coastal aquatic system and provides a framework for understanding the relative importance of salinity, planktonic-versus-benthic habitats and nutrient availability in shaping aquatic microbial metabolic processes, particularly in tidal lagoon systems. Video abstract.
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Affiliation(s)
- Hwee Sze Tee
- School of Biological Sciences, University of Auckland, Auckland, 1010 New Zealand
| | - David Waite
- School of Biological Sciences, University of Auckland, Auckland, 1010 New Zealand
- Current address: Ministry for Primary Industries, Auckland, New Zealand
| | - Gavin Lear
- School of Biological Sciences, University of Auckland, Auckland, 1010 New Zealand
| | - Kim Marie Handley
- School of Biological Sciences, University of Auckland, Auckland, 1010 New Zealand
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15
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Wong XY, Quesada-González D, Manickam S, Muthoosamy K. Fluorescence "turn-off/turn-on" biosensing of metal ions by gold nanoclusters, folic acid and reduced graphene oxide. Anal Chim Acta 2021; 1175:338745. [PMID: 34330444 DOI: 10.1016/j.aca.2021.338745] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/30/2021] [Accepted: 06/05/2021] [Indexed: 10/21/2022]
Abstract
Metal ions homeostasis plays an important role in biological processes. The ability to detect the concentration of metal ions in biological fluids is often challenged by the obvious interference or competitive binding nature of other alkaline metals ions. Common analytical techniques employed for metal ions detection are electrochemical, fluorescence and colorimetric methods. However, most reported metal ions sensors are complicated, time-consuming and involve costly procedures with limited effectiveness. Herein, a nanobiosensor for detecting sodium and potassium ions using folic acid-functionalised reduced graphene oxide-modified RNase A gold nanoclusters (FA-rGO-RNase A/AuNCs) based on fluorescence "turn-off/turn-on" is presented. Firstly, a facile and optimised protocol for the fabrication of RNase A/AuNCs is developed. The activity of RNase A protein after the formation of RNase A/AuNCs is studied. RNase A/AuNCs is then loaded onto FA-rGO, in which FA-rGO is used as a potential carrier and fluorescence quencher for RNase A/AuNCs. Finally, a fluorescence "turn-on" sensing strategy is developed using the as-synthesised FA-rGO-RNase A/AuNCs to detect sodium and potassium ions. The developed nanobiosensor revealed an excellent sensing performance and meets the sensitivity required to detect both sodium and potassium ions. To the best of our knowledge, this is the first work done on determining the RNase A protein activity in RNase A/AuNCs and exploring the potential application of RNase A/AuNCs as a metal ion sensor. This work serves as a proof-of-concept for combining the potential of drug delivery, active targeting and therapy on cancer cells, as well as biosensing of metal ions into a single platform.
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Affiliation(s)
- Xin Yi Wong
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia
| | - Daniel Quesada-González
- Paperdrop Diagnostics, Av. de Can Domènech S/n, Eureka Building, Campus UAB, 08193, Bellaterra, Barcelona, Spain
| | - Sivakumar Manickam
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia; Nanotechnology Research Group, Centre of Nanotechnology and Advanced Materials, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia; Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan, BE1410, Brunei Darussalam
| | - Kasturi Muthoosamy
- Nanotechnology Research Group, Centre of Nanotechnology and Advanced Materials, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia.
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Proteins maintain hydration at high [KCl] concentration regardless of content in acidic amino acids. Biophys J 2021; 120:2746-2762. [PMID: 34087206 PMCID: PMC8390907 DOI: 10.1016/j.bpj.2021.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/22/2021] [Accepted: 05/19/2021] [Indexed: 11/23/2022] Open
Abstract
Proteins of halophilic organisms, which accumulate molar concentrations of KCl in their cytoplasm, have a much higher content in acidic amino acids than proteins of mesophilic organisms. It has been proposed that this excess is necessary to maintain proteins hydrated in an environment with low water activity, either via direct interactions between water and the carboxylate groups of acidic amino acids or via cooperative interactions between acidic amino acids and hydrated cations. Our simulation study of five halophilic proteins and five mesophilic counterparts does not support either possibility. The simulations use the AMBER ff14SB force field with newly optimized Lennard-Jones parameters for the interactions between carboxylate groups and potassium ions. We find that proteins with a larger fraction of acidic amino acids indeed have higher hydration levels, as measured by the concentration of water in their hydration shell and the number of water/protein hydrogen bonds. However, the hydration level of each protein is identical at low (bKCl = 0.15 mol/kg) and high (bKCl = 2 mol/kg) KCl concentrations; excess acidic amino acids are clearly not necessary to maintain proteins hydrated at high salt concentration. It has also been proposed that cooperative interactions between acidic amino acids in halophilic proteins and hydrated cations stabilize the folded protein structure and would lead to slower dynamics of the solvation shell. We find that the translational dynamics of the solvation shell is barely distinguishable between halophilic and mesophilic proteins; if such a cooperative effect exists, it does not have that entropic signature.
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17
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Ashraf H, Guo Y, Wang N, Pang S, Zhang YH. Hygroscopicity of Hofmeister Salts and Glycine Aerosols-Salt Specific Interactions. J Phys Chem A 2021; 125:1589-1597. [PMID: 33576639 DOI: 10.1021/acs.jpca.0c10710] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Hofmeister effect of inorganic ions to precipitate proteins has been used to understand the coagulation phenomenon in colloid and protein science. Herein, for the first time, this effect is studied on the hygroscopicity of aerosols using ATR-FTIR spectroscopy. The representative Hofmeister salts (MgSO4, KCl, NH4NO3) and amino acid (glycine) with different amino acid/salt molar ratios (ASRs) are mixed and atomized into micrometer-sized particles. For mixed kosmotrope (MgSO4)/glycine and chaotrope (NH4NO3)/glycine with an ASR of 1:1, both ERHs (efflorescence relative humidities) and DRHs (deliquescence relative humidities) are absent. However, for the mixtures of glycine and neutral salt (KCl), no DRH is observed while 66.2 and 61.4% ERH of glycine is detected for mixtures with ASRs of 1:1 and 1:3, respectively, which is similar to pure glycine. For the mixture of NH4NO3/glycine with an ASR of 1:3, ERH and DRH are found to be 15.4 and 32.2% RH, less than that of pure NH4NO3. Further, interactions between glycine-salt and/or water is also studied in the mixtures during hydration and dehydration. Water-mediated ion-glycine interaction is detected based on the two glycine bands merging into one band. Glycine-SO42- interaction is present for glycine/sulfate in all ASRs, while glycine-NO3- interaction is only seen for 1:3 glycine/NH4NO3 mixtures during hydration. This work opens a window to understand the Hofmeister effect on the hygroscopicity of atmospheric aerosols.
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Affiliation(s)
- Hamad Ashraf
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P R China
| | - Yaxin Guo
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P R China
| | - Na Wang
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P R China
| | - Shufeng Pang
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P R China
| | - Yun-Hong Zhang
- The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P R China
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18
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Bruce EE, Bui PT, Cao M, Cremer PS, van der Vegt NFA. Contact Ion Pairs in the Bulk Affect Anion Interactions with Poly( N-isopropylacrylamide). J Phys Chem B 2021; 125:680-688. [PMID: 33406822 DOI: 10.1021/acs.jpcb.0c11076] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Salt effects on the solubility of uncharged polymers in aqueous solutions are usually dominated by anions, while the role of the cation with which they are paired is often ignored. In this study, we examine the influence of three aqueous metal iodide salt solutions (LiI, NaI, and CsI) on the phase transition temperature of poly(N-isopropylacrylamide) (PNIPAM) by measuring the turbidity change of the solutions. Weakly hydrated anions, such as iodide, are known to interact with the polymer and thereby lead to salting-in behavior at low salt concentration followed by salting-out behavior at higher salt concentration. When varying the cation type, an unexpected salting-out trend is observed at higher salt concentrations, Cs+ > Na+ > Li+. Using molecular dynamics simulations, it is demonstrated that this originates from contact ion pair formation in the bulk solution, which introduces a competition for iodide ions between the polymer and cations. The weakly hydrated cation, Cs+, forms contact ion pairs with I- in the bulk solution, leading to depletion of CsI from the polymer-water interface. Microscopically, this is correlated with the repulsion of iodide ions from the amide moiety.
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Affiliation(s)
- Ellen E Bruce
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Pho T Bui
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mengrui Cao
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Paul S Cremer
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Nico F A van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
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19
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Ota C, Fukuda Y, Tanaka SI, Takano K. Spectroscopic Evidence of the Salt-Induced Conformational Change around the Localized Electric Charges on the Protein Surface of Fibronectin Type III. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:14243-14254. [PMID: 33197316 DOI: 10.1021/acs.langmuir.0c02367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effect of salt on the electrostatic interaction of a protein is an important issue, because addition of salt affects protein stability and association/aggregation. Although adding salt is a generally recognized strategy to improve protein stability, this improvement does not necessarily occur. The lack of an effect upon the addition of salt was previously confirmed for the tenth fibronectin type III domain from human fibronectin (FN3) by thermal stability analysis. However, the detailed molecular mechanism is unknown. In the present study, by employing the negatively charged carboxyl triad on the surface of FN3 as a case study, the molecular mechanism of the inefficient NaCl effect on protein stability was experimentally addressed using spectroscopic methods. Complementary analysis using Raman spectroscopy and 8-anilino-1-naphthalenesulfonic acid fluorescence revealed the three-phase behavior of the salt-protein interaction between NaCl and FN3 over a wide salt concentration range from 100 mM to 4.0 M, suggesting that the Na+-specific binding to the negatively charged carboxyl triad causes a local conformational change around the binding site with an accompanying structural change in the overall protein, which contributes to the protein's structural destabilization. This spectroscopic evidence clarifies the molecular understanding of the inefficiency of salt to improve protein stability. The findings will inform the optimization of formulation conditions.
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Affiliation(s)
- Chikashi Ota
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Yui Fukuda
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
| | - Shun-Ichi Tanaka
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
| | - Kazufumi Takano
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
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20
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Zhao J, Wang J. Specific and non-specific interactions between metal cations and zwitterionic alanine tripeptide in saline solutions reported by the symmetric carboxylate stretching and amide-II vibrations. Phys Chem Chem Phys 2020; 22:25042-25053. [PMID: 33112337 DOI: 10.1039/d0cp04247a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The "specific" interaction between metal cations (Na+, Ca2+, Mg2+, and Zn2+) and the charged COO- group, and the "non-specific" interaction between these cations and the peptide backbone of a zwitterionic trialanine (Ala3) in aqueous solutions were examined in detail, using linear infrared (IR) absorptions of the COO- symmetric stretching and the amide-II (mainly the C-N stretching) modes as IR probes. Different IR spectral changes in peak positions and intensities of the two IR probes clearly demonstrate their sensitivities to nearby cation distributions in distance and population. Quantum chemistry calculations and molecular dynamics simulations were used to describe the cation-peptide interaction picture. These combined results suggest that Na+ and Ca2+ tend to bind to the COO- group in the bidentate form, while Mg2+ and Zn2+ tend to bind to the COO- group in the pseudo-bridging form. The results also show that while all three divalent cations indirectly interact with the peptide backbone with large population, Ca2+ and Mg2+ can be sometimes distributed very close to the backbone. Such a non-specific cation interaction can be moderately sensed by the C-N stretching of the amide-II mode when cations approach the polar amide C[double bond, length as m-dash]O group, and is also influenced by the NH3+ charge group located at the N-terminus. The results suggest that the experimentally observed complication of the Hofmeister cation series shall be understood as a combined specific and non-specific cation-peptide interactions.
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Affiliation(s)
- Juan Zhao
- Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
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21
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Bruce EE, Okur HI, Stegmaier S, Drexler CI, Rogers BA, van der Vegt NFA, Roke S, Cremer PS. Molecular Mechanism for the Interactions of Hofmeister Cations with Macromolecules in Aqueous Solution. J Am Chem Soc 2020; 142:19094-19100. [PMID: 33124825 DOI: 10.1021/jacs.0c07214] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ion identity and concentration influence the solubility of macromolecules. To date, substantial effort has been focused on obtaining a molecular level understanding of specific effects for anions. By contrast, the role of cations has received significantly less attention and the underlying mechanisms by which cations interact with macromolecules remain more elusive. To address this issue, the solubility of poly(N-isopropylacrylamide), a thermoresponsive polymer with an amide moiety on its side chain, was studied in aqueous solutions with a series of nine different cation chloride salts as a function of salt concentration. Phase transition temperature measurements were correlated to molecular dynamics simulations. The results showed that although all cations were on average depleted from the macromolecule/water interface, more strongly hydrated cations were able to locally accumulate around the amide oxygen. These weakly favorable interactions helped to partially offset the salting-out effect. Moreover, the cations approached the interface together with chloride counterions in solvent-shared ion pairs. Because ion pairing was concentration-dependent, the mitigation of the dominant salting-out effect became greater as the salt concentration was increased. Weakly hydrated cations showed less propensity for ion pairing and weaker affinity for the amide oxygen. As such, there was substantially less mitigation of the net salting-out effect for these ions, even at high salt concentrations.
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Affiliation(s)
- Ellen E Bruce
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Halil I Okur
- Department of Chemistry, and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey.,Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sina Stegmaier
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | | | | | - Nico F A van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt, Germany
| | - Sylvie Roke
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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22
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Gschwend GC, Girault HH. Discrete Helmholtz model: a single layer of correlated counter-ions. Metal oxides and silica interfaces, ion-exchange and biological membranes. Chem Sci 2020; 11:10304-10312. [PMID: 34094294 PMCID: PMC8162434 DOI: 10.1039/d0sc03748f] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/09/2020] [Indexed: 01/31/2023] Open
Abstract
The mechanism by which interfaces in solution can be polarised depends on the nature of the charge carriers. In the case of a conductor, the charge carriers are electrons and the polarisation is homogeneous in the plane of the electrode. In the case of an insulator covered by ionic moieties, the polarisation is inhomogeneous and discrete in the plane of the interface. Despite these fundamental differences, these systems are usually treated in the same theoretical framework that relies on the Poisson-Boltzmann equation for the solution side. In this perspective, we show that interfaces polarised by discrete charge distributions are rather ubiquitous and that their associated potential drop significantly differs from those of conductor-electrolyte interfaces. We show that these configurations, spanning liquid-liquid interfaces, charged silica-water interfaces, metal oxide interfaces, supercapacitors, ion-exchange membranes and even biological membranes can be uniformly treated under a common "Discrete Helmholtz" model where the discrete charges are compensated by a single layer of correlated counter-ions, thereby generating a sharp potential drop at the interface.
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Affiliation(s)
- Grégoire C Gschwend
- Laboratoire d'Electrochimie Physique et Analytique (LEPA), École Polytechnique Fédérale de Lausanne (EPFL) Rue de l'Industrie 17 CH-1951 Sion Switzerland
| | - Hubert H Girault
- Laboratoire d'Electrochimie Physique et Analytique (LEPA), École Polytechnique Fédérale de Lausanne (EPFL) Rue de l'Industrie 17 CH-1951 Sion Switzerland
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23
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Wang G, Zhou Y, Lin H, Jing Z, Liu H, Zhu F. Structure of aqueous sodium acetate solutions by X-Ray scattering and density functional theory. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2020-0402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The structure of aq. sodium acetate solution (CH3COONa, NaOAc) was studied by X-ray scattering and density function theory (DFT). For the first hydrated layer of Na+, coordination number (CN) between Na+ and O(W, I) decreases from 5.02 ± 0.85 at 0.976 mol/L to 3.62 ± 1.21 at 4.453 mol/L. The hydration of carbonyl oxygen (OC) and hydroxyl oxygen (OOC) of CH3COO− were investigated separately and the OC shows a stronger hydration bonds comparing with OOC. With concentrations increasing, the hydration shell structures of CH3COO− are not affected by the presence of large number of ions, each CH3COO− group binds about 6.23 ± 2.01 to 7.35 ± 1.73 water molecules, which indicates a relatively strong interaction between CH3COO− and water molecules. The larger uncertainty of the CN of Na+ and OC(OOC) reflects the relative looseness of Na-OC and Na-OOC ion pairs in aq. NaOAc solutions, even at the highest concentration (4.453 mol/L), suggesting the lack of contact ion pair (CIP) formation. In aq. NaOAc solutions, the so called “structure breaking” property of Na+ and CH3COO− become effective only for the second hydration sphere of bulk water. The DFT calculations of CH3COONa (H2O)n=5–7 clusters suggest that the solvent-shared ion pair (SIP) structures appear at n = 6 and become dominant at n = 7, which is well consistent with the result from X-ray scattering.
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Affiliation(s)
- Guangguo Wang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources , Chinese Academy of Sciences , Qinghai, 810008 , China
- Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province , Xining, 810008 , China
- University of Chinese Academy of Sciences , Beijing, 100049 , China
| | - Yongquan Zhou
- Qinghai Institute of Salt Lakes , Chinese Academy of Sciences , Qinghai, 810008 , China
| | - He Lin
- Shanghai Institute of Applied Physics , Chinese Academy of Sciences , Shanghai, 201204 , China
| | - Zhuanfang Jing
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources , Chinese Academy of Sciences , Qinghai, 810008 , China
- Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province , Xining, 810008 , China
- University of Chinese Academy of Sciences , Beijing, 100049 , China
| | - Hongyan Liu
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources , Chinese Academy of Sciences , Qinghai, 810008 , China
- Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province , Xining, 810008 , China
- University of Chinese Academy of Sciences , Beijing, 100049 , China
| | - Fayan Zhu
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources , Chinese Academy of Sciences , Qinghai, 810008 , China
- Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province , Xining, 810008 , China
- University of Chinese Academy of Sciences , Beijing, 100049 , China
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Abstract
AbstractThe strong, long-range electrostatic forces described by Coulomb's law disappear for ions in water, and the behavior of these ions is instead controlled by their water affinity – a weak, short-range force which arises from their charge density. This was established experimentally in the mid-1980s by size-exclusion chromatography on carefully calibrated Sephadex®G-10 (which measures the effective volume and thus the water affinity of an ion) and by neutron diffraction with isotopic substitution (which measures the density and orientation of water molecules near the diffracting ion and thus its water affinity). These conclusions have been confirmed more recently by molecular dynamics simulations, which explicitly model each individual water molecule. This surprising change in force regime occurs because the oppositely charged ions in aqueous salt solutions exist functionally as ion pairs (separated by 0, 1 or 2 water molecules) as has now been shown by dielectric relaxation spectroscopy; this cancels out the strong long-range electrostatic forces and allows the weak, short-range water affinity effects to come to the fore. This microscopic structure of aqueous salt solutions is not captured by models utilizing a macroscopic dielectric constant. Additionally, the Law of Matching Water Affinity, first described in 1997 and 2004, establishes that contact ion pair formation is controlled by water affinity and is a major determinant of the solubility of charged species since only a net neutral species can change phases.
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25
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Westerfield J, Gupta C, Scott HL, Ye Y, Cameron A, Mertz B, Barrera FN. Ions Modulate Key Interactions between pHLIP and Lipid Membranes. Biophys J 2019; 117:920-929. [PMID: 31422821 DOI: 10.1016/j.bpj.2019.07.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 07/05/2019] [Accepted: 07/22/2019] [Indexed: 02/04/2023] Open
Abstract
The pH-low insertion peptide (pHLIP) is used for targeted delivery of drug cargoes to acidic tissues such as tumors. The extracellular acidosis found in solid tumors triggers pHLIP to transition from a membrane-adsorbed state to fold into a transmembrane α-helix. Different factors influence the acidity required for pHLIP to insert into lipid membranes. One of them is the lipid headgroup composition, which defines the electrostatic profile of the membrane. However, the molecular interactions that drive the adsorption of pHLIP to the bilayer surface are poorly understood. In this study, we combine biophysical experiments and all-atom molecular dynamics simulations to understand the role played by electrostatics in the interaction between pHLIP and a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer. We observed that the solution ionic strength affects the structure of pHLIP at the membrane surface as well as the acidity needed for different steps in the membrane insertion process. In particular, our simulations revealed that an increase in ionic strength affected both pHLIP and the bilayer; the coordination of sodium ions with the C-terminus of pHLIP led to localized changes in helicity, whereas the coordination of sodium ions with the phosphate moiety of the phosphocholine headgroups had a condensing effect on our model bilayer. These results are relevant to our understanding of environmental influences on the ability of pHLIP to adsorb to the cell membrane and are useful in our fundamental understanding of the absorption of pH-responsive peptides and cell-penetrating peptides.
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Affiliation(s)
- Justin Westerfield
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Chitrak Gupta
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia
| | - Haden L Scott
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Yujie Ye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Alayna Cameron
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Blake Mertz
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia; WVU Cancer Institute, West Virginia University, Morgantown, West Virginia.
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee.
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26
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Gregory KP, Webber GB, Wanless EJ, Page AJ. Lewis Strength Determines Specific-Ion Effects in Aqueous and Nonaqueous Solvents. J Phys Chem A 2019; 123:6420-6429. [DOI: 10.1021/acs.jpca.9b04004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kasimir P. Gregory
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Grant B. Webber
- School of Engineering, The University of Newcastle, Callaghan, New South Wales 2308, Australia
- Priority Research Centre for Advanced Particle Processing and Transport, The University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Erica J. Wanless
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia
- Priority Research Centre for Advanced Particle Processing and Transport, The University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Alister J. Page
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia
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27
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Sun CQ, Huang Y, Zhang X. Hydration of Hofmeister ions. Adv Colloid Interface Sci 2019; 268:1-24. [PMID: 30921543 DOI: 10.1016/j.cis.2019.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 01/08/2023]
Abstract
Water dissolves salt into ions and then hydrates the ions to form an aqueous solution. Hydration of ions deforms the hydrogen bonding network and triggers the solution with what the pure water never shows such as conductivity, molecular diffusivity, thermal stability, surface stress, solubility, and viscosity, having enormous impact to many branches in biochemistry, chemistry, physics, and energy and environmental industry sectors. However, regulations for the solute-solute-solvent interactions are still open for exploration. From the perspective of the screened ionic polarization and O:H-O bond relaxation, this treatise features the recent progress and a perspective in understanding the hydration dynamics of Hofmeister ions in the typical YI, NaX, ZX2, and NaT salt solutions (Y = Li, Na, K, Rb, Cs; X = F, Cl, Br, I; Z = Mg, Ca, Ba, Sr; T = ClO4, NO3, HSO4, SCN). Phonon spectrometric analysis turned out the f(C) number fraction of bonds transition from the mode of deionized water to the hydrating. The linear f(C) ∝ C form features the invariant hydration volume of small cations that are fully-screened by their hydration H2O dipoles. The nonlinear f(C) ∝ 1 - exp.(-C/C0) form describes that the number insufficiency of the ordered hydrating H2O dipoles partially screens the anions. Molecular anions show stronger yet shorter electric field of dipoles. The screened ionic polarization, inter-solute interaction, and O:H-O bond transition unify the solution conductivity, surface stress, viscosity, and critical energies for phase transition.
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Indrakumar S, Zalar M, Pohl C, Nørgaard A, Streicher W, Harris P, Golovanov AP, Peters GH. Conformational Stability Study of a Therapeutic Peptide Plectasin Using Molecular Dynamics Simulations in Combination with NMR. J Phys Chem B 2019; 123:4867-4877. [DOI: 10.1021/acs.jpcb.9b02370] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Sowmya Indrakumar
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Matja Zalar
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, Manchester M1 7DN, U.K
| | - Christin Pohl
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Novozymes, Krogshoejvej 36, Bagsvaerd 2880, Denmark
| | | | | | - Pernille Harris
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Alexander P. Golovanov
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, Manchester M1 7DN, U.K
| | - Günther H.J. Peters
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
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29
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Fels J, Kusche-Vihrog K. Endothelial Nanomechanics in the Context of Endothelial (Dys)function and Inflammation. Antioxid Redox Signal 2019; 30:945-959. [PMID: 29433330 PMCID: PMC6354603 DOI: 10.1089/ars.2017.7327] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 08/31/2017] [Indexed: 12/31/2022]
Abstract
SIGNIFICANCE Stiffness of endothelial cells is closely linked to the function of the vasculature as it regulates the release of vasoactive substances such as nitric oxide (NO) and reactive oxygen species. The outer layer of endothelial cells, consisting of the glycocalyx above and the cortical zone beneath the plasma membrane, is a vulnerable compartment able to adapt its nanomechanical properties to any changes of forces exerted by the adjacent blood stream. Sustained stiffening of this layer contributes to the development of endothelial dysfunction and vascular pathologies. Recent Advances: The development of specific techniques to quantify the mechanical properties of cells enables the detailed investigation of the mechanistic link between structure and function of cells. CRITICAL ISSUES Challenging the mechanical stiffness of cells, for instance, by inflammatory mediators can lead to the development of endothelial dysfunction. Prevention of sustained stiffening of the outer layer of endothelial cells in turn improves endothelial function. FUTURE DIRECTIONS The mechanical properties of cells can be used as critical marker and test system for the proper function of the vascular system. Pharmacological substances, which are able to improve endothelial nanomechanics and function, could take a new importance in the prevention and treatment of vascular diseases. Thus, detailed knowledge acquisition about the structure/function relationship of endothelial cells and the underlying signaling pathways should be promoted.
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Affiliation(s)
- Johannes Fels
- Institute of Cell Dynamics and Imaging, University of Münster, Münster, Germany
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30
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Friedman R. Simulations of Biomolecules in Electrolyte Solutions. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201800163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ran Friedman
- Department of Chemistry and Biomedical SciencesLinnæus UniversityKalmar SE‐391 82 Sweden
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31
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Sun CQ. Aqueous charge injection: solvation bonding dynamics, molecular nonbond interactions, and extraordinary solute capabilities. INT REV PHYS CHEM 2018. [DOI: 10.1080/0144235x.2018.1544446] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Chang Q. Sun
- EBEAM, Yangtze Normal University, Chongqing, People's Republic of China
- NOVITAS, EEE, Nanyang Technological University, Singapore, Singapore
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32
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Mukherjee K, Schwaab G, Havenith M. Cation-specific interactions of protein surface charges in dilute aqueous salt solutions: a combined study using dielectric relaxation spectroscopy and Raman spectroscopy. Phys Chem Chem Phys 2018; 20:29306-29313. [PMID: 30444249 DOI: 10.1039/c8cp05011b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We exploited glycine as a zwitterionic model system to experimentally probe the cation specific interaction of protein surface charges in dilute (≤0.25 mol L-1) aqueous solutions of four biologically relevant inorganic salts, NaCl, KCl, MgCl2 and CaCl2, via dielectric relaxation spectroscopy (DRS) and Raman spectroscopy. Glycine is the simplest building block of proteins and it exposes the same charged groups (carboxylate and ammonium) to the solvent that dominate the protein-water interface. As a counter ion, we selected Cl- due to its biological importance. For all systems, we performed simultaneous fitting of the real (ε') and imaginary (ε″) parts of the dielectric functions, assuming a multimodal relaxation model, obtained from concentration dependent dielectric measurements at ∼293 K. We observe a reduction of the dielectric amplitude for the glycine relaxation while the corresponding time constant shows only small (<7%) deviations compared to aqueous glycine solutions. We propose that the observed reduction in dielectric amplitude is due to a reduction of the effective dipole moment (µeff) of zwitterionic glycine caused by the interaction of glycine with the ion even at very low (0.05 M) salt concentrations. The interaction between divalent metal ions and zwitterionic glycine is increased compared to the monovalent cation-zwitterion interaction; a finding that is also supported by Raman spectroscopy. Our combined dielectric relaxation and Raman spectroscopic study indicates that ion-glycine interactions are weak and mediated by the solvent. Cation-specificity of protein surface charges is also observed in dilute salt solutions (≤0.25 mol L-1), where electrostatic interactions dominate.
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Affiliation(s)
- K Mukherjee
- Ruhr University Bochum, Faculty of Chemistry and Biochemistry, Physical Chemistry 2, Germany.
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33
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Ngo VA, Fanning JK, Noskov SY. Comparative Analysis of Protein Hydration from MD simulations with Additive and Polarizable Force Fields. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800106] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Van A. Ngo
- Department of Biological SciencesCentre for Molecular Simulation and Biochemistry Research ClusterUniversity of Calgary Calgary Alberta T2N 1N4 Canada
| | - John Keenan Fanning
- Department of Biological SciencesCentre for Molecular Simulation and Biochemistry Research ClusterUniversity of Calgary Calgary Alberta T2N 1N4 Canada
| | - Sergei Yu Noskov
- Department of Biological SciencesCentre for Molecular Simulation and Biochemistry Research ClusterUniversity of Calgary Calgary Alberta T2N 1N4 Canada
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34
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Peng X, Cashman NR, Plotkin SS. Prediction of Misfolding-Specific Epitopes in SOD1 Using Collective Coordinates. J Phys Chem B 2018; 122:11662-11676. [PMID: 30351123 DOI: 10.1021/acs.jpcb.8b07680] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We introduce a global, collective coordinate bias into molecular dynamics simulations that partially unfolds a protein, in order to predict misfolding-specific epitopes based on the regions that locally unfold. Several metrics are used to measure local disorder, including solvent exposed surface area (SASA), native contacts ( Q), and root mean squared fluctuations (RMSF). The method is applied to Cu, Zn superoxide dismutase (SOD1). For this protein, the processes of monomerization, metal loss, and conformational unfolding due to microenvironmental stresses are all separately taken into account. Several misfolding-specific epitopes are predicted, and consensus epitopes are calculated. These predicted epitopes are consistent with the "lower-resolution" peptide sequences used to raise disease-specific antibodies, but the epitopes derived from collective coordinates contain shorter, more refined sequences for the key residues constituting the epitope.
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Affiliation(s)
- Xubiao Peng
- Department of Physics and Astronomy , University of British Columbia , Vancouver , British Columbia V6T 1Z1 , Canada.,Center for Quantum Technology Research, School of Physics , Beijing Institute of Technology , Haidian, Beijing 100081 , China
| | - Neil R Cashman
- Brain Research Centre , University of British Columbia , Vancouver , British Columbia V6T 2B5 , Canada
| | - Steven S Plotkin
- Department of Physics and Astronomy, and Genome Sciences and Technology Program , University of British Columbia , Vancouver , British Columbia V6T 1Z1 , Canada
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35
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Schneeberger EM, Breuker K. Replacing H + by Na + or K + in phosphopeptide anions and cations prevents electron capture dissociation. Chem Sci 2018; 9:7338-7353. [PMID: 30542537 PMCID: PMC6237128 DOI: 10.1039/c8sc02470g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 07/07/2018] [Indexed: 01/29/2023] Open
Abstract
By successively replacing H+ by Na+ or K+ in phosphopeptide anions and cations, we show that the efficiency of fragmentation into c and z˙ or c˙ and z fragments from N-Cα backbone bond cleavage by negative ion electron capture dissociation (niECD) and electron capture dissociation (ECD) substantially decreases with increasing number of alkali ions attached. In proton-deficient phosphopeptide ions with a net charge of 2-, we observed an exponential decrease in electron capture efficiency with increasing number of Na+ or K+ ions attached, suggesting that electrons are preferentially captured at protonated sites. In proton-abundant phosphopeptide ions with a net charge of 3+, the electron capture efficiency was not affected by replacing up to four H+ ions with Na+ or K+ ions, but the yield of c, z˙ and c˙, z fragments from N-Cα backbone bond cleavage generally decreased next to Na+ or K+ binding sites. We interpret the site-specific decrease in fragmentation efficiency as Na+ or K+ binding to backbone amide oxygen in competition with interactions of protonated sites that would otherwise lead to backbone cleavage into c, z˙ or c˙, z fragments. Our findings seriously challenge the hypothesis that the positive charge responsible for ECD into c, z˙ or c˙, z fragments can generally be a sodium or other metal ion instead of a proton.
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Affiliation(s)
- Eva-Maria Schneeberger
- Institute of Organic Chemistry , Center for Molecular Biosciences Innsbruck (CMBI) , University of Innsbruck , Innrain 80/82 , 6020 Innsbruck , Austria . ; http://www.bioms-breuker.at/
| | - Kathrin Breuker
- Institute of Organic Chemistry , Center for Molecular Biosciences Innsbruck (CMBI) , University of Innsbruck , Innrain 80/82 , 6020 Innsbruck , Austria . ; http://www.bioms-breuker.at/
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36
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Abstract
Salts differ in their ability to stabilize protein conformations, thereby affecting the thermodynamics and kinetics of protein folding. We developed a coarse-grained protein model that can predict salt-induced changes in protein properties by using the transfer free-energy data of various chemical groups from water to salt solutions. Using this model and molecular dynamics simulations, we probed the effect of seven different salts on the folding thermodynamics of the DNA binding domain of lac repressor protein ( lac-DBD) and N-terminal domain of ribosomal protein (NTL9). We show that a salt can act as a protein stabilizing or destabilizing agent depending on the protein sequence and folded state topology. The computed thermodynamic properties, especially the m values for various salts, which reveal the relative ability of a salt to stabilize the protein folded state, are in quantitative agreement with the experimentally measured values. The computations show that the degree of protein compaction in the denatured ensemble strongly depends on the salt identity, and for the same variation in salt concentration, the compaction in the protein dimensions varies from ∼4% to ∼30% depending on the salt. The transition-state ensemble (TSE) of lac-DBD is homogeneous and polarized, while the TSE of NTL9 is heterogeneous and diffusive. Salts induce subtle structural changes in the TSE that are in agreement with Hammond's postulate. The barrier to protein folding tends to disappear in the presence of moderate concentrations (∼3-4 m) of strongly stabilizing salts.
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Affiliation(s)
- Hiranmay Maity
- Solid State and Structural Chemistry Unit , Indian Institute of Science , Bengaluru , Karnataka , India 560012
| | - Aswathy N Muttathukattil
- Solid State and Structural Chemistry Unit , Indian Institute of Science , Bengaluru , Karnataka , India 560012
| | - Govardhan Reddy
- Solid State and Structural Chemistry Unit , Indian Institute of Science , Bengaluru , Karnataka , India 560012
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37
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Hillyer MB, Gan H, Gibb BC. Precision Switching in a Discrete Supramolecular Assembly: Alkali Metal Ion‐Carboxylate Selectivities and the Cationic Hofmeister Effect. Chemphyschem 2018; 19:2285-2289. [DOI: 10.1002/cphc.201800554] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Matthew B. Hillyer
- Department of Chemistry Tulane University 6400 Freret Street New Orleans, Louisiana USA 70115
| | - Haiying Gan
- Department of Chemistry Tulane University 6400 Freret Street New Orleans, Louisiana USA 70115
| | - Bruce C. Gibb
- Department of Chemistry Tulane University 6400 Freret Street New Orleans, Louisiana USA 70115
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38
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Zhang Q, Pan Z, Zhang L, Zhang R, Chen Z, Jin T, Wu T, Chen X, Zhuang W. Ion effect on the dynamics of water hydrogen bonding network: A theoretical and computational spectroscopy point of view. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2018. [DOI: 10.1002/wcms.1373] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Qiang Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
- Department of ChemistryBohai UniversityJinzhouChina
| | - Zhijun Pan
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
| | - Lu Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
| | - Ruiting Zhang
- School of Physics and Optoelectronic EngineeringXidian UniversityXi'anChina
| | - Zhening Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
| | - Tan Jin
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
| | - Tianmin Wu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
| | - Xian Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
| | - Wei Zhuang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouChina
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39
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D'Oronzo E, Secundo F, Minofar B, Kulik N, Pometun AA, Tishkov VI. Activation/Inactivation Role of Ionic Liquids on Formate Dehydrogenase fromPseudomonassp. 101 and Its Mutated Thermostable Form. ChemCatChem 2018. [DOI: 10.1002/cctc.201800145] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Erica D'Oronzo
- Istituto di Chimica del Riconoscimento Molecolare, CNR; Via Mario Bianco 9 20131 Milan Italy
| | - Francesco Secundo
- Istituto di Chimica del Riconoscimento Molecolare, CNR; Via Mario Bianco 9 20131 Milan Italy
| | - Babak Minofar
- Institute of Microbiology; Academy of, Sciences of the Czech Republic; Zamek 136 37333 Nove Hrady Czech Republic
- Faculty of Science; University of South Bohemia; Branišovská 1760 37005 České Budějovice Czech Republic
| | - Natallia Kulik
- Institute of Microbiology; Academy of, Sciences of the Czech Republic; Zamek 136 37333 Nove Hrady Czech Republic
| | - Anastasia A. Pometun
- Innovations and High Technologies MSU Ltd.; Tsymlyanskaya ul., 16-96 109451 Moscow Russian Federation
- A.N. Bach Institute of Biochemistry; Research Center, of Biotechnology of the Russian Academy of Sciences; bld. 2 Leninsky Ave. Moscow 119071 Russian Federation
| | - Vladimir I. Tishkov
- Innovations and High Technologies MSU Ltd.; Tsymlyanskaya ul., 16-96 109451 Moscow Russian Federation
- Chemistry Faculty; M.V. Lomonosov Moscow State University; Leninskie Gory 1-3 119991 Moscow Russian Federation
- A.N. Bach Institute of Biochemistry; Research Center, of Biotechnology of the Russian Academy of Sciences; bld. 2 Leninsky Ave. Moscow 119071 Russian Federation
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40
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Ariz-Extreme I, Hub JS. Assigning crystallographic electron densities with free energy calculations-The case of the fluoride channel Fluc. PLoS One 2018; 13:e0196751. [PMID: 29771936 PMCID: PMC5957342 DOI: 10.1371/journal.pone.0196751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/18/2018] [Indexed: 11/25/2022] Open
Abstract
Approximately 90% of the structures in the Protein Data Bank (PDB) were obtained by X-ray crystallography or electron microscopy. Whereas the overall quality of structure is considered high, thanks to a wide range of tools for structure validation, uncertainties may arise from density maps of small molecules, such as organic ligands, ions or water, which are non-covalently bound to the biomolecules. Even with some experience and chemical intuition, the assignment of such disconnected electron densities is often far from obvious. In this study, we suggest the use of molecular dynamics (MD) simulations and free energy calculations, which are well-established computational methods, to aid in the assignment of ambiguous disconnected electron densities. Specifically, estimates of (i) relative binding affinities, for instance between an ion and water, (ii) absolute binding free energies, i.e., free energies for transferring a solute from bulk solvent to a binding site, and (iii) stability assessments during equilibrium simulations may reveal the most plausible assignments. We illustrate this strategy using the crystal structure of the fluoride specific channel (Fluc), which contains five disconnected electron densities previously interpreted as four fluoride and one sodium ion. The simulations support the assignment of the sodium ion. In contrast, calculations of relative and absolute binding free energies as well as stability assessments during free MD simulations suggest that four of the densities represent water molecules instead of fluoride. The assignment of water is compatible with the loss of these densities in the non-conductive F82I/F85I mutant of Fluc. We critically discuss the role of the ion force fields for the calculations presented here. Overall, these findings indicate that MD simulations and free energy calculations are helpful tools for modeling water and ions into crystallographic density maps.
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Affiliation(s)
- Igor Ariz-Extreme
- Institute for Microbiology and Genetics, University of Goettingen, Göttingen, Germany
| | - Jochen S. Hub
- Institute for Microbiology and Genetics, University of Goettingen, Göttingen, Germany
- * E-mail:
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41
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Lee E, Choi JH, Cho M. The effect of Hofmeister anions on water structure at protein surfaces. Phys Chem Chem Phys 2018; 19:20008-20015. [PMID: 28722047 DOI: 10.1039/c7cp02826a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
To understand the effects of specific ions on protein-water interactions and the thermodynamic stability of proteins in salt solutions, we use a molecular dynamics (MD) simulation to examine the water structure, orientational distribution, and dynamics near the surface of ubiquitin. In particular, we consider NaCl, NaBF4, NaSCN, and NaClO4 salt solutions containing ubiquitin, where the anions of the latter three salts are well-known chaotropic ions in the Hofmiester anion series. The number of hydrogen bonds (H-bonds) per water molecule is found to decrease significantly at the ubiquitin-water interface, indicating a significant disruption of the water H-bonding network. The distribution of the water H-bond numbers near the protein surface is modulated by dissolved ions, and the extent of the ion effect on the H-bonding network structure follows the order of the Hofmeister anion series, while there are no specific ion effects on water properties at distances larger than 5 Å from the protein surface. From detailed analyses of the surface area, volume, and root-mean-square deviation (RMSD) of ubiquitin, we show that changes in the properties of the protein could originate from the disruption of the water H-bond network induced by ions with a higher affinity for the protein surface instead of direct protein residue-ion interactions. An interesting observation made here is that the orientational distribution of water molecules at the protein-water interface is close to random, but there is a slight preference for interfacial water molecules with a straddle structure within 2.5 Å of the protein surface, where one of the two OH groups points away from the protein surface and the other points toward the surface. In addition, comparing the MD simulation results for ubiquitin solutions with dissolved NaSCN and KSCN, we show that Na+ affects the water H-bonding structure at the protein surface more than K+. It is clear that the H-bonding network structure of water more than one water layer away from the protein surface is not distinguishably different from that of neat water. We thus anticipate that the present work will provide insights into the scale of specific ion effects on the H-bonding structure and orientational distribution of water in the vicinity of protein surfaces in aqueous solutions.
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Affiliation(s)
- Euihyun Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Republic of Korea.
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42
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Zhao J, Wang J. Direct Anionic Effect on Water Structure and Indirect Anionic Effect on Peptide Backbone Hydration State Revealed by Thin-Layer Infrared Spectroscopy. J Phys Chem B 2018; 122:68-76. [PMID: 29232512 DOI: 10.1021/acs.jpcb.7b09591] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, the anionic effect on water structure and on the peptide backbone and water interaction was investigated directly in aqueous solution using thin-layer transmission infrared spectroscopy. The chaotropic anions were found to weaken the water hydrogen-bonding strength and red shift the HOH bending frequency, while the kosmotropic anions were found to strengthen the water hydrogen-bonding network and blue shift the HOH bending frequency. The kosmotropes, especially F-, blue shift the vibrational frequencies of both amide II and amide III bands of N-methylacetamide (NMA), indicating NMA is in the "salting-in" state; while the chaotropes (Cl-, NO3-, Br-, I-, and SCN-) red shift the frequencies of the two normal modes, indicating NMA is in the "salting-out" state. Furthermore, the changes of the vibrational frequencies of the HOH bending, amide II and III bands were found to generally follow the Hofmeister anionic series. Our results suggest that hydrated anion influences the peptide backbone mainly through the N-H group, but a weak and indirect effect through the amide C═O group also contributes. Thus, these amide modes can be used as vibrational measures of anionic influences on peptide backbone's hydration state. Our work also suggests that deuteration of the amide unit decreases the sensitivity of the amide II and III vibrational modes in this regard.
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Affiliation(s)
- Juan Zhao
- Beijing National Laboratory for Molecular Sciences; Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China.,University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Jianping Wang
- Beijing National Laboratory for Molecular Sciences; Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China.,University of Chinese Academy of Sciences , Beijing 100049, P. R. China
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43
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Ivanović MT, Bruetzel LK, Shevchuk R, Lipfert J, Hub JS. Quantifying the influence of the ion cloud on SAXS profiles of charged proteins. Phys Chem Chem Phys 2018; 20:26351-26361. [DOI: 10.1039/c8cp03080d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
MD simulations and Poisson–Boltzmann calculations predict ion cloud effects on SAXS experiments.
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Affiliation(s)
- Miloš T. Ivanović
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics
- 37077 Göttingen
- Germany
| | - Linda K. Bruetzel
- Ludwig-Maximilian-Universität München, Department of Physics
- 80799 München
- Germany
| | - Roman Shevchuk
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics
- 37077 Göttingen
- Germany
| | - Jan Lipfert
- Ludwig-Maximilian-Universität München, Department of Physics
- 80799 München
- Germany
| | - Jochen S. Hub
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics
- 37077 Göttingen
- Germany
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44
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Li RZ, Deng SHM, Hou GL, Valiev M, Wang XB. Photoelectron spectroscopy of solvated dicarboxylate and alkali metal ion clusters, M+[O2C(CH2)2CO2]2− [H2O]n (M = Na, K; n = 1–6). Phys Chem Chem Phys 2018; 20:29051-29060. [DOI: 10.1039/c8cp03896a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present results of combined experimental photoelectron spectroscopy and theoretical modeling studies of solvated dicarboxylate species (−O2C(CH2)2CO2−) in complex with Na+ and K+ metal cations.
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Affiliation(s)
- Ren-Zhong Li
- College of Environmental and Chemical Engineering
- Xi’an Polytechnic University
- Xi’an
- China
- Physical Sciences Division
| | - Shihu H. M. Deng
- Physical Sciences Division
- Pacific Northwest National Laboratory
- Washington 99352
- USA
| | - Gao-Lei Hou
- Physical Sciences Division
- Pacific Northwest National Laboratory
- Washington 99352
- USA
| | - Marat Valiev
- Environmental Molecular Sciences Laboratory
- Pacific Northwest National Laboratory
- Washington 99352
- USA
| | - Xue-Bin Wang
- Physical Sciences Division
- Pacific Northwest National Laboratory
- Washington 99352
- USA
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45
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Tang S, Tang L, Lu X, Liu H, Moore JS. Programmable Payload Release from Transient Polymer Microcapsules Triggered by a Specific Ion Coactivation Effect. J Am Chem Soc 2017; 140:94-97. [DOI: 10.1021/jacs.7b11022] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Shijia Tang
- Beckman
Institute for Advanced Science and Technology, ‡Department of Materials
Science and Engineering, and ∥Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Liuyan Tang
- Beckman
Institute for Advanced Science and Technology, ‡Department of Materials
Science and Engineering, and ∥Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Xiaocun Lu
- Beckman
Institute for Advanced Science and Technology, ‡Department of Materials
Science and Engineering, and ∥Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Huiying Liu
- Beckman
Institute for Advanced Science and Technology, ‡Department of Materials
Science and Engineering, and ∥Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jeffrey S. Moore
- Beckman
Institute for Advanced Science and Technology, ‡Department of Materials
Science and Engineering, and ∥Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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46
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Smith JW, Saykally RJ. Soft X-ray Absorption Spectroscopy of Liquids and Solutions. Chem Rev 2017; 117:13909-13934. [DOI: 10.1021/acs.chemrev.7b00213] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Jacob W. Smith
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Lab, Berkeley, California 94720, United States
| | - Richard J. Saykally
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Lab, Berkeley, California 94720, United States
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47
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Olivieri G, Parry KM, D’Auria R, Tobias DJ, Brown MA. Specific Anion Effects on Na+ Adsorption at the Aqueous Solution–Air Interface: MD Simulations, SESSA Calculations, and Photoelectron Spectroscopy Experiments. J Phys Chem B 2017; 122:910-918. [DOI: 10.1021/acs.jpcb.7b06981] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Giorgia Olivieri
- Department
of Materials, Laboratory for Surface Science and Technology, ETH Zürich, Vladimir-Prelog-Weg 5, CH-8093, Zürich, Switzerland
| | - Krista M. Parry
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Raffaella D’Auria
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Douglas J. Tobias
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Matthew A. Brown
- Department
of Materials, Laboratory for Surface Science and Technology, ETH Zürich, Vladimir-Prelog-Weg 5, CH-8093, Zürich, Switzerland
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48
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Kurita O, Sago T, Umetani K, Kokean Y, Yamaoka C, Takahashi N, Iwamoto H. Feasible protein aggregation of phosphorylated poly-γ-glutamic acid derivative from Bacillus subtilis (natto). Int J Biol Macromol 2017; 103:484-492. [PMID: 28527993 DOI: 10.1016/j.ijbiomac.2017.05.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/27/2017] [Accepted: 05/15/2017] [Indexed: 11/24/2022]
Abstract
Poly-γ-glutamic acid (PGA) was modified with phosphorylating agents such as sodium metaphosphate and potassium metaphosphate in the culture medium of Bacillus subtilis (natto). The highly phosphorylated PGA derivatives were prepared and investigated for their chemical and physicochemical properties. The PGA derivatives had approximately 7% (W/W) inorganic phosphorus and characteristic absorbance PO2- bands at 1082cm-1 and 1260cm-1 by Fourier Transform Infrared Spectroscopy. The derivative modified by sodium metaphosphate (J-5) was easily hydrated in water and had extremely low viscosity. The shear rate-induced transition leading to the decrease of viscosity was not observed in J-5 whereas the derivative modified by potassium metaphosphate (J-6) as well as unmodified PGA (J-1) showed the typical decrease of viscosity. In circular dichroism (CD) measurement of J-5, there was a significant loss of the negative chirality CD signal, implying that protein aggregation occured at decreasing pH from 6.2 to 4.4. The thioflavin T fluorescence intensity of the aqueous solution in the J-5 was extremely high despite the absence of heat-treatment. The results indicate that the J-5 is the likeliest type of aggregation by β-sheet cross-linking which is relevant to protein diseases like Alzheimer's disease.
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Affiliation(s)
- Osamu Kurita
- Mie Prefecture Industrial Research Institute, 5-5-45 Takajaya, Tsu, Mie514-0819, Japan.
| | - Toru Sago
- Mie Prefecture Industrial Research Institute, 5-5-45 Takajaya, Tsu, Mie514-0819, Japan
| | - Kaori Umetani
- Mie Prefecture Industrial Research Institute, 5-5-45 Takajaya, Tsu, Mie514-0819, Japan
| | - Yasushi Kokean
- Mie Prefecture Industrial Research Institute, 5-5-45 Takajaya, Tsu, Mie514-0819, Japan
| | - Chizuru Yamaoka
- Mie Prefecture Industrial Research Institute, 5-5-45 Takajaya, Tsu, Mie514-0819, Japan
| | - Nobuyuki Takahashi
- Division of Applied Life Science, Graduate School of Agriculture, Kyoto University, Gokashou, Uji, Kyoto, Japan
| | - Hiroyuki Iwamoto
- Department of Biotechnology, Faculty of Life Science, Fukuyama University, 1 Sanzo, Gakuen-cho, Fukuyama, Hiroshima 729-0292, Japan
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49
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Kroeger T, Frieg B, Zhang T, Hansen FK, Marmann A, Proksch P, Nagel-Steger L, Groth G, Smits SHJ, Gohlke H. EDTA aggregates induce SYPRO orange-based fluorescence in thermal shift assay. PLoS One 2017; 12:e0177024. [PMID: 28472107 PMCID: PMC5417642 DOI: 10.1371/journal.pone.0177024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/29/2017] [Indexed: 12/16/2022] Open
Abstract
Ethylenediaminetetraacetic acid (EDTA) is widely used in the life sciences as chelating ligand of metal ions. However, formation of supramolecular EDTA aggregates at pH > 8 has been reported, which may lead to artifactual assay results. When applied as a buffer component at pH ≈ 10 in differential scanning fluorimetry (TSA) using SYPRO Orange as fluorescent dye, we observed a sharp change in fluorescence intensity about 20°C lower than expected for the investigated protein. We hypothesized that this change results from SYPRO Orange/EDTA interactions. TSA experiments in the presence of SYPRO Orange using solutions that contain EDTA-Na+ but no protein were performed. The TSA experiments provide evidence that suggests that at pH > 9, EDTA4- interacts with SYPRO Orange in a temperature-dependent manner, leading to a fluorescence signal yielding a "denaturation temperature" of ~68°C. Titrating Ca2+ to SYPRO Orange and EDTA solutions quenched fluorescence. Ethylene glycol tetraacetic acid (EGTA) behaved similarly to EDTA. Analytical ultracentrifugation corroborated the formation of EDTA aggregates. Molecular dynamics simulations of free diffusion of EDTA-Na+ and SYPRO Orange of in total 27 μs suggested the first structural model of EDTA aggregates in which U-shaped EDTA4- arrange in an inverse bilayer-like manner, exposing ethylene moieties to the solvent, with which SYPRO Orange interacts. We conclude that EDTA aggregates induce a SYPRO Orange-based fluorescence in TSA. These results make it relevant to ascertain that future TSA results are not influenced by interference between EDTA, or EDTA-related molecules, and the fluorescent dye.
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Affiliation(s)
- Tobias Kroeger
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Benedikt Frieg
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Tao Zhang
- Institute for Physical Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
| | - Finn K. Hansen
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Andreas Marmann
- Institute for Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Peter Proksch
- Institute for Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Luitgard Nagel-Steger
- Institute for Physical Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
| | - Georg Groth
- Institute for Biochemical Plant Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sander H. J. Smits
- Institute for Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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50
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Schierke F, Wyrwoll MJ, Wisdorf M, Niedzielski L, Maase M, Ruck T, Meuth SG, Kusche-Vihrog K. Nanomechanics of the endothelial glycocalyx contribute to Na +-induced vascular inflammation. Sci Rep 2017; 7:46476. [PMID: 28406245 PMCID: PMC5390251 DOI: 10.1038/srep46476] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/20/2017] [Indexed: 12/11/2022] Open
Abstract
High dietary salt (NaCl) is a known risk factor for cardiovascular pathologies and inflammation. High plasma Na+ concentrations (high Na+) have been shown to stiffen the endothelial cortex and decrease nitric oxide (NO) release, a hallmark of endothelial dysfunction. Here we report that chronic high Na+ damages the endothelial glycocalyx (eGC), induces release of inflammatory cytokines from the endothelium and promotes monocyte adhesion. Single cell force spectroscopy reveals that high Na+ enhances vascular adhesion protein-1 (VCAM-1)-dependent adhesion forces between monocytes and endothelial surface, giving rise to increased numbers of adherent monocytes on the endothelial surface. Mineralocorticoid receptor antagonism with spironolactone prevents high Na+-induced eGC deterioration, decreases monocyte-endothelium interactions, and restores endothelial function, indicated by increased release of NO. Whereas high Na+ decreases NO release, it induces endothelial release of the pro-inflammatory cytokines IL-1ß and TNFα. However, in contrast to chronic salt load (hours), in vivo and in vitro, an acute salt challenge (minutes) does not impair eGC function. This study identifies the eGC as important mediator of inflammatory processes and might further explain how dietary salt contributes to endothelialitis and cardiovascular pathologies by linking endothelial nanomechanics with vascular inflammation.
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Affiliation(s)
- Florian Schierke
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Margot J Wyrwoll
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Martin Wisdorf
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Leon Niedzielski
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Martina Maase
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Tobias Ruck
- Department of Neurology, University of Münster, 48149 Münster, Germany
| | - Sven G Meuth
- Department of Neurology, University of Münster, 48149 Münster, Germany
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