1
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Hoffman DJ, Van Driel TB, Kroll T, Crissman CJ, Ryland ES, Nelson KJ, Cordones AA, Koralek JD, DePonte DP. Microfluidic liquid sheets as large-area targets for high repetition XFELs. Front Mol Biosci 2022; 9:1048932. [PMID: 36567947 PMCID: PMC9780453 DOI: 10.3389/fmolb.2022.1048932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022] Open
Abstract
The high intensity of X-ray free electron lasers (XFELs) can damage solution-phase samples on every scale, ranging from the molecular or electronic structure of a sample to the macroscopic structure of a liquid microjet. By using a large surface area liquid sheet microjet as a sample target instead of a standard cylindrical microjet, the incident X-ray spot size can be increased such that the incident intensity falls below the damage threshold. This capability is becoming particularly important for high repetition rate XFELs, where destroying a target with each pulse would require prohibitively large volumes of sample. We present here a study of microfluidic liquid sheet dimensions as a function of liquid flow rate. Sheet lengths, widths and thickness gradients are shown for three styles of nozzles fabricated from isotropically etched glass. In-vacuum operation and sample recirculation using these nozzles is demonstrated. The effects of intense XFEL pulses on the structure of a liquid sheet are also briefly examined.
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Affiliation(s)
- David J. Hoffman
- SLAC National Accelerator Laboratory, Menlo Park, CA, United States
| | - Tim B. Van Driel
- SLAC National Accelerator Laboratory, Menlo Park, CA, United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, United States
| | - Christopher J. Crissman
- SLAC National Accelerator Laboratory, Menlo Park, CA, United States,United States Military Academy, West Point, NY, United States
| | - Elizabeth S. Ryland
- SLAC National Accelerator Laboratory, Stanford PULSE Institute, Menlo Park, CA, United States
| | - Kacie J. Nelson
- SLAC National Accelerator Laboratory, Stanford PULSE Institute, Menlo Park, CA, United States
| | - Amy A. Cordones
- SLAC National Accelerator Laboratory, Stanford PULSE Institute, Menlo Park, CA, United States
| | - Jake D. Koralek
- SLAC National Accelerator Laboratory, Menlo Park, CA, United States
| | - Daniel P. DePonte
- SLAC National Accelerator Laboratory, Menlo Park, CA, United States,*Correspondence: Daniel P. DePonte,
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2
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Koebke KJ, Pinter TBJ, Pitts WC, Pecoraro VL. Catalysis and Electron Transfer in De Novo Designed Metalloproteins. Chem Rev 2022; 122:12046-12109. [PMID: 35763791 PMCID: PMC10735231 DOI: 10.1021/acs.chemrev.1c01025] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
One of the hallmark advances in our understanding of metalloprotein function is showcased in our ability to design new, non-native, catalytically active protein scaffolds. This review highlights progress and milestone achievements in the field of de novo metalloprotein design focused on reports from the past decade with special emphasis on de novo designs couched within common subfields of bioinorganic study: heme binding proteins, monometal- and dimetal-containing catalytic sites, and metal-containing electron transfer sites. Within each subfield, we highlight several of what we have identified as significant and important contributions to either our understanding of that subfield or de novo metalloprotein design as a discipline. These reports are placed in context both historically and scientifically. General suggestions for future directions that we feel will be important to advance our understanding or accelerate discovery are discussed.
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Affiliation(s)
- Karl J. Koebke
- Department of Chemistry, University of Michigan Ann Arbor, MI 48109 USA
| | | | - Winston C. Pitts
- Department of Chemistry, University of Michigan Ann Arbor, MI 48109 USA
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3
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Schröder GC, Meilleur F. Metalloprotein catalysis: structural and mechanistic insights into oxidoreductases from neutron protein crystallography. Acta Crystallogr D Struct Biol 2021; 77:1251-1269. [PMID: 34605429 PMCID: PMC8489226 DOI: 10.1107/s2059798321009025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
Metalloproteins catalyze a range of reactions, with enhanced chemical functionality due to their metal cofactor. The reaction mechanisms of metalloproteins have been experimentally characterized by spectroscopy, macromolecular crystallography and cryo-electron microscopy. An important caveat in structural studies of metalloproteins remains the artefacts that can be introduced by radiation damage. Photoreduction, radiolysis and ionization deriving from the electromagnetic beam used to probe the structure complicate structural and mechanistic interpretation. Neutron protein diffraction remains the only structural probe that leaves protein samples devoid of radiation damage, even when data are collected at room temperature. Additionally, neutron protein crystallography provides information on the positions of light atoms such as hydrogen and deuterium, allowing the characterization of protonation states and hydrogen-bonding networks. Neutron protein crystallography has further been used in conjunction with experimental and computational techniques to gain insight into the structures and reaction mechanisms of several transition-state metal oxidoreductases with iron, copper and manganese cofactors. Here, the contribution of neutron protein crystallography towards elucidating the reaction mechanism of metalloproteins is reviewed.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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4
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Mitra S, Prakash D, Rajabimoghadam K, Wawrzak Z, Prasad P, Wu T, Misra SK, Sharp JS, Garcia-Bosch I, Chakraborty S. De Novo Design of a Self-Assembled Artificial Copper Peptide that Activates and Reduces Peroxide. ACS Catal 2021; 11:10267-10278. [DOI: 10.1021/acscatal.1c02132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Suchitra Mitra
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
| | - Divyansh Prakash
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
| | | | - Zdzislaw Wawrzak
- Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
| | - Pallavi Prasad
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
| | - Tong Wu
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Sandeep K. Misra
- Department of Biomolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Joshua S. Sharp
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
- Department of Biomolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Isaac Garcia-Bosch
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Saumen Chakraborty
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, United States
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5
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Pfanzagl V, Beale JH, Michlits H, Schmidt D, Gabler T, Obinger C, Djinović-Carugo K, Hofbauer S. X-ray-induced photoreduction of heme metal centers rapidly induces active-site perturbations in a protein-independent manner. J Biol Chem 2020; 295:13488-13501. [PMID: 32723869 DOI: 10.1074/jbc.ra120.014087] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/24/2020] [Indexed: 12/31/2022] Open
Abstract
Since the advent of protein crystallography, atomic-level macromolecular structures have provided a basis to understand biological function. Enzymologists use detailed structural insights on ligand coordination, interatomic distances, and positioning of catalytic amino acids to rationalize the underlying electronic reaction mechanisms. Often the proteins in question catalyze redox reactions using metal cofactors that are explicitly intertwined with their function. In these cases, the exact nature of the coordination sphere and the oxidation state of the metal is of utmost importance. Unfortunately, the redox-active nature of metal cofactors makes them especially susceptible to photoreduction, meaning that information obtained by photoreducing X-ray sources about the environment of the cofactor is the least trustworthy part of the structure. In this work we directly compare the kinetics of photoreduction of six different heme protein crystal species by X-ray radiation. We show that a dose of ∼40 kilograys already yields 50% ferrous iron in a heme protein crystal. We also demonstrate that the kinetics of photoreduction are completely independent from variables unique to the different samples tested. The photoreduction-induced structural rearrangements around the metal cofactors have to be considered when biochemical data of ferric proteins are rationalized by constraints derived from crystal structures of reduced enzymes.
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Affiliation(s)
- Vera Pfanzagl
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria.
| | | | - Hanna Michlits
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Daniel Schmidt
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Thomas Gabler
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Christian Obinger
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna, Austria; Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Stefan Hofbauer
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria.
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6
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Xia M, Chen Y, Ma J, Yin X, Wang L, Wu W, Xiong G, Sun W, Zhou Y. Effects of low frequency magnetic field on myoglobin oxidation stability. Food Chem 2020; 309:125651. [DOI: 10.1016/j.foodchem.2019.125651] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 02/06/2023]
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7
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Redox thermodynamics of B-class dye-decolorizing peroxidases. J Inorg Biochem 2019; 199:110761. [PMID: 31325671 DOI: 10.1016/j.jinorgbio.2019.110761] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/22/2019] [Accepted: 07/08/2019] [Indexed: 11/23/2022]
Abstract
With >5000 annotated genes dye-decolorizing peroxidases (DyPs) represent a heme b peroxidase family of broad functional diversity. Bacterial B-class DyPs are poor peroxidases of unknown physiological function. Hydrogen peroxide efficiently mediates the rapid formation of Compound I in B-class DyPs, which, however, is stable and shows modest reactivity towards organic and inorganic electron donors. To understand these characteristics, we have investigated the redox thermodynamics of the one-electron reduction of the ferric high-spin form of wild-type B-class DyP from the pathogenic bacterium Klebsiella pneumoniae (KpDyP) and the variants D143A, R232A and D143A/R232A. These distal amino acids are fully conserved in all DyPs and play important roles in Compound I formation and maintenance of the heme cavity architecture and substrate access route(s). The E°' values of the respective redox couples Fe(III)/Fe(II) varied from -350 mV (wild-type KpDyP) to -299 mV (D143A/R232A) at pH 7.0. Variable-temperature spectroelectrochemical experiments revealed that the reduction reaction of B-class DyPs is enthalpically unfavored but entropically favored with significant differences in enthalpic and entropic contributions to E°' between the four proteins. Molecular dynamics simulations demonstrated the impact of solvent reorganization on the entropy change during reduction reaction and revealed the dynamics and restriction of substrate access channels. Obtained data are discussed with respect to the poor peroxidase activities of B-class DyPs and compared with heme peroxidases from other (super)families as well as with chlorite dismutases, which do not react with hydrogen peroxide but share a similar fold and heme cavity architecture.
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8
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Wherland S, Pecht I. Radiation chemists look at damage in redox proteins induced by X-rays. Proteins 2018; 86:817-826. [DOI: 10.1002/prot.25521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/26/2018] [Accepted: 04/25/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Scot Wherland
- Department of Chemistry; Washington State University; Pullman Washington
| | - Israel Pecht
- Department of Immunology; The Weizmann Institute of Science; Rehovot 76100 Israel
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9
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Handing KB, Niedzialkowska E, Shabalin IG, Kuhn ML, Zheng H, Minor W. Characterizing metal-binding sites in proteins with X-ray crystallography. Nat Protoc 2018; 13:1062-1090. [PMID: 29674755 PMCID: PMC6235626 DOI: 10.1038/nprot.2018.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Metals have crucial roles in many physiological, pathological, toxicological, pharmaceutical, and diagnostic processes. Proper handling of metal-containing macromolecule samples for structural studies is not trivial, and failure to handle them properly is often a source of irreproducibility caused by issues such as pH changes, incorporation of unexpected metals, or oxidization/reduction of the metal. This protocol outlines the guidelines and best practices for characterizing metal-binding sites in protein structures and alerts experimenters to potential pitfalls during the preparation and handling of metal-containing protein samples for X-ray crystallography studies. The protocol features strategies for controlling the sample pH and the metal oxidation state, recording X-ray fluorescence (XRF) spectra, and collecting diffraction data sets above and below the corresponding metal absorption edges. This protocol should allow experimenters to gather sufficient evidence to unambiguously determine the identity and location of the metal of interest, as well as to accurately characterize the coordinating ligands in the metal binding environment within the protein. Meticulous handling of metal-containing macromolecule samples as described in this protocol should enhance experimental reproducibility in biomedical sciences, especially in X-ray macromolecular crystallography. For most samples, the protocol can be completed within a period of 7-190 d, most of which (2-180 d) is devoted to growing the crystal. The protocol should be readily understandable to structural biologists, particularly protein crystallographers with an intermediate level of experience.
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Affiliation(s)
- Katarzyna B Handing
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Virginia, Charlottesville, Virginia, USA
| | - Ewa Niedzialkowska
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Virginia, Charlottesville, Virginia, USA
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Krakow, Poland
| | - Ivan G Shabalin
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Virginia, Charlottesville, Virginia, USA
| | - Misty L Kuhn
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California, USA
| | - Heping Zheng
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Virginia, Charlottesville, Virginia, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Virginia, Charlottesville, Virginia, USA
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10
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Borek D, Bromberg R, Hattne J, Otwinowski Z. Real-space analysis of radiation-induced specific changes with independent component analysis. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:451-467. [PMID: 29488925 PMCID: PMC5829680 DOI: 10.1107/s1600577517018148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 12/19/2017] [Indexed: 05/06/2023]
Abstract
A method of analysis is presented that allows for the separation of specific radiation-induced changes into distinct components in real space. The method relies on independent component analysis (ICA) and can be effectively applied to electron density maps and other types of maps, provided that they can be represented as sets of numbers on a grid. Here, for glucose isomerase crystals, ICA was used in a proof-of-concept analysis to separate temperature-dependent and temperature-independent components of specific radiation-induced changes for data sets acquired from multiple crystals across multiple temperatures. ICA identified two components, with the temperature-independent component being responsible for the majority of specific radiation-induced changes at temperatures below 130 K. The patterns of specific temperature-independent radiation-induced changes suggest a contribution from the tunnelling of electron holes as a possible explanation. In the second case, where a group of 22 data sets was collected on a single thaumatin crystal, ICA was used in another type of analysis to separate specific radiation-induced effects happening on different exposure-level scales. Here, ICA identified two components of specific radiation-induced changes that likely result from radiation-induced chemical reactions progressing with different rates at different locations in the structure. In addition, ICA unexpectedly identified the radiation-damage state corresponding to reduced disulfide bridges rather than the zero-dose extrapolated state as the highest contrast structure. The application of ICA to the analysis of specific radiation-induced changes in real space and the data pre-processing for ICA that relies on singular value decomposition, which was used previously in data space to validate a two-component physical model of X-ray radiation-induced changes, are discussed in detail. This work lays a foundation for a better understanding of protein-specific radiation chemistries and provides a framework for analysing effects of specific radiation damage in crystallographic and cryo-EM experiments.
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Affiliation(s)
- Dominika Borek
- Department of Biophysics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Raquel Bromberg
- Department of Biophysics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Johan Hattne
- Department of Biophysics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Zbyszek Otwinowski
- Department of Biophysics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
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11
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Schaffner I, Mlynek G, Flego N, Pühringer D, Libiseller-Egger J, Coates L, Hofbauer S, Bellei M, Furtmüller PG, Battistuzzi G, Smulevich G, Djinović-Carugo K, Obinger C. Molecular Mechanism of Enzymatic Chlorite Detoxification: Insights from Structural and Kinetic Studies. ACS Catal 2017; 7:7962-7976. [PMID: 29142780 PMCID: PMC5678291 DOI: 10.1021/acscatal.7b01749] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 09/22/2017] [Indexed: 01/19/2023]
Abstract
![]()
The
heme enzyme chlorite dismutase (Cld) catalyzes the degradation
of chlorite to chloride and dioxygen. Although structure and steady-state
kinetics of Clds have been elucidated, many questions remain (e.g.,
the mechanism of chlorite cleavage and the pH dependence of the reaction).
Here, we present high-resolution X-ray crystal structures of a dimeric
Cld at pH 6.5 and 8.5, its fluoride and isothiocyanate complexes and
the neutron structure at pH 9.0 together with the pH dependence of
the Fe(III)/Fe(II) couple, and the UV–vis and resonance Raman
spectral features. We demonstrate that the distal Arg127 cannot act
as proton acceptor and is fully ionized even at pH 9.0 ruling out
its proposed role in dictating the pH dependence of chlorite degradation.
Stopped-flow studies show that (i) Compound I and hypochlorite do
not recombine and (ii) Compound II is the immediately formed redox
intermediate that dominates during turnover. Homolytic cleavage of
chlorite is proposed.
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Affiliation(s)
- Irene Schaffner
- Department
of Chemistry, Division of Biochemistry, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Georg Mlynek
- Department
for Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Nicola Flego
- Dipartimento
di Chimica “Ugo Schiff”, Università di Firenze, Via della
Lastruccia 3-13, I-50019 Sesto Fiorentino (FI), Italy
| | - Dominic Pühringer
- Department
for Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Julian Libiseller-Egger
- Department
of Chemistry, Division of Biochemistry, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Leighton Coates
- Biology
and Soft Matter Division, Oak Ridge National Laboratory, 1 Bethel
Valley Road, Oak Ridge, Tennessee 37831, United States
| | - Stefan Hofbauer
- Department
of Chemistry, Division of Biochemistry, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Marzia Bellei
- Department
of Life Sciences, University of Modena and Reggio Emilia, Via Campi
103, 41125 Modena, Italy
| | - Paul G. Furtmüller
- Department
of Chemistry, Division of Biochemistry, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Gianantonio Battistuzzi
- Department
of Chemistry and Geology, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Giulietta Smulevich
- Dipartimento
di Chimica “Ugo Schiff”, Università di Firenze, Via della
Lastruccia 3-13, I-50019 Sesto Fiorentino (FI), Italy
| | - Kristina Djinović-Carugo
- Department
for Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
- Department
of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Christian Obinger
- Department
of Chemistry, Division of Biochemistry, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
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12
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Abstract
Radiation damage inflicted on macromolecular crystals during X-ray diffraction experiments remains a limiting factor for structure solution, even when samples are cooled to cryotemperatures (~100 K). Efforts to establish mitigation strategies are ongoing and various approaches, summarized below, have been investigated over the last 15 years, resulting in a deeper understanding of the physical and chemical factors affecting damage rates. The recent advent of X-ray free electron lasers permits "diffraction-before-destruction" by providing highly brilliant and short (a few tens of fs) X-ray pulses. New fourth generation synchrotron sources now coming on line with higher X-ray flux densities than those available from third generation synchrotrons will bring the issue of radiation damage once more to the fore for structural biologists.
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Affiliation(s)
- Elspeth F Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Martin Weik
- Institut de Biologie Structurale, University of Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38044, Grenoble, France.
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13
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Morita Y, Oohora K, Mizohata E, Sawada A, Kamachi T, Yoshizawa K, Inoue T, Hayashi T. Crystal Structures and Coordination Behavior of Aqua- and Cyano-Co(III) Tetradehydrocorrins in the Heme Pocket of Myoglobin. Inorg Chem 2016; 55:1287-95. [DOI: 10.1021/acs.inorgchem.5b02598] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yoshitsugu Morita
- Department of Applied Chemistry, Graduate
School of Engineering, Osaka University, Suita 565-0871, Japan
| | - Koji Oohora
- Department of Applied Chemistry, Graduate
School of Engineering, Osaka University, Suita 565-0871, Japan
- Frontier Research Base for Global Young
Researchers, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
| | - Eiichi Mizohata
- Department of Applied Chemistry, Graduate
School of Engineering, Osaka University, Suita 565-0871, Japan
| | - Akiyoshi Sawada
- Institute
for Materials Chemistry and Engineering and International Research
Center for Molecular Systems, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takashi Kamachi
- Institute
for Materials Chemistry and Engineering and International Research
Center for Molecular Systems, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute
for Materials Chemistry and Engineering and International Research
Center for Molecular Systems, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
- Elements
Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Nishikyo-ku, Kyoto 615-8520, Japan
| | - Tsuyoshi Inoue
- Department of Applied Chemistry, Graduate
School of Engineering, Osaka University, Suita 565-0871, Japan
| | - Takashi Hayashi
- Department of Applied Chemistry, Graduate
School of Engineering, Osaka University, Suita 565-0871, Japan
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14
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Abstract
Although crystallographers typically seek to mitigate radiation damage in macromolecular crystals, in some cases, radiation damage to specific atoms can be used to determine phases de novo. This process is called radiation damage-induced phasing or "RIP." Here, we provide a general overview of the method and a practical set of data collection and processing strategies for phasing macromolecular structures using RIP.
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Affiliation(s)
- Chloe Zubieta
- Structural Biology Group, European Synchrotron Radiation Facility, Grenoble, France
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15
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Serrano-Posada H, Centeno-Leija S, Rojas-Trejo SP, Rodríguez-Almazán C, Stojanoff V, Rudiño-Piñera E. X-ray-induced catalytic active-site reduction of a multicopper oxidase: structural insights into the proton-relay mechanism and O2-reduction states. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:2396-411. [PMID: 26627648 PMCID: PMC4934174 DOI: 10.1107/s1399004715018714] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 10/05/2015] [Indexed: 12/14/2022]
Abstract
During X-ray data collection from a multicopper oxidase (MCO) crystal, electrons and protons are mainly released into the system by the radiolysis of water molecules, leading to the X-ray-induced reduction of O2 to 2H2O at the trinuclear copper cluster (TNC) of the enzyme. In this work, 12 crystallographic structures of Thermus thermophilus HB27 multicopper oxidase (Tth-MCO) in holo, apo and Hg-bound forms and with different X-ray absorbed doses have been determined. In holo Tth-MCO structures with four Cu atoms, the proton-donor residue Glu451 involved in O2 reduction was found in a double conformation: Glu451a (∼7 Å from the TNC) and Glu451b (∼4.5 Å from the TNC). A positive peak of electron density above 3.5σ in an Fo - Fc map for Glu451a O(ℇ2) indicates the presence of a carboxyl functional group at the side chain, while its significant absence in Glu451b strongly suggests a carboxylate functional group. In contrast, for apo Tth-MCO and in Hg-bound structures neither the positive peak nor double conformations were observed. Together, these observations provide the first structural evidence for a proton-relay mechanism in the MCO family and also support previous studies indicating that Asp106 does not provide protons for this mechanism. In addition, eight composite structures (Tth-MCO-C1-8) with different X-ray-absorbed doses allowed the observation of different O2-reduction states, and a total depletion of T2Cu at doses higher than 0.2 MGy showed the high susceptibility of this Cu atom to radiation damage, highlighting the importance of taking radiation effects into account in biochemical interpretations of an MCO structure.
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Affiliation(s)
- Hugo Serrano-Posada
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, 62210 Cuernavaca, MOR, Mexico
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, DF, Mexico
| | - Sara Centeno-Leija
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, DF, Mexico
| | - Sonia Patricia Rojas-Trejo
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, 62210 Cuernavaca, MOR, Mexico
| | - Claudia Rodríguez-Almazán
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, 62210 Cuernavaca, MOR, Mexico
| | - Vivian Stojanoff
- NSLS, Brookhaven National Laboratory, 75 Brookhaven Avenue, Building 725D, Upton, NY 11973-5000, USA
| | - Enrique Rudiño-Piñera
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, 62210 Cuernavaca, MOR, Mexico
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16
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Knipp M, Ogata H, Soavi G, Cerullo G, Allegri A, Abbruzzetti S, Bruno S, Viappiani C, Bidon-Chanal A, Luque FJ. Structure and dynamics of the membrane attaching nitric oxide transporter nitrophorin 7. F1000Res 2015; 4:45. [PMID: 26167269 PMCID: PMC4482215 DOI: 10.12688/f1000research.6060.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/28/2015] [Indexed: 11/20/2022] Open
Abstract
Nitrophorins represent a unique class of heme proteins that are able to perform the delicate transportation and release of the free-radical gaseous messenger nitric oxide (NO) in a pH-triggered manner. Besides its ability to bind to phospholipid membranes, the N-terminus contains an additional Leu-Pro-Gly stretch, which is a unique sequence trait, and the heme cavity is significantly altered with respect to other nitrophorins. These distinctive features encouraged us to solve the X-ray crystallographic structures of NP7 at low and high pH and bound with different heme ligands (nitric oxide, histamine, imidazole). The overall fold of the lipocalin motif is well preserved in the different X-ray structures and resembles the fold of other nitrophorins. However, a chain-like arrangement in the crystal lattice due to a number of head-to-tail electrostatic stabilizing interactions is found in NP7. Furthermore, the X-ray structures also reveal ligand-dependent changes in the orientation of the heme, as well as in specific interactions between the A-B and G-H loops, which are considered to be relevant for the biological function of nitrophorins. Fast and ultrafast laser triggered ligand rebinding experiments demonstrate the pH-dependent ligand migration within the cavities and the exit route. Finally, the topological distribution of pockets located around the heme as well as from inner cavities present at the rear of the protein provides a distinctive feature in NP7, so that while a loop gated exit mechanism to the solvent has been proposed for most nitrophorins, a more complex mechanism that involves several interconnected gas hosting cavities is proposed for NP7.
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Affiliation(s)
- Markus Knipp
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr, 45470, Germany
| | - Hideaki Ogata
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr, 45470, Germany
| | - Giancarlo Soavi
- Dipartimento di Fisica, Politecnico di Milano, Milano, 20133, Italy
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Milano, 20133, Italy
| | - Alessandro Allegri
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parma, 43124, Italy
| | - Stefania Abbruzzetti
- Dipartimento di Bioscienze, Università di Parma, Parma, 43124, Italy ; NEST, Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Pisa, 56127, Italy
| | - Stefano Bruno
- Dipartimento di Farmacia, Università di Parma, Parma, 43124, Italy
| | - Cristiano Viappiani
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parma, 43124, Italy ; NEST, Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Pisa, 56127, Italy
| | - Axel Bidon-Chanal
- Departament de Fisicoquímica, Facultat de Farmàcia and Institute of Biomedicine, Universitat de Barcelona, Santa Coloma de Gramenet, E-08921, Spain
| | - F Javier Luque
- Departament de Fisicoquímica, Facultat de Farmàcia and Institute of Biomedicine, Universitat de Barcelona, Santa Coloma de Gramenet, E-08921, Spain
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17
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von Stetten D, Giraud T, Carpentier P, Sever F, Terrien M, Dobias F, Juers DH, Flot D, Mueller-Dieckmann C, Leonard GA, de Sanctis D, Royant A. In crystallo optical spectroscopy (icOS) as a complementary tool on the macromolecular crystallography beamlines of the ESRF. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:15-26. [PMID: 25615856 PMCID: PMC4304682 DOI: 10.1107/s139900471401517x] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 06/27/2014] [Indexed: 01/04/2023]
Abstract
The analysis of structural data obtained by X-ray crystallography benefits from information obtained from complementary techniques, especially as applied to the crystals themselves. As a consequence, optical spectroscopies in structural biology have become instrumental in assessing the relevance and context of many crystallographic results. Since the year 2000, it has been possible to record such data adjacent to, or directly on, the Structural Biology Group beamlines of the ESRF. A core laboratory featuring various spectrometers, named the Cryobench, is now in its third version and houses portable devices that can be directly mounted on beamlines. This paper reports the current status of the Cryobench, which is now located on the MAD beamline ID29 and is thus called the ID29S-Cryobench (where S stands for `spectroscopy'). It also reviews the diverse experiments that can be performed at the Cryobench, highlighting the various scientific questions that can be addressed.
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Affiliation(s)
| | - Thierry Giraud
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | | | - Franc Sever
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | - Maxime Terrien
- Université Grenoble Alpes, IBS, F-38044 Grenoble, France
- CNRS, IBS, F-38044 Grenoble, France
- CEA, IBS, F-38044 Grenoble, France
| | - Fabien Dobias
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | - Douglas H. Juers
- Department of Physics, Whitman College, Walla Walla, WA 99362, USA
| | - David Flot
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | | | | | | | - Antoine Royant
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
- Université Grenoble Alpes, IBS, F-38044 Grenoble, France
- CNRS, IBS, F-38044 Grenoble, France
- CEA, IBS, F-38044 Grenoble, France
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18
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Spectroscopic and computational insight into the activation of O2 by the mononuclear Cu center in polysaccharide monooxygenases. Proc Natl Acad Sci U S A 2014; 111:8797-802. [PMID: 24889637 DOI: 10.1073/pnas.1408115111] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strategies for O2 activation by copper enzymes were recently expanded to include mononuclear Cu sites, with the discovery of the copper-dependent polysaccharide monooxygenases, also classified as auxiliary-activity enzymes 9-11 (AA9-11). These enzymes are finding considerable use in industrial biofuel production. Crystal structures of polysaccharide monooxygenases have emerged, but experimental studies are yet to determine the solution structure of the Cu site and how this relates to reactivity. From X-ray absorption near edge structure and extended X-ray absorption fine structure spectroscopies, we observed a change from four-coordinate Cu(II) to three-coordinate Cu(I) of the active site in solution, where three protein-derived nitrogen ligands coordinate the Cu in both redox states, and a labile hydroxide ligand is lost upon reduction. The spectroscopic data allowed for density functional theory calculations of an enzyme active site model, where the optimized Cu(I) and (II) structures were consistent with the experimental data. The O2 reactivity of the Cu(I) site was probed by EPR and stopped-flow absorption spectroscopies, and a rapid one-electron reduction of O2 and regeneration of the resting Cu(II) enzyme were observed. This reactivity was evaluated computationally, and by calibration to Cu-superoxide model complexes, formation of an end-on Cu-AA9-superoxide species was found to be thermodynamically favored. We discuss how this thermodynamically difficult one-electron reduction of O2 is enabled by the unique protein structure where two nitrogen ligands from His1 dictate formation of a T-shaped Cu(I) site, which provides an open coordination position for strong O2 binding with very little reorganization energy.
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19
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Sigfridsson KGV, Chernev P, Leidel N, Popović-Bijelić A, Gräslund A, Haumann M. Rapid X-ray photoreduction of dimetal-oxygen cofactors in ribonucleotide reductase. J Biol Chem 2013; 288:9648-9661. [PMID: 23400774 DOI: 10.1074/jbc.m112.438796] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prototypic dinuclear metal cofactors with varying metallation constitute a class of O2-activating catalysts in numerous enzymes such as ribonucleotide reductase. Reliable structures are required to unravel the reaction mechanisms. However, protein crystallography data may be compromised by x-ray photoreduction (XRP). We studied XPR of Fe(III)Fe(III) and Mn(III)Fe(III) sites in the R2 subunit of Chlamydia trachomatis ribonucleotide reductase using x-ray absorption spectroscopy. Rapid and biphasic x-ray photoreduction kinetics at 20 and 80 K for both cofactor types suggested sequential formation of (III,II) and (II,II) species and similar redox potentials of iron and manganese sites. Comparing with typical x-ray doses in crystallography implies that (II,II) states are reached in <1 s in such studies. First-sphere metal coordination and metal-metal distances differed after chemical reduction at room temperature and after XPR at cryogenic temperatures, as corroborated by model structures from density functional theory calculations. The inter-metal distances in the XPR-induced (II,II) states, however, are similar to R2 crystal structures. Therefore, crystal data of initially oxidized R2-type proteins mostly contain photoreduced (II,II) cofactors, which deviate from the native structures functional in O2 activation, explaining observed variable metal ligation motifs. This situation may be remedied by novel femtosecond free electron-laser protein crystallography techniques.
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Affiliation(s)
| | - Petko Chernev
- Free University Berlin, Institute of Experimental Physics, 14195 Berlin, Germany
| | - Nils Leidel
- Free University Berlin, Institute of Experimental Physics, 14195 Berlin, Germany
| | - Ana Popović-Bijelić
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Michael Haumann
- Free University Berlin, Institute of Experimental Physics, 14195 Berlin, Germany.
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20
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van Wonderen JH, Kostrz DN, Dennison C, MacMillan F. Refined distances between paramagnetic centers of a multi-copper nitrite reductase determined by pulsed EPR (iDEER) spectroscopy. Angew Chem Int Ed Engl 2013; 52:1990-3. [PMID: 23296685 PMCID: PMC3596801 DOI: 10.1002/anie.201208166] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Indexed: 11/12/2022]
Affiliation(s)
- Jessica H van Wonderen
- Henry Wellcome Unit of Biological EPR, School of Chemistry, University of East Anglia, Norwich, UK
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21
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van Wonderen JH, Kostrz DN, Dennison C, MacMillan F. Refined Distances Between Paramagnetic Centers of a Multi-Copper Nitrite Reductase Determined by Pulsed EPR (iDEER) Spectroscopy. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Allan EG, Kander MC, Carmichael I, Garman EF. To scavenge or not to scavenge, that is STILL the question. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:23-36. [PMID: 23254653 PMCID: PMC3526919 DOI: 10.1107/s0909049512046237] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 11/08/2012] [Indexed: 05/23/2023]
Abstract
An extensive radiation chemistry literature would suggest that the addition of certain radical scavengers might mitigate the effects of radiation damage during protein crystallography diffraction data collection. However, attempts to demonstrate and quantify such an amelioration and its dose dependence have not yielded consistent results, either at room temperature (RT) or 100 K. Here the information thus far available is summarized and reasons for this lack of quantitative success are identified. Firstly, several different metrics have been used to monitor and quantify the rate of damage, and, as shown here, these can give results which are in conflict regarding scavenger efficacy. In addition, significant variation in results from data collected from crystals treated in nominally the same way has been observed. Secondly, typical crystallization conditions contain substantial concentrations of chemical species which already interact strongly with some of the X-ray-induced radicals that the added scavengers are intended to intercept. These interactions are probed here by the complementary technique of on-line microspectrophotometry carried out on solutions and crystals held both at 100 K and RT, the latter enabled by the use of a beamline-mounted humidifying device. With the help of computational chemistry, attempts are made to assign some of the characteristic spectral features observed experimentally. A further source of uncertainty undoubtedly lies in the challenge of reliably measuring the parameters necessary for the accurate calculation of the absorbed dose (e.g. crystal size and shape, beam profile) and its distribution within the volume of the crystal (an issue addressed in detail in another article in this issue). While microspectrophotometry reveals that the production of various species can be quenched by the addition of scavengers, it is less clear that this observation can be translated into a significant gain in crystal dose tolerance for macromolecular crystallographers.
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Affiliation(s)
- Elizabeth G. Allan
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Melissa C. Kander
- Notre Dame Radiation Laboratory, and Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556, USA
| | - Ian Carmichael
- Notre Dame Radiation Laboratory, and Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556, USA
| | - Elspeth F. Garman
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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23
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Warkentin M, Hopkins JB, Badeau R, Mulichak AM, Keefe LJ, Thorne RE. Global radiation damage: temperature dependence, time dependence and how to outrun it. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:7-13. [PMID: 23254651 PMCID: PMC3526918 DOI: 10.1107/s0909049512048303] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 11/25/2012] [Indexed: 05/22/2023]
Abstract
A series of studies that provide a consistent and illuminating picture of global radiation damage to protein crystals, especially at temperatures above ∼200 K, are described. The radiation sensitivity shows a transition near 200 K, above which it appears to be limited by solvent-coupled diffusive processes. Consistent with this interpretation, a component of global damage proceeds on timescales of several minutes at 180 K, decreasing to seconds near room temperature. As a result, data collection times of order 1 s allow up to half of global damage to be outrun at 260 K. Much larger damage reductions near room temperature should be feasible using larger dose rates delivered using microfocused beams, enabling a significant expansion of structural studies of proteins under more nearly native conditions.
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Affiliation(s)
| | | | - Ryan Badeau
- Physics Department, Cornell University, Ithaca, NY 14853, USA
| | | | - Lisa J. Keefe
- IMCA-CAT, Argonne National Laboratory, Argonne, IL 60439, USA
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24
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Hofbauer S, Bellei M, Sündermann A, Pirker KF, Hagmüller A, Mlynek G, Kostan J, Daims H, Furtmüller PG, Djinović-Carugo K, Oostenbrink C, Battistuzzi G, Obinger C. Redox thermodynamics of high-spin and low-spin forms of chlorite dismutases with diverse subunit and oligomeric structures. Biochemistry 2012; 51:9501-12. [PMID: 23126649 PMCID: PMC3557923 DOI: 10.1021/bi3013033] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Chlorite dismutases (Clds) are heme b-containing
oxidoreductases that convert chlorite to chloride and dioxygen. In
this work, the thermodynamics of the one-electron reduction of the
ferric high-spin forms and of the six-coordinate low-spin cyanide
adducts of the enzymes from Nitrobacter winogradskyi (NwCld) and Candidatus “Nitrospira defluvii”
(NdCld) were determined through spectroelectrochemical experiments.
These proteins belong to two phylogenetically separated lineages that
differ in subunit (21.5 and 26 kDa, respectively) and oligomeric (dimeric
and pentameric, respectively) structure but exhibit similar chlorite
degradation activity. The E°′ values
for free and cyanide-bound proteins were determined to be −119
and −397 mV for NwCld and −113 and −404 mV for
NdCld, respectively (pH 7.0, 25 °C). Variable-temperature spectroelectrochemical
experiments revealed that the oxidized state of both proteins is enthalpically
stabilized. Molecular dynamics simulations suggest that changes in
the protein structure are negligible, whereas solvent reorganization
is mainly responsible for the increase in entropy during the redox
reaction. Obtained data are discussed with respect to the known structures
of the two Clds and the proposed reaction mechanism.
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Affiliation(s)
- Stefan Hofbauer
- Department of Chemistry, Division of Biochemistry, VIBT-Vienna Institute of BioTechnology, BOKU-University of Natural Resources and Life Sciences, A-1190 Vienna, Austria
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25
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Davis KM, Mattern BA, Pacold JI, Zakharova T, Brewe D, Kosheleva I, Henning RW, Graber TJ, Heald SM, Seidler GT, Pushkar Y. Fast Detection Allows Analysis of the Electronic Structure of Metalloprotein by X-ray Emission Spectroscopy at Room Temperature. J Phys Chem Lett 2012; 3:1858-1864. [PMID: 22919444 PMCID: PMC3423219 DOI: 10.1021/jz3006223] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The paradigm of "detection-before-destruction" was tested for a metalloprotein complex exposed at room temperature to the high x-ray flux typical of third generation synchrotron sources. Following the progression of the x-ray induced damage by Mn Kβ x-ray emission spectroscopy, we demonstrated the feasibility of collecting room temperature data on the electronic structure of native Photosystem II, a trans-membrane metalloprotein complex containing a Mn(4)Ca cluster. The determined non-damaging observation timeframe (about 100 milliseconds using continuous monochromatic beam, deposited dose 1*10(7) photons/µm(2) or 1.3*10(4) Gy, and 66 microseconds in pulsed mode using pink beam, deposited dose 4*10(7) photons/µm(2) or 4.2*10(4) Gy) is sufficient for the analysis of this protein's electron dynamics and catalytic mechanism at room temperature. Reported time frames are expected to be representative for other metalloproteins. The described instrumentation, based on the short working distance dispersive spectrometer, and experimental methodology is broadly applicable to time-resolved x-ray emission analysis at synchrotron and x-ray free-electron laser light sources.
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Affiliation(s)
| | - Brian A. Mattern
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Joseph I. Pacold
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | | | - Dale Brewe
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439
| | - Irina Kosheleva
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Robert W. Henning
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Timothy J. Graber
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Steve M. Heald
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439
| | - Gerald T. Seidler
- Department of Physics, University of Washington, Seattle, WA 98195, USA
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26
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De la Mora E, Lovett JE, Blanford CF, Garman EF, Valderrama B, Rudino-Pinera E. Structural changes caused by radiation-induced reduction and radiolysis: the effect of X-ray absorbed dose in a fungal multicopper oxidase. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:564-77. [PMID: 22525754 PMCID: PMC3335286 DOI: 10.1107/s0907444912005343] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 02/07/2012] [Indexed: 02/20/2023]
Abstract
X-ray radiation induces two main effects at metal centres contained in protein crystals: radiation-induced reduction and radiolysis and a resulting decrease in metal occupancy. In blue multicopper oxidases (BMCOs), the geometry of the active centres and the metal-to-ligand distances change depending on the oxidation states of the Cu atoms, suggesting that these alterations are catalytically relevant to the binding, activation and reduction of O(2). In this work, the X-ray-determined three-dimensional structure of laccase from the basidiomycete Coriolopsis gallica (Cg L), a high catalytic potential BMCO, is described. By combining spectroscopic techniques (UV-Vis, EPR and XAS) and X-ray crystallography, structural changes at and around the active copper centres were related to pH and absorbed X-ray dose (energy deposited per unit mass). Depletion of two of the four active Cu atoms as well as low occupancies of the remaining Cu atoms, together with different conformations of the metal centres, were observed at both acidic pH and high absorbed dose, correlating with more reduced states of the active coppers. These observations provide additional evidence to support the role of flexibility of copper sites during O(2) reduction. This study supports previous observations indicating that interpretations regarding redox state and metal coordination need to take radiation effects explicitly into account.
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Affiliation(s)
- Eugenio De la Mora
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Cuernavaca, Morelos 62210, Mexico
| | - Janet E. Lovett
- Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, England
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
- EaStCHEM School of Chemistry, Joseph Black Building, The King’s Buildings, Edinburgh EH9 3JJ, Scotland
| | - Christopher F. Blanford
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, England
- School of Materials, University of Manchester, Manchester Interdisciplinary Biocentre, 131 Princess Street, Manchester M1 7DN, England
| | - Elspeth F. Garman
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England
| | - Brenda Valderrama
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Cuernavaca, Morelos 62210, Mexico
| | - Enrique Rudino-Pinera
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Cuernavaca, Morelos 62210, Mexico
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27
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Leidel N, Popović-Bijelić A, Havelius KGV, Chernev P, Voevodskaya N, Gräslund A, Haumann M. High-valent [MnFe] and [FeFe] cofactors in ribonucleotide reductases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:430-44. [PMID: 22222354 DOI: 10.1016/j.bbabio.2011.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/13/2011] [Accepted: 12/16/2011] [Indexed: 11/30/2022]
Abstract
Ribonucleotide reductases (RNRs) are essential for DNA synthesis in most organisms. In class-Ic RNR from Chlamydia trachomatis (Ct), a MnFe cofactor in subunit R2 forms the site required for enzyme activity, instead of an FeFe cofactor plus a redox-active tyrosine in class-Ia RNRs, for example in mouse (Mus musculus, Mm). For R2 proteins from Ct and Mm, either grown in the presence of, or reconstituted with Mn and Fe ions, structural and electronic properties of higher valence MnFe and FeFe sites were determined by X-ray absorption spectroscopy and complementary techniques, in combination with bond-valence-sum and density functional theory calculations. At least ten different cofactor species could be tentatively distinguished. In Ct R2, two different Mn(IV)Fe(III) site configurations were assigned either L(4)Mn(IV)(μO)(2)Fe(III)L(4) (metal-metal distance of ~2.75Å, L = ligand) prevailing in metal-grown R2, or L(4)Mn(IV)(μO)(μOH)Fe(III)L(4) (~2.90Å) dominating in metal-reconstituted R2. Specific spectroscopic features were attributed to an Fe(IV)Fe(III) site (~2.55Å) with a L(4)Fe(IV)(μO)(2)Fe(III)L(3) core structure. Several Mn,Fe(III)Fe(III) (~2.9-3.1Å) and Mn,Fe(III)Fe(II) species (~3.3-3.4Å) likely showed 5-coordinated Mn(III) or Fe(III). Rapid X-ray photoreduction of iron and shorter metal-metal distances in the high-valent states suggested radiation-induced modifications in most crystal structures of R2. The actual configuration of the MnFe and FeFe cofactors seems to depend on assembly sequences, bound metal type, valence state, and previous catalytic activity involving subunit R1. In Ct R2, the protonation of a bridging oxide in the Mn(IV)(μO)(μOH)Fe(III) core may be important for preventing premature site reduction and initiation of the radical chemistry in R1.
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Affiliation(s)
- Nils Leidel
- Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin, Germany
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Ferguson-Miller S, Hiser C, Liu J. Gating and regulation of the cytochrome c oxidase proton pump. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:489-94. [PMID: 22172738 DOI: 10.1016/j.bbabio.2011.11.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 11/23/2011] [Accepted: 11/24/2011] [Indexed: 10/14/2022]
Abstract
As a consumer of 95% of the oxygen we breathe, cytochrome c oxidase plays a major role in the energy balance of the cell. Regulation of its oxygen reduction and proton pumping activity is therefore critical to physiological function in health and disease. The location and structure of pathways for protons that are required to support cytochrome c oxidase activity are still under debate, with respect to their requirements for key residues and fixed waters, and how they are gated to prevent (or allow) proton backflow. Recent high resolution structures of bacterial and mammalian forms reveal conserved lipid and steroid binding sites as well as redox-linked conformational changes that provide new insights into potential regulatory ligands and gating modes. Mechanistic interpretation of these findings and their significance for understanding energy regulation is discussed.
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Serrano-Posada H, Valderrama B, Stojanoff V, Rudiño-Piñera E. Thermostable multicopper oxidase from Thermus thermophilus HB27: crystallization and preliminary X-ray diffraction analysis of apo and holo forms. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:1595-8. [PMID: 22139175 PMCID: PMC3232148 DOI: 10.1107/s174430911103805x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 09/17/2011] [Indexed: 11/10/2022]
Abstract
A thermostable multicopper oxidase from Thermus thermophilus HB27 (Tth-MCO) was successfully crystallized using the sitting-drop and hanging-drop vapour-diffusion methods. Crystallization conditions and preliminary X-ray diffraction data to 1.5 Å resolution obtained using synchrotron radiation at 100 K are reported. The crystals belonged to space group C222(1), with unit-cell parameters a = 93.6, b = 110.3, c = 96.3 Å. A monomer in the asymmetric unit yielded a Matthews coefficient (V(M)) of 2.60 Å(3) Da(-1) and a solvent content of 53%. An inactive enzyme form, apo-Tth-MCO, was also crystallized and diffraction data were collected to 1.7 Å resolution. In addition, a second inactive form of the enzyme, Hg-Tth-MCO, was obtained by soaking apo-Tth-MCO crystals with mercury(II) chloride and data were collected to a resolution of 1.7 Å.
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Affiliation(s)
- Hugo Serrano-Posada
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, UNAM, Avenida Universidad 2001, Chamilpa, 62210 Cuernavaca, Morelos, Mexico
| | - Brenda Valderrama
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, UNAM, Avenida Universidad 2001, Chamilpa, 62210 Cuernavaca, Morelos, Mexico
| | - Vivian Stojanoff
- NSLS, Brookhaven National Laboratory, 75 Brookhaven Avenue, Building 725D, Upton, New York 11973-5000, USA
| | - Enrique Rudiño-Piñera
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, UNAM, Avenida Universidad 2001, Chamilpa, 62210 Cuernavaca, Morelos, Mexico
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Kmetko J, Warkentin M, Englich U, Thorne RE. Can radiation damage to protein crystals be reduced using small-molecule compounds? ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2011; 67:881-93. [PMID: 21931220 PMCID: PMC3176623 DOI: 10.1107/s0907444911032835] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 08/12/2011] [Indexed: 11/10/2022]
Abstract
Recent studies have defined a data-collection protocol and a metric that provide a robust measure of global radiation damage to protein crystals. Using this protocol and metric, 19 small-molecule compounds (introduced either by cocrystallization or soaking) were evaluated for their ability to protect lysozyme crystals from radiation damage. The compounds were selected based upon their ability to interact with radiolytic products (e.g. hydrated electrons, hydrogen, hydroxyl and perhydroxyl radicals) and/or their efficacy in protecting biological molecules from radiation damage in dilute aqueous solutions. At room temperature, 12 compounds had no effect and six had a sensitizing effect on global damage. Only one compound, sodium nitrate, appeared to extend crystal lifetimes, but not in all proteins and only by a factor of two or less. No compound provided protection at T=100 K. Scavengers are ineffective in protecting protein crystals from global damage because a large fraction of primary X-ray-induced excitations are generated in and/or directly attack the protein and because the ratio of scavenger molecules to protein molecules is too small to provide appreciable competitive protection. The same reactivity that makes some scavengers effective radioprotectors in protein solutions may explain their sensitizing effect in the protein-dense environment of a crystal. A more productive focus for future efforts may be to identify and eliminate sensitizing compounds from crystallization solutions.
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Affiliation(s)
- Jan Kmetko
- Physics Department, Kenyon College, Gambier, OH 43022, USA
| | | | - Ulrich Englich
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853, USA
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Yang J, Regier T, Dynes JJ, Wang J, Shi J, Peak D, Zhao Y, Hu T, Chen Y, Tse JS. Soft X-ray Induced Photoreduction of Organic Cu(II) Compounds Probed by X-ray Absorption Near-Edge (XANES) Spectroscopy. Anal Chem 2011; 83:7856-62. [DOI: 10.1021/ac201622g] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jianjun Yang
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029, P.R. China
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Canada S7N 5E2
| | - Tom Regier
- Canadian Light Source Inc., University of Saskatchewan, Saskatoon, Canada S7N 0X4
| | - James J. Dynes
- Canadian Light Source Inc., University of Saskatchewan, Saskatoon, Canada S7N 0X4
| | - Jian Wang
- Canadian Light Source Inc., University of Saskatchewan, Saskatoon, Canada S7N 0X4
| | - Jiyan Shi
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029, P.R. China
| | - Derek Peak
- Department of Soil Science, University of Saskatchewan, Saskatoon, Canada S7N 5A8
| | - Yidong Zhao
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, P.R. China
| | - Tiandou Hu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, P.R. China
| | - Yingxu Chen
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029, P.R. China
| | - John S Tse
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Canada S7N 5E2
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De la Mora E, Carmichael I, Garman EF. Effective scavenging at cryotemperatures: further increasing the dose tolerance of protein crystals. JOURNAL OF SYNCHROTRON RADIATION 2011; 18:346-57. [PMID: 21525642 DOI: 10.1107/s0909049511007163] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 02/24/2011] [Indexed: 05/21/2023]
Abstract
The rate of radiation damage to macromolecular crystals at both room temperature and 100 K has previously been shown to be reduced by the use of certain radical scavengers. Here the effects of sodium nitrate, an electron scavenger, are investigated at 100 K. For sodium nitrate at a concentration of 0.5 M in chicken egg-white lysozyme crystals, the dose tolerance is increased by a factor of two as judged from the global damage parameters, and no specific structural damage to the disulfide bonds is seen until the dose is greatly in excess (more than a factor of five) of the value at which damage appears in electron density maps derived from a scavenger-free crystal. In the electron density maps, ordered nitrate ions adjacent to the disulfide bonds are seen to lose an O atom, and appear to protect the disulfide bonds. In addition, results reinforcing previous reports on the effectiveness of ascorbate are presented. The mechanisms of action of both scavengers in the crystalline environment are elucidated.
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Affiliation(s)
- Eugenio De la Mora
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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Garman EF, Weik M. Macromolecular crystallography radiation damage research: what's new? JOURNAL OF SYNCHROTRON RADIATION 2011; 18:313-7. [PMID: 21525638 PMCID: PMC3083910 DOI: 10.1107/s0909049511013859] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 04/12/2011] [Indexed: 05/05/2023]
Abstract
Radiation damage in macromolecular crystallography has become a mainstream concern over the last ten years. The current status of research into this area is briefly assessed, and the ten new papers published in this issue are set into the context of previous work in the field. Some novel and exciting developments emerging over the last two years are also summarized.
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Affiliation(s)
- Elspeth F. Garman
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Martin Weik
- Comissariat à l’Energie Atomique, Institut de Biologie Structurale, F-38054 Grenoble, France
- CNRS, UMR5075, F-38027 Grenoble, France
- Université Joseph Fourier, F-38000 Grenoble, France
- ESRF, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex, France
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Homer C, Cooper L, Gonzalez A. Energy dependence of site-specific radiation damage in protein crystals. JOURNAL OF SYNCHROTRON RADIATION 2011; 18:338-45. [PMID: 21525641 PMCID: PMC3083911 DOI: 10.1107/s0909049511005504] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 02/14/2011] [Indexed: 05/21/2023]
Abstract
It is important to consider radiation damage to crystals caused by data collection when solving structures and critical when determining protein function, which can often depend on very subtle structural characteristics. In this study the rate of damage to specific sites in protein crystals cooled at 100 K is found to depend on the energy of the incident X-ray beam. Several lysozyme crystals were each subjected to 3-26 MGy of cumulative X-ray exposure by collecting multiple data sets from each crystal at either 9 keV or 14 keV. The integrated electron density surrounding each S atom in the structure was calculated for each data set and the change in electron density was evaluated as a function of dose at the two energies. The rate of electron density decrease per cubic Å per MGy was determined to be greater at 14 keV than at 9 keV for cysteine sulfurs involved in disulphide bridges; no statistically significant differences in the decay rates were found for methionine sulfurs. These preliminary results imply that it might be possible to minimize certain types of specific radiation damage by an appropriate choice of energy. Further experiments studying a variety of photolabile sites over a wider range of energies are needed to confirm this conclusion.
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Affiliation(s)
| | - Laura Cooper
- SSRL, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Ana Gonzalez
- SSRL, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
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36
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Stabilizing role of glutamic acid 222 in the structure of Enhanced Green Fluorescent Protein. J Struct Biol 2011; 174:385-90. [PMID: 21335090 DOI: 10.1016/j.jsb.2011.02.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 01/28/2011] [Accepted: 02/10/2011] [Indexed: 11/23/2022]
Abstract
Enhanced Green Fluorescent Protein (EGFP) is a variant of wild-type Green Fluorescent Protein from the jellyfish Aequorea victoria, whose mutations S65T and F64L increase brightness and folding efficiency. EGFP is extensively used in cell biology and biochemistry as a colocalization or expression reporter. Surprisingly, the structure of this very popular protein has not been determined yet. We report here its crystallographic structure at 1.5Å resolution which shows significant differences in the vicinity of residue 64 and of the chromophore. In particular, two conformations are observed for the key residue glutamic acid 222, in apparent contradiction with the single fluorescence lifetime of the protein. We then show that X-ray induced decarboxylation of Glu222 during diffraction data collection results in the disruption of a hydrogen-bond network near the chromophore. Using single-crystal microspectrophotometry, we demonstrate that this correlates with a significant loss of the fluorescence properties. We thus propose a mechanism of bleaching of the protein at low temperature. Taken together, these two sets of results highlight the stabilizing role of Glu222 to the chromophore cavity of EGFP.
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37
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Carpentier P, Royant A, Weik M, Bourgeois D. Raman-Assisted Crystallography Suggests a Mechanism of X-Ray-Induced Disulfide Radical Formation and Reparation. Structure 2010; 18:1410-9. [DOI: 10.1016/j.str.2010.09.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 08/27/2010] [Accepted: 09/23/2010] [Indexed: 11/24/2022]
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Hersleth HP, Andersson KK. How different oxidation states of crystalline myoglobin are influenced by X-rays. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1814:785-96. [PMID: 20691815 DOI: 10.1016/j.bbapap.2010.07.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/14/2010] [Accepted: 07/20/2010] [Indexed: 10/19/2022]
Abstract
X-ray induced radiation damage of protein crystals is well known to occur even at cryogenic temperatures. Redox active sites like metal sites seem especially vulnerable for these radiation-induced reductions. It is essential to know correctly the oxidation state of metal sites in protein crystal structures to be able to interpret the structure-function relation. Through previous structural studies, we have tried to characterise and understand the reactions between myoglobin and peroxides. These reaction intermediates are relevant because myoglobin is proposed to take part as scavenger of reactive oxygen species during oxidative stress, and because these intermediates are similar among the haem peroxidases and oxygenases. We have in our previous studies shown that these different myoglobin states are influenced by the X-rays used. In this study, we have in detail investigated the impact that X-rays have on these different oxidation states of myoglobin. An underlying goal has been to find a way to be able to determine mostly unreduced states. We have by using single-crystal light absorption spectroscopy found that the different oxidation states of myoglobin are to a different extent influenced by the X-rays (e.g. ferric Fe(III) myoglobin is faster reduced than ferryl Fe(IV)═O myoglobin). We observe that the higher oxidation states are not reduced to normal ferrous Fe(II) or ferric Fe(III) states, but end up in some intermediate and possibly artificial states. For ferric myoglobin, it seems that annealing of the radiation-induced/reduced state can reversibly more or less give the starting point (ferric myoglobin). Both scavengers and different dose-rates might influence to which extent the different states are affected by the X-rays. Our study shows that it is essential to do a time/dose monitoring of the influence X-rays have on each specific redox-state with spectroscopic techniques like single-crystal light absorption spectroscopy. This will determine to which extent you can collect X-ray diffraction data on your crystal before it becomes too heavily influenced/reduced by X-rays. This article is part of a Special Issue entitled: Protein Structure and Function in the Crystalline State.
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Affiliation(s)
- Hans-Petter Hersleth
- Department of Molecular Biosciences, University of Oslo, P.O. Box 1041 Blindern, NO-0316 Oslo, Norway.
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Garman EF. Radiation damage in macromolecular crystallography: what is it and why should we care? ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:339-51. [PMID: 20382986 PMCID: PMC2852297 DOI: 10.1107/s0907444910008656] [Citation(s) in RCA: 237] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 03/06/2010] [Indexed: 11/10/2022]
Abstract
Radiation damage inflicted during diffraction data collection in macromolecular crystallography has re-emerged in the last decade as a major experimental and computational challenge, as even for crystals held at 100 K it can result in severe data-quality degradation and the appearance in solved structures of artefacts which affect biological interpretations. Here, the observable symptoms and basic physical processes involved in radiation damage are described and the concept of absorbed dose as the basic metric against which to monitor the experimentally observed changes is outlined. Investigations into radiation damage in macromolecular crystallography are ongoing and the number of studies is rapidly increasing. The current literature on the subject is compiled as a resource for the interested researcher.
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Affiliation(s)
- Elspeth F Garman
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England.
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41
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Nowak E, Brzuszkiewicz A, Dauter M, Dauter Z, Rosenbaum G. To scavenge or not to scavenge: that is the question. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2009; 65:1004-6. [PMID: 19690379 DOI: 10.1107/s0907444909026821] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2009] [Accepted: 07/08/2009] [Indexed: 11/10/2022]
Abstract
Analysis of a series of diffraction data sets measured from four native as well as four nicotinic acid-soaked crystals of trypsin at 100 K shows a high variability in radiation-sensitivity among individual crystals for both nicotinic acid-soaked and native crystals. The level of radiation-sensitivity and the extent of its variability is statistically indistinguishable between the two conditions. This suggests that this potential scavenger does not have any statistically significant effect on the amount of radiation damage incurred in the crystals on X-ray irradiation. This is in contrast to previous results [Kauffmann et al. (2006), Structure, 14, 1099-1105] where only one crystal specimen was used for each condition (native and nicotinic acid-soaked).
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Affiliation(s)
- Elzbieta Nowak
- Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439, USA
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