1
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Tamhankar A, Wensien M, Jannuzzi SAV, Chatterjee S, Lassalle-Kaiser B, Tittmann K, DeBeer S. In Solution Identification of the Lysine-Cysteine Redox Switch with a NOS Bridge in Transaldolase by Sulfur K-Edge X-ray Absorption Spectroscopy. J Phys Chem Lett 2024; 15:4263-4267. [PMID: 38607253 PMCID: PMC11056971 DOI: 10.1021/acs.jpclett.4c00484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/13/2024]
Abstract
A novel covalent post-translational modification (lysine-NOS-cysteine) was discovered in proteins, initially in the enzyme transaldolase of Neisseria gonorrhoeae (NgTAL) [Nature 2021, 593, 460-464], acting as a redox switch. The identification of this novel linkage in solution was unprecedented until now. We present detection of the NOS redox switch in solution using sulfur K-edge X-ray absorption spectroscopy (XAS). The oxidized NgTAL spectrum shows a distinct shoulder on the low-energy side of the rising edge, corresponding to a dipole-allowed transition from the sulfur 1s core to the unoccupied σ* orbital of the S-O group in the NOS bridge. This feature is absent in the XAS spectrum of reduced NgTAL, where Lys-NOS-Cys is absent. Our experimental and calculated XAS data support the presence of a NOS bridge in solution, thus potentially facilitating future studies on enzyme activity regulation mediated by the NOS redox switches, drug discovery, biocatalytic applications, and protein design.
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Affiliation(s)
- Ashish Tamhankar
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Marie Wensien
- Department
of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermonotowa-Weg 3, 37077 Göttingen, Germany
- Max
Planck Institute for Multidisciplinary Sciences Göttingen, 37075 Göttingen, Germany
| | - Sergio A. V. Jannuzzi
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Sayanti Chatterjee
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
- Department
of Chemistry, Indian Institute of Technology
Roorkee, Roorkee, 247667 Uttarakhand, India
| | | | - Kai Tittmann
- Department
of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermonotowa-Weg 3, 37077 Göttingen, Germany
- Max
Planck Institute for Multidisciplinary Sciences Göttingen, 37075 Göttingen, Germany
| | - Serena DeBeer
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
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2
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Tung CY, Tseng YT, Lu TT, Liaw WF. Insight into the Electronic Structure of Biomimetic Dinitrosyliron Complexes (DNICs): Toward the Syntheses of Amido-Bridging Dinuclear DNICs. Inorg Chem 2021; 60:15846-15873. [PMID: 34009960 DOI: 10.1021/acs.inorgchem.1c00566] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ubiquitous function of nitric oxide (NO) guided the biological discovery of the natural dinitrosyliron unit (DNIU) [Fe(NO)2] as an intermediate/end product after Fe nitrosylation of nonheme cofactors. Because of the natural utilization of this cofactor for the biological storage and delivery of NO, a bioinorganic study of synthetic dinitrosyliron complexes (DNICs) has been extensively explored in the last 2 decades. The bioinorganic study of DNICs involved the development of synthetic methodology, spectroscopic discrimination, biological application of NO-delivery reactivity, and translational application to the (catalytic) transformation of small molecules. In this Forum Article, we aim to provide a systematic review of spectroscopic and computational insights into the bonding nature within the DNIU [Fe(NO)2] and the electronic structure of different types of DNICs, which highlights the synchronized advance in synthetic methodology and spectroscopic tools. With regard to the noninnocent nature of a NO ligand, spectroscopic and computational tools were utilized to provide qualitative/quantitative assignment of oxidation states of Fe and NO in DNICs with different redox levels and ligation modes as well as to probe the Fe-NO bonding interaction modulated by supporting ligands. Besides the strong antiferromagnetic coupling between high-spin Fe and paramagnetic NO ligands within the covalent DNIU [Fe(NO)2], in polynuclear DNICs, the effects of the Fe···Fe distance, nature of the bridging ligands, and type of bridging modes on the regulation of the magnetic coupling among paramagnetic DNIU [Fe(NO)2] are further reviewed. In the last part of this Forum Article, the sequential reaction of {Fe(NO)2}10 DNIC [(NO)2Fe(AMP)] (1-red) with NO(g), HBF4, and KC8 establishes a synthetic cycle, {Fe(NO)2}9-{Fe(NO)2}9 DNIC [(NO)2Fe(μ-dAMP)2Fe(NO)2] (1) → {Fe(NO)2}9 DNIC [(NO2)Fe(AMP)][BF4] (1-H) → {Fe(NO)2}10 DNIC 1-red → DNIC 1, for the transformation of NO into HNO/N2O. Of importance, the NO-induced transformation of {Fe(NO)2}10 DNIC 1-red and [(NO)2Fe(DTA)] (2-red; DTA = diethylenetriamine) unravels a synthetic strategy for preparation of the {Fe(NO)2}9-{Fe(NO)2}9 DNICs [(NO)2Fe(μ-NHR)2Fe(NO)2] containing amido-bridging ligands, which hold the potential to feature distinctive physical properties, chemical reactivities, and biological applications.
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Affiliation(s)
- Chi-Yen Tung
- Department of Chemistry, National Tsing Hua University (NTHU), Hsinchu 30013 Taiwan
| | - Yu-Ting Tseng
- Department of Chemistry, National Tsing Hua University (NTHU), Hsinchu 30013 Taiwan
| | - Tsai-Te Lu
- Institute of Biomedical Engineering, National Tsing Hua University (NTHU), Hsinchu 30013, Taiwan
| | - Wen-Feng Liaw
- Department of Chemistry, National Tsing Hua University (NTHU), Hsinchu 30013 Taiwan
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3
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Ye L, Rouxel JR, Asban S, Rösner B, Mukamel S. Probing Molecular Chirality by Orbital-Angular-Momentum-Carrying X-ray Pulses. J Chem Theory Comput 2019; 15:4180-4186. [PMID: 31125229 DOI: 10.1021/acs.jctc.9b00346] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A twisted X-ray beam with orbital angular momentum is employed in a theoretical study to probe molecular chirality. A nonlocal response description of the matter-field coupling is adopted to account for the field short wavelength and the structured spatial profile. We use the minimal-coupling Hamiltonian, which implicitly takes into account the multipole contributions to all orders. The combined interactions of the spin and orbital angular momentum of the X-ray beam give rise to circular-helical dichroism signals, which are stronger than ordinary circular dichroism signals, and may serve as a useful tool for the study of molecular chirality in the X-ray regime.
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Affiliation(s)
- Lyuzhou Ye
- Department of Chemistry and Department of Physics and Astronomy , University of California , Irvine , California 92697 , United States
| | - Jérémy R Rouxel
- Laboratory of Ultrafast Spectroscopy , École Polytechnique Fédérale de Lausanne , Lausanne CH-1015 , Switzerland.,Paul Scherrer Institut , Villigen-PSI 5232 , Switzerland
| | - Shahaf Asban
- Department of Chemistry and Department of Physics and Astronomy , University of California , Irvine , California 92697 , United States
| | | | - Shaul Mukamel
- Department of Chemistry and Department of Physics and Astronomy , University of California , Irvine , California 92697 , United States
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4
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Zhang B, Sels A, Salassa G, Pollitt S, Truttmann V, Rameshan C, Llorca J, Olszewski W, Rupprechter G, Bürgi T, Barrabés N. Ligand Migration from Cluster to Support: A Crucial Factor for Catalysis by Thiolate-protected Gold Clusters. ChemCatChem 2018; 10:5372-5376. [PMID: 30713589 PMCID: PMC6348379 DOI: 10.1002/cctc.201801474] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 09/17/2018] [Indexed: 12/11/2022]
Abstract
Thiolate protected metal clusters are valuable precursors for the design of tailored nanosized catalysts. Their performance can be tuned precisely at atomic level, e. g. by the configuration/type of ligands or by partial/complete removal of the ligand shell through controlled pre-treatment steps. However, the interaction between the ligand shell and the oxide support, as well as ligand removal by oxidative pre-treatment, are still poorly understood. Typically, it was assumed that the thiolate ligands are simply converted into SO2, CO2 and H2O. Herein, we report the first detailed observation of sulfur ligand migration from Au to the oxide support upon deposition and oxidative pre-treatment, employing mainly S K-edge XANES. Consequently, thiolate ligand migration not only produces clean Au cluster surfaces but also the surrounding oxide support is modified by sulfur-containing species, with pronounced effects on catalytic properties.
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Affiliation(s)
- Bei Zhang
- Department of Physical ChemistryUniversity of GenevaQuai Ernest-Ansermet 30CH-1211GenevaSwitzerland
| | - Annelies Sels
- Department of Physical ChemistryUniversity of GenevaQuai Ernest-Ansermet 30CH-1211GenevaSwitzerland
| | - Giovanni Salassa
- Department of Physical ChemistryUniversity of GenevaQuai Ernest-Ansermet 30CH-1211GenevaSwitzerland
| | - Stephan Pollitt
- Institute of Materials ChemistryTechnische Universität WienGetreidemarkt 9/BC/011060ViennaAustria
| | - Vera Truttmann
- Institute of Materials ChemistryTechnische Universität WienGetreidemarkt 9/BC/011060ViennaAustria
| | - Christoph Rameshan
- Institute of Materials ChemistryTechnische Universität WienGetreidemarkt 9/BC/011060ViennaAustria
| | - Jordi Llorca
- Institute of Energy Technologies, Dep. of Chemical Engineering and Barcelona Research Center in Multiscale Science and EngineeringUniversitat Politècnica de Catalunya EEBEEduard Maristany 1608019BarcelonaSpain
| | - Wojciech Olszewski
- ALBA Synchrotron Light FacilityCarrer de la Llum 2–2608290 Cerdanyola del VallèsBarcelonaSpain
- Faculty of PhysicsUniversity of Bialystok1 L K. Ciolkowskiego Str.15-245BialystokPoland
| | - Günther Rupprechter
- Institute of Materials ChemistryTechnische Universität WienGetreidemarkt 9/BC/011060ViennaAustria
| | - Thomas Bürgi
- Department of Physical ChemistryUniversity of GenevaQuai Ernest-Ansermet 30CH-1211GenevaSwitzerland
| | - Noelia Barrabés
- Institute of Materials ChemistryTechnische Universität WienGetreidemarkt 9/BC/011060ViennaAustria
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5
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Farfan GA, Apprill A, Webb SM, Hansel CM. Coupled X-ray Fluorescence and X-ray Absorption Spectroscopy for Microscale Imaging and Identification of Sulfur Species within Tissues and Skeletons of Scleractinian Corals. Anal Chem 2018; 90:12559-12566. [PMID: 30277756 DOI: 10.1021/acs.analchem.8b02638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Identifying and mapping the wide range of sulfur species within complex matrices presents a challenge for understanding the distribution of these important biomolecules within environmental and biological systems. Here, we present a coupled micro X-ray fluorescence (μXRF) and X-ray absorption near-edge structure (XANES) spectroscopy method for determining the presence of specific sulfur species in coral tissues and skeletons at high spatial resolution. By using multiple energy stacks and principal component analysis of a large spectral database, we were able to more accurately identify sulfur species components and distinguish different species and distributions of sulfur formerly unresolved by previous studies. Specifically, coral tissues were dominated by more reduced sulfur species, such as glutathione disulfide, cysteine, and sulfoxide, as well as organic sulfate as represented by chondroitin sulfate. Sulfoxide distributions were visually correlated with the presence of zooxanthellae endosymbionts. Coral skeletons were composed primarily of carbonate-associated sulfate (CAS) along with minor contributions from organic sulfate and a separate inorganic sulfate likely in the form of adsorbed sulfate. This coupled XRF-XANES approach allows for a more accurate and informative view of sulfur within biological systems in situ and holds great promise for pairing with other techniques to allow for a more encompassing understanding of elemental distributions within the environment.
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Affiliation(s)
| | | | - Samuel M Webb
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
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6
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Porcaro F, Roudeau S, Carmona A, Ortega R. Advances in element speciation analysis of biomedical samples using synchrotron-based techniques. Trends Analyt Chem 2018. [DOI: 10.1016/j.trac.2017.09.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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7
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Ochmann M, Hussain A, von Ahnen I, Cordones AA, Hong K, Lee JH, Ma R, Adamczyk K, Kim TK, Schoenlein RW, Vendrell O, Huse N. UV-Photochemistry of the Disulfide Bond: Evolution of Early Photoproducts from Picosecond X-ray Absorption Spectroscopy at the Sulfur K-Edge. J Am Chem Soc 2018; 140:6554-6561. [PMID: 29771112 DOI: 10.1021/jacs.7b13455] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have investigated dimethyl disulfide as the basic moiety for understanding the photochemistry of disulfide bonds, which are central to a broad range of biochemical processes. Picosecond time-resolved X-ray absorption spectroscopy at the sulfur K-edge provides unique element-specific insight into the photochemistry of the disulfide bond initiated by 267 nm femtosecond pulses. We observe a broad but distinct transient induced absorption spectrum which recovers on at least two time scales in the nanosecond range. We employed RASSCF electronic structure calculations to simulate the sulfur-1s transitions of multiple possible chemical species, and identified the methylthiyl and methylperthiyl radicals as the primary reaction products. In addition, we identify disulfur and the CH2S thione as the secondary reaction products of the perthiyl radical that are most likely to explain the observed spectral and kinetic signatures of our experiment. Our study underscores the importance of elemental specificity and the potential of time-resolved X-ray spectroscopy to identify short-lived reaction products in complex reaction schemes that underlie the rich photochemistry of disulfide systems.
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Affiliation(s)
- Miguel Ochmann
- Department of Physics , University of Hamburg and Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science , 22761 Hamburg , Germany
| | - Abid Hussain
- Department of Physics , University of Hamburg and Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science , 22761 Hamburg , Germany
| | - Inga von Ahnen
- Department of Physics , University of Hamburg and Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science , 22761 Hamburg , Germany
| | - Amy A Cordones
- Ultrafast X-ray Science Lab, Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Kiryong Hong
- Department of Chemistry and Chemistry Institute of Functional Materials , Pusan National University , Busan 46241 , South Korea
| | - Jae Hyuk Lee
- Ultrafast X-ray Science Lab, Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Rory Ma
- Department of Chemistry and Chemistry Institute of Functional Materials , Pusan National University , Busan 46241 , South Korea
| | - Katrin Adamczyk
- Department of Physics , University of Hamburg and Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science , 22761 Hamburg , Germany
| | - Tae Kyu Kim
- Department of Chemistry and Chemistry Institute of Functional Materials , Pusan National University , Busan 46241 , South Korea
| | - Robert W Schoenlein
- Ultrafast X-ray Science Lab, Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Oriol Vendrell
- Center for Free-Electron Laser Science , DESY and The Hamburg Centre for Ultrafast Imaging , 22607 Hamburg , Germany
| | - Nils Huse
- Department of Physics , University of Hamburg and Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science , 22761 Hamburg , Germany
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8
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Enriquez Garcia A, Jalilehvand F. Aerobic reactions of antitumor active dirhodium(II) tetraacetate Rh 2(CH 3COO) 4 with glutathione. J Biol Inorg Chem 2018; 23:231-239. [PMID: 29214420 PMCID: PMC5816706 DOI: 10.1007/s00775-017-1524-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/29/2017] [Indexed: 12/27/2022]
Abstract
The aerobic reaction between glutathione (H3A) and dirhodium(II) tetraacetate, Rh2(AcO)4 (AcO- = CH3COO-), in aqueous solution (pH 7.4) breaks up the direct RhII-RhII bond and its carboxylate framework, as evidenced by UV-Vis spectroscopy. After purifying the reaction product using size exclusion chromatography, electrospray ionization mass spectrometry (ESI-MS) of the solution showed binuclear [Formula: see text] and [Formula: see text] ions. Evaporation yielded a solid compound, [Formula: see text], for which Rh K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy revealed ~ 2 Rh-O (2.08 ± 0.02 Å) and ~ 4 Rh-S (2.33 ± 0.02 Å) bond distances around each RhIII center, and the RhIII··RhIII distance 3.11 ± 0.02 Å, close to that in dirhodium(III) complexes with three bridging thiolates connecting [Formula: see text] units. The 13C CPMAS NMR spectrum of the RhIII-glutathione complex showed a change ∆δ C > 6 ppm in the chemical shift of the COO- signal, indicating some carboxylate coordination to the Rh(III) ions. This study shows that under aerobic conditions glutathione enables oxidation of Rh2(AcO)4 and thus reduces its antitumor efficiency. The reaction of Rh2(AcO)4 with glutathione was investigated by ESI-MS, UV-Vis, 13C NMR and X-ray absorption spectroscopy, revealing that glutathione breaks down the carboxylate framework enabling oxidization of the [Formula: see text] core to Rh(III) dimeric units, bridged by three thiolates.
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Affiliation(s)
- Alejandra Enriquez Garcia
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Farideh Jalilehvand
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
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9
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Zanzen U, Bovenkamp-Langlois L, Klysubun W, Hormes J, Prange A. The interaction of copper ions with Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli: an X-ray absorption near-edge structure (XANES) spectroscopy study. Arch Microbiol 2017; 200:401-412. [PMID: 29181710 DOI: 10.1007/s00203-017-1454-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/13/2017] [Accepted: 11/14/2017] [Indexed: 01/26/2023]
Abstract
The antimicrobial properties of copper ions have been known for a long time. However, the exact mechanism of action of the transition metal on microorganisms has long been unclear. X-ray absorption near-edge structure (XANES) spectroscopy at the Cu K edge allows the determination of copper speciation in Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa that have been treated with Cu(II) and Cu(I) solutions. The death/inactivation of the bacteria was observed using plate counting and light microscopy. The Cu K-XANES spectra of the two Gram-negative bacteria are different than those of the Gram-positive strain. The results clearly show that the Cu+-S bond contributes to the antibacterial activity of copper, as in the case of silver. The detailed evaluation of the differentiated absorption spectra shows that Cu+ (not Cu2+) is the dominant ion that binds to the bacteria. Because Cu+ is not the most common copper ion, copper is not as effective an antibacterial agent as silver, whose common valency is actually + 1. Any reaction of copper with phosphorus from the bacteria can be excluded after the evaluation of the absorption spectra.
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Affiliation(s)
- Ulrike Zanzen
- Microbiology and Food Hygiene, Department of Food Sciences, Niederrhein University of Applied Sciences, Rheydter Strasse 277, 41065, Mönchengladbach, Germany.,Institute for Virology and Microbiology, University of Witten/Herdecke, 58448, Witten, Germany
| | - Lisa Bovenkamp-Langlois
- Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA, 70806, USA
| | - Wantana Klysubun
- SIAM Photon Source, Synchrotron Light Research Institute, 111 University Avenue, Muang District, Nakhon Ratchasima, 30000, Thailand
| | - Josef Hormes
- Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA, 70806, USA.,Institute of Physics, University of Bonn, 53115, Bonn, Germany
| | - Alexander Prange
- Microbiology and Food Hygiene, Department of Food Sciences, Niederrhein University of Applied Sciences, Rheydter Strasse 277, 41065, Mönchengladbach, Germany. .,Institute for Virology and Microbiology, University of Witten/Herdecke, 58448, Witten, Germany. .,Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA, 70806, USA.
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10
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Jalilehvand F, Enriquez Garcia A, Niksirat P. Reactions of Antitumor Active Dirhodium(II) Tetraacetate Rh 2(CH 3COO) 4 with Cysteine and Its Derivatives. ACS OMEGA 2017; 2:6174-6186. [PMID: 31457864 PMCID: PMC6644637 DOI: 10.1021/acsomega.7b01090] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/21/2017] [Indexed: 05/10/2023]
Abstract
We have combined results from several spectroscopic techniques to investigate the aerobic reactions of Rh2(AcO)4 (AcO- = CH3COO-) with l-cysteine (H2Cys) and its derivatives d-penicillamine (3,3'-dimethylcysteine, H2Pen), with steric hindrance at the thiol group, and N-acetyl-l-cysteine (H2NAC), with its amino group blocked. Previous investigations have shown that antitumor active dirhodium(II) carboxylates may irreversibly inhibit enzymes containing a thiol group at or near their active sites. Also, cysteine, the only thiol-containing proteinogenic amino acid, interacts in vivo with this class of antitumor compounds, but structural information on the products of such reactions is lacking. In the present study, the reactions of Rh2(AcO)4 and H2L were carried out in aqueous solutions at the pH of mixing (acidic) and at physiological pH, using the different mole ratios 1:2, 1:4, and 1:6, which resulted in the same products in increasing yields. Electrospray ionization mass spectrometry (ESI-MS) indicates formation of dimeric [RhIII 2Pen4]2- or oligomeric {RhIII 2L4} n (L = Cys, NAC) complexes with bridging thiolate groups. Analyses of Rh K edge extended X-ray absorption fine structure (EXAFS) data reveal 3-4 Rh-S and 2-3 Rh-(N/O) bonds around six-coordinated Rh(III) ions at mean distances of 2.33 ± 0.02 and 2.09 ± 0.02 Å, respectively. In the N-acetyl-l-cysteine compound, the RhIII···RhIII distance 3.10 ± 0.02 Å obtained from the EXAFS spectrum supports trithiolate bridges between the Rh(III) ions, as was also found when using glutathione as ligand. In the cysteine and penicillamine complexes, double thiolate bridges join the Rh(III) ions, with the nonbridging Cys2- and Pen2- ligands in tridentate chelating (S,N,O) mode, which is consistent with the ΔδC = 7.3-8.4 ppm shift of the COO- signal in their carbon-13 cross polarization magic angle spinning (CPMAS) NMR spectra. For the penicillamine complex, the 2475.6 eV peak in its S K edge X-ray absorption near edge structure (XANES) spectrum shows partial oxidation, probably caused by peroxide generated from reduction of dissolved O2, of thiolato to sulfenato (S=O) groups, which were also identified by ESI-MS for all three {RhIII 2L4} n compounds.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Alejandra Enriquez Garcia
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Pantea Niksirat
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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11
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Ding F, Tsuchiya T, Manby FR, Miller TF. Linear-Response Time-Dependent Embedded Mean-Field Theory. J Chem Theory Comput 2017; 13:4216-4227. [DOI: 10.1021/acs.jctc.7b00666] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Feizhi Ding
- Division
of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Takashi Tsuchiya
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Frederick R. Manby
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Thomas F. Miller
- Division
of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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12
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Hackett MJ, Paterson PG, Pickering IJ, George GN. Imaging Taurine in the Central Nervous System Using Chemically Specific X-ray Fluorescence Imaging at the Sulfur K-Edge. Anal Chem 2016; 88:10916-10924. [PMID: 27700065 DOI: 10.1021/acs.analchem.6b02298] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A method to image taurine distributions within the central nervous system and other organs has long been sought. Since taurine is small and mobile, it cannot be chemically "tagged" and imaged using conventional immuno-histochemistry methods. Combining numerous indirect measurements, taurine is known to play critical roles in brain function during health and disease and is proposed to act as a neuro-osmolyte, neuro-modulator, and possibly a neuro-transmitter. Elucidation of taurine's neurochemical roles and importance would be substantially enhanced by a direct method to visualize alterations, due to physiological and pathological events in the brain, in the local concentration of taurine at or near cellular spatial resolution in vivo or in situ in tissue sections. We thus have developed chemically specific X-ray fluorescence imaging (XFI) at the sulfur K-edge to image the sulfonate group in taurine in situ in ex vivo tissue sections. To our knowledge, this represents the first undistorted imaging of taurine distribution in brain at 20 μm resolution. We report quantitative technique validation by imaging taurine in the cerebellum and hippocampus regions of the rat brain. Further, we apply the technique to image taurine loss from the vulnerable CA1 (cornus ammonis 1) sector of the rat hippocampus following global brain ischemia. The location-specific loss of taurine from CA1 but not CA3 neurons following ischemia reveals osmotic stress may be a key factor in delayed neurodegeneration after a cerebral ischemic insult and highlights the significant potential of chemically specific XFI to study the role of taurine in brain disease.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, Curtin University , GPO Box U1987, Perth, Western Australia 6845, Australia
| | - Phyllis G Paterson
- College of Pharmacy and Nutrition, University of Saskatchewan , 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
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13
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Hackett MJ, George GN, Pickering IJ, Eames BF. Chemical Biology in the Embryo: In Situ Imaging of Sulfur Biochemistry in Normal and Proteoglycan-Deficient Cartilage Matrix. Biochemistry 2016; 55:2441-51. [PMID: 26985789 DOI: 10.1021/acs.biochem.5b01136] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proteoglycans (PGs) are heavily glycosylated proteins that play major structural and biological roles in many tissues. Proteoglycans are abundant in cartilage extracellular matrix; their loss is a main feature of the joint disease osteoarthritis. Proteoglycan function is regulated by sulfation-sulfate ester formation with specific sugar residues. Visualization of sulfation within cartilage matrix would yield vital insights into its biological roles. We present synchrotron-based X-ray fluorescence imaging of developing zebrafish cartilage, providing the first in situ maps of sulfate ester distribution. Levels of both sulfur and sulfate esters decrease as cartilage develops through late phase differentiation (maturation or hypertrophy), suggesting a functional link between cartilage matrix sulfur content and chondrocyte differentiation. Genetic experiments confirm that sulfate ester levels were due to cartilage proteoglycans and support the hypothesis that sulfate ester levels regulate chondrocyte differentiation. Surprisingly, in the PG synthesis mutant, the total level of sulfur was not significantly reduced, suggesting sulfur is distributed in an alternative chemical form during lowered cartilage proteoglycan production. Fourier transform infrared imaging indicated increased levels of protein in the mutant fish, suggesting that this alternative sulfur form might be ascribed to an increased level of protein synthesis in the mutant fish, as part of a compensatory mechanism.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C9, Canada.,Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C9, Canada.,Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - B Frank Eames
- Department of Anatomy and Cell Biology, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E5, Canada
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14
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Asfaw HD, Younesi R, Valvo M, Maibach J, Ångström J, Tai CW, Bacsik Z, Sahlberg M, Nyholm L, Edström PK. Boosting the thermal stability of emulsion-templated polymers via sulfonation: an efficient synthetic route to hierarchically porous carbon foams. ChemistrySelect 2016. [DOI: 10.1002/slct.201600139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Habtom D. Asfaw
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Reza Younesi
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Mario Valvo
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Julia Maibach
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Jonas Ångström
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Cheuk-Wai Tai
- Department of Materials and Environmental Chemistry; Arrhenius Laboratory; Stockholm University; S-10691 Stockholm Sweden
| | - Zoltan Bacsik
- Department of Materials and Environmental Chemistry; Arrhenius Laboratory; Stockholm University; S-10691 Stockholm Sweden
| | - Martin Sahlberg
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Leif Nyholm
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
| | - Prof Kristina Edström
- Department of Chemistry; Ångström Laboratory; Uppsala University; Lagerhyddsvägen 1, Box 538 75121 Uppsala Sweden
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15
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Brown DS, Eames BF. Emerging tools to study proteoglycan function during skeletal development. Methods Cell Biol 2016; 134:485-530. [PMID: 27312503 DOI: 10.1016/bs.mcb.2016.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the past 20years, appreciation for the varied roles of proteoglycans (PGs), which are specific types of sugar-coated proteins, has increased dramatically. PGs in the extracellular matrix were long known to impart structural functions to many tissues, especially articular cartilage, which cushions bones and allows mobility at skeletal joints. Indeed, osteoarthritis is a debilitating disease associated with loss of PGs in articular cartilage. Today, however, PGs have a demonstrated role in cell biological processes, such as growth factor signalling, prompting new perspectives on the etiology of PG-associated diseases. Here, we review diseases associated with defects in PG synthesis and sulfation, also highlighting current understanding of the underlying genetics, biochemistry, and cell biology. Since most research has analyzed a class of PGs called heparan sulfate PGs, more attention is paid here to studies of chondroitin sulfate PGs (CSPGs), which are abundant in cartilage. Interestingly, CSPG synthesis is tightly linked to the cell biological processes of secretion and lysosomal degradation, suggesting that these systems may be linked genetically. Animal models of loss of CSPG function have revealed CSPGs to impact skeletal development. Specifically, our work from a mutagenesis screen in zebrafish led to the hypothesis that cartilage PGs normally delay the timing of endochondral ossification. Finally, we outline emerging approaches in zebrafish that may revolutionize the study of cartilage PG function, including transgenic methods and novel imaging techniques. Our recent work with X-ray fluorescent imaging, for example, enables direct correlation of PG function with PG-dependent biological processes.
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Affiliation(s)
- D S Brown
- University of Saskatchewan, Saskatoon, SK, Canada
| | - B F Eames
- University of Saskatchewan, Saskatoon, SK, Canada
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16
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Hackett MJ, Smith SE, Caine S, Nichol H, George GN, Pickering IJ, Paterson PG. Novel bio-spectroscopic imaging reveals disturbed protein homeostasis and thiol redox with protein aggregation prior to hippocampal CA1 pyramidal neuron death induced by global brain ischemia in the rat. Free Radic Biol Med 2015; 89:806-18. [PMID: 26454085 PMCID: PMC5509437 DOI: 10.1016/j.freeradbiomed.2015.08.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 08/16/2015] [Accepted: 08/31/2015] [Indexed: 10/22/2022]
Abstract
Global brain ischemia resulting from cardiac arrest and cardiac surgery can lead to permanent brain damage and mental impairment. A clinical hallmark of global brain ischemia is delayed neurodegeneration, particularly within the CA1 subsector of the hippocampus. Unfortunately, the biochemical mechanisms have not been fully elucidated, hindering optimization of current therapies (i.e., therapeutic hypothermia) or development of new therapies. A major limitation to elucidating the mechanisms that contribute to neurodegeneration and understanding how these are influenced by potential therapies is the inability to relate biochemical markers to alterations in the morphology of individual neurons. Although immunocytochemistry allows imaging of numerous biochemical markers at the sub-cellular level, it is not a direct chemical imaging technique and requires successful "tagging" of the desired analyte. Consequently, important biochemical parameters, particularly those that manifest from oxidative damage to biological molecules, such as aggregated protein levels, have been notoriously difficult to image at the cellular or sub-cellular level. It has been hypothesized that reactive oxygen species (ROS) generated during ischemia and reperfusion facilitate protein aggregation, impairing neuronal protein homeostasis (i.e., decreasing protein synthesis) that in turn promotes neurodegeneration. Despite indirect evidence for this theory, direct measurements of morphology and ROS induced biochemical damage, such as increased protein aggregates and decreased protein synthesis, within the same neuron is lacking, due to the unavailability of a suitable imaging method. Our experimental approach has incorporated routine histology with novel wide-field synchrotron radiation Fourier transform infrared imaging (FTIRI) of the same neurons, ex vivo within brain tissue sections. The results demonstrate for the first time that increased protein aggregation and decreased levels of total protein occur in the same CA1 pyramidal neurons 1 day after global ischemia. Further, analysis of serial tissue sections using X-ray absorption spectroscopy at the sulfur K-edge has revealed that CA1 pyramidal neurons have increased disulfide levels, a direct indicator of oxidative stress, at this time point. These changes at 1 day after ischemia precede a massive increase in aggregated protein and disulfide levels concomitant with loss of neuron integrity 2 days after ischemia. Therefore, this study has provided direct support for a correlative mechanistic link in both spatial and temporal domains between oxidative stress, protein aggregation and altered protein homeostasis prior to irreparable neuron damage following global ischemia.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Shari E Smith
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Sally Caine
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Helen Nichol
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada; Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada; Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Phyllis G Paterson
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada.
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Lin H, Ye C, Lv L, Zheng CR, Zhang S, Zheng L, Zhao Y, Yu X. Characterization of extracellular polymeric substances in the biofilms of typical bacteria by the sulfur K-edge XANES spectroscopy. J Environ Sci (China) 2014; 26:1763-1768. [PMID: 25108733 DOI: 10.1016/j.jes.2014.06.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 12/28/2013] [Accepted: 01/13/2014] [Indexed: 06/03/2023]
Abstract
A combined approach of physicochemical extraction and sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to characterize the extracellular polymeric substances (EPS) of typical bacterial biofilms in this study. Physicochemical analysis showed variation of the contents of DNA, polysaccharide and protein in different fractions of EPS in different mediums. The sulfur K-edge XANES analysis yielded a variety of spectra. Spectral fitting of the XANES spectra utilizing a large set of model compounds showed that there was more reduced sulfur in both LB-EPS (loosely bound EPS) and TB-EPS (tightly bound EPS) of all the biofilms in LB medium than in R2A medium. More oxidized sulfur was identified in LB-EPS than that in TB-EPS, suggesting different niches and physiological heterogeneity in the biofilms. Our results suggested that the sulfur K-edge XANES can be a useful tool to analyze the sulfur speciation in EPS of biofilms.
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Affiliation(s)
- Huirong Lin
- Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China.
| | - Chengsong Ye
- Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China
| | - Lu Lv
- Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China
| | | | - Shenghua Zhang
- Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China
| | - Lei Zheng
- Institute of High Energy Physics, Chinese Academy of Science, Beijing Synchrotron Radiation Facility, Beijing 100049, China
| | - Yidong Zhao
- Institute of High Energy Physics, Chinese Academy of Science, Beijing Synchrotron Radiation Facility, Beijing 100049, China
| | - Xin Yu
- Institute of Urban Environment, Chinese Academy of Science, Xiamen 361021, China.
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18
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Chemical sensitivity of sulfur 1s NEXAFS spectroscopy II: Speciation of disulfide functional groups. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.10.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Behyan S, Hu Y, Urquhart SG. Chemical sensitivity of sulfur 1s NEXAFS spectroscopy I: Speciation of sulfoxides and sulfones. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.10.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Wang L, Li J, Pan J, Jiang X, Ji Y, Li Y, Qu Y, Zhao Y, Wu X, Chen C. Revealing the binding structure of the protein corona on gold nanorods using synchrotron radiation-based techniques: understanding the reduced damage in cell membranes. J Am Chem Soc 2013; 135:17359-68. [PMID: 24215358 DOI: 10.1021/ja406924v] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Regarding the importance of the biological effects of nanomaterials, there is still limited knowledge about the binding structure and stability of the protein corona on nanomaterials and the subsequent impacts. Here we designed a hard serum albumin protein corona (BSA) on CTAB-coated gold nanorods (AuNRs) and captured the structure of protein adsorption using synchrotron radiation X-ray absorption spectroscopy, microbeam X-ray fluorescent spectroscopy, and circular dichroism in combination with molecular dynamics simulations. The protein adsorption is attributed to at least 12 Au-S bonds and the stable corona reduced the cytotoxicity of CTAB/AuNRs. These combined strategies using physical, chemical, and biological approaches will improve our understanding of the protective effects of protein coronas against the toxicity of nanomaterials. These findings have shed light on a new strategy for studying interactions between proteins and nanomaterials, and this information will help further guide the rational design of nanomaterials for safe and effective biomedical applications.
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Affiliation(s)
- Liming Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China and Institute of High Energy Physics , Beijing, China
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21
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Liu Y, Sun C, Bolin T, Wu T, Liu Y, Sternberg M, Sun S, Lin XM. Kinetic pathway of palladium nanoparticle sulfidation process at high temperatures. NANO LETTERS 2013; 13:4893-4901. [PMID: 24067076 DOI: 10.1021/nl402768b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A significant issue related to Palladium (Pd) based catalysts is that sulfur-containing species, such as alkanethiols, can form a PdSx underlayer on nanoparticle surface and subsequently poison the catalysts. Understanding the exact reaction pathway, the degree of sulfidation, the chemical stoichiometry, and the temperature dependence of this process is critically important. Combining energy-filtered transmission electron microscopy (EFTEM), X-ray diffraction (XRD), and X-ray absorption spectroscopy experiments at the S K-, Pd K-, and L2,3-edges, we show the kinetic pathway of Pd nanoparticle sulfidation process with the addition of excess amount of octadecanethiol at different temperatures, up to 250 °C. We demonstrate that the initial polycrystalline Pd-oleylamine nanoparticles gradually become amorphous PdSx nanoparticles, with the sulfur atomic concentration eventually saturating at Pd/S = 66:34 at 200 °C. This final chemical stoichiometry of the sulfurized nanoparticles closely matches that of the crystalline P16S7 phase (30.4% S), albeit being structurally amorphous. Sulfur diffusion into the nanoparticle depends strongly on the temperature. At 90 °C, sulfidation remains limited at the surface of nanoparticles even with extended heating time; whereas at higher temperatures beyond 125 °C, sulfidation occurs rapidly in the interior of the particles, far beyond what can be described as a core-shell model. This indicates sulfur diffusion from the surface to the interior of the particle is subject to a diffusion barrier and likely first go through the grain boundaries of the nanoparticle.
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Affiliation(s)
- Yi Liu
- Center for Nanoscale Materials and ‡Advanced Photon Source, Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States
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22
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Bovenkamp GL, Zanzen U, Krishna KS, Hormes J, Prange A. X-ray absorption near-edge structure (XANES) spectroscopy study of the interaction of silver ions with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. Appl Environ Microbiol 2013; 79:6385-90. [PMID: 23934494 PMCID: PMC3811211 DOI: 10.1128/aem.01688-13] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/05/2013] [Indexed: 11/20/2022] Open
Abstract
Silver ions are widely used as antibacterial agents, but the basic molecular mechanism of this effect is still poorly understood. X-ray absorption near-edge structure (XANES) spectroscopy at the Ag LIII, S K, and P K edges reveals the chemical forms of silver in Staphylococcus aureus and Escherichia coli (Ag(+) treated). The Ag LIII-edge XANES spectra of the bacteria are all slightly different and very different from the spectra of silver ions (silver nitrate and silver acetate), which confirms that a reaction occurs. Death or inactivation of bacteria was observed by plate counting and light microscopy. Silver bonding to sulfhydryl groups (Ag-S) in cysteine and Ag-N or Ag-O bonding in histidine, alanine, and DL-aspartic acid was detected by using synthesized silver-amino acids. Significantly lower silver-cysteine content, coupled with higher silver-histidine content, in Gram-positive S. aureus and Listeria monocytogenes cells indicates that the peptidoglycan multilayer could be buffering the biocidal effect of silver on Gram-positive bacteria, at least in part. Bonding of silver to phosphate groups was not detected. Interaction with DNA or proteins can occur through Ag-N bonding. The formation of silver-cysteine can be confirmed for both bacterial cell types, which supports the hypothesis that enzyme-catalyzed reactions and the electron transport chain within the cell are disrupted.
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Affiliation(s)
- Gudrun Lisa Bovenkamp
- Institute of Physics, University of Bonn, Bonn, Germany
- Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, Baton Rouge, Louisiana, USA
| | - Ulrike Zanzen
- Competence Center for Microbiology & Biotechnology (CCMB), Niederrhein University of Applied Sciences, Mönchengladbach, Germany
| | - Katla Sai Krishna
- Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, Baton Rouge, Louisiana, USA
| | - Josef Hormes
- Institute of Physics, University of Bonn, Bonn, Germany
- Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, Baton Rouge, Louisiana, USA
- Canadian Light Source (CLS), University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Alexander Prange
- Center for Advanced Microstructures and Devices (CAMD), Louisiana State University, Baton Rouge, Louisiana, USA
- Competence Center for Microbiology & Biotechnology (CCMB), Niederrhein University of Applied Sciences, Mönchengladbach, Germany
- Institute for Virology and Microbiology, University of Witten/Herdecke, Witten, Germany
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23
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Behyan S, Hu Y, Urquhart SG. Sulfur 1s near edge x-ray absorption fine structure spectroscopy of thiophenic and aromatic thioether compounds. J Chem Phys 2013; 138:214302. [PMID: 23758366 DOI: 10.1063/1.4807604] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Thiophenic compounds are major constituents of fossil fuels and pose problems for fuel refinement. The quantification and speciation of these compounds is of great interest in different areas such as biology, fossil fuels studies, geology, and archaeology. Sulfur 1s Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy has emerged as a qualitative and quantitative method for sulfur speciation. A firm understanding of the sulfur 1s NEXAFS spectra of organosulfur species is required for these analytical studies. To support this development, the sulfur 1s NEXAFS spectra of simple thiols and thioethers were previously examined, and are now extended to studies of thiophenic and aromatic thioether compounds, in the gas and condensed phases. High-resolution spectra have been further analyzed with the aid of Improved Virtual Orbital (IVO) and Δ(self-consistent field) ab initio calculations. Experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve the assignment of spectroscopic features important for the speciation and quantification of sulfur compounds. Systematic differences between gas and condensed phases are also explored; these differences suggest a significant role for conformational effects in the NEXAFS spectra of condensed species.
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Affiliation(s)
- Shirin Behyan
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
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24
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Dutta A, Flores M, Roy S, Schmitt JC, Hamilton GA, Hartnett HE, Shearer J, Jones AK. Sequential oxidations of thiolates and the cobalt metallocenter in a synthetic metallopeptide: implications for the biosynthesis of nitrile hydratase. Inorg Chem 2013; 52:5236-45. [PMID: 23587023 PMCID: PMC4046696 DOI: 10.1021/ic400171z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cobalt nitrile hydratases (Co-NHase) contain a catalytic cobalt(III) ion coordinated in an N2S3 first coordination sphere composed of two amidate nitrogens and three cysteine-derived sulfur donors: a thiolate (-SR), a sulfenate (-S(R)O(-)), and a sulfinate (-S(R)O2(-)). The sequence of biosynthetic reactions that leads to the post-translational oxidations of the metal and the sulfur ligands is unknown, but the process is believed to be initiated directly by oxygen. Herein we utilize cobalt bound in an N2S2 first coordination sphere by a seven amino acid peptide known as SODA (ACDLPCG) to model this oxidation process. Upon exposure to oxygen, Co-SODA is oxidized in two steps. In the first fast step (seconds), magnetic susceptibility measurements demonstrated that the metallocenter remains paramagnetic, that is, Co(2+), and sulfur K-edge X-ray absorption spectroscopy (XAS) is used to show that one of the thiolates is oxidized to sulfinate. In a second process on a longer time scale (hours), magnetic susceptibility measurements and Co K-edge XAS show that the metal is oxidized to Co(3+). Unlike other model complexes, additional slow oxidation of the second thiolate in Co-SODA is not observed, and a catalytically active complex is never formed. The likely reason is the absence of the axial thiolate ligand. In essence, the reactivity of Co-SODA can be described as between previously described models which either quickly convert to final product or are stable in air, and it offers a first glimpse into a possible oxidation pathway for nitrile hydratase biosynthesis.
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Affiliation(s)
- Arnab Dutta
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287
- Center for Bio-Inspired Solar Fuel Production, Arizona State University, Tempe, AZ 85287
| | - Marco Flores
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287
| | - Souvik Roy
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287
- Center for Bio-Inspired Solar Fuel Production, Arizona State University, Tempe, AZ 85287
| | | | | | - Hilairy E. Hartnett
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287
- School of Earth and Space Exploration; Arizona State University, Tempe, AZ 85287
| | - Jason Shearer
- Department of Chemistry, University of Nevada, Reno, Nevada 89557
| | - Anne K. Jones
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287
- Center for Bio-Inspired Solar Fuel Production, Arizona State University, Tempe, AZ 85287
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25
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Hummer AA, Rompel A. X-Ray Absorption Spectroscopy. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 93:257-305. [DOI: 10.1016/b978-0-12-416596-0.00008-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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26
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Hackett MJ, Smith SE, Paterson PG, Nichol H, Pickering IJ, George GN. X-ray absorption spectroscopy at the sulfur K-edge: a new tool to investigate the biochemical mechanisms of neurodegeneration. ACS Chem Neurosci 2012; 3:178-85. [PMID: 22860187 PMCID: PMC3369794 DOI: 10.1021/cn200097s] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 01/02/2011] [Indexed: 12/12/2022] Open
Abstract
Sulfur containing molecules such as thiols, disulfides, sulfoxides, sulfonic acids, and sulfates may contribute to neurodegenerative processes. However, previous study in this field has been limited by the lack of in situ analytical techniques. This limitation may now be largely overcome following the development of synchrotron radiation X-ray absorption spectroscopy at the sulfur K-edge, which has been validated as a novel tool to investigate and image the speciation of sulfur in situ. In this investigation, we build the foundation required for future application of this technique to study and image the speciation of sulfur in situ within brain tissue. This study has determined the effect of sample preparation and fixation methods on the speciation of sulfur in thin sections of rat brain tissue, determined the speciation of sulfur within specific brain regions (brain stem and cerebellum), and identified sulfur specific markers of peroxidative stress following metal catalyzed reactive oxygen species production. X-ray absorption spectroscopy at the sulfur K-edge is now poised for an exciting new range of applications to study thiol redox, methionine oxidation, and the role of taurine and sulfatides during neurodegeneration.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatchewan S7NSE2, Canada
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27
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Ončák M, Berka K, Slavíček P. Novel Covalent Bond in Proteins: Calculations on Model Systems Question the Bond Stability. Chemphyschem 2011; 12:3449-57. [DOI: 10.1002/cphc.201100664] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Indexed: 11/12/2022]
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28
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Behyan S, Hu Y, Urquhart SG. Sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) of thiol and thioether compounds. J Chem Phys 2011; 134:244304. [DOI: 10.1063/1.3602218] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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29
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Lu TT, Lai SH, Li YW, Hsu IJ, Jang LY, Lee JF, Chen IC, Liaw WF. Discrimination of Mononuclear and Dinuclear Dinitrosyl Iron Complexes (DNICs) by S K-Edge X-ray Absorption Spectroscopy: Insight into the Electronic Structure and Reactivity of DNICs. Inorg Chem 2011; 50:5396-406. [DOI: 10.1021/ic102108b] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Tsai-Te Lu
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Szu-Hsueh Lai
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ya-Wen Li
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei 10608, Taiwan
| | - I-Jui Hsu
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Ling-Yun Jang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Jyh-Fu Lee
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - I-Chia Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wen-Feng Liaw
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
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Zhou X, Wang L, Sun X, Yang X, Chen C, Wang Q, Yang X. Cinnabar is not converted into methylmercury by human intestinal bacteria. JOURNAL OF ETHNOPHARMACOLOGY 2011; 135:110-115. [PMID: 21382464 DOI: 10.1016/j.jep.2011.02.032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/09/2011] [Accepted: 02/27/2011] [Indexed: 05/30/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Cinnabar (Cin), a naturally occurring mercuric sulfide (HgS), is a mineral widely used in traditional Chinese medicine throughout history. As for the toxicity of cinnabar, one important assumption is that cinnabar may be transformed into highly toxic methylmercury by gastrointestinal flora. There is no evidence in humans to support this assumption. AIM OF THE STUDY To investigate the biotransformation of cinnabar (HgS) in the human intestinal bacteria with modern analytical techniques. MATERIALS AND METHODS A gas chromatograph, equipped with electron capture detection (GC-ECD) and mass spectrometry (GC-MS), were used to detect the formation of methylmercury after incubation of cinnabar with human intestinal bacteria. The content of soluble mercury in the bacteria media was determined by cold vapor-atomic absorption spectrometry (CV-AAS). In addition, X-ray absorption near-edge structure spectroscopy (XANES) was used to confirm the possible transformation of cinnabar in the bacteria media, and under mimetic intestinal condition by measuring the species of sulfur and mercury in the reaction extraction of cinnabar and Na(2)S mixture. RESULTS No methylmercury was detected by both GC-ECD and GC-MS, which suggest that cinnabar (HgS) is not methylated in the human intestine. A small amount of soluble mercury was found to be released in the flora medium of HgS or cinnabar by CV-AAS. The XANES analyses revealed that polysulfides exist in the flora medium, and the simulated results showed that the products by incubating cinnabar with Na(2)S were mercuric polysulfides. CONCLUSION These results showed that under gut flora conditions cinnabar would be transformed into mercuric polysulfides rather than methylmercury. Our work provides evidences of nontoxic transformation of cinnabar in the human intestinal bacteria.
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Affiliation(s)
- Xinrui Zhou
- State Key Laboratories of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, PR China
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31
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Mijovilovich A, Pettersson LGM, de Groot FMF, Weckhuysen BM. Functional Groups and Sulfur K-Edge XANES Spectra: Divalent Sulfur and Disulfides. J Phys Chem A 2010; 114:9523-8. [DOI: 10.1021/jp103109y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ana Mijovilovich
- Inorganic Chemistry and Catalysis group, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Department of Physics, Alba Nova, Stockholm University, SE 106 9 L Stockholm, Sweden
| | - Lars G. M. Pettersson
- Inorganic Chemistry and Catalysis group, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Department of Physics, Alba Nova, Stockholm University, SE 106 9 L Stockholm, Sweden
| | - Frank M. F. de Groot
- Inorganic Chemistry and Catalysis group, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Department of Physics, Alba Nova, Stockholm University, SE 106 9 L Stockholm, Sweden
| | - Bert M. Weckhuysen
- Inorganic Chemistry and Catalysis group, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Department of Physics, Alba Nova, Stockholm University, SE 106 9 L Stockholm, Sweden
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32
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Characterization of gold nanorods in vivo by integrated analytical techniques: their uptake, retention, and chemical forms. Anal Bioanal Chem 2009; 396:1105-14. [DOI: 10.1007/s00216-009-3302-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 10/20/2009] [Accepted: 11/06/2009] [Indexed: 12/30/2022]
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Franz B, Lichtenberg H, Hormes J, Dahl C, Prange A. The speciation of soluble sulphur compounds in bacterial culture fluids by X-ray absorption near edge structure spectroscopy. ENVIRONMENTAL TECHNOLOGY 2009; 30:1281-1289. [PMID: 19950470 DOI: 10.1080/09593330903055635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Over the last decade X-ray absorption near edge structure (XANES) spectroscopy has been used in an increasing number of microbiological studies. In addition to other applications it has served as a valuable tool for the investigation of the sulphur globules deposited intra- or extracellularly by certain photo- and chemotrophic sulphur-oxidizing (Sox) bacteria. For XANES measurements, these deposits can easily be concentrated by filtration or sedimentation through centrifugation. However, during oxidative metabolism of reduced sulphur compounds, such as sulphide or thiosulphate, sulphur deposits are not the only intermediates formed. Soluble intermediates such as sulphite may also be produced and released into the medium. In this study, we explored the potential of XANES spectroscopy for the detection and speciation of sulphur compounds in culture supernatants of the phototrophic purple sulphur bacterium Allochromatium vinosum. More specifically, we investigated A. vinosum DeltasoxY, a strain with an in frame deletion of the soxY gene. This gene encodes an essential component of the thiosulphate-oxidizing Sox enzyme complex. Improved sample preparation techniques developed for the DeltasoxY strain allowed for the first time not only the qualitative but also the quantitative analysis of bacterial culture supernatants by XANES spectroscopy. The results thus obtained verified and supplemented conventional HPLC analysis of soluble sulphur compounds. Sulphite and also oxidized organic sulphur compounds were shown by XANES spectroscopy to be present, some of which were not seen when standard HPLC protocols were used.
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Affiliation(s)
- Bettina Franz
- Niederrhein University of Applied Sciences, Microbiology and Food Hygiene, Mönchengladbach, Germany
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34
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Abstract
AbstractSulphur K-edge X-ray absorption near edge structure (XANES) spectroscopy was used to identify sulphur compounds in PM10 samples collected simultaneously at two sites with different environmental situations in the province of Trieste (NE of Italy), during summer and winter seasons respectively. The first site is an industrial site located near a steel mill plant and the second is a coastal site. The sulphur speciation at the industrial site has shown the presence of the following sulphur compounds in both seasons: organic compounds (thiophenes or Polycyclic Aromatic Sulphur Heterocycles — PAHs) and sulphates while in the winter season sulphites were also present. In the coastal site organic compounds (thiophenes or PASHs) and sulphate were found during winter season, moreover bisulphates were found during summer season. Relative percentages of the different sulphur compounds have shown that sulphate is the most abundant form of sulphur in the industrial site samples during both seasons and in the coastal site sample collected during the winter season (> 98%); in the coastal site sample collected during the summer season the relative percentages of bisulphate and sulphate were around 40% and 60% respectively.
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35
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Jürgensen A. X-ray absorption spectroscopy of aqueous solutions in the X-ray energy region from 1800 to 3700 eV. CAN J CHEM 2009. [DOI: 10.1139/v09-023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A methodology for the X-ray XANES and EXAFS analyses of aqueous solutions was developed for the Double Crystal Monochromator (DCM) beamline of the Canadian Synchrotron Radiation Facility (CSRF). The technique is based on the implementation of a liquid cell, which is compatible with the standard solid-state sample holding mechanism used at the beamlines of CSRF and the Canadian Light Source (CLS). Aluminized Mylar film with a thickness of 5 μm has been thoroughly investigated for use as a window material for the cell, and found acceptable for the collection of the S, Cl, and K K-edge spectra of ions in aqueous solution, but not for P K-edge or Rb L2,3-edge spectra. Some of the limitations of this methodology, such as diffusion of the solution through the window and the detection limit at low ion concentration, are investigated and discussed.
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Affiliation(s)
- Astrid Jürgensen
- Canadian Synchrotron Radiation Facility, Synchrotron Radiation Center, 3731 Schneider Drive, Stoughton, WI 53589, USA
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36
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Risberg ED, Jalilehvand F, Leung BO, Pettersson LGM, Sandström M. Theoretical and experimental sulfur K-edge X-ray absorption spectroscopic study of cysteine, cystine, homocysteine, penicillamine, methionine and methionine sulfoxide. Dalton Trans 2009:3542-58. [PMID: 19381417 DOI: 10.1039/b819257j] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The experimental sulfur K-edge X-ray absorption near-edge structure (XANES) spectra of the amino acids cysteine, homocysteine, penicillamine, methionine, including the oxidation products methionine sulfoxide and the disulfide cystine, have been analyzed by transition potential DFT calculations. The absolute energies and intensities of the main pre-edge sulfur 1s electron transitions have been computed to determine the character of the receiving unoccupied molecular orbitals (MO), and to investigate the influence of external interactions, especially by introducing water molecules hydrogen-bonded to the ionic species present in different pH ranges. When the thiol group deprotonates for cysteine, homocysteine and penicillamine and also for the cysteine residue in glutathione the energy of the main transition, to an MO with antibonding sigma*(S-H) character, reduces by approximately 1.1 eV and the receiving MO obtains sigma*(S-C) character. The changes in transition energy due to hydrogen-bonding were in most cases found to be relatively small, although the transition intensities could vary significantly due to the changes induced in the molecular charge distribution, thereby affecting the shapes of the spectral features. For the cysteine and penicillamine zwitterions deconvolution of the experimental spectra allowed the microscopic acid dissociation constants to be extracted separately for the thiol and the protonated amine groups, pK(a)(S) = 8.5 +/- 0.1 and 8.2 +/- 0.1, and pK(a)(N) = 8.9 +/- 0.1 and 8.8 +/- 0.1, respectively, with the thiol group in both cases being the more acidic. Coordination of cysteine to nickel(II) or mercury(II) introduced a new low energy transition involving metal ion orbitals in the receiving LUMO. The small experimentally observed energy differences between the similar main absorption features of the cysteine and methionine zwitterions, 0.2-0.3 eV in comparable surrounding, as well as a minor difference in their intensities, are reflected in the calculated transitions. The S K-edge XANES spectrum of the disulfide cystine displays a characteristic double peak with the lower energy transition (2469.9 eV) into the antibonding sigma*(S-S) MO. The second peak, at 2471.5 eV in aqueous solution, contains several transitions into MOs with sigma*(S-C) character involving also charge transfer to the water molecules hydrating the protonated amine groups (NH(3)(+)) of cystine. For solid cystine without hydrogen bonding the experimental energy difference between the two peaks is 0.2 eV larger, while no such increase occurs for the oxidized disulfide of glutathione, with a similar -S-S- bond between its cysteine residues as in cystine, because the amine groups are engaged in peptide bonds. This study shows that externally induced changes in the intramolecular bonding, e.g., by coordination, conformation geometry or hydrogen-bonding, can significantly influence the S K-edge spectra, and emphasizes the importance of a similar chemical surrounding when choosing the model compounds for standard spectra of sulfur functional groups, used to deconvolute composite experimental spectra.
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Affiliation(s)
- Emiliana Damian Risberg
- Department of Physical, Inorganic and Structural Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
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Mijovilovich A, Pettersson LGM, Mangold S, Janousch M, Susini J, Salome M, de Groot FMF, Weckhuysen BM. The Interpretation of Sulfur K-Edge XANES Spectra: A Case Study on Thiophenic and Aliphatic Sulfur Compounds. J Phys Chem A 2009; 113:2750-6. [DOI: 10.1021/jp806823c] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. Mijovilovich
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - L. G. M. Pettersson
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - S. Mangold
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - M. Janousch
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - J. Susini
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - M. Salome
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - F. M. F. de Groot
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
| | - B. M. Weckhuysen
- Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands, Department of Physics, AlbaNova, Stockholm University, SE 106 9 L Stockholm, Sweden, ANKA, Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein, Germany, Swiss Light Source, Paul Scherrer Institute, CH 5232 Villigen, Switzerland, and X-ray Microscopy
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38
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Karunakaran-Datt A, Kennepohl P. Redox Photochemistry of Methionine by Sulfur K-edge X-ray Absorption Spectroscopy: Potential Implications for Cataract Formation. J Am Chem Soc 2009; 131:3577-82. [DOI: 10.1021/ja806946r] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
| | - Pierre Kennepohl
- The University of British Columbia, Department of Chemistry, Vancouver, BC V6T 1Z1
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39
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He H, Zhang CG, Xia JL, Peng AA, Yang Y, Jiang HC, Zheng L, Ma CY, Zhao YD, Nie ZY, Qiu GZ. Investigation of elemental sulfur speciation transformation mediated by Acidithiobacillus ferrooxidans. Curr Microbiol 2008; 58:300-7. [PMID: 19085035 DOI: 10.1007/s00284-008-9330-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 11/10/2008] [Accepted: 11/11/2008] [Indexed: 10/21/2022]
Abstract
The speciation transformation of elemental sulfur mediated by the leaching bacterium Acidithiobacillus ferrooxidans was investigated using an integrated approach including scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, and X-ray absorption near edge spectroscopy (XANES). Our results showed that when grown on elemental sulfur powder, At. ferrooxidans ATCC23270 cells were first attached to sulfur particles and modified the surface sulfur with some amphiphilic compounds. In addition, part of the elemental sulfur powder might be converted to polysulfides. Furthermore, sulfur globules were accumulated inside the cells. XANES spectra of these cells suggested that these globules consisted of elemental sulfur bound to thiol groups of protein.
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Affiliation(s)
- Huan He
- Key Laboratory of Biometallurgy of Ministry of Education of China, School of Minerals Processing & Bioengineering, Central South University, Changsha, Hunan 410083, China.
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40
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Struis RPWJ, Ludwig C, Barrelet T, Krähenbühl U, Rennenberg H. Studying sulfur functional groups in Norway spruce year rings using S L-edge total electron yield spectroscopy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 403:196-206. [PMID: 18617221 DOI: 10.1016/j.scitotenv.2008.05.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 05/13/2008] [Accepted: 05/21/2008] [Indexed: 05/26/2023]
Abstract
Profiles of the major sulfur functional groups in mature Norway spruce wood tissue have been established for the first time. The big challenge was the development of a method suitable for sulfur speciation in samples with very low sulfur content (<100 ppm). This became possible by synchrotron X-ray absorption spectroscopy at the sulfur L-edge in total electron yield (TEY) detection mode with thin gold-coated wood slices. Functional groups were identified using sulfur compound spectra as fingerprints. Latewood of single year rings revealed metabolic plausible sulfur forms, particularly inorganic sulfide, organic disulfide, methylthiol, and highly oxidized sulfur. Form-specific profiles with Norway spruces from three different Swiss forest sites revealed high, but hitherto little-noticed, sulfur intensities attributable to natural heartwood formation and a common, but physiologically unexpected maximum around year ring 1986 with trees from the industrialized Swiss Plateau. It is hypothesized whether it may have resulted from the huge reduction in sulfur emissions after 1980 due to Swiss policy. Comparison with total S content profiles from optical emission spectroscopy underlined the more accurate and temporally better resolved TEY data with single wood year rings and it opened novel insights into the wood cell chemistry.
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Affiliation(s)
- Rudolf P W J Struis
- Paul Scherrer Institute, General Energy Research Department, LEM, CH-5232 Villigen PSI, Switzerland.
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41
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Liu X, Zheng F, Jürgensen A, Perez-Dieste V, Petrovykh DY, Abbott NL, Himpsel FJ. Self-assembly of biomolecules at surfaces characterized by NEXAFS. CAN J CHEM 2007. [DOI: 10.1139/v07-079] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Surface science has made great strides towards tailoring surface properties via self-assembly of nanoscale molecular adsorbates. It is now possible to functionalize surfaces with complex biomolecules such as DNA and proteins. This brief overview shows how NEXAFS (near edge X-ray absorption fine structure spectroscopy) can be used to characterize the assembly of biological molecules at surfaces in atom- and orbital-specific fashion. To illustrate the range of applications, we begin with simple self-assembled monolayers (SAMs), proceed to SAMs with customized terminal groups, and finish with DNA oligonucleotides and Ribonuclease A, a small protein containing 124 amino acids. The N 1s absorption edge is particularly useful for characterizing DNA and proteins because it selectively interrogates the π* orbitals in nucleobases and the peptide bonds in proteins. Information about the orientation of molecular orbitals is obtained from the polarization dependence. Quantitative NEXAFS models explain the polarization dependence in terms of molecular orientation and structure.Key words: NEXAFS, bio-interfaces, ribonuclease A, immobilization, orientation.
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42
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Risberg ED, Eriksson L, Mink J, Pettersson LGM, Skripkin MY, Sandström M. Sulfur X-ray Absorption and Vibrational Spectroscopic Study of Sulfur Dioxide, Sulfite, and Sulfonate Solutions and of the Substituted Sulfonate Ions X3CSO3- (X = H, Cl, F). Inorg Chem 2007; 46:8332-48. [PMID: 17784748 DOI: 10.1021/ic062440i] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra have been recorded and the S(1s) electron excitations evaluated by means of density functional theory-transition potential (DFT-TP) calculations to provide insight into the coordination, bonding, and electronic structure. The XANES spectra for the various species in sulfur dioxide and aqueous sodium sulfite solutions show considerable differences at different pH values in the environmentally important sulfite(IV) system. In strongly acidic (pH < approximately 1) aqueous sulfite solution the XANES spectra confirm that the hydrated sulfur dioxide molecule, SO2(aq), dominates. The theoretical spectra are consistent with an OSO angle of approximately 119 degrees in gas phase and acetonitrile solution, while in aqueous solution hydrogen bonding reduces the angle to approximately 116 degrees . The hydration affects the XANES spectra also for the sulfite ion, SO32-. At intermediate pH ( approximately 4) the two coordination isomers, the sulfonate (HSO3-) and hydrogen sulfite (SO3H-) ions with the hydrogen atom coordinated to sulfur and oxygen, respectively, could be distinguished with the ratio HSO3-:SO3H- about 0.28:0.72 at 298 K. The relative amount of HSO3- increased with increasing temperature in the investigated range from 275 to 343 K. XANES spectra of sulfonate, methanesulfonate, trichloromethanesulfonate, and trifluoromethanesulfonate compounds, all with closely similar S-O bond distances in tetrahedral configuration around the sulfur atom, were interpreted by DFT-TP computations. The energy of their main electronic transition from the sulfur K-shell is about 2478 eV. The additional absorption features are similar when a hydrogen atom or an electron-donating methyl group is bonded to the -SO3 group. Significant changes occur for the electronegative trichloromethyl (Cl3C-) and trifluoromethyl (F3C-) groups, which strongly affect the distribution especially of the pi electrons around the sulfur atom. The S-D bond distance 1.38(2) A was obtained for the deuterated sulfonate (DSO3-) ion by Rietveld analysis of neutron powder diffraction data of CsDSO3. Raman and infrared absorption spectra of the CsHSO3, CsDSO3, H3CSO3Na, and Cl3CSO3Na.H2O compounds and Raman spectra of the sulfite solutions have been interpreted by normal coordinate calculations. The C-S stretching force constant for the trichloromethanesulfonate ion obtains an anomalously low value due to steric repulsion between the Cl3C- and -SO3 groups. The S-O stretching force constants were correlated with corresponding S-O bond distances for several oxosulfur species.
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Affiliation(s)
- Emiliana Damian Risberg
- Department of Physical, Inorganic and Structural Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
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43
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Martin-Diaconescu V, Kennepohl P. Sulfur K-Edge XAS as a Probe of Sulfur-Centered Radical Intermediates. J Am Chem Soc 2007; 129:3034-5. [PMID: 17319664 DOI: 10.1021/ja0676760] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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44
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Engel AS, Lichtenberg H, Prange A, Hormes J. Speciation of sulfur from filamentous microbial mats from sulfidic cave springs using X-ray absorption near-edge spectroscopy. FEMS Microbiol Lett 2007; 269:54-62. [PMID: 17227465 DOI: 10.1111/j.1574-6968.2006.00600.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Most transformations within the sulfur cycle are controlled by the biosphere, and deciphering the abiotic and biotic nature and turnover of sulfur is critical to understand the geochemical and ecological changes that have occurred throughout the Earth's history. Here, synchrotron radiation-based sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy is used to examine sulfur speciation in natural microbial mats from two aphotic (cave) settings. Habitat geochemistry, microbial community compositions, and sulfur isotope systematics were also evaluated. Microorganisms associated with sulfur metabolism dominated the mats, including members of the Epsilonproteobacteria and Gammaproteobacteria. These groups have not been examined previously by sulfur K-edge XANES. All of the mats consisted of elemental sulfur, with greater contributions of cyclo-octasulfur (S8) compared with polymeric sulfur (Smicro). While this could be a biological fingerprint for some bacteria, the signature may also indicate preferential oxidation of Smicro and S8 accumulation. Higher sulfate content correlated to less S8 in the presence of Epsilonproteobacteria. Sulfur isotope compositions confirmed that sulfur content and sulfur speciation may not correlate to microbial metabolic processes in natural samples, thereby complicating the interpretation of modern and ancient sulfur records.
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Affiliation(s)
- Annette Summers Engel
- Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA.
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45
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Abstract
To understand the many important functions of sulfur, a ubiquitous element in biological systems, in the environment and for industrial applications, detailed analyses are needed. Characterization of the variety of sulfur functional groups in a natural sample, often occurring in a wide range of oxidation states, became possible when the development of dedicated X-ray absorption near-edge structure (XANES) spectroscopy started in the mid-1980s. This tutorial review provides an overview of sulfur XANES spectroscopic investigations into the role of sulfur in all kinds of natural samples, from sediment and oil to marine-archaeological wood and plants.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, CanadaT2N 1N4.
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46
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Fayard B, Fay N, David G, Doucet J, Melki R. Packing of the prion Ure2p in protein fibrils probed by fluorescence X-ray near-edge structure spectroscopy at sulfur K-edge. J Mol Biol 2005; 356:843-9. [PMID: 16405906 DOI: 10.1016/j.jmb.2005.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2005] [Revised: 11/28/2005] [Accepted: 12/02/2005] [Indexed: 11/22/2022]
Abstract
The soluble protein Ure2p from the yeast Saccharomyces cerevisiae assembles in vitro into straight and insoluble protein fibrils, through subtle changes of conformation. Whereas the structure of soluble Ure2p has been revealed by X-ray crystallography, further characterization of the structure of insoluble Ure2p fibrils is needed. We performed X-ray absorption near-edge spectroscopy (XANES) at the sulfur K-edge to probe the state of Cys221 in the fibrillar form of Ure2pC221 and provide structural information on the structure of Ure2p within fibrils. Although the Ure2p dimer dissociation into its constituent monomers has proven to be a prerequisite for assembly into fibrils, we showed the ability of every Ure2pC221 monomer to establish disulfide bonds upon incubation of the fibrils under oxidizing conditions. Our result indicates either that the constituent unit of the fibrillar form of the protein is a dimeric Ure2p or that the fibrils are made of protofilaments assembled in such a way that the residue C221 from a Ure2p molecule in one protofilament is located in the vicinity of a C221 residue from another molecule belonging to a neighbor protofilament.
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Affiliation(s)
- Barbara Fayard
- Laboratoire de Physique des Solides, Université Paris-Sud, F-91405 Orsay cedex, France.
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Cuif JP, Dauphin Y. The two-step mode of growth in the scleractinian coral skeletons from the micrometre to the overall scale. J Struct Biol 2005; 150:319-31. [PMID: 15890280 DOI: 10.1016/j.jsb.2005.03.004] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Revised: 03/08/2005] [Accepted: 03/09/2005] [Indexed: 11/15/2022]
Abstract
It has been known since the 19th century that coral skeletons are built of aragonite crystals with taxonomy-linked arrangements, but the way by which each coral species controls this crystallization process remains an unsolved question. The problem became still more intriguing when it was shown that isotopic compositions of coral aragonite were subject to taxonomy-linked influences (the "vital effect"). On the other hand, presence of an organic component in coral skeletons is also long known, but localization of these compounds is admittedly restricted to particular structures called "centres of calcifications." Fibres, the largely predominant part of the coral skeletons, are usually considered as purely mineral units. In this paper, it is shown that in both "centres of calcification" and fibres, organic compounds are associated with the mineral material at a deep structural level. A series of variously scaled observations and localized measurements allow recognition of the presence of an organic component at the nanometre scale. Far from being a freely operating process, crystallization of coral fibres is thus permanently controlled by the polyp basal ectoderm through a cyclic two-step process acting at the micrometre-scale. The biomineralization cycle begins by secretion of a proteoglycan matrix. As the composition of these sugars-proteins assemblages has been shown taxonomy dependent, the hypothesis can be made that multiple and long recognized specificities of coral skeletons are linked to this biochemically driven crystallization process. Additionally, this new concept of the biomineralization process in coral skeletons provides us with an access to the long term evolution of the Scleractinia. Remarkably, results of a skeleton-based approach using microstructural criteria (i.e., the spatial relationships of "centres of calcification" and the three-dimensional arrangements of fibres), are consistent with a molecular phylogenetic analysis carried out on the same species. Clearly, at the overall ontogenic level, the two-step growth mode of coral skeletons is also a valuable tool to reconstruct the evolutionary history of Scleractinia.
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Affiliation(s)
- Jean-Pierre Cuif
- UMR 8148 IDES, Geology, bat. 504, Université Paris XI-Orsay, F-91405 Orsay cedex, France.
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Szilagyi RK, Schwab DE. Sulfur K-edge X-ray absorption spectroscopy as an experimental probe for S-nitroso proteins. Biochem Biophys Res Commun 2005; 330:60-4. [DOI: 10.1016/j.bbrc.2005.02.127] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Indexed: 11/30/2022]
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Roux S, Garcia B, Bridot JL, Salomé M, Marquette C, Lemelle L, Gillet P, Blum L, Perriat P, Tillement O. Synthesis, characterization of dihydrolipoic acid capped gold nanoparticles, and functionalization by the electroluminescent luminol. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:2526-2536. [PMID: 15752049 DOI: 10.1021/la048082i] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The use of gold nanoparticles as biological probes requires the improvement of colloidal stability. Dihydrolipoic acid (DHLA), a dithiol obtained by the reduction of thioctic acid, appears therefore very attractive for the stabilization and the further functionalization of gold nanoparticles because DHLA is characterized by a carboxylic acid group and two thiol functions. The ionizable carboxylic acid groups ensure, for pH > or = 8, the water solubility of DHLA-capped gold (Au@DHLA) nanoparticles, prepared by the Brust protocol, and the stability of the resulting colloid by electrostatic repulsions. Moreover almost all DHLA, adsorbed onto gold, adopts a conformation allowing their immobilization by both sulfur ends. It is proved by sulfur K-edge X-ray absorption near edge structure spectroscopy, which appears as an appropriate tool for determining the chemical form of sulfur atoms present in the organic monolayer. Such a grafting renders the DHLA monolayers more resistant to displacement by dithiothreitol than mercaptoundecanoic acid monolayers. The presence of DHLA on gold particles allows their functionalization by the electroluminescent luminol through amine coupling reactions assisted by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide. As a luminol-functionalized particle is nine times as bright as a single luminol molecule, the use of the particles as a biological probe with a lower threshold of detection is envisaged.
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Affiliation(s)
- Stéphane Roux
- Laboratoire de Physico-Chimie des Matériaux Luminescents, UMR CNRS 5620, Université Claude Bernard Lyon 1, Domaine Scientifique de la Doua, 69622 Villeurbanne Cedex, France.
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Garcia B, Salome M, Lemelle L, Bridot JL, Gillet P, Perriat P, Roux S, Tillement O. Sulfur K-edge XANES study of dihydrolipoic acid capped gold nanoparticles: dihydrolipoic acid is bound by both sulfur ends. Chem Commun (Camb) 2005:369-71. [PMID: 15645040 DOI: 10.1039/b411231h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dihydrolipoic acid (DHLA) capped gold nanoparticles (Au@DHLA) are characterized in solid and liquid states by sulfur K-edge XANES spectroscopy; it clearly shows that DHLA is anchored to gold thanks to both sulfur ends.
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Affiliation(s)
- Bruno Garcia
- Laboratoire de Physico-Chimie des Matériaux Luminescents, UMR CNRS 5620, Université Claude Bernard Lyon 1, Domaine Scientifique de la Doua, 69622 Villeurbanne Cedex, France
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