1
|
Singh SK, Atanasov M, Neese F. Challenges in Multireference Perturbation Theory for the Calculations of the g-Tensor of First-Row Transition-Metal Complexes. J Chem Theory Comput 2018; 14:4662-4677. [DOI: 10.1021/acs.jctc.8b00513] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saurabh Kumar Singh
- Department of Molecular Theory and Spectroscopy, Max-Planck Institute for Kohlenforschung, Kaiser Wilhelm-Platz-1, Mülheim an der Ruhr, Germany
| | - Mihail Atanasov
- Department of Molecular Theory and Spectroscopy, Max-Planck Institute for Kohlenforschung, Kaiser Wilhelm-Platz-1, Mülheim an der Ruhr, Germany
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Akad. Georgi Bontchev Street 11, 1113 Sofia, Bulgaria
| | - Frank Neese
- Department of Molecular Theory and Spectroscopy, Max-Planck Institute for Kohlenforschung, Kaiser Wilhelm-Platz-1, Mülheim an der Ruhr, Germany
| |
Collapse
|
2
|
Glasbrenner M, Vogler S, Ochsenfeld C. Gauge-origin dependence in electronic g-tensor calculations. J Chem Phys 2018; 148:214101. [DOI: 10.1063/1.5028454] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael Glasbrenner
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| | - Sigurd Vogler
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| | - Christian Ochsenfeld
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| |
Collapse
|
3
|
Lohmiller T, Vibhute MA, Lubitz W, Savitsky A. Multifrequency Multiresonance EPR Investigation of Halogen-bonded Complexes Involving Neutral Nitroxide Radicals. ACTA ACUST UNITED AC 2016. [DOI: 10.1515/zpch-2016-0870] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Halogen-bonded complexes with neutral nitroxide radicals as the Lewis base have been investigated in liquid and frozen solutions by multifrequency CW and pulse EPR spectroscopies, including ENDOR and ELDOR-detected NMR (EDNMR) techniques. The non-covalent interaction with iodopentafluorobenzene as halogen-bond donor is shown to affect a variety of EPR parameters of the stable nitroxide radicals. In liquid solution, only bulk effects on the EPR signal, i.e. isotropic g value, isotropic 14N hyperfine coupling and linewidth, are observed. Experiments on frozen solutions allow for a more in-depth dissection of complexing effects. W-band EPR spectra at cryogenic temperatures exhibit multiple signal components of different 14N hyperfine interactions and spectral widths. This demonstrates the coexistence of several halogen-bonded complexes that differ in donor-acceptor binding geometries. These complexes have different relaxation properties, which allow for their spectral discrimination. 19F ENDOR experiments prove the origin of these effects to be different specific intermolecular interactions rather than a consequence of changes in the solvation environment. The EPR spectra yet reveal a strong influence of solvent composition on the amount of the various complexes formed. The introduced methodology for the characterization of such adducts improves our understanding of halogen bonding and could be helpful in the development of tailor-made donors and complexes for specific applications.
Collapse
Affiliation(s)
- Thomas Lohmiller
- Max-Planck-Institut für Chemische Energiekonversion, 45470 Mülheim an der Ruhr, Germany
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Mahesh A. Vibhute
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion, 45470 Mülheim an der Ruhr, Germany
| | - Anton Savitsky
- Max-Planck-Institut für Chemische Energiekonversion, 45470 Mülheim an der Ruhr, Germany
| |
Collapse
|
4
|
Mathies G, Caporini MA, Michaelis VK, Liu Y, Hu KN, Mance D, Zweier JL, Rosay M, Baldus M, Griffin RG. Efficient Dynamic Nuclear Polarization at 800 MHz/527 GHz with Trityl-Nitroxide Biradicals. Angew Chem Int Ed Engl 2015; 54:11770-4. [PMID: 26268156 PMCID: PMC5407364 DOI: 10.1002/anie.201504292] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/16/2015] [Indexed: 11/08/2022]
Abstract
Cross-effect (CE) dynamic nuclear polarization (DNP) is a rapidly developing technique that enhances the signal intensities in magic-angle spinning (MAS) NMR spectra. We report CE DNP experiments at 211, 600, and 800 MHz using a new series of biradical polarizing agents referred to as TEMTriPols, in which a nitroxide (TEMPO) and a trityl radical are chemically tethered. The TEMTriPol molecule with the optimal performance yields a record (1) H NMR signal enhancement of 65 at 800 MHz at a concentration of 10 mM in a glycerol/water solvent matrix. The CE DNP enhancement for the TEMTriPol biradicals does not decrease as the magnetic field is increased in the manner usually observed for bis-nitroxides. Instead, the relatively strong exchange interaction between the trityl and nitroxide moieties determines the magnetic field at which the optimum enhancement is observed.
Collapse
Affiliation(s)
- Guinevere Mathies
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA).
| | - Marc A Caporini
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, MA 01821 (USA)
- Current address: Amgen Inc., 360 Binney Street, Cambridge, MA 02142 (USA)
| | - Vladimir K Michaelis
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA)
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling, Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin 300070 (China).
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210 (USA).
| | - Kan-Nian Hu
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA)
- Current address: Vertex Pharmaceuticals Incorporated, 50 Northern Avenue, Boston, MA 02210 (USA)
| | - Deni Mance
- NMR Spectroscopy, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht (The Netherlands)
| | - Jay L Zweier
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210 (USA)
| | - Melanie Rosay
- Bruker BioSpin Corporation, 15 Fortune Drive, Billerica, MA 01821 (USA)
| | - Marc Baldus
- NMR Spectroscopy, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht (The Netherlands)
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory, Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139 (USA).
| |
Collapse
|
5
|
Mathies G, Caporini MA, Michaelis VK, Liu Y, Hu KN, Mance D, Zweier JL, Rosay M, Baldus M, Griffin RG. Efficient Dynamic Nuclear Polarization at 800 MHz/527 GHz with Trityl-Nitroxide Biradicals. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504292] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
6
|
Nalepa A, Möbius K, Lubitz W, Savitsky A. High-field ELDOR-detected NMR study of a nitroxide radical in disordered solids: towards characterization of heterogeneity of microenvironments in spin-labeled systems. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 242:203-213. [PMID: 24685717 DOI: 10.1016/j.jmr.2014.02.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 02/27/2014] [Accepted: 02/28/2014] [Indexed: 06/03/2023]
Abstract
The combination of high-field EPR with site-directed spin-labeling (SDSL) techniques employing nitroxide radicals has turned out to be particularly powerful in probing the polarity and proticity characteristics of protein/matrix systems. This information is concluded from the principal components of the nitroxide Zeeman (g), nitrogen hyperfine (A) and quadrupole (P) tensors of the spin labels attached to specific sites. Recent multi-frequency high-field EPR studies underlined the complexity of the problem to treat the nitroxide microenvironment in proteins adequately due to inherent heterogeneities which result in several principal x-components of the nitroxide g-tensor. Concomitant, but distinctly different nitrogen hyperfine components could, however, not be determined from high-field cw EPR experiments owing to the large intrinsic EPR linewidth in fully protonated guest/host systems. It is shown in this work that, using the W-band (95GHz) ELDOR- (electron-electron double resonance) detected NMR (EDNMR) method, different principal nitrogen hyperfine, Azz, and quadrupole, Pzz, tensor values of a nitroxide radical in glassy 2-propanol matrix can be measured with high accuracy. They belong to nitroxides with different hydrogen-bond situations. The satisfactory resolution and superior sensitivity of EDNMR as compared to the standard ENDOR (electron-nuclear double resonance) method are demonstrated.
Collapse
Affiliation(s)
- Anna Nalepa
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Klaus Möbius
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany; Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Anton Savitsky
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
| |
Collapse
|
7
|
Application of Electron Paramagnetic Resonance Spectroscopy for Validation of the Novel (AN+DN) Solvent Polarity Scale. Int J Mol Sci 2008. [DOI: 10.3390/ijms9071321] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
8
|
Savitsky A, Dubinskii AA, Plato M, Grishin YA, Zimmermann H, Möbius K. High-Field EPR and ESEEM Investigation of the Nitrogen Quadrupole Interaction of Nitroxide Spin Labels in Disordered Solids: Toward Differentiation between Polarity and Proticity Matrix Effects on Protein Function. J Phys Chem B 2008; 112:9079-90. [DOI: 10.1021/jp711640p] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Savitsky
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany, Semenov Institute of Chemical Physics, Kosygina str. 4, 119991 Moscow, Russia, Institute of Chemical Kinetics and Combustion, Institutskaya str. 3, 630090 Novosibirsk, Russia, and Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - A. A. Dubinskii
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany, Semenov Institute of Chemical Physics, Kosygina str. 4, 119991 Moscow, Russia, Institute of Chemical Kinetics and Combustion, Institutskaya str. 3, 630090 Novosibirsk, Russia, and Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - M. Plato
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany, Semenov Institute of Chemical Physics, Kosygina str. 4, 119991 Moscow, Russia, Institute of Chemical Kinetics and Combustion, Institutskaya str. 3, 630090 Novosibirsk, Russia, and Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - Y. A. Grishin
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany, Semenov Institute of Chemical Physics, Kosygina str. 4, 119991 Moscow, Russia, Institute of Chemical Kinetics and Combustion, Institutskaya str. 3, 630090 Novosibirsk, Russia, and Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - H. Zimmermann
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany, Semenov Institute of Chemical Physics, Kosygina str. 4, 119991 Moscow, Russia, Institute of Chemical Kinetics and Combustion, Institutskaya str. 3, 630090 Novosibirsk, Russia, and Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - K. Möbius
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany, Semenov Institute of Chemical Physics, Kosygina str. 4, 119991 Moscow, Russia, Institute of Chemical Kinetics and Combustion, Institutskaya str. 3, 630090 Novosibirsk, Russia, and Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| |
Collapse
|
9
|
Smirnova TI, Chadwick TG, Voinov MA, Poluektov O, van Tol J, Ozarowski A, Schaaf G, Ryan MM, Bankaitis VA. Local polarity and hydrogen bonding inside the Sec14p phospholipid-binding cavity: high-field multi-frequency electron paramagnetic resonance studies. Biophys J 2007; 92:3686-95. [PMID: 17325006 PMCID: PMC1853156 DOI: 10.1529/biophysj.106.097899] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sec14p promotes the energy-independent transfer of either phosphatidylinositol (PtdIns) or phosphatidylcholine (PtdCho) between lipid bilayers in vitro and represents the major PtdIns/PtdCho transfer protein in the budding yeast Saccharomyces cerevisiae. Herein, we employ multi-frequency high-field electron paramagnetic resonance (EPR) to analyze the electrostatic and hydrogen-bonding microenvironments for series of doxyl-labeled PtdCho molecules bound by Sec14p in a soluble protein-PtdCho complex. A structurally similar compound, 5-doxyl stearic acid dissolved in a series of solvents, was used for experimental calibration. The experiments yielded two-component rigid limit 130- and 220-GHz EPR spectra with excellent resolution in the gx region. Those components were assigned to hydrogen-bonded and nonhydrogen-bonded nitroxide species. Partially resolved 130-GHz EPR spectra from n-doxyl-PtdCho bound to Sec14p were analyzed using this two-component model and allowed quantification of two parameters. First, the fraction of hydrogen-bonded nitroxide species for each n-doxyl-PtdCho was calculated. Second, the proticity profile along the phospholipid-binding cavity of Sec14p was characterized. The data suggest the polarity gradient inside the Sec14p cavity is a significant contributor to the driving molecular forces for extracting a phospholipid from the bilayer. Finally, the enhanced g-factor resolution of EPR at 130 and 220 GHz provides researchers with a spectroscopic tool to deconvolute two major contributions to the x-component of the nitroxide g-matrix: hydrogen-bond formation and local electrostatic effects.
Collapse
Affiliation(s)
- Tatyana I Smirnova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Sinnecker S, Rajendran A, Klamt A, Diedenhofen M, Neese F. Calculation of Solvent Shifts on Electronic g-Tensors with the Conductor-Like Screening Model (COSMO) and Its Self-Consistent Generalization to Real Solvents (Direct COSMO-RS). J Phys Chem A 2006; 110:2235-45. [PMID: 16466261 DOI: 10.1021/jp056016z] [Citation(s) in RCA: 477] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conductor-like screening model (COSMO) was used to investigate the solvent influence on electronic g-values of organic radicals. The previously studied diphenyl nitric oxide and di-tert-butyl nitric oxide radicals were taken as test cases. The calculations employed spin-unrestricted density functional theory and the BP and B3LYP density functionals. The g-tensors were calculated as mixed second derivative properties with respect to the external magnetic field and the electron magnetic moment. The first-order response of the Kohn-Sham orbitals with respect to the external magnetic field was determined through the coupled-perturbed DFT approach. The spin-orbit coupling operator was treated using an accurate multicenter spin-orbit mean-field (SOMF) approach. Provided that important hydrogen bonds are explicitly modeled by a supermolecule approach and that the basis set is sufficiently saturated, the COSMO calculations lead to accurate predictions of isotropic g-shifts with deviations of not more than 100 ppm relative to experiment. Very accurate results were obtained by employing a recently developed self-consistent modification of the COSMO method to real solvents (COSMO-RS), which we briefly introduce in this paper as direct COSMO-RS (D-COSMO-RS). This model gives isotropic g-shifts of similar high accuracy for water without using the supermolecule approach. This is an important result because it solves many of the problems associated with the supermolecule approach such as local minima and the choice of a suitable model system. Thus, the self-consistent D-COSMO-RS incorporates some specific solvation effects into continuum models, in particular it appears to successfully model the effects of hydrogen bonding. Although not yet widely validated, this opens a novel approach for the calculation of properties which so far only could be calculated by the inclusion of explicit solvent molecules in continuum solvation methods.
Collapse
Affiliation(s)
- Sebastian Sinnecker
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | | | | | | | | |
Collapse
|
11
|
Marsh D, Kurad D, Livshits VA. High-field spin-label EPR of lipid membranes. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2005; 43 Spec no.:S20-5. [PMID: 16235222 DOI: 10.1002/mrc.1680] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
High-field EPR of spin-labelled lipid chains has proved to be an extremely productive means for biophysical investigations of phospholipid bilayer membranes. Results on the following three topics are reviewed: 1. Non-axial ordering of lipid chains in cholesterol-containing membranes; 2. Transmembrane polarity profiles and water penetration in lipid membranes; 3. Role of HF-EPR in multi-frequency spectral simulations to investigate lipid-chain dynamics in membranes. These results are obtained from phosphatidylcholine spin probes with the nitroxide systematically stepped down the sn-2 chain, in fully hydrated bilayer membranes of dimyristoyl phosphatidylcholine (DMPC)-containing cholesterol.
Collapse
Affiliation(s)
- Derek Marsh
- Max-Planck Institut für biophysikalische Chemie, 37070 Göttingen, Germany.
| | | | | |
Collapse
|
12
|
Erilov DA, Bartucci R, Guzzi R, Shubin AA, Maryasov AG, Marsh D, Dzuba SA, Sportelli L. Water Concentration Profiles in Membranes Measured by ESEEM of Spin-Labeled Lipids. J Phys Chem B 2005; 109:12003-13. [PMID: 16852481 DOI: 10.1021/jp050886z] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Electron spin-echo envelope modulation (ESEEM) spectroscopy of phospholipids spin-labeled systematically down the sn-2 chain was used to detect the penetration of water (D2O) into bilayer membranes of dipalmitoyl phosphatidylcholine with and without 50 mol % cholesterol. Three-pulse stimulated echoes allow the resolution of two superimposed 2H-ESEEM spectral components of different widths, for spin labels located in the upper part of the lipid chains. Quantum chemical calculations (DFT) and ESEEM simulations assign the broad spectral component to one or two D2O molecules that are directly hydrogen bonded to the N-O group of the spin label. Classical ESEEM simulations establish that the narrow spectral component arises from nonbonded water (D2O) molecules that are free in the hydrocarbon chain region of the bilayer membrane. The amplitudes of the broad 2H-ESEEM spectral component correlate directly with those of the narrow component for spin labels at different positions down the lipid chain, reflecting the local H-bonding equilibria. The D2O-ESEEM amplitudes decrease with position down the chain toward the bilayer center, displaying a sigmoidal dependence on position that is characteristic of transmembrane polarity profiles established by other less direct spin-labeling methods. The midpoint of the sigmoidal profile is shifted toward the membrane center for membranes without cholesterol, relative to those with cholesterol, and the D2O-ESEEM amplitude in the outer regions of the chain is greater in the presence of cholesterol than in its absence. For both membrane types, the D2O amplitude is almost vanishingly small at the bilayer center. The water-penetration profiles reverse correlate with the lipid-chain packing density, as reflected by 1H-ESEEM intensities from protons of the membrane matrix. An analysis of the H-bonding equilibria provides essential information on the binding of water molecules to H-bond acceptors within the hydrophobic interior of membranes. For membranes containing cholesterol, approximately 40% of the nitroxides in the region adjacent to the lipid headgroups are H bonded to water, of which ca. 15% are doubly H bonded. Corresponding H-bonded populations in membranes without cholesterol are ca. 20%, of which ca. 6% are doubly bonded.
Collapse
Affiliation(s)
- Denis A Erilov
- Dipartimento di Fisica and Unità INFM, Università della Calabria, I-87036 Arcavacata di Rende (CS), Italy
| | | | | | | | | | | | | | | |
Collapse
|
13
|
High Field ESR: Applications to Protein Structure and Dynamics. ACTA ACUST UNITED AC 2004. [DOI: 10.1007/978-1-4757-4379-1_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
14
|
|
15
|
PLATO MARTIN, STEINHOFF HEINZJÜRGEN, WEGENER CHRISTOPH, TÖRRING JENST, SAVITSKY ANTON, MÖBIUS KLAUS. Molecular orbital study of polarity and hydrogen bonding effects on thegand hyperfine tensors of site directed NO spin labelled bacteriorhodopsin. Mol Phys 2002. [DOI: 10.1080/00268970210166246] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
16
|
Engström M, Vaara J, Schimmelpfennig B, Ågren H. Density Functional Theory Calculations of Electron Paramagnetic Resonance Parameters of a Nitroxide Spin Label in Tissue Factor and Factor VIIa Protein Complex. J Phys Chem B 2002. [DOI: 10.1021/jp022070t] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maria Engström
- Institute of Physics and Measurement Technology, Linköping University, S-58183 Linköping, Sweden
| | - Juha Vaara
- Department of Chemistry, P.O.B. 55 (A.I. Virtasen aukio 1), FIN-00014 University of Helsinki, Finland
| | - Bernd Schimmelpfennig
- Department of Biotechnology, Laboratory of Theoretical Chemistry, Royal Institute of Technology, S-10691 Stockholm, Sweden
| | - Hans Ågren
- Department of Biotechnology, Laboratory of Theoretical Chemistry, Royal Institute of Technology, S-10691 Stockholm, Sweden
| |
Collapse
|
17
|
Pushkar YN, Zech SG, Stehlik D, Brown S, van der Est A, Zimmermann H. Orientation and Protein−Cofactor Interactions of Monosubstituted n-Alkyl Naphthoquinones in the A1 Binding Site of Photosystem I. J Phys Chem B 2002. [DOI: 10.1021/jp0265743] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | - Herbert Zimmermann
- Max-Planck Institut für medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany
| |
Collapse
|
18
|
Neese F. Prediction of electron paramagnetic resonance g values using coupled perturbed Hartree–Fock and Kohn–Sham theory. J Chem Phys 2001. [DOI: 10.1063/1.1419058] [Citation(s) in RCA: 504] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
19
|
Owenius R, Engström M, Lindgren M, Huber M. Influence of Solvent Polarity and Hydrogen Bonding on the EPR Parameters of a Nitroxide Spin Label Studied by 9-GHz and 95-GHz EPR Spectroscopy and DFT Calculations. J Phys Chem A 2001. [DOI: 10.1021/jp0116914] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rikard Owenius
- IFM-Departments of Chemical Physics and Computational Physics, Linköping University, SE-581 83 Linköping, Sweden
| | - Maria Engström
- IFM-Departments of Chemical Physics and Computational Physics, Linköping University, SE-581 83 Linköping, Sweden
| | - Mikael Lindgren
- IFM-Departments of Chemical Physics and Computational Physics, Linköping University, SE-581 83 Linköping, Sweden
| | - Martina Huber
- Huygens Laboratory, MAT Group, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| |
Collapse
|