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Effect of Ultrafiltered Milk on the Rheological and Microstructure Properties of Cream Cheese Acid Gels. FOOD BIOPROCESS TECH 2023. [DOI: 10.1007/s11947-022-02991-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
AbstractThe addition of ultrafiltered (UF) milk retentate is known to impact milk properties during mozzarella and cheddar cheese production, but the effect during cream cheese production is less well understood. Little is known about the impact of UF retentate on the intermediate stages of manufacture, such as protein assembly and the formation of hydrated acid gel structures. Here, milk prepared for cream cheese manufacture using a concentration factor of 2.5 or 5 had a similar particle size distribution to unconcentrated cheese milk after homogenization but increased viscosity and a slower rate of acidification, which could be altered by increasing starter culture concentration. The acid gels formed contained more protein and fat, resulting in a higher storage modulus, firmness, and viscosity. A denser microstructure was observed in acid gels formed with UF retentate addition, and quantitative two- or three-dimensional analysis of confocal images found a greater volume percentage of protein and fat, decreased porosity, and increased coalescence of fat. The mobility of water, as assessed by proton nuclear magnetic resonance, was reduced in the dense UF gel networks. Water movement was partially obstructed, although diffusion was possible between interconnected serum pores. These insights improve our understanding of acid gel formation. They can be used by manufacturers to further optimize the early and intermediate stages of cream cheese production when using concentrated milk to reduce acid whey production and lay the foundation for larger pilot scale studies of intermediate and final cream cheese structure.
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Gao T, Korb JP, Lukšič M, Mériguet G, Malikova N, Rollet AL. Ion influence on surface water dynamics and proton exchange at protein surfaces - A unified model for transverse and longitudinal NMR relaxation dispersion. J Mol Liq 2022; 367:120451. [PMID: 37790165 PMCID: PMC10544814 DOI: 10.1016/j.molliq.2022.120451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In all biologically relevant media, proteins interact in the presence of surrounding ions, and such interactions are water-mediated. Water molecules play a crucial role in the restructuring of proteins in solution and indeed in their biological activity. Surface water dynamics and proton exchange at protein surfaces is investigated here using NMR relaxometry, for two well-known globular proteins, lysozyme and bovine serum albumin, with particular attention to the role of surface ions. We present a unified model of surface water dynamics and proton exchange, accounting simultaneously for the observed longitudinal and transverse relaxation rates. The most notable effect of salt (0.1 M) concerns the slow surface water dynamics, related to rare water molecules embedded in energy wells on the protein surface. This response is protein-specific. On the other hand, the proton exchange time between labile protein-protons and water-protons at the protein surface seems to be very similar for the two proteins and is insensitive to the addition of salts at the concentration studied.
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Affiliation(s)
- Tadeja Gao
- Sorbonne Université/CNRS, Laboratoire Physico-Chimie des Électrolytes et Nano-Systèmes Interfaciaux (PHENIX), 4 place Jussieu, Paris, France
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana SI-1000, Slovenia
| | - Jean-Pierre Korb
- Sorbonne Université/CNRS, Laboratoire Physico-Chimie des Électrolytes et Nano-Systèmes Interfaciaux (PHENIX), 4 place Jussieu, Paris, France
| | - Miha Lukšič
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana SI-1000, Slovenia
| | - Guillaume Mériguet
- Sorbonne Université/CNRS, Laboratoire Physico-Chimie des Électrolytes et Nano-Systèmes Interfaciaux (PHENIX), 4 place Jussieu, Paris, France
| | - Natalie Malikova
- Sorbonne Université/CNRS, Laboratoire Physico-Chimie des Électrolytes et Nano-Systèmes Interfaciaux (PHENIX), 4 place Jussieu, Paris, France
| | - Anne-Laure Rollet
- Sorbonne Université/CNRS, Laboratoire Physico-Chimie des Électrolytes et Nano-Systèmes Interfaciaux (PHENIX), 4 place Jussieu, Paris, France
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Simari C, Prejanò M, Lufrano E, Sicilia E, Nicotera I. Exploring the Structure-Performance Relationship of Sulfonated Polysulfone Proton Exchange Membrane by a Combined Computational and Experimental Approach. Polymers (Basel) 2021; 13:959. [PMID: 33804763 PMCID: PMC8003876 DOI: 10.3390/polym13060959] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 01/01/2023] Open
Abstract
Sulfonated Polysulfone (sPSU) is emerging as a concrete alternative to Nafion ionomer for the development of proton exchange electrolytic membranes for low cost, environmentally friendly and high-performance PEM fuel cells. This ionomer has recently gained great consideration since it can effectively combine large availability on the market, excellent film-forming ability and remarkable thermo-mechanical resistance with interesting proton conductive properties. Despite the great potential, however, the morphological architecture of hydrated sPSU is still unknown. In this study, computational and experimental advanced tools are combined to preliminary describe the relationship between the microstructure of highly sulfonated sPSU (DS = 80%) and its physico-chemical, mechanical and electrochemical features. Computer simulations allowed for describing the architecture and to estimate the structural parameters of the sPSU membrane. Molecular dynamics revealed an interconnected lamellar-like structure for hydrated sPSU, with ionic clusters of about 14-18 Å in diameter corresponding to the hydrophilic sulfonic-acid-containing phase. Water dynamics were investigated by 1H Pulsed Field Gradient (PFG) NMR spectroscopy in a wide temperature range (20-120 °C) and the self-diffusion coefficients data were analyzed by a "two-sites" model. It allows to estimate the hydration number in excellent agreement with the theoretical simulation (e.g., about 8 mol H2O/mol SO3- @ 80 °C). The PEM performance was assessed in terms of dimensional, thermo-mechanical and electrochemical properties by swelling tests, DMA and EIS, respectively. The peculiar microstructure of sPSU provides a wider thermo-mechanical stability in comparison to Nafion, but lower dimensional and conductive features. Nonetheless, the single H2/O2 fuel cell assembled with sPSU exhibited better features than any earlier published hydrocarbon ionomers, thus opening interesting perspectives toward the design and preparation of high-performing sPSU-based PEMs.
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Affiliation(s)
- Cataldo Simari
- Department of Chemistry and Chemical Technologies—CTC, University of Calabria, Via Pietro Bucci, 87036 Rende, Italy; (E.L.); (E.S.); (I.N.)
| | - Mario Prejanò
- Department of Chemistry and Chemical Technologies—CTC, University of Calabria, Via Pietro Bucci, 87036 Rende, Italy; (E.L.); (E.S.); (I.N.)
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Di Tullio V, Zumbulyadis N, Centeno SA, Catalano J, Wagner M, Dybowski C. Water Diffusion and Transport in Oil Paints as Studied by Unilateral NMR and
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H High‐Resolution MAS‐NMR Spectroscopy. Chemphyschem 2019; 21:113-119. [DOI: 10.1002/cphc.201900858] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Valeria Di Tullio
- Department of Scientific Research The Metropolitan Museum of Art New York, NY USA
- Magnetic Resonance Laboratory “Annalaura Segre” ISB-CNR Rome Italy
| | - Nicholas Zumbulyadis
- Independent Researcher, Rochester NY USA
- Department of Chemistry and Biochemistry University of Delaware Newark, DE USA
| | - Silvia A. Centeno
- Department of Scientific Research The Metropolitan Museum of Art New York, NY USA
| | - Jaclyn Catalano
- Department of Chemistry and Biochemistry Montclair State University Montclair, NJ USA
| | - Molly Wagner
- Department of Chemistry and Biochemistry University of Delaware Newark, DE USA
| | - Cecil Dybowski
- Department of Chemistry and Biochemistry University of Delaware Newark, DE USA
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Ramler J, Poater J, Hirsch F, Ritschel B, Fischer I, Bickelhaupt FM, Lichtenberg C. Carbon monoxide insertion at a heavy p-block element: unprecedented formation of a cationic bismuth carbamoyl. Chem Sci 2019; 10:4169-4176. [PMID: 31057745 PMCID: PMC6471928 DOI: 10.1039/c9sc00278b] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 02/27/2019] [Indexed: 12/20/2022] Open
Abstract
Major advances in the chemistry of 5th and 6th row heavy p-block element compounds have recently uncovered intriguing reactivity patterns towards small molecules such as H2, CO2, and ethylene. However, well-defined, homogeneous insertion reactions with carbon monoxide, one of the benchmark substrates in this field, have not been reported to date. We demonstrate here, that a cationic bismuth amide undergoes facile insertion of CO into the Bi-N bond under mild conditions. This approach grants direct access to the first cationic bismuth carbamoyl species. Its characterization by NMR, IR, and UV/vis spectroscopy, elemental analysis, single-crystal X-ray analysis, cyclic voltammetry, and DFT calculations revealed intriguing properties, such as a reversible electron transfer at the bismuth center and an absorption feature at 353 nm ascribed to a transition involving σ- and π-type orbitals of the bismuth-carbamoyl functionality. A combined experimental and theoretical approach provided insight into the mechanism of CO insertion. The substrate scope could be extended to isonitriles.
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Affiliation(s)
- Jacqueline Ramler
- Institute of Inorganic Chemistry , Julius-Maximilians Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
| | - Jordi Poater
- ICREA , Pg. Lluís Companys 23 , 08010 Barcelona , Spain
- Universitat de Barcelona , Departament de Química Inorgànica i Orgànica & IQTCUB , Martí i Franquès 1-11 , 08028 Barcelona , Spain
| | - Florian Hirsch
- Institute of Physical Chemistry , Julius-Maximilians Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
| | - Benedikt Ritschel
- Institute of Inorganic Chemistry , Julius-Maximilians Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
| | - Ingo Fischer
- Institute of Physical Chemistry , Julius-Maximilians Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
| | - F Matthias Bickelhaupt
- Vrije Universiteit Amsterdam , Department of Theoretical Chemistry , Amsterdam Center for Multiscale Modeling (ACMM) , The Netherlands .
- Radboud University , Institute for Molecules and Materials , Heyendaalseweg 135 , 6525 AJ Nijmegen , The Netherlands
| | - Crispin Lichtenberg
- Institute of Inorganic Chemistry , Julius-Maximilians Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
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Janc T, Lukšič M, Vlachy V, Rigaud B, Rollet AL, Korb JP, Mériguet G, Malikova N. Ion-specificity and surface water dynamics in protein solutions. Phys Chem Chem Phys 2018; 20:30340-30350. [PMID: 30488933 PMCID: PMC6318450 DOI: 10.1039/c8cp06061d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ion-specific effects at the protein surface are investigated here in light of the changes they infer to surface water dynamics, as observed by 1H NMR relaxation (at 20 MHz). Two well-known proteins, hen egg-white lysozyme (LZM) and bovine serum albumin (BSA), show qualitatively opposite trends in the transverse relaxation rate, R2(1H), along a series of different monovalent salt anions in the solution. Presence of salt ions increases R2(1H) in the case of lysozyme and diminishes it in the case of BSA. The effect magnifies for larger and more polarizable ions. The same contrasting effect between the two proteins is observed for protein-solvent proton exchange. This hints at subtle effects ion-binding might have on the accessibility of water surface sites on the protein. We suggest that the combination of the density of surface charge residues and surface roughness, at the atomic scale, dictates the response to the presence of salt ions and is proper to each protein. Further, a dramatic increase in R2(1H) is found to correlate closely with the formation of protein aggregates. The same ordering of salts in their ability to aggregate lysozyme, as seen previously by cloud point measurements, is reproduced here by R2(1H). 1H NMR relaxation data is supplemented by 35Cl and 14N NMR relaxation for selected salt ions to probe the ion-binding itself.
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Affiliation(s)
- Tadeja Janc
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, SI-1000 Ljubljana, Slovenia
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7
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Canevali C, Fasoli M, Bertasa M, Botteon A, Colombo A, Di Tullio V, Capitani D, Proietti N, Scalarone D, Sansonetti A. A multi-analytical approach for the study of copper stain removal by agar gels. Microchem J 2016. [DOI: 10.1016/j.microc.2016.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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de Kort DW, van Duynhoven JP, Van As H, Mariette F. Nanoparticle diffusometry for quantitative assessment of submicron structure in food biopolymer networks. Trends Food Sci Technol 2015. [DOI: 10.1016/j.tifs.2014.11.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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9
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Ying R, Saulnier L, Bouchet B, Barron C, Ji S, Rondeau-Mouro C. Multiscale characterization of arabinoxylan and β-glucan composite films. Carbohydr Polym 2015; 122:248-54. [PMID: 25817666 DOI: 10.1016/j.carbpol.2015.01.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/16/2014] [Accepted: 01/02/2015] [Indexed: 11/29/2022]
Abstract
Composite films made with Arabinoxylans (AXs) (with high, middle and low level of substitution by arabinose) and (1 → 3)(1 → 4)-β-D-glucans (BGs) extracted from cereal cell walls have been prepared and analyzed using microscopy (SEM and LSCFM), DSC, mechanical tests and TD-NMR spectroscopy. The objectives were to correlate molecular and physico-chemical properties of films with mechanical and hydration properties of wheat cell walls. A phase separation phenomenon was observed for films made with highly substituted AXs and BGs at a ratio AX/BG of 60/40. This phase separation was correlated with lower dipolar interactions between polysaccharide chains and a decrease of ultimate strain and stress of films. Highly substituted AX and BG composite films exhibited very weak mechanical properties in agreement with weaker interactions between the polymer chains. This effect was supported by NMR results showing that interactions between AXs and BGs decreased with increased substitution of AXs in composite films. Lower dipolar interactions between polysaccharides favored the water mobility in relation with a higher specific surface area of polysaccharides in films but also higher distances between polysaccharide chains so larger nanopores in composite films made within highly substituted AXs. These multiscale characterizations agreed with the structural changes observed in wheat grain during its development.
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Affiliation(s)
- Ruifeng Ying
- College of Light Industry of Science and Engineering, Nanjing Forest University, Nanjing 210037, PR China; UR1268 Biopolymères, Interactions, Assemblages, INRA, F-44316 Nantes, France
| | - Luc Saulnier
- UR1268 Biopolymères, Interactions, Assemblages, INRA, F-44316 Nantes, France
| | - Brigitte Bouchet
- UR1268 Biopolymères, Interactions, Assemblages, INRA, F-44316 Nantes, France
| | - Cécile Barron
- Unité mixte de Recherches Ingénierie des Agropolymères et Technologies Emergentes, INRA-ENSAM-UMII-CIRAD, 2 place Viala, 34060 Montpellier, France
| | - Sujie Ji
- College of Light Industry of Science and Engineering, Nanjing Forest University, Nanjing 210037, PR China
| | - Corinne Rondeau-Mouro
- UR1268 Biopolymères, Interactions, Assemblages, INRA, F-44316 Nantes, France; Irstea, UR TERE, 17 avenue de Cucillé, CS 64427, F-35044 Rennes, France.
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10
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Alekseev GV, Khripov AA. Method of Rapid Remote Control of Casein Concentration in Dairy Products in Unopened Packages. J FOOD PROCESS ENG 2014. [DOI: 10.1111/jfpe.12121] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gennady Valentinovich Alekseev
- ITMO University; Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics; St. Petersburg 191002 Russia
| | - Anatoly Anatolevich Khripov
- ITMO University; Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics; St. Petersburg 191002 Russia
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12
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Mulas G, Roggio T, Uzzau S, Anedda R. A new magnetic resonance imaging approach for discriminating Sardinian sheep milk cheese made from heat-treated or raw milk. J Dairy Sci 2013; 96:7393-403. [PMID: 24119804 DOI: 10.3168/jds.2013-6607] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 08/24/2013] [Indexed: 11/19/2022]
Abstract
The evaluation of milk heat treatment on dairy products via reliable analytical methods is a challenging issue that involves both industrial and fundamental research. We describe a new magnetic resonance imaging (MRI) protocol for discriminating Sardinian sheep milk cheese originating from heat-treated or raw milk. Thirty-six samples (18 pecorino cheeses manufactured from heat-treated milk and 18 Fiore Sardo cheeses made from raw milk) were investigated by means of MRI and bi-exponential signal decay analysis. The protocol is capable of discerning cheeses by virtue of the different distribution of the transversal (T2) relaxation time constant. Cheeses from heat-treated milk showed a significantly higher area fraction (≈70-80%), corresponding to the fast relaxing water protons (T2 ≈ 9 ms), compared with raw milk cheeses, whereas the opposite was observed for the long T2 (T2 ≈ 35 ms) proton population. The MRI protocol described is rapid and nondestructive, and it provides statistically significant discrimination between ewe milk cheeses made from heat-treated and raw milk.
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Affiliation(s)
- G Mulas
- Porto Conte Ricerche S.r.l., SP 55 Porto Conte/Capo Caccia Km 8.400, Loc Tramariglio 07041 Alghero (SS), Italy
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Acchione M, Lee YC, DeSantis ME, Lipschultz CA, Wlodawer A, Li M, Shanmuganathan A, Walter RL, Smith-Gill S, Barchi JJ. Specific fluorine labeling of the HyHEL10 antibody affects antigen binding and dynamics. Biochemistry 2012; 51:6017-27. [PMID: 22769726 PMCID: PMC3508667 DOI: 10.1021/bi300455t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To more fully understand the molecular mechanisms responsible for variations in binding affinity with antibody maturation, we explored the use of site specific fluorine labeling and (19)F nuclear magnetic resonance (NMR). Several single-chain (scFv) antibodies, derived from an affinity-matured series of anti-hen egg white lysozyme (HEL) mouse IgG1, were constructed with either complete or individual replacement of tryptophan residues with 5-fluorotryptophan ((5F)W). An array of biophysical techniques was used to gain insight into the impact of fluorine substitution on the overall protein structure and antigen binding. SPR measurements indicated that (5F)W incorporation lowered binding affinity for the HEL antigen. The degree of analogue impact was residue-dependent, and the greatest decrease in affinity was observed when (5F)W was substituted for residues near the binding interface. In contrast, corresponding crystal structures in complex with HEL were essentially indistinguishable from the unsubstituted antibody. (19)F NMR analysis showed severe overlap of signals in the free fluorinated protein that was resolved upon binding to antigen, suggesting very distinct chemical environments for each (5F)W in the complex. Preliminary relaxation analysis suggested the presence of chemical exchange in the antibody-antigen complex that could not be observed by X-ray crystallography. These data demonstrate that fluorine NMR can be an extremely useful tool for discerning structural changes in scFv antibody-antigen complexes with altered function that may not be discernible by other biophysical techniques.
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Affiliation(s)
- Mauro Acchione
- Structural Biophysics Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Yi-Chien Lee
- Chemical Biology Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Morgan E. DeSantis
- Structural Biophysics Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Claudia A. Lipschultz
- Structural Biophysics Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Alexander Wlodawer
- Macromolecular Crystallography Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Mi Li
- Macromolecular Crystallography Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
- Basic Research Program, SAIC-Frederick, Frederick, Maryland 21702, United States
| | - Aranganathan Shanmuganathan
- Structural Biophysics Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Richard L. Walter
- Structural Biophysics Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Sandra Smith-Gill
- Structural Biophysics Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Joseph J. Barchi
- Chemical Biology Laboratory, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
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14
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Films of arabinoxylans and β-glucans extracted from cereal grains: Molecular motions by TD-NMR. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.05.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Le Feunteun S, Diat O, Guillermo A, Poulesquen A, Podor R. NMR 1D-imaging of water infiltration into mesoporous matrices. Magn Reson Imaging 2010; 29:443-55. [PMID: 21129875 DOI: 10.1016/j.mri.2010.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 09/07/2010] [Accepted: 10/07/2010] [Indexed: 11/27/2022]
Abstract
It is shown that coupling nuclear magnetic resonance (NMR) 1D-imaging with the measure of NMR relaxation times and self-diffusion coefficients can be a very powerful approach to investigate fluid infiltration into porous media. Such an experimental design was used to study the very slow seeping of pure water into hydrophobic materials. We consider here three model samples of nuclear waste conditioning matrices which consist in a dispersion of NaNO(3) (highly soluble) and/or BaSO(4) (poorly soluble) salt grains embedded in a bitumen matrix. Beyond studying the moisture progression according to the sample depth, we analyze the water NMR relaxation times and self-diffusion coefficients along its 1D-concentration profile to obtain spatially resolved information on the solution properties and on the porous structure at different scales. It is also shown that, when the relaxation or self-diffusion properties are multimodal, the 1D-profile of each water population is recovered. Three main levels of information were disclosed along the depth-profiles. They concern (i) the water uptake kinetics, (ii) the salinity and the molecular dynamics of the infiltrated solutions and (iii) the microstructure of the water-filled porosities: open networks coexisting with closed pores. All these findings were fully validated and enriched by NMR cryoporometry experiments and by performing environmental scanning electronic microscopy observations. Surprisingly, results clearly show that insoluble salts enhance the water progression and thereby increase the capability of the material to uptake water.
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Davies E, Huang Y, Harper JB, Hook JM, Thomas DS, Burgar IM, Lillford PJ. Dynamics of water in agar gels studied using low and high resolution 1H NMR spectroscopy. Int J Food Sci Technol 2010. [DOI: 10.1111/j.1365-2621.2010.02448.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Enantiodifferent proton exchange in alanine and asparagine in the presence of H(2)(17)O. J Mol Evol 2010; 71:23-33. [PMID: 20593168 DOI: 10.1007/s00239-010-9361-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Accepted: 05/26/2010] [Indexed: 10/19/2022]
Abstract
Using Time Domain (1)H Nuclear Magnetic Resonance with H (2) (17) O (H (2) (17) O-TD-(1)HNMR), we found [H (2) (17) O]- and pH-controlled chiral differences in proton exchange properties in alanine (Ala) and asparagine (Asn). To minimize and equalize chemical impurities, Asn enantiomers were purified by crystallization from racemic solution. At <0.1 M H (2) (17) O, a shift in isoelectric pH (pI) occurred, approximately 1.14 kJ mol(-1) L: -D: -Asn DeltaDeltaG (o)' in the 5.91-6.42 pH range. One potential source for this asymmetry is the enantio-different magnetic moments (L: mu upward arrow not equal D: mu downward arrow) produced by neutral ring currents in the chiral center, leading to enantio-different nuclear spin organization and charge distribution in the amino group. At >or=pI, dissimilar interactions may occur in the hydration of the amino group with H (2) (17) O (NH(2)/H (2) (17) O not equal NH(2)/H (2) (16) O; NH(3) (+)/H (2) (17) O not equal NH(2)/H (2) (17) O; L: -*C-NH(2)/H (2) (17) O not equal D: -*C-NH(2)/H (2) (17) O). As L: mu upward arrow not equal D: mu downward arrow, the L: -*C-amino and the D: -*C-amino groups are diastereo spin-isomers. The nuclear spin of (17)O may be parallel or antiparallel with the ortho-(1)H(1)H pair; hence two ortho-H (2) (17) O molecules exist, also diastereo spin-isomers. As the pK of H (2) (17) O is different from H (2) (16) O, dissimilarities between L: -*C- and D: -*C-amino groups are converted into proton exchange differences. During H (2) (17) O-TD-(1)HNMR, the H (2) (17) O molecule is a "probe" of the state of the amino group. Regarding prebiotic evolution: prebiotic chirality may not require stochastic symmetry breaking or preexisting chiral conditions; chemical chiral effects due to L: mu upward arrow not equal D: mu downward arrow are small and need chiral amplification to generate an enantiomeric excess significant for prebiotic evolution; and prebiotic symmetry breaking was homochiral because the effect of L: mu upward arrow and D: mu downward arrow on the amino group should be similar in all alpha amino acids.
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Mitchell J, Chandrasekera TC, Gladden LF. Obtaining true transverse relaxation time distributions in high-field NMR measurements of saturated porous media: Removing the influence of internal gradients. J Chem Phys 2010; 132:244705. [DOI: 10.1063/1.3446805] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Calucci L, Forte C, Ranucci E. Water/polymer interactions in poly(amidoamine) hydrogels by H1 nuclear magnetic resonance relaxation and magnetization transfer. J Chem Phys 2008; 129:064511. [DOI: 10.1063/1.2968606] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jee J, Ishima R, Gronenborn AM. Characterization of Specific Protein Association by 15N CPMG Relaxation Dispersion NMR: The GB1A34F Monomer−Dimer Equilibrium. J Phys Chem B 2007; 112:6008-12. [DOI: 10.1021/jp076094h] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- JunGoo Jee
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260
| | - Angela M. Gronenborn
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260
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Scorei RI, Cimpoiaşu VM, Popa R. TD-1HNMR measurements show enantioselective dissociation of ribose and glucose in the presence of H2(17)O. ASTROBIOLOGY 2007; 7:733-744. [PMID: 17963473 DOI: 10.1089/ast.2006.0076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We used Time Domain (1)H Nuclear Magnetic Resonance (NMR) to characterize changes in proton exchange between water and sugar enantiomers at different concentrations of H(2)(17)O (approximately 15-450 mM) and found that dissociation of the (-)-enantiomers of glucose and ribose occurs at significantly higher rates at higher concentrations of H(2)(17)O. The mechanism behind this enantioselective effect is unclear. The hypothesis we propose is that the large magnetic field (B(o) approximately 0.6T) applied during NMR measurements induces electric moments opposite in sign for the D and L-isomers. Because (17)O has a nuclear electric quadrupole moment not = 0, asymmetrically hydrated complexes may form between the B(o)-polarized enantiomers and H(2)(17)O. Either H(2)(17)O is more often hydrating the (+) than the (-)-enantiomers--and consequently pK differences between H(2)(16)O and H(2)(17)O lead to differences in proton exchange between enantiomers and water--or the orientation of H(2)(17)O relative to the B(o)-polarized enantiomers is different, in total or in part, which leads to hydrated complexes with different spatial geometries and different proton exchange properties. This effect is significant for Magneto-Chiral Stereo-Chemistry (MCSC) and astrobiology, and it may help us better understand specific instances of mass independent isotopic fractionation and aid in the development of new technologies for chiral and isotopic separation.
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Hürlimann MD, Burcaw L, Song YQ. Quantitative characterization of food products by two-dimensional D– and – distribution functions in a static gradient. J Colloid Interface Sci 2006; 297:303-11. [PMID: 16300777 DOI: 10.1016/j.jcis.2005.10.047] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Revised: 10/17/2005] [Accepted: 10/22/2005] [Indexed: 11/24/2022]
Abstract
We present new NMR techniques to characterize food products that are based on the measurement of two-dimensional diffusion-T2 relaxation and T1-T2 relaxation distribution functions. These measurements can be performed in magnets of modest strength and low homogeneity and do not require pulsed gradients. As an illustration, we present measurements on a range of dairy products that include milks, yogurt, cream, and cheeses. The two-dimensional distribution functions generally exhibit two distinct components that correspond to the aqueous phase and the liquid fat content. The aqueous phase exhibits a relatively sharp peak, characterized by a large T1/T2 ratio of around 4. The diffusion coefficient and relaxation times are reduced from the values for bulk water by an amount that is sample specific. The fat signal has a similar signature in all samples. It is characterized by a wide T2 distribution and a diffusion coefficient of 10(-11) m2/s for a diffusion time of 40 ms, determined by bounded diffusion in the fat globules of 3 microm diameter.
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Affiliation(s)
- Martin D Hürlimann
- Schlumberger-Doll Research, 36 Old Quarry Road, Ridgefield, CT 06877, USA.
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