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Samajdar RN, Bhattacharyya AJ. Structure-Redox Response Correlation in a Few Select Heme Systems Using X-ray Absorption Spectroelectrochemistry. J Phys Chem B 2021; 125:5258-5264. [PMID: 33983739 DOI: 10.1021/acs.jpcb.1c02180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heme based biomolecules control some of the most crucial life processes, such as oxygen and electron transport during respiration and energy metabolism, respectively. The active site of the heme, viz., the metal center, plays a key role and attributes functionality to these biomolecules. During the oxygen binding and debinding processes, it is important to note that the oxidation state of iron in hemoglobin (+II in the native form) does not undergo any change. However, the spin states of the metal center change. We present here a comprehensive study of the redox response of such molecules, based on the electronic structure of the active site. The local electronic structure of heme in a few selective molecular systems is studied in operando via synchrotron X-ray absorption spectroscopy (Fe K-edge) and cyclic voltammetry. Our objective is to identify the electronic structural parameters that can effectively be correlated with the redox reversibility. Evolution in these parameters can be followed to trace the overall changes in redox state of the system. Our data indicate that axial coordination and spin state of the iron center are two such parameters that are intimately connected with the redox response.
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Affiliation(s)
- Rudra N Samajdar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Aninda J Bhattacharyya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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2
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Ardiccioni C, Arcovito A, Della Longa S, van der Linden P, Bourgeois D, Weik M, Montemiglio LC, Savino C, Avella G, Exertier C, Carpentier P, Prangé T, Brunori M, Colloc’h N, Vallone B. Ligand pathways in neuroglobin revealed by low-temperature photodissociation and docking experiments. IUCRJ 2019; 6:832-842. [PMID: 31576217 PMCID: PMC6760443 DOI: 10.1107/s2052252519008157] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 06/06/2019] [Indexed: 06/10/2023]
Abstract
A combined biophysical approach was applied to map gas-docking sites within murine neuroglobin (Ngb), revealing snapshots of events that might govern activity and dynamics in this unique hexacoordinate globin, which is most likely to be involved in gas-sensing in the central nervous system and for which a precise mechanism of action remains to be elucidated. The application of UV-visible microspectroscopy in crystallo, solution X-ray absorption near-edge spectroscopy and X-ray diffraction experiments at 15-40 K provided the structural characterization of an Ngb photolytic intermediate by cryo-trapping and allowed direct observation of the relocation of carbon monoxide within the distal heme pocket after photodissociation. Moreover, X-ray diffraction at 100 K under a high pressure of dioxygen, a physiological ligand of Ngb, unravelled the existence of a storage site for O2 in Ngb which coincides with Xe-III, a previously described docking site for xenon or krypton. Notably, no other secondary sites were observed under our experimental conditions.
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Affiliation(s)
- Chiara Ardiccioni
- Department of Life and Environmental Sciences, New York–Marche Structural Biology Center (NY-MaSBiC), Polytechnic University of Marche, Ancona, Italy
| | - Alessandro Arcovito
- Istituto di Biochimica e Biochimica Clinica, Universitá Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Universitario Agostino Gemelli–IRCCS, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Stefano Della Longa
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Peter van der Linden
- European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France
- Partnership for Soft Condensed Matter (PSCM), 38043 Grenoble, France
| | | | - Martin Weik
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Linda Celeste Montemiglio
- Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Institute of Molecular Biology and Pathology, National Research Council, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Istituto Pasteur–Fondazione Cenci Bolognetti, Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Carmelinda Savino
- Institute of Molecular Biology and Pathology, National Research Council, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Giovanna Avella
- Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Chemistry Department, Merck Serono S.p.A., Via Casilina 125, 00176 Rome, Italy
| | - Cécile Exertier
- Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Philippe Carpentier
- European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France
- CEA/DRF/BIG/CBM/BioCat LCBM CNRS UMR 5249, Université Grenoble Alpes, 38000 Grenoble, France
| | - Thierry Prangé
- CiTeCoM UMR 8038 CNRS, Université Paris Descartes, Paris, France
| | - Maurizio Brunori
- Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Nathalie Colloc’h
- ISTCT UMR 6030 CNRS Université de Caen Normandie CEA, CERVOxy Team, Centre Cyceron, Caen, France
| | - Beatrice Vallone
- Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Institute of Molecular Biology and Pathology, National Research Council, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Istituto Pasteur–Fondazione Cenci Bolognetti, Department of Biochemical Sciences ‘A. Rossi Fanelli’, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
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Soldatov MA, Martini A, Bugaev AL, Pankin I, Medvedev PV, Guda AA, Aboraia AM, Podkovyrina YS, Budnyk AP, Soldatov AA, Lamberti C. The insights from X-ray absorption spectroscopy into the local atomic structure and chemical bonding of Metal–organic frameworks. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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4
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Chillemi G, Anselmi M, Sanna N, Padrin C, Balducci L, Cammarata M, Pace E, Chergui M, Benfatto M. Dynamic multiple-scattering treatment of X-ray absorption: Parameterization of a new molecular dynamics force field for myoglobin. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2018; 5:054101. [PMID: 30246048 PMCID: PMC6135643 DOI: 10.1063/1.5031806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
We present a detailed analysis of the X-ray absorption near-edge structure (XANES) data on the Fe K-edge of CO Myoglobin based on a combined procedure of Molecular Dynamics (MD) calculations and MXAN (Minuit XANes) data analysis that we call D-MXAN. The ability of performing quantitative XANES data analysis allows us to refine classical force field MD parameters, thus obtaining a reliable tool for the atomic investigation of this important model system for biological macromolecules. The iterative procedure here applied corrects the greatest part of the structural discrepancy between classical MD sampling and experimental determinations. Our procedure, moreover, is able to discriminate between different heme conformational basins visited during the MD simulation, thus demonstrating the necessity of a sampling on the order of tens of nanoseconds, even for an application such X-ray absorption spectroscopy data analysis.
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Affiliation(s)
- Giovanni Chillemi
- Authors to whom correspondence should be addressed: , Telephone: +39 06 44486 706 and , Telephone: +39–06-9403–2884
| | - Massimiliano Anselmi
- Institute for Microbiology and Genetics, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | | | - Cristiano Padrin
- CINECA, SuperComputing Applications and Innovation Department, Via dei Tizii 6, 00185 Roma, Italy
| | - Lodovico Balducci
- Université de Rennes 1, CNRS, Univ. Bretagne Loire, Institut de Physique de Rennes, UMR 6251, Rennes F-35042, France
| | - Marco Cammarata
- Université de Rennes 1, CNRS, Univ. Bretagne Loire, Institut de Physique de Rennes, UMR 6251, Rennes F-35042, France
| | - Elisabetta Pace
- Laboratori Nazionali di Frascati, INFN- Via E. Fermi 44, 00044 Frascati, Italy
| | - Majed Chergui
- Lab. of Ultrafast Spectroscopy (LSU) and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB, Station 6, CH-1015 Lausanne, Switzerland
| | - Maurizio Benfatto
- Laboratori Nazionali di Frascati, INFN- Via E. Fermi 44, 00044 Frascati, Italy
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5
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Chillemi G, Pace E, D'Abramo M, Benfatto M. Equilibrium between 5- and 6-Fold Coordination in the First Hydration Shell of Cu(II). J Phys Chem A 2016; 120:3958-65. [PMID: 27195961 DOI: 10.1021/acs.jpca.6b03569] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hydration structure dynamics of Cu(II) ion is characterized by a combination of classical molecular dynamics simulation and X-ray absorption near-edge spectroscopy. Previous experimental data have been analyzed on the basis of 5- or 6-fold first hydration structure, with a quite well-established equatorial structure. This 4-fold equatorial geometry has been our starting point to develop a simple but effective in silico model, which provides ab initio theoretical X-ray absorption spectra in very good agreement with the experimental data. Our results point out two equally populated 6- and 5-fold hydration structures with remarkable different water residence times of 5 and 98 ps, respectively, and a low free energy barrier between first and second hydration shell.
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Affiliation(s)
- Giovanni Chillemi
- SCAI SuperComputing Applications and Innovation Department , Cineca Via dei Tizii, 6. 00185 Rome, Italy
| | - Elisabetta Pace
- Laboratori Nazionali di Frascati-INFN , Post Office Box 13, 00044 Frascati, Italy
| | - Marco D'Abramo
- Dipartimento di Chimica, Università di Roma "La Sapienza" , Ple A. Moro 5, 00185 Rome, Italy
| | - Maurizio Benfatto
- Laboratori Nazionali di Frascati-INFN , Post Office Box 13, 00044 Frascati, Italy
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6
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La Penna G, Minicozzi V, Morante S, Rossi GC, Stellato F. A first-principle calculation of the XANES spectrum of Cu2+ in water. J Chem Phys 2015; 143:124508. [DOI: 10.1063/1.4931808] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- G. La Penna
- CNR–Institute for Chemistry of Organometallic Compounds, Sesto Fiorentino 50019, Italy
| | - V. Minicozzi
- INFN, Rome “Tor Vergata,” Rome 00133, Italy
- Department of Physics, University of Rome “Tor Vergata,” Rome 00133, Italy
| | - S. Morante
- INFN, Rome “Tor Vergata,” Rome 00133, Italy
- Department of Physics, University of Rome “Tor Vergata,” Rome 00133, Italy
| | - G. C. Rossi
- INFN, Rome “Tor Vergata,” Rome 00133, Italy
- Department of Physics, University of Rome “Tor Vergata,” Rome 00133, Italy
- Centro Studi e Ricerche “Enrico Fermi,” Roma 00184, Italy
| | - F. Stellato
- INFN, Rome “Tor Vergata,” Rome 00133, Italy
- Department of Physics, University of Rome “Tor Vergata,” Rome 00133, Italy
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7
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Zitolo A, Goellner V, Armel V, Sougrati MT, Mineva T, Stievano L, Fonda E, Jaouen F. Identification of catalytic sites for oxygen reduction in iron- and nitrogen-doped graphene materials. NATURE MATERIALS 2015; 14:937-42. [PMID: 26259106 DOI: 10.1038/nmat4367] [Citation(s) in RCA: 886] [Impact Index Per Article: 98.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 06/05/2015] [Indexed: 05/22/2023]
Abstract
While platinum has hitherto been the element of choice for catalysing oxygen electroreduction in acidic polymer fuel cells, tremendous progress has been reported for pyrolysed Fe-N-C materials. However, the structure of their active sites has remained elusive, delaying further advance. Here, we synthesized Fe-N-C materials quasi-free of crystallographic iron structures after argon or ammonia pyrolysis. These materials exhibit nearly identical Mössbauer spectra and identical X-ray absorption near-edge spectroscopy (XANES) spectra, revealing the same Fe-centred moieties. However, the much higher activity and basicity of NH3-pyrolysed Fe-N-C materials demonstrates that the turnover frequency of Fe-centred moieties depends on the physico-chemical properties of the support. Following a thorough XANES analysis, the detailed structures of two FeN4 porphyrinic architectures with different O2 adsorption modes were then identified. These porphyrinic moieties are not easily integrated in graphene sheets, in contrast with Fe-centred moieties assumed hitherto for pyrolysed Fe-N-C materials. These new insights open the path to bottom-up synthesis approaches and studies on site-support interactions.
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Affiliation(s)
- Andrea Zitolo
- Synchrotron SOLEIL, L'orme des Merisiers, BP 48 Saint Aubin, 91192 Gif-sur-Yvette, France
| | - Vincent Goellner
- Institut Charles Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier, 34095 Montpellier, France
| | - Vanessa Armel
- Institut Charles Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier, 34095 Montpellier, France
| | - Moulay-Tahar Sougrati
- Institut Charles Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier, 34095 Montpellier, France
| | - Tzonka Mineva
- Institut Charles Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier, 34095 Montpellier, France
| | - Lorenzo Stievano
- Institut Charles Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier, 34095 Montpellier, France
| | - Emiliano Fonda
- Synchrotron SOLEIL, L'orme des Merisiers, BP 48 Saint Aubin, 91192 Gif-sur-Yvette, France
| | - Frédéric Jaouen
- Institut Charles Gerhardt Montpellier, UMR 5253, CNRS, Université Montpellier, 34095 Montpellier, France
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8
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van der Veen RM, Penfold TJ, Zewail AH. Ultrafast core-loss spectroscopy in four-dimensional electron microscopy. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2015; 2:024302. [PMID: 26798793 PMCID: PMC4711615 DOI: 10.1063/1.4916897] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/23/2015] [Indexed: 05/06/2023]
Abstract
We demonstrate ultrafast core-electron energy-loss spectroscopy in four-dimensional electron microscopy as an element-specific probe of nanoscale dynamics. We apply it to the study of photoexcited graphite with femtosecond and nanosecond resolutions. The transient core-loss spectra, in combination with ab initio molecular dynamics simulations, reveal the elongation of the carbon-carbon bonds, even though the overall behavior is a contraction of the crystal lattice. A prompt energy-gap shrinkage is observed on the picosecond time scale, which is caused by local bond length elongation and the direct renormalization of band energies due to temperature-dependent electron-phonon interactions.
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Affiliation(s)
| | - Thomas J Penfold
- SwissFEL, Paul Scherrer Institut , 5232 Villigen PSI, Switzerland
| | - Ahmed H Zewail
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology , Pasadena, California 91125, USA
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9
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Garino C, Borfecchia E, Gobetto R, van Bokhoven JA, Lamberti C. Determination of the electronic and structural configuration of coordination compounds by synchrotron-radiation techniques. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.03.027] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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10
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11
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Zitolo A, Migliorati V, Aquilanti G, D’Angelo P. On the possibility of using XANES to investigate bromide-based ionic liquids. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.10.086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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D'Angelo P, Migliorati V, Spezia R, De Panfilis S, Persson I, Zitolo A. K-edge XANES investigation of octakis(DMSO)lanthanoid(III) complexes in DMSO solution and solid iodides. Phys Chem Chem Phys 2013; 15:8684-91. [PMID: 23657739 DOI: 10.1039/c3cp50842k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The potential of high energy XANES (X-ray absorption near edge structure) as a tool for the structural analysis of lanthanoid-containing systems has been explored. The K-edge XANES spectra of La(3+), Gd(3+), and Lu(3+) ions both in DMSO solution and solid octakis(DMSO)lanthanoid(III) iodides have been analysed. Although the K-edges of lanthanoids cover the energy range of 38 (La) to 65 (Lu) keV, the large widths of the core hole states do not appreciably reduce the potential structural information of the XANES data. We show that, for lanthanoid compounds, accurate structural parameters are obtained from the analysis of K-edge XANES signals if a deconvolution procedure is carried out. We found that in solid octakis(DMSO)lanthanoid(III) iodides the Ln(3+) ions are coordinated by eight DMSO ligands arranged in a quite symmetric fashion. In DMSO solution the Ln(3+) ions retain a regular eight-coordination structure and the coordination number does not change along the series. In contrast to when in water the second coordination shell has been found to provide a negligible contribution to the XANES spectra of Ln(3+) ions in DMSO solution.
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Affiliation(s)
- Paola D'Angelo
- Dipartimento di Chimica, Università di Roma La Sapienza, P.le A. Moro 5, 00185 Roma, Italy.
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D'Angelo P, Della Longa S, Arcovito A, Mancini G, Zitolo A, Chillemi G, Giachin G, Legname G, Benetti F. Effects of the pathological Q212P mutation on human prion protein non-octarepeat copper-binding site. Biochemistry 2012; 51:6068-79. [PMID: 22788868 DOI: 10.1021/bi300233n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Prion diseases are a class of fatal neurodegenerative disorders characterized by brain spongiosis, synaptic degeneration, microglia and astrocytes activation, neuronal loss and altered redox control. These maladies can be sporadic, iatrogenic and genetic. The etiological agent is the prion, a misfolded form of the cellular prion protein, PrP(C). PrP(C) interacts with metal ions, in particular copper and zinc, through the octarepeat and non-octarepeat binding sites. The physiological implication of this interaction is still unclear, as is the role of metals in the conversion. Since prion diseases present metal dyshomeostasis and increased oxidative stress, we described the copper-binding site located in the human C-terminal domain of PrP-HuPrP(90-231), both in the wild-type protein and in the protein carrying the pathological mutation Q212P. We used the synchrotron-based X-ray absorption fine structure technique to study the Cu(II) and Cu(I) coordination geometries in the mutant, and we compared them with those obtained using the wild-type protein. By analyzing the extended X-ray absorption fine structure and the X-ray absorption near-edge structure, we highlighted changes in copper coordination induced by the point mutation Q212P in both oxidation states. While in the wild-type protein the copper-binding site has the same structure for both Cu(II) and Cu(I), in the mutant the coordination site changes drastically from the oxidized to the reduced form of the copper ion. Copper-binding sites in the mutant resemble those obtained using peptides, confirming the loss of short- and long-range interactions. These changes probably cause alterations in copper homeostasis and, consequently, in redox control.
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Affiliation(s)
- Paola D'Angelo
- Department of Chemistry, University of Rome La Sapienza, P.le Aldo Moro 5, I-00185 Rome, Italy.
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Ye Q, Zhou J, Zhao T, Zhao H, Chu W, Sheng Z, Chen X, Marcelli A, Luo Y, Wu Z. Identification of 13- and 14-coordinated structures of first hydrated shell of [AuCl4](-) acid aqueous solution by combination of MD and XANES. J Phys Chem B 2012; 116:7866-73. [PMID: 22686423 DOI: 10.1021/jp3026623] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular dynamics simulations combined with multiple scatting X-ray absorption spectral calculations have been employed to study the local geometry of an [AuCl4](-) cluster in acid aqueous solution. It is found that the previously assumed simple octahedral structure with two H atoms located in the axial position of the [AuCl4](-) plane fails to correctly reproduce the experimental X-ray absorption spectra. Molecular dynamics simulations have revealed a very complicated first hydrated water shell that mainly consists of 13 or 14 ligand water molecules. In general, the first hydrated water molecules are located in two orthogonal quasi-elliptic surfaces around [AuCl4](-) cluster. The water molecules' configuration in the first hydrated shell is further confirmed by the X-ray absorption spectral analysis, which gives a good agreement with the experiment when the 13-hydrated and 14-hydrated complexes are evenly mixed. It shows the power of the combined molecular dynamics simulations and spectra calculations in determining the local structure of molecular ligands around the metal center.
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Affiliation(s)
- Qing Ye
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics , CAS, 100049 Beijing, China
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15
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Chillemi G, De Santis S, Falconi M, Mancini G, Migliorati V, Battistoni A, Pacello F, Desideri A, D'Angelo P. Carbon monoxide binding to the heme group at the dimeric interface modulates structure and copper accessibility in the Cu,Zn superoxide dismutase from Haemophilus ducreyi: in silico and in vitro evidences. J Biomol Struct Dyn 2012; 30:269-79. [PMID: 22686457 DOI: 10.1080/07391102.2012.680028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
X-ray absorption near-edge structure (XANES) spectroscopy and molecular dynamics (MD) simulations have been jointly applied to the study of the Cu,Zn superoxide dismutase from Haemophilus ducreyi (HdSOD) in interaction with the carbon monoxide molecule. The configurational flexibility of the Fe(II)-heme group, intercalated between the two subunits, has been sampled by MD simulations and included in the XANES data analysis without optimization in the structural parameter space. Our results provide an interpretation of the observed discrepancy in the Fe-heme distances as detected by extended X-ray absorption fine structure (EXAFS) spectroscopy and the classical XANES analysis, in which the structural parameters are optimized in a unique structure. Moreover, binding of the CO molecule to the heme induces a long range effect on the Cu,Zn active site, as evidenced by both MD simulations and in vitro experiments. MD simulation of the CO bound system, in fact, highlighted a structural rearrangement of the protein-protein hydrogen bond network in the region of the Cu,Zn active site, correlated with an increase in water accessibility at short distance from the copper atom. In line, in vitro experiments evidenced an increase of copper accessibility to a chelating agent when the CO molecule binds to the heme group, as compared to a heme deprived HdSOD. Altogether, our results support the hypothesis that the HdSOD is a heme-sensor protein, in which binding to small gaseous molecules modulates the enzyme superoxide activity as an adaptive response to the bacterial environment.
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Migliorati V, Zitolo A, Chillemi G, D'Angelo P. Influence of the Second Coordination Shell on the XANES Spectra of the Zn2+ Ion in Water and Methanol. Chempluschem 2012. [DOI: 10.1002/cplu.201100070] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Penfold TJ, Curchod BFE, Tavernelli I, Abela R, Rothlisberger U, Chergui M. Simulations of X-ray absorption spectra: the effect of the solvent. Phys Chem Chem Phys 2012; 14:9444-50. [DOI: 10.1039/c2cp24080g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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