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Dobre A, Koutsoukos S, Philippi F, Rauber D, Kay CWM, Palumbo O, Roessler MM, Welton T. Understanding the effects of targeted modifications on the 1 : 2 Choline And GEranate structure. Phys Chem Chem Phys 2024; 26:8858-8872. [PMID: 38426306 DOI: 10.1039/d3cp05271k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
1 : 2 Choline-and-geranate (CAGE) is an ionic liquid (IL) widely studied for its biomedical applications. However, both its industrial-scale preparation and its long-term storage are problematic so finding more suitable candidates which retain its advantageous properties is crucial. As a first step towards this we have conducted a targeted modification study to understand the effects of specific functional groups on the properties of CAGE. 1 : 2 Choline-and-octanoate and 1 : 2 butyltrimethylammonium-and-octanoate were synthesised and their thermal and rheological properties examined in comparison to those of CAGE. Using differential scanning calorimetry and polarising microscopy, the model compound was found to be an isotropic liquid, while the analogues were room-temperature liquid-crystals which transition to isotropic liquids upon heating. Dynamic mechanical analysis showed that the thermal behaviour of the studied systems was even more complex, with the ILs also undergoing a thermally-activated relaxation process. Furthermore, we have used electron paramagnetic resonance (EPR) spectroscopy, along with a variety of spin probes with different functional groups, in order to understand the chemical environment experienced by solutes in each system. The EPR spectra indicate that the radicals experience two distinct environments (polar and nonpolar) in the liquid-crystalline phase, but only one average environment in the isotropic phase. The liquid-crystalline phase experiments also showed that the relative populations of the two domains depend on the nature of the solutes, with polar or strongly hydrogen-bonding solutes preferring the polar domain. For charged solutes, the EPR spectra showed line-broadening, suggesting that their ionic nature leads to complex, unresolved interactions.
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Affiliation(s)
- Ana Dobre
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.
| | - Spyridon Koutsoukos
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.
- Centre for Pulse EPR Spectroscopy (PEPR), Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Frederik Philippi
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.
| | - Daniel Rauber
- Department of Chemistry, Saarland University, Campus B2.2, Saarbrücken, Germany
| | - Christopher W M Kay
- Department of Chemistry, Saarland University, Campus B2.2, Saarbrücken, Germany
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK
| | - Oriele Palumbo
- Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Maxie M Roessler
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.
- Centre for Pulse EPR Spectroscopy (PEPR), Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Tom Welton
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.
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2
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Hashemi Haeri H, Schneegans N, Eisenschmidt-Bönn D, Brandt W, Wittstock U, Hinderberger D. Characterization of the active site in the thiocyanate-forming protein from Thlaspi arvense (TaTFP) using EPR spectroscopy. Biol Chem 2024; 405:105-118. [PMID: 37586381 DOI: 10.1515/hsz-2023-0187] [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: 04/16/2023] [Accepted: 07/19/2023] [Indexed: 08/18/2023]
Abstract
Glucosinolates are plant thioglucosides, which act as chemical defenses. Upon tissue damage, their myrosinase-catalyzed hydrolysis yields aglucones that rearrange to toxic isothiocyanates. Specifier proteins such as thiocyanate-forming protein from Thlaspi arvense (TaTFP) are non-heme iron proteins, which capture the aglucone to form alternative products, e.g. nitriles or thiocyanates. To resolve the electronic state of the bound iron cofactor in TaTFP, we applied continuous wave electron paramagnetic resonance (CW EPR) spectroscopy at X-and Q-band frequencies (∼9.4 and ∼34 GHz). We found characteristic features of high spin and low spin states of a d 5 electronic configuration and local rhombic symmetry during catalysis. We monitored the oxidation states of bound iron during conversion of allylglucosinolate by myrosinase and TaTFP in presence and absence of supplemented Fe2+. Without added Fe2+, most high spin features of bound Fe3+ were preserved, while different g'-values of the low spin part indicated slight rearrangements in the coordination sphere and/or structural geometry. We also examined involvement of the redox pair Fe3+/Fe2 in samples with supplemented Fe2+. The absence of any EPR signal related to Fe3+ or Fe2+ using an iron-binding deficient TaTFP variant allowed us to conclude that recorded EPR signals originated from the bound iron cofactor.
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Affiliation(s)
- Haleh Hashemi Haeri
- Martin Luther University Halle-Wittenberg, Institute of Chemistry, Von-Danckelmann-Platz 4, D-06120 Halle (Saale), Germany
| | - Nicola Schneegans
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - Daniela Eisenschmidt-Bönn
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Wolfgang Brandt
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany
| | - Ute Wittstock
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - Dariush Hinderberger
- Martin Luther University Halle-Wittenberg, Institute of Chemistry, Von-Danckelmann-Platz 4, D-06120 Halle (Saale), Germany
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3
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Brás EM, Zimmermann C, Fausto R, Suhm MA. Benchmarking the anisotropy of nitroxyl radical solvation with IR spectroscopy. Phys Chem Chem Phys 2024; 26:5822-5829. [PMID: 38314587 DOI: 10.1039/d3cp05668f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Two simple nitroxyl radicals, di-tert-butyl nitroxyl (DTBN) and 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) are solvated by one or two water, methanol, tert-butyl alcohol or phenol molecules. The resulting low temperature IR spectra of the vacuum-isolated microsolvates in the OH stretching range are assigned based on harmonic DFT predictions for closed shell solvent dimers and trimers and their offset from experiment, to minimise theory-guided assignment bias. Systematic conformational preferences for the first and second solvent molecule are observed, depending on the conformational rigidity of the radical. These assignments are collected into an experimental benchmark data set and used to assess the spectral predicting power of different DFT approaches. The goal is to find inexpensive computational methods which provide reliable spectral predictions for this poorly explored class of microsolvates.
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Affiliation(s)
- Elisa M Brás
- University of Göttingen, Institute of Physical Chemistry, Tammannstr. 6, 37077 Göttingen, Germany.
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Charlotte Zimmermann
- University of Göttingen, Institute of Physical Chemistry, Tammannstr. 6, 37077 Göttingen, Germany.
| | - Rui Fausto
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- Faculty of Sciences and Letters, Department of Physics, Istanbul Kultur University, Ataköy Campus, Bakirköy 34156, Istanbul, Turkey
| | - Martin A Suhm
- University of Göttingen, Institute of Physical Chemistry, Tammannstr. 6, 37077 Göttingen, Germany.
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4
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Träger J, Meister A, Hause G, Harauz G, Hinderberger D. Shaping membrane interfaces in lipid vesicles mimicking the cytoplasmic leaflet of myelin through variation of cholesterol and myelin basic protein contents. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184179. [PMID: 37244538 DOI: 10.1016/j.bbamem.2023.184179] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/23/2023] [Accepted: 05/20/2023] [Indexed: 05/29/2023]
Abstract
Myelin basic protein (MBP) is an intrinsically disordered protein and in the central nervous system (CNS) mainly responsible for connecting the cytoplasmic surfaces of the multilamellar, compact myelin. Increased posttranslational modification of MBP is linked to both, the natural development (from adolescent to adult brains) of myelin, and features of multiple sclerosis. Here, we study how a combination of this intrinsically disordered myelin protein with varying the natural cholesterol content may alter the characteristics of myelin-like membranes and interactions between these membranes. Large unilamellar vesicles (LUVs) with a composition mimicking the cytoplasmic leaflet of myelin were chosen as the model system, in which different parameters contributing to the interactions between the lipid membrane and MBP were investigated. While we use cryo-transmission electron microscopy (TEM) for imaging, dynamic light scattering (DLS) and electrophoretic measurements through continuously-monitored phase-analysis light scattering (cmPALS) were used for a more global overview of particle size and charge, and electron paramagnetic resonance (EPR) spectroscopy was utilized for local behavior of lipids in the vesicles' membranes in aqueous solution. The cholesterol content was varied from 060 % in these LUVs and measurements were performed in the presence and absence of MBP. We find that the composition of the lipid layers is relevant to the interaction with MBP. Not only the size, the shape and the aggregation behavior of the vesicles depend on the cholesterol content, but also within each membrane, cholesterol's freedom of movement, its environmental polarity and its distribution were found to depend on the content using the EPR-active spin-labeled cholesterol (CSOSL). In addition, DLS and EPR measurements probing the transition temperatures of the lipid phases allow a correlation of specific behavior with the human body temperature of 37 °C. Overall, our results aid in understanding the importance of the native cholesterol content in the healthy myelin membrane, which serves as the basis for stable and optimum protein-bilayer interactions. Although studied in this specific myelin-like system, from a more general and materials science-oriented point of view, we could establish how membrane and vesicle properties depend on cholesterol and/or MBP content, which might be useful generally when specific membrane and vesicle characteristics are sought for.
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Affiliation(s)
- Jennica Träger
- Institute of Chemistry, Physical Chemistry - Complex Self-organizing Systems, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Saxony-Anhalt, Germany; Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, Germany
| | - Annette Meister
- Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, Germany; Institute of Biochemistry, Physical Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - Gerd Hause
- Biocenter, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - George Harauz
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Dariush Hinderberger
- Institute of Chemistry, Physical Chemistry - Complex Self-organizing Systems, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Saxony-Anhalt, Germany; Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, Germany.
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5
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Haeri H, Eisermann J, Schimm H, Büscher A, Hoyer P, Hinderberger D. Profound Changes in Functional Structure and Dynamics of Serum Albumin in Children with Nephrotic Syndrome: An Exploratory Research Study. J Med Chem 2023; 66:12115-12129. [PMID: 37648246 PMCID: PMC10510392 DOI: 10.1021/acs.jmedchem.3c00680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 09/01/2023]
Abstract
Patients with nephrotic syndrome (NS) suffer from urinary loss of albumin. As a cause, previous studies focused on the glomerular filter rather than analyzing the molecular properties of albumin itself. Later one was initiated by clinical observations indicating unexplained molecular alterations of human serum albumin (HSA) in an NS pediatric patient. Therefore, we examined serum from eight pediatric patients with steroid-sensitive and -resistant NS and compared it with serum from healthy subjects as well as commercial HSA. We used dynamic and electrophoretic light scattering to characterize the protein size and effective surface charge and electron paramagnetic resonance spectroscopy to measure the local environment and binding dynamics of up to seven fatty acids associated with HSA. Our findings suggest that pronounced differences in binding behavior and surface charge of HSA could enhance their filtration through the GBM, leading to direct toxicity of HSA to podocytes.
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Affiliation(s)
- Haleh
H. Haeri
- Physical
Chemistry, Complex Self-Organizing Systems, Martin Luther University
Halle-Wittenberg, Institute of Chemistry, Von Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Jana Eisermann
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Ln, W12 0BZ London, U.K.
| | - Heike Schimm
- Physical
Chemistry, Complex Self-Organizing Systems, Martin Luther University
Halle-Wittenberg, Institute of Chemistry, Von Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Anja Büscher
- Universitätsklinikum
Essen (AöR), Klinik für Kinderheilkunde II, Zentrum
für Kinder- und Jugendmedizin, Hufelandstraße 55, D-45147 Essen, Germany
| | - Peter Hoyer
- Universitätsklinikum
Essen (AöR), Klinik für Kinderheilkunde II, Zentrum
für Kinder- und Jugendmedizin, Hufelandstraße 55, D-45147 Essen, Germany
| | - Dariush Hinderberger
- Physical
Chemistry, Complex Self-Organizing Systems, Martin Luther University
Halle-Wittenberg, Institute of Chemistry, Von Danckelmann-Platz 4, 06120 Halle (Saale), Germany
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Elkhanoufi S, Stefania R, Alberti D, Baroni S, Aime S, Geninatti Crich S. Highly Sensitive “Off/On” EPR Probes to Monitor Enzymatic Activity. Chemistry 2022; 28:e202104563. [PMID: 35175676 PMCID: PMC9314618 DOI: 10.1002/chem.202104563] [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: 12/23/2021] [Indexed: 11/16/2022]
Abstract
The assessment of unregulated level of enzyme activity is a crucial parameter for early diagnoses in a wide range of pathologies. In this study, we propose the use of electron paramagnetic resonance (EPR) as an easy method to probe carboxylesterase (CE) enzymatic activity in vitro. For this application, were synthesized two amphiphilic, nitroxide containing esters, namely Tempo‐C12 (T‐C12) and Tempo‐2‐C12 (T‐2‐C12). They exhibit low solubility in water and form stable micelles in which the radicals are EPR almost silent, but the hydrolysis of the ester bond yields narrows and intense EPR signals. The intensity of the EPR signals is proportional to the enzymatic activity. CEs1, CEs2 and esterase from porcine liver (PLE) were investigated. The obtained results show that T‐C12 and T‐2‐C12‐containing systems display a much higher selectivity toward the CEs2, with a Limit of Detection of the same order of those ones obtained with optical methods.
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Affiliation(s)
- Sabrina Elkhanoufi
- University of Torino Department of Molecular Biotechnology and Health Sciences via Nizza 52 10126 Torino Italy
| | - Rachele Stefania
- University of Torino Department of Molecular Biotechnology and Health Sciences via Nizza 52 10126 Torino Italy
| | - Diego Alberti
- University of Torino Department of Molecular Biotechnology and Health Sciences via Nizza 52 10126 Torino Italy
| | - Simona Baroni
- University of Torino Department of Molecular Biotechnology and Health Sciences via Nizza 52 10126 Torino Italy
| | - Silvio Aime
- University of Torino Department of Molecular Biotechnology and Health Sciences via Nizza 52 10126 Torino Italy
| | - Simonetta Geninatti Crich
- University of Torino Department of Molecular Biotechnology and Health Sciences via Nizza 52 10126 Torino Italy
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Byra N, Krukowski S, Sadlo J, Kolodziejski W. Composites Containing Nanohydroxyapatites and a Stable TEMPO Radical: Preparation and Characterization Using Spectrophotometry, EPR and 1H MAS NMR. MATERIALS 2022; 15:ma15062043. [PMID: 35329493 PMCID: PMC8952365 DOI: 10.3390/ma15062043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/05/2022] [Accepted: 03/08/2022] [Indexed: 02/01/2023]
Abstract
Hydroxyapatite is the main constituent of mammalian hard tissues. Basic applications of synthetic hydroxyapatites include bone and dental implantology and drug delivery systems. The study of hydroxyapatite surface properties could give greater insight into the processes of bone mineralization and degradation. Nitroxide radicals are stable radicals that exhibit anticancer and antioxidative properties and are often used as spin probes to study the dynamics of complex biological systems. In this work, we attempted to adsorb the stable 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) on two hydroxyapatites (HAs) differing in specific surface area and the degree of hydration. The adsorption was carried out from cyclohexane, 1-chlorobutane and water. The solutions after adsorption were studied spectrophotometrically, while the obtained composites were characterized via NMR and EPR spectroscopy. The results show that it is possible to reproducibly obtain fairly stable composites, where the main factors influencing the adsorbed amount of the radical are solvent polarity and specific surface area of hydroxyapatite. The Langmuir isotherm was determined to be the most suitable adsorption model. The analysis of EPR and NMR spectra allowed us to determine the distribution of the TEMPO molecules on the hydroxyapatite surface, as well as a probable adsorption mechanism. The HA/TEMPO composites could potentially be used to study certain properties of hydroxyapatite surfaces with EPR spectroscopy. They could also be used as fillers after hard tissue surgery, as well as metal-free MRI contrasts.
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Affiliation(s)
- Natalia Byra
- Department of Analytical Chemistry, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland; (S.K.); (W.K.)
- Correspondence:
| | - Sylwester Krukowski
- Department of Analytical Chemistry, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland; (S.K.); (W.K.)
| | - Jaroslaw Sadlo
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland;
| | - Waclaw Kolodziejski
- Department of Analytical Chemistry, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland; (S.K.); (W.K.)
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Inhomogeneities in PNIPAM Aqueous Solutions: The Inside View by Spin Probe EPR Spectroscopy. Polymers (Basel) 2021; 13:polym13213829. [PMID: 34771385 PMCID: PMC8588346 DOI: 10.3390/polym13213829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 01/15/2023] Open
Abstract
Coil to globule transition in poly(N-isopropylacrylamide) aqueous solutions was studied using spin probe continuous-wave electronic paramagnetic resonance (CW EPR) spectroscopy with an amphiphilic TEMPO radical as a guest molecule. Using Cu(II) ions as the “quencher” for fast-moving radicals in the liquid phase allowed obtaining the individual spectra of TEMPO radicals in polymer globule and observing inhomogeneities in solutions before globule collapsing. EPR spectra simulations confirm the formation of molten globules at the first step with further collapsing and water molecules coming out of the globule, making it denser.
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9
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Brás EM, Fischer TL, Suhm MA. The Hydrates of TEMPO: Water Vibrations Reveal Radical Microsolvation. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Elisa M. Brás
- CQC Department of Chemistry University of Coimbra 3004-535 Coimbra Portugal
- Institut für Physikalische Chemie Georg-August-Universität Göttingen Tammannstr. 6 37077 Göttingen Germany
| | - Taija L. Fischer
- Institut für Physikalische Chemie Georg-August-Universität Göttingen Tammannstr. 6 37077 Göttingen Germany
| | - Martin A. Suhm
- Institut für Physikalische Chemie Georg-August-Universität Göttingen Tammannstr. 6 37077 Göttingen Germany
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10
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Brás EM, Fischer TL, Suhm MA. The Hydrates of TEMPO: Water Vibrations Reveal Radical Microsolvation. Angew Chem Int Ed Engl 2021; 60:19013-19017. [PMID: 34165885 PMCID: PMC8456822 DOI: 10.1002/anie.202104496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/01/2021] [Indexed: 12/12/2022]
Abstract
An organic radical monohydrate complex is detected in vacuum isolation at low temperature by FTIR supersonic jet spectroscopy for the first time. It is shown to exhibit a rich conformational and vibrational coupling dynamics, which can be drastically reduced by appropriate isotope substitution. Its detection with a new gas recycling infrared spectrometer demonstrates the thermal metastability of the gaseous TEMPO radical even under humid gas conditions. Compared to its almost isoelectronic and isostructural, closed shell ketone analogue, the hydrogen bond of the solvating water is found to be less directional, but stronger and more strongly downshifting the bonded water OH stretch vibration. A second solvent water directs the first one into a metastable hydrogen bond position to solvate the nitrogen center and the first water at the same time.
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Affiliation(s)
- Elisa M. Brás
- CQCDepartment of ChemistryUniversity of Coimbra3004-535CoimbraPortugal
- Institut für Physikalische ChemieGeorg-August-Universität GöttingenTammannstr. 637077GöttingenGermany
| | - Taija L. Fischer
- Institut für Physikalische ChemieGeorg-August-Universität GöttingenTammannstr. 637077GöttingenGermany
| | - Martin A. Suhm
- Institut für Physikalische ChemieGeorg-August-Universität GöttingenTammannstr. 637077GöttingenGermany
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11
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Roos AH, Hoffmann JF, Binder WH, Hinderberger D. Nanoscale structure and dynamics of thermoresponsive single-chain nanoparticles investigated by EPR spectroscopy. SOFT MATTER 2021; 17:7032-7037. [PMID: 34251013 DOI: 10.1039/d1sm00582k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We characterize temperature-dependent macroscopic and nanoscopic phase transitions and nanoscopic pre-transitions of water-soluble single chain nanoparticles (SCNPs). The studied SCNPs are based on polymers displaying lower-critical solution temperature (LCST) behavior and show nanoscale compartmentation. SCNPs are amenable to continuous wave electron paramagnetic resonance (CW EPR) spectroscopy to study how amphiphilic, non-covalently added nitroxide spin probes or covalently attached spin labels sample their environment concerning nanoscale structures (polarity, hydrophilicity/-phobicity) and dynamics. These SCNPs are formed through single-chain collapse and have been shown to have nanosized compartments that are rigidified during the crosslinking process. We analyze the temperature-dependent phase transitions of spin-labeled SCNPs by rigorous spectral simulations of a series of multicomponent EPR-spectra that derive from the nanoinhomogeneities (1) that are due to the single-chain compartmentation in SCNPs and (2) the transformation upon temperature change due to the LCST behavior. These transitions of the SCNPs and their respective polymer precursors can be monitored and understood on the nanoscale by following EPR-spectroscopic parameters like hyperfine couplings that depend on the surrounding solvent molecules or Heisenberg spin exchange between small molecule spin probes or covalently attached spin labels in the nanocompartments. In particular, for one SCNP, we find an interesting behavior that we ascribe to the properties of the nanosized inner core with continuous effects before and jump-like changes after the macroscopic thermal collapse, indicating highly efficient desolvation and compaction upon an increase in temperature and aggregation of individual nanoparticles above the collapse temperature.
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Affiliation(s)
- Andreas H Roos
- Institute of Chemistry, Martin Luther University (MLU) Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Justus F Hoffmann
- Institute of Chemistry, Martin Luther University (MLU) Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Wolfgang H Binder
- Institute of Chemistry, Martin Luther University (MLU) Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Dariush Hinderberger
- Institute of Chemistry, Martin Luther University (MLU) Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
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Eisermann J, Hoffmann M, Schöffmann FA, Das M, Vargas C, Keller S, Hinderberger D. Molecular‐Level Interactions of Nanodisc‐Forming Copolymers Dissected by EPR Spectroscopy. MACROMOL CHEM PHYS 2021. [DOI: 10.1002/macp.202100051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Jana Eisermann
- Institute of Chemistry–Physical Chemistry–Complex Self‐Organizing Systems Martin Luther University (MLU) Halle‐Wittenberg Von‐Danckelmann‐Platz 4 06120 Halle (Saale) Germany
- Department of Chemistry – Molecular Sciences Research Hub Imperial College London 82 Wood Ln London W12 0BZ UK
| | - Matthias Hoffmann
- Institute of Chemistry–Physical Chemistry–Complex Self‐Organizing Systems Martin Luther University (MLU) Halle‐Wittenberg Von‐Danckelmann‐Platz 4 06120 Halle (Saale) Germany
- Interdisciplinary Research Center HALOmem MLU Halle‐Wittenberg Charles Tanford Protein Center Kurt‐Mothes‐Str. 3a 06120 Halle (Saale) Germany
| | - Florian A. Schöffmann
- Institute of Chemistry–Physical Chemistry–Complex Self‐Organizing Systems Martin Luther University (MLU) Halle‐Wittenberg Von‐Danckelmann‐Platz 4 06120 Halle (Saale) Germany
- Interdisciplinary Research Center HALOmem MLU Halle‐Wittenberg Charles Tanford Protein Center Kurt‐Mothes‐Str. 3a 06120 Halle (Saale) Germany
| | - Manabendra Das
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Erwin‐Schrödinger‐Str. 13 67663 Kaiserslautern Germany
| | - Carolyn Vargas
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Erwin‐Schrödinger‐Str. 13 67663 Kaiserslautern Germany
- Department of Biophysics Institute of Molecular Biosciences (IMB) NAWI Graz University of Graz Humboldtstr Graz 8010 Austria
- Field of Excellence BioHealth University of Graz Humboldtstr, 50/I Graz 8010 Austria
- BioTechMed‐Graz Mozartstr, 12/II Graz 8010 Austria
| | - Sandro Keller
- Molecular Biophysics Technische Universität Kaiserslautern (TUK) Erwin‐Schrödinger‐Str. 13 67663 Kaiserslautern Germany
- Department of Biophysics Institute of Molecular Biosciences (IMB) NAWI Graz University of Graz Humboldtstr Graz 8010 Austria
- Field of Excellence BioHealth University of Graz Humboldtstr, 50/I Graz 8010 Austria
- BioTechMed‐Graz Mozartstr, 12/II Graz 8010 Austria
| | - Dariush Hinderberger
- Institute of Chemistry–Physical Chemistry–Complex Self‐Organizing Systems Martin Luther University (MLU) Halle‐Wittenberg Von‐Danckelmann‐Platz 4 06120 Halle (Saale) Germany
- Interdisciplinary Research Center HALOmem MLU Halle‐Wittenberg Charles Tanford Protein Center Kurt‐Mothes‐Str. 3a 06120 Halle (Saale) Germany
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H. Haeri H, Jerschabek V, Sadeghi A, Hinderberger D. Copper–Calcium Poly(Acrylic Acid) Composite Hydrogels as Studied by Electron Paramagnetic Resonance (EPR) Spectroscopy. MACROMOL CHEM PHYS 2020. [DOI: 10.1002/macp.202000262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Haleh H. Haeri
- Institut für Chemie Martin‐Luther‐Universität Halle‐Wittenberg Von‐Danckelmann‐Platz 4 Halle (Saale) 06120 Germany
| | - Vanessa Jerschabek
- Institut für Chemie Martin‐Luther‐Universität Halle‐Wittenberg Von‐Danckelmann‐Platz 4 Halle (Saale) 06120 Germany
| | - Arash Sadeghi
- Institut für Chemie Martin‐Luther‐Universität Halle‐Wittenberg Von‐Danckelmann‐Platz 4 Halle (Saale) 06120 Germany
| | - Dariush Hinderberger
- Institut für Chemie Martin‐Luther‐Universität Halle‐Wittenberg Von‐Danckelmann‐Platz 4 Halle (Saale) 06120 Germany
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Haeri HH, Tomaszewski J, Phytides B, Schimm H, Möslein G, Niedergethmann M, Hinderberger D, Gelos M. Identification of Patients with Pancreatic Cancer by Electron Paramagnetic Resonance Spectroscopy of Fatty Acid Binding to Human Serum Albumin. ACS Pharmacol Transl Sci 2020; 3:1188-1198. [PMID: 33344896 DOI: 10.1021/acsptsci.0c00116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Indexed: 12/11/2022]
Abstract
An effective biological marker for pancreatic adenocarcinoma (PAC) is not available so far. Here, we investigate how electron paramagnetic resonance (EPR) spectroscopy of spin-labeled fatty acid (FA) molecules binding to human serum albumin (HSA) in human serum is a suitable method for the identification of patients with PAC through detection of PAC-induced changes of FA binding to albumin. The functionality of HSA to bind FA is investigated in serum samples of 35 patients with PAC, 26 patients with benign pancreatic tumors (BPD), and 24 healthy individuals by continuous wave (CW) EPR spectroscopy by simply dissolving 16-DOXYL stearic acid as spin-labeled FA. It is found that FA binding to HSA in PAC is significantly modified when compared with healthy and BPD individuals. The PAC group could best be discriminated from the healthy group based on EPR characteristics at the loading ratio of 1:4 (HSA:FA), while patients with PAC and BPD are distinguishable at a loading ratio of 1:6. Using nanoscale distance measurements through double electron-electron resonance (DEER), it is found that the distribution of FAs in the HSA of one PAC patient is similar to that of FAs in healthy individuals. Combining all EPR spectroscopic data, this leads to a tentative molecular interpretation of only small changes in hydration at the protein's surface as origin of the detectable characteristics for PAC patients. Thus, EPR of FA/HSA binding is a simple and promising tool for clinical detection of patients with PAC and needs to be tested with larger ensembles of different patient groups.
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Affiliation(s)
- Haleh H Haeri
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Jörg Tomaszewski
- Department of General and Visceral Surgery, Alfried Krupp Krankenhaus Essen, Essen, Nordrhein-Westfalen 45276, Germany
| | - Bettina Phytides
- Department of General and Visceral Surgery, Alfried Krupp Krankenhaus Essen, Essen, Nordrhein-Westfalen 45276, Germany
| | - Heike Schimm
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Gabriela Möslein
- Faculty of Health Sciences, University of Witten/Herdecke, Witten, Nordrhein-Westfalen 58448, Germany
| | - Marco Niedergethmann
- Department of General and Visceral Surgery, Alfried Krupp Krankenhaus Essen, Essen, Nordrhein-Westfalen 45276, Germany
| | - Dariush Hinderberger
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Marcos Gelos
- Faculty of Health Sciences, University of Witten/Herdecke, Witten, Nordrhein-Westfalen 58448, Germany
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