1
|
Borgstahl G, Azadmanesh J, Slobodnik K, Struble L, Cone E, Dasgupta M, Lutz W, Kumar S, Natarajan A, Coates L, Weiss K, Myles D, Kroll T. The role of Tyr34 in proton-coupled electron transfer of human manganese superoxide dismutase. RESEARCH SQUARE 2024:rs.3.rs-4494128. [PMID: 38946943 PMCID: PMC11213228 DOI: 10.21203/rs.3.rs-4494128/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Human manganese superoxide dismutase (MnSOD) plays a crucial role in controlling levels of reactive oxygen species (ROS) by converting superoxide (O2 ●-) to molecular oxygen (O2) and hydrogen peroxide (H2O2) with proton-coupled electron transfers (PCETs). The reactivity of human MnSOD is determined by the state of a key catalytic residue, Tyr34, that becomes post-translationally inactivated by nitration in various diseases associated with mitochondrial dysfunction. We previously reported that Tyr34 has an unusual pKa due to its proximity to the Mn metal and undergoes cyclic deprotonation and protonation events to promote the electron transfers of MnSOD. To shed light on the role of Tyr34 MnSOD catalysis, we performed neutron diffraction, X-ray spectroscopy, and quantum chemistry calculations of Tyr34Phe MnSOD in various enzymatic states. The data identifies the contributions of Tyr34 in MnSOD activity that support mitochondrial function and presents a thorough characterization of how a single tyrosine modulates PCET catalysis.
Collapse
|
2
|
Azadmanesh J, Slobodnik K, Struble LR, Cone EA, Dasgupta M, Lutz WE, Kumar S, Natarajan A, Coates L, Weiss KL, Myles DAA, Kroll T, Borgstahl GEO. The role of Tyr34 in proton-coupled electron transfer of human manganese superoxide dismutase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596464. [PMID: 38853997 PMCID: PMC11160768 DOI: 10.1101/2024.05.29.596464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Human manganese superoxide dismutase (MnSOD) plays a crucial role in controlling levels of reactive oxygen species (ROS) by converting superoxide (O 2 •- ) to molecular oxygen (O 2 ) and hydrogen peroxide (H 2 O 2 ) with proton-coupled electron transfers (PCETs). The reactivity of human MnSOD is determined by the state of a key catalytic residue, Tyr34, that becomes post-translationally inactivated by nitration in various diseases associated with mitochondrial dysfunction. We previously reported that Tyr34 has an unusual pK a due to its proximity to the Mn metal and undergoes cyclic deprotonation and protonation events to promote the electron transfers of MnSOD. To shed light on the role of Tyr34 MnSOD catalysis, we performed neutron diffraction, X-ray spectroscopy, and quantum chemistry calculations of Tyr34Phe MnSOD in various enzymatic states. The data identifies the contributions of Tyr34 in MnSOD activity that support mitochondrial function and presents a thorough characterization of how a single tyrosine modulates PCET catalysis.
Collapse
|
3
|
Borgstahl G, Azadmanesh J, Slobodnik K, Struble L, Lutz W, Coates L, Weiss K, Myles D, Kroll T. Revealing the atomic and electronic mechanism of human manganese superoxide dismutase product inhibition. RESEARCH SQUARE 2024:rs.3.rs-3880128. [PMID: 38405788 PMCID: PMC10889052 DOI: 10.21203/rs.3.rs-3880128/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Human manganese superoxide dismutase (MnSOD) is a crucial oxidoreductase that maintains the vitality of mitochondria by converting O 2 ∙ - to O 2 and H 2 O 2 with proton-coupled electron transfers (PCETs). Since changes in mitochondrial H 2 O 2 concentrations are capable of stimulating apoptotic signaling pathways, human MnSOD has evolutionarily gained the ability to be highly inhibited by its own product, H 2 O 2 . A separate set of PCETs is thought to regulate product inhibition, though mechanisms of PCETs are typically unknown due to difficulties in detecting the protonation states of specific residues that coincide with the electronic state of the redox center. To shed light on the underlying mechanism, we combined neutron diffraction and X-ray absorption spectroscopy of the product-bound, trivalent, and divalent states to reveal the all-atom structures and electronic configuration of the metal. The data identifies the product-inhibited complex for the first time and a PCET mechanism of inhibition is constructed.
Collapse
|
4
|
Azadmanesh J, Slobodnik K, Struble LR, Lutz WE, Coates L, Weiss KL, Myles DAA, Kroll T, Borgstahl GEO. Revealing the atomic and electronic mechanism of human manganese superoxide dismutase product inhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577433. [PMID: 38328249 PMCID: PMC10849630 DOI: 10.1101/2024.01.26.577433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Human manganese superoxide dismutase (MnSOD) is a crucial oxidoreductase that maintains the vitality of mitochondria by converting O 2 ●- to O 2 and H 2 O 2 with proton-coupled electron transfers (PCETs). Since changes in mitochondrial H 2 O 2 concentrations are capable of stimulating apoptotic signaling pathways, human MnSOD has evolutionarily gained the ability to be highly inhibited by its own product, H 2 O 2 . A separate set of PCETs is thought to regulate product inhibition, though mechanisms of PCETs are typically unknown due to difficulties in detecting the protonation states of specific residues that coincide with the electronic state of the redox center. To shed light on the underlying mechanism, we combined neutron diffraction and X-ray absorption spectroscopy of the product-bound, trivalent, and divalent states to reveal the all-atom structures and electronic configuration of the metal. The data identifies the product-inhibited complex for the first time and a PCET mechanism of inhibition is constructed.
Collapse
|
5
|
Lutz WE, Azadmanesh J, Lovelace JJ, Kolar C, Coates L, Weiss KL, Borgstahl GEO. Perfect Crystals: microgravity capillary counterdiffusion crystallization of human manganese superoxide dismutase for neutron crystallography. NPJ Microgravity 2023; 9:39. [PMID: 37270576 PMCID: PMC10238240 DOI: 10.1038/s41526-023-00288-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 05/25/2023] [Indexed: 06/05/2023] Open
Abstract
The NASA mission Perfect Crystals used the microgravity environment on the International Space Station (ISS) to grow crystals of human manganese superoxide dismutase (MnSOD)-an oxidoreductase critical for mitochondrial vitality and human health. The mission's overarching aim is to perform neutron protein crystallography (NPC) on MnSOD to directly visualize proton positions and derive a chemical understanding of the concerted proton electron transfers performed by the enzyme. Large crystals that are perfect enough to diffract neutrons to sufficient resolution are essential for NPC. This combination, large and perfect, is hard to achieve on Earth due to gravity-induced convective mixing. Capillary counterdiffusion methods were developed that provided a gradient of conditions for crystal growth along with a built-in time delay that prevented premature crystallization before stowage on the ISS. Here, we report a highly successful and versatile crystallization system to grow a plethora of crystals for high-resolution NPC.
Collapse
Affiliation(s)
- William E Lutz
- Eppley Institute for Research in Cancer and Allied Diseases, 986805 Nebraska Medical Center, Omaha, NE, 68198-6805, USA
| | - Jahaun Azadmanesh
- Eppley Institute for Research in Cancer and Allied Diseases, 986805 Nebraska Medical Center, Omaha, NE, 68198-6805, USA
| | - Jeffrey J Lovelace
- Eppley Institute for Research in Cancer and Allied Diseases, 986805 Nebraska Medical Center, Omaha, NE, 68198-6805, USA
| | - Carol Kolar
- Eppley Institute for Research in Cancer and Allied Diseases, 986805 Nebraska Medical Center, Omaha, NE, 68198-6805, USA
| | - Leighton Coates
- Second Target Station, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831, USA
| | - Kevin L Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831, USA
| | - Gloria E O Borgstahl
- Eppley Institute for Research in Cancer and Allied Diseases, 986805 Nebraska Medical Center, Omaha, NE, 68198-6805, USA.
- Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA.
| |
Collapse
|
6
|
Tandrup T, Lo Leggio L, Meilleur F. Joint X-ray/neutron structure of Lentinus similis AA9_A at room temperature. Acta Crystallogr F Struct Biol Commun 2023; 79:1-7. [PMID: 36598350 PMCID: PMC9813973 DOI: 10.1107/s2053230x22011335] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper metalloenzymes which cleave polysaccharides oxidatively and are important in pathogen biology, carbon cycling and biotechnology. The Lentinus similis family AA9 isoform A (LsAA9_A) has been extensively studied as a model system because its activity towards smaller soluble saccharide substrates has allowed detailed structural characterization of its interaction with a variety of substrates by X-ray crystallography at high resolution. Here, the joint X-ray/neutron room-temperature crystallographic structure of carbohydrate-free LsAA9_A in the copper(II) resting state refined against X-ray and neutron data at 2.1 and 2.8 Å resolution, respectively, is presented. The results provide an experimental determination of the protonation states of the copper(II)-coordinating residues and second-shell residues in LsAA9_A, paving the way for future neutron crystallographic studies of LPMO-carbohydrate complexes.
Collapse
Affiliation(s)
- Tobias Tandrup
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Campus Box 7622, Raleigh, NC 27695, USA,Neutron Scattering Division, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831, USA,Correspondence e-mail:
| |
Collapse
|
7
|
Schröder GC, O'Dell WB, Webb SP, Agarwal PK, Meilleur F. Capture of activated dioxygen intermediates at the copper-active site of a lytic polysaccharide monooxygenase. Chem Sci 2022; 13:13303-13320. [PMID: 36507176 PMCID: PMC9683017 DOI: 10.1039/d2sc05031e] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/19/2022] [Indexed: 11/24/2022] Open
Abstract
Metalloproteins perform a diverse array of redox-related reactions facilitated by the increased chemical functionality afforded by their metallocofactors. Lytic polysaccharide monooxygenases (LPMOs) are a class of copper-dependent enzymes that are responsible for the breakdown of recalcitrant polysaccharides via oxidative cleavage at the glycosidic bond. The activated copper-oxygen intermediates and their mechanism of formation remains to be established. Neutron protein crystallography which permits direct visualization of protonation states was used to investigate the initial steps of oxygen activation directly following active site copper reduction in Neurospora crassa LPMO9D. Herein, we cryo-trap an activated dioxygen intermediate in a mixture of superoxo and hydroperoxo states, and we identify the conserved second coordination shell residue His157 as the proton donor. Density functional theory calculations indicate that both superoxo and hydroperoxo active site states are stable. The hydroperoxo formed is potentially an early LPMO catalytic reaction intermediate or the first step in the mechanism of hydrogen peroxide formation in the absence of substrate. We observe that the N-terminal amino group of the copper coordinating His1 remains doubly protonated directly following molecular oxygen reduction by copper. Aided by molecular dynamics and mining minima free energy calculations we establish that the conserved second-shell His161 in MtPMO3* displays conformational flexibility in solution and that this flexibility is also observed, though to a lesser extent, in His157 of NcLPMO9D. The imidazolate form of His157 observed in our structure following oxygen intermediate protonation can be attributed to abolished His157 flexibility due steric hindrance in the crystal as well as the solvent-occluded active site environment due to crystal packing. A neutron crystal structure of NcLPMO9D at low pH further supports occlusion of the active site since His157 remains singly protonated even at acidic conditions.
Collapse
Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State UniversityRaleighNC 27695USA,Neutron Scattering Division, Oak Ridge National LaboratoryOak RidgeTN 37831USA
| | - William B. O'Dell
- Department of Molecular and Structural Biochemistry, North Carolina State UniversityRaleighNC 27695USA,Neutron Scattering Division, Oak Ridge National LaboratoryOak RidgeTN 37831USA
| | - Simon P. Webb
- VeraChem LLC12850 Middlebrook Rd. Ste 205GermantownMD 20874-5244USA
| | - Pratul K. Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State UniversityStillwaterOK 74078USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State UniversityRaleighNC 27695USA,Neutron Scattering Division, Oak Ridge National LaboratoryOak RidgeTN 37831USA
| |
Collapse
|
8
|
Borgstahl GEO, O'Dell WB, Egli M, Kern JF, Kovalevsky A, Lin JYY, Myles D, Wilson MA, Zhang W, Zwart P, Coates L. EWALD: A macromolecular diffractometer for the second target station. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:064103. [PMID: 35778015 DOI: 10.1063/5.0090810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Revealing the positions of all the atoms in large macromolecules is powerful but only possible with neutron macromolecular crystallography (NMC). Neutrons provide a sensitive and gentle probe for the direct detection of protonation states at near-physiological temperatures and clean of artifacts caused by x rays or electrons. Currently, NMC use is restricted by the requirement for large crystal volumes even at state-of-the-art instruments such as the macromolecular neutron diffractometer at the Spallation Neutron Source. EWALD's design will break the crystal volume barrier and, thus, open the door for new types of experiments, the study of grand challenge systems, and the more routine use of NMC in biology. EWALD is a single crystal diffractometer capable of collecting data from macromolecular crystals on orders of magnitude smaller than what is currently feasible. The construction of EWALD at the Second Target Station will cause a revolution in NMC by enabling key discoveries in the biological, biomedical, and bioenergy sciences.
Collapse
Affiliation(s)
- Gloria E O Borgstahl
- Eppley Institute for Cancer and Allied Diseases, 986805 Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
| | - William B O'Dell
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA and Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
| | - Martin Egli
- Department of Biochemistry, Center for Structural Biology, Vanderbilt University, School of Medicine, Nashville, Tennessee 37232-0146, USA
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - Jiao Y Y Lin
- Second Target Station, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - Dean Myles
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - Mark A Wilson
- Department of Biochemistry and the Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Wen Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, Indiana 46202, USA
| | - Petrus Zwart
- Center for Advanced Mathematics in Energy Research Applications, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Leighton Coates
- Second Target Station, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| |
Collapse
|
9
|
Correy GJ, Kneller DW, Phillips G, Pant S, Russi S, Cohen AE, Meigs G, Holton JM, Gahbauer S, Thompson MC, Ashworth A, Coates L, Kovalevsky A, Meilleur F, Fraser JS. The mechanisms of catalysis and ligand binding for the SARS-CoV-2 NSP3 macrodomain from neutron and x-ray diffraction at room temperature. SCIENCE ADVANCES 2022; 8:eabo5083. [PMID: 35622909 PMCID: PMC9140965 DOI: 10.1126/sciadv.abo5083] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/11/2022] [Indexed: 05/04/2023]
Abstract
The nonstructural protein 3 (NSP3) macrodomain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Mac1) removes adenosine diphosphate (ADP) ribosylation posttranslational modifications, playing a key role in the immune evasion capabilities of the virus responsible for the coronavirus disease 2019 pandemic. Here, we determined neutron and x-ray crystal structures of the SARS-CoV-2 NSP3 macrodomain using multiple crystal forms, temperatures, and pHs, across the apo and ADP-ribose-bound states. We characterize extensive solvation in the Mac1 active site and visualize how water networks reorganize upon binding of ADP-ribose and non-native ligands, inspiring strategies for displacing waters to increase the potency of Mac1 inhibitors. Determining the precise orientations of active site water molecules and the protonation states of key catalytic site residues by neutron crystallography suggests a catalytic mechanism for coronavirus macrodomains distinct from the substrate-assisted mechanism proposed for human MacroD2. These data provoke a reevaluation of macrodomain catalytic mechanisms and will guide the optimization of Mac1 inhibitors.
Collapse
Affiliation(s)
- Galen J. Correy
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Daniel W. Kneller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Swati Pant
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Silvia Russi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Aina E. Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - George Meigs
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - James M. Holton
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stefan Gahbauer
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael C. Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA 95343, USA
| | - Alan Ashworth
- Helen Diller Family Comprehensive Cancer, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Leighton Coates
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
- Second Target Station, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, U.S. Department of Energy, Washington, DC 20585, USA
| | - Flora Meilleur
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - James S. Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| |
Collapse
|
10
|
Correy GJ, Kneller DW, Phillips G, Pant S, Russi S, Cohen AE, Meigs G, Holton JM, Gahbauer S, Thompson MC, Ashworth A, Coates L, Kovalevsky A, Meilleur F, Fraser JS. The mechanisms of catalysis and ligand binding for the SARS-CoV-2 NSP3 macrodomain from neutron and X-ray diffraction at room temperature. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.02.07.479477. [PMID: 35169801 PMCID: PMC8845425 DOI: 10.1101/2022.02.07.479477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The NSP3 macrodomain of SARS CoV 2 (Mac1) removes ADP-ribosylation post-translational modifications, playing a key role in the immune evasion capabilities of the virus responsible for the COVID-19 pandemic. Here, we determined neutron and X-ray crystal structures of the SARS-CoV-2 NSP3 macrodomain using multiple crystal forms, temperatures, and pHs, across the apo and ADP-ribose-bound states. We characterize extensive solvation in the Mac1 active site, and visualize how water networks reorganize upon binding of ADP-ribose and non-native ligands, inspiring strategies for displacing waters to increase potency of Mac1 inhibitors. Determining the precise orientations of active site water molecules and the protonation states of key catalytic site residues by neutron crystallography suggests a catalytic mechanism for coronavirus macrodomains distinct from the substrate-assisted mechanism proposed for human MacroD2. These data provoke a re-evaluation of macrodomain catalytic mechanisms and will guide the optimization of Mac1 inhibitors.
Collapse
Affiliation(s)
- Galen J Correy
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
| | - Daniel W Kneller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Swati Pant
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Silvia Russi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Menlo Park, CA 94025, USA
| | - Aina E Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Menlo Park, CA 94025, USA
| | - George Meigs
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94158, USA
| | - James M Holton
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Center, Menlo Park, CA 94025, USA
- Department of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94158, USA
| | - Stefan Gahbauer
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Michael C Thompson
- Department of Chemistry and Chemical Biology, University of California Merced, CA 95343, USA
| | - Alan Ashworth
- Helen Diller Family Comprehensive Cancer, University of California San Francisco, CA 94158, USA
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Flora Meilleur
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
| |
Collapse
|
11
|
Azadmanesh J, Lutz WE, Coates L, Weiss KL, Borgstahl GEO. Cryotrapping peroxide in the active site of human mitochondrial manganese superoxide dismutase crystals for neutron diffraction. Acta Crystallogr F Struct Biol Commun 2022; 78:8-16. [PMID: 34981770 PMCID: PMC8725007 DOI: 10.1107/s2053230x21012413] [Citation(s) in RCA: 6] [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: 09/21/2021] [Accepted: 11/22/2021] [Indexed: 12/28/2022] Open
Abstract
Structurally identifying the enzymatic intermediates of redox proteins has been elusive due to difficulty in resolving the H atoms involved in catalysis and the susceptibility of ligand complexes to photoreduction from X-rays. Cryotrapping ligands for neutron protein crystallography combines two powerful tools that offer the advantage of directly identifying hydrogen positions in redox-enzyme intermediates without radiolytic perturbation of metal-containing active sites. However, translating cryogenic techniques from X-ray to neutron crystallography is not straightforward due to the large crystal volumes and long data-collection times. Here, methods have been developed to visualize the evasive peroxo complex of manganese superoxide dismutase (MnSOD) so that all atoms, including H atoms, could be visualized. The subsequent cryocooling and ligand-trapping methods resulted in neutron data collection to 2.30 Å resolution. The P6122 crystal form of MnSOD is challenging because it has some of the largest unit-cell dimensions (a = b = 77.8, c = 236.8 Å) ever studied using high-resolution cryo-neutron crystallography. The resulting neutron diffraction data permitted the visualization of a dioxygen species bound to the MnSOD active-site metal that was indicative of successful cryotrapping.
Collapse
Affiliation(s)
- Jahaun Azadmanesh
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, USA
| | - William E. Lutz
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, USA
| | - Leighton Coates
- Second Target Station, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Gloria E. O. Borgstahl
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, USA
| |
Collapse
|
12
|
Kneller DW, Li H, Galanie S, Phillips G, Labbé A, Weiss KL, Zhang Q, Arnould MA, Clyde A, Ma H, Ramanathan A, Jonsson CB, Head MS, Coates L, Louis JM, Bonnesen PV, Kovalevsky A. Structural, Electronic, and Electrostatic Determinants for Inhibitor Binding to Subsites S1 and S2 in SARS-CoV-2 Main Protease. J Med Chem 2021; 64:17366-17383. [PMID: 34705466 PMCID: PMC8565456 DOI: 10.1021/acs.jmedchem.1c01475] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Indexed: 02/08/2023]
Abstract
Creating small-molecule antivirals specific for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins is crucial to battle coronavirus disease 2019 (COVID-19). SARS-CoV-2 main protease (Mpro) is an established drug target for the design of protease inhibitors. We performed a structure-activity relationship (SAR) study of noncovalent compounds that bind in the enzyme's substrate-binding subsites S1 and S2, revealing structural, electronic, and electrostatic determinants of these sites. The study was guided by the X-ray/neutron structure of Mpro complexed with Mcule-5948770040 (compound 1), in which protonation states were directly visualized. Virtual reality-assisted structure analysis and small-molecule building were employed to generate analogues of 1. In vitro enzyme inhibition assays and room-temperature X-ray structures demonstrated the effect of chemical modifications on Mpro inhibition, showing that (1) maintaining correct geometry of an inhibitor's P1 group is essential to preserve the hydrogen bond with the protonated His163; (2) a positively charged linker is preferred; and (3) subsite S2 prefers nonbulky modestly electronegative groups.
Collapse
Affiliation(s)
- Daniel W. Kneller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
| | - Hui Li
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Stephanie Galanie
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
| | - Audrey Labbé
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
| | - Qiu Zhang
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
| | - Mark A. Arnould
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Austin Clyde
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Data Science and Learning Division, Argonne National Laboratory, Lemont, IL 60439, USA
- Department of Computer Science, University of Chicago, Chicago, IL 60615, USA
| | - Heng Ma
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Data Science and Learning Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Arvind Ramanathan
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Data Science and Learning Division, Argonne National Laboratory, Lemont, IL 60439, USA
- Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL 60615
| | - Colleen B. Jonsson
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Martha S. Head
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Leighton Coates
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Second Target Station, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - John M. Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, MD 20892-0520, USA
| | - Peter V. Bonnesen
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, Washington, DC, 20585, USA
| |
Collapse
|
13
|
Harp JM, Coates L, Sullivan B, Egli M. Water structure around a left-handed Z-DNA fragment analyzed by cryo neutron crystallography. Nucleic Acids Res 2021; 49:4782-4792. [PMID: 33872377 PMCID: PMC8096259 DOI: 10.1093/nar/gkab264] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 03/28/2021] [Accepted: 03/31/2021] [Indexed: 02/03/2023] Open
Abstract
Even in high-quality X-ray crystal structures of oligonucleotides determined at a resolution of 1 Å or higher, the orientations of first-shell water molecules remain unclear. We used cryo neutron crystallography to gain insight into the H-bonding patterns of water molecules around the left-handed Z-DNA duplex [d(CGCGCG)]2. The neutron density visualized at 1.5 Å resolution for the first time allows us to pinpoint the orientations of most of the water molecules directly contacting the DNA and of many second-shell waters. In particular, H-bond acceptor and donor patterns for water participating in prominent hydration motifs inside the minor groove, on the convex surface or bridging nucleobase and phosphate oxygen atoms are finally revealed. Several water molecules display entirely unexpected orientations. For example, a water molecule located at H-bonding distance from O6 keto oxygen atoms of two adjacent guanines directs both its deuterium atoms away from the keto groups. Exocyclic amino groups of guanine (N2) and cytosine (N4) unexpectedly stabilize waters H-bonded to O2 keto oxygens from adjacent cytosines and O6 keto oxygens from adjacent guanines, respectively. Our structure offers the most detailed view to date of DNA solvation in the solid-state undistorted by metal ions or polyamines.
Collapse
Affiliation(s)
- Joel M Harp
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Brendan Sullivan
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Martin Egli
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA
| |
Collapse
|
14
|
Doucet M, Samarakoon AM, Do C, Heller WT, Archibald R, Alan Tennant D, Proffen T, Granroth GE. Machine learning for neutron scattering at ORNL *. MACHINE LEARNING: SCIENCE AND TECHNOLOGY 2021. [DOI: 10.1088/2632-2153/abcf88] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Abstract
Machine learning (ML) offers exciting new opportunities to extract more information from scattering data. At neutron scattering user facilities, ML has the potential to help accelerate scientific productivity by empowering facility users with insight into their data which has traditionally been supplied by scattering experts. Such support can help in both speeding up common modeling problems for users, as well as help solve harder problems that are normally time consuming and difficult to address with standard methods. This article explores the recent ML work undertaken at Oak Ridge National Laboratory involving neutron scattering data. We cover materials structure modeling for diffuse scattering, powder diffraction, and small-angle scattering. We also discuss how ML can help to model the response of the instrument more precisely, as well as enable quick extraction of information from neutron data. The application of super-resolution techniques to small-angle scattering and peak extraction for diffraction will be discussed.
Collapse
|
15
|
Kneller D, Phillips G, Weiss KL, Zhang Q, Coates L, Kovalevsky A. Direct Observation of Protonation State Modulation in SARS-CoV-2 Main Protease upon Inhibitor Binding with Neutron Crystallography. J Med Chem 2021; 64:4991-5000. [PMID: 33755450 PMCID: PMC8009097 DOI: 10.1021/acs.jmedchem.1c00058] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Indexed: 02/08/2023]
Abstract
The main protease (3CL Mpro) from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, is an essential enzyme for viral replication with no human counterpart, making it an attractive drug target. To date, no small-molecule clinical drugs are available that specifically inhibit SARS-CoV-2 Mpro. To aid rational drug design, we determined a neutron structure of Mpro in complex with the α-ketoamide inhibitor telaprevir at near-physiological (22 °C) temperature. We directly observed protonation states in the inhibitor complex and compared them with those in the ligand-free Mpro, revealing modulation of the active-site protonation states upon telaprevir binding. We suggest that binding of other α-ketoamide covalent inhibitors can lead to the same protonation state changes in the Mpro active site. Thus, by studying the protonation state changes induced by inhibitors, we provide crucial insights to help guide rational drug design, allowing precise tailoring of inhibitors to manipulate the electrostatic environment of SARS-CoV-2 Mpro.
Collapse
Affiliation(s)
- Daniel
W. Kneller
- Neutron
Scattering Division, Oak Ridge National
Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
- National
Virtual Biotechnology Laboratory, US Department of Energy, Washington, D.C. 20585, United States
| | - Gwyndalyn Phillips
- Neutron
Scattering Division, Oak Ridge National
Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
- National
Virtual Biotechnology Laboratory, US Department of Energy, Washington, D.C. 20585, United States
| | - Kevin L. Weiss
- Neutron
Scattering Division, Oak Ridge National
Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
- National
Virtual Biotechnology Laboratory, US Department of Energy, Washington, D.C. 20585, United States
| | - Qiu Zhang
- Neutron
Scattering Division, Oak Ridge National
Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
- National
Virtual Biotechnology Laboratory, US Department of Energy, Washington, D.C. 20585, United States
| | - Leighton Coates
- National
Virtual Biotechnology Laboratory, US Department of Energy, Washington, D.C. 20585, United States
- Second
Target Station, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| | - Andrey Kovalevsky
- Neutron
Scattering Division, Oak Ridge National
Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
- National
Virtual Biotechnology Laboratory, US Department of Energy, Washington, D.C. 20585, United States
| |
Collapse
|
16
|
Direct detection of coupled proton and electron transfers in human manganese superoxide dismutase. Nat Commun 2021; 12:2079. [PMID: 33824320 PMCID: PMC8024262 DOI: 10.1038/s41467-021-22290-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 02/26/2021] [Indexed: 11/30/2022] Open
Abstract
Human manganese superoxide dismutase is a critical oxidoreductase found in the mitochondrial matrix. Concerted proton and electron transfers are used by the enzyme to rid the mitochondria of O2•−. The mechanisms of concerted transfer enzymes are typically unknown due to the difficulties in detecting the protonation states of specific residues and solvent molecules at particular redox states. Here, neutron diffraction of two redox-controlled manganese superoxide dismutase crystals reveal the all-atom structures of Mn3+ and Mn2+ enzyme forms. The structures deliver direct data on protonation changes between oxidation states of the metal. Observations include glutamine deprotonation, the involvement of tyrosine and histidine with altered pKas, and four unusual strong-short hydrogen bonds, including a low barrier hydrogen bond. We report a concerted proton and electron transfer mechanism for human manganese superoxide dismutase from the direct visualization of active site protons in Mn3+ and Mn2+ redox states. Human manganese superoxide dismutase (MnSOD) is an oxidoreductase that uses concerted proton and electron transfers to reduce the levels of superoxide radicals in mitochondria, but mechanistic insights into this process are limited. Here, the authors report neutron crystal structures of Mn3+SOD and Mn2+SOD, revealing changes in the protonation states of key residues in the enzyme active site during the redox cycle.
Collapse
|
17
|
Schröder GC, O’Dell WB, Swartz PD, Meilleur F. Preliminary results of neutron and X-ray diffraction data collection on a lytic polysaccharide monooxygenase under reduced and acidic conditions. Acta Crystallogr F Struct Biol Commun 2021; 77:128-133. [PMID: 33830078 PMCID: PMC8034432 DOI: 10.1107/s2053230x21002399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/02/2021] [Indexed: 11/10/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-center enzymes that are involved in the oxidative cleavage of the glycosidic bond in crystalline cellulose and other polysaccharides. The LPMO reaction is initiated by the addition of a reductant and oxygen to ultimately form an unknown activated copper-oxygen species that is responsible for polysaccharide-substrate H-atom abstraction. Given the sensitivity of metalloproteins to radiation damage, neutron protein crystallography provides a nondestructive technique for structural characterization while also informing on the positions of H atoms. Neutron cryo-crystallography permits the trapping of catalytic intermediates, thereby providing insight into the protonation states and chemical nature of otherwise short-lived species in the reaction mechanism. To characterize the reaction-mechanism intermediates of LPMO9D from Neurospora crassa, a cryo-neutron diffraction data set was collected from an ascorbate-reduced crystal. A second neutron diffraction data set was collected at room temperature from an LPMO9D crystal exposed to low-pH conditions to probe the protonation states of ionizable groups involved in catalysis under acidic conditions.
Collapse
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
| | - William B. O’Dell
- 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
| | - Paul D. Swartz
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, 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
| |
Collapse
|
18
|
Kneller DW, Phillips G, Kovalevsky A, Coates L. Room-temperature neutron and X-ray data collection of 3CL M pro from SARS-CoV-2. Acta Crystallogr F Struct Biol Commun 2020; 76:483-487. [PMID: 33006576 PMCID: PMC7531248 DOI: 10.1107/s2053230x20011814] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/27/2020] [Indexed: 01/16/2023] Open
Abstract
The replication of SARS-CoV-2 produces two large polyproteins, pp1a and pp1ab, that are inactive until cleavage by the viral chymotrypsin-like cysteine protease enzyme (3CL Mpro) into a series of smaller functional proteins. At the heart of 3CL Mpro is an unusual catalytic dyad formed by the side chains of His41 and Cys145 and a coordinated water molecule. The catalytic mechanism by which the enzyme operates is still unknown, as crucial information on the protonation states within the active site is unclear. To experimentally determine the protonation states of the catalytic site and of the other residues in the substrate-binding cavity, and to visualize the hydrogen-bonding networks throughout the enzyme, room-temperature neutron and X-ray data were collected from a large H/D-exchanged crystal of ligand-free (apo) 3CL Mpro.
Collapse
Affiliation(s)
- Daniel W. Kneller
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
| | - Leighton Coates
- National Virtual Biotechnology Laboratory, US Department of Energy, USA
- Second Target Station, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37830, USA
| |
Collapse
|
19
|
Abstract
This chapter introduces this topic for the whole volume. It is not a review, rather it presents the basics, the key considerations and forward references to the other chapters. This starts by setting the scene of principles and overall strategy, moves onto planning an experiment including its feasibility and then outlines practicalities with options for the experiment. The crystal structure that results will lead to publication and associated with it, Protein Data Bank deposition.
Collapse
|
20
|
Langan PS, Sullivan B, Weiss KL, Coates L. Probing the role of the conserved residue Glu166 in a class A β-lactamase using neutron and X-ray protein crystallography. Acta Crystallogr D Struct Biol 2020; 76:118-123. [PMID: 32038042 PMCID: PMC7008513 DOI: 10.1107/s2059798319016334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/03/2019] [Indexed: 11/10/2022] Open
Abstract
The amino-acid sequence of the Toho-1 β-lactamase contains several conserved residues in the active site, including Ser70, Lys73, Ser130 and Glu166, some of which coordinate a catalytic water molecule. This catalytic water molecule is essential in the acylation and deacylation parts of the reaction mechanism through which Toho-1 inactivates specific antibiotics and provides resistance to its expressing bacterial strains. To investigate the function of Glu166 in the acylation part of the catalytic mechanism, neutron and X-ray crystallographic studies were performed on a Glu166Gln mutant. The structure of this class A β-lactamase mutant provides several insights into its previously reported reduced drug-binding kinetic rates. A joint refinement of both X-ray and neutron diffraction data was used to study the effects of the Glu166Gln mutation on the active site of Toho-1. This structure reveals that while the Glu166Gln mutation has a somewhat limited impact on the positions of the conserved amino acids within the active site, it displaces the catalytic water molecule from the active site. These subtle changes offer a structural explanation for the previously observed decreases in the binding of non-β-lactam inhibitors such as the recently developed diazobicyclooctane inhibitor avibactam.
Collapse
Affiliation(s)
- Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Brendan Sullivan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
21
|
|
22
|
Yamada T, Yano N, Hosoya T, Kusaka K. Single-crystal time-of-flight neutron Laue methods: application to manganese catalase from Thermus thermophilus HB27. J Appl Crystallogr 2019. [DOI: 10.1107/s1600576719010239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The IBARAKI biological crystal diffractometer (iBIX) was used in single-crystal time-of-flight neutron diffraction experiments on manganese catalase from Thermus thermophilus. The unit-cell dimensions were 133 × 133 × 133 Å, which is close to the designed maximum limitation of iBIX (135 × 135 × 135 Å). The optimum integration box sizes were set and the degree of integration box overlap was calculated for each Laue spot. Using the overlap ratio as the criterion, the selection of the diffraction intensity data was performed to give a minimum R
p.i.m.. Subsequently, diffraction intensity data from Laue spots with overlap ratios ≤0.1 were selected and a complete reflection data set with d
min = 2.35 Å was obtained. Joint X-ray and neutron structure refinements were also successfully performed. It was difficult to determine the structures and protonation states of all the oxygen atoms in the manganese cluster owing to the disordered structure. No hydrogen atom was observed on the ordered μ-bridging oxygen atom O1003. Instead, this oxygen atom probably forms a hydrogen bond with Thr39. In addition, the refinements clearly showed the protonation states of the amino acid residues and hydrogen bonds, as observed in Tyr192, Glu167 and Glu280. This first neutron crystal structure of manganese catalase shows that iBIX can provide acceptable diffraction data for neutron single-crystal analyses of at least 2.4 Å resolution within the original targeted unit-cell dimensions of 135 × 135 × 135 Å.
Collapse
|
23
|
Sullivan B, Archibald R, Azadmanesh J, Vandavasi VG, Langan PS, Coates L, Lynch V, Langan P. BraggNet: integrating Bragg peaks using neural networks. J Appl Crystallogr 2019; 52:854-863. [PMID: 31396028 PMCID: PMC6662992 DOI: 10.1107/s1600576719008665] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 06/17/2019] [Indexed: 10/14/2023] Open
Abstract
Neutron crystallography offers enormous potential to complement structures from X-ray crystallography by clarifying the positions of low-Z elements, namely hydrogen. Macromolecular neutron crystallography, however, remains limited, in part owing to the challenge of integrating peak shapes from pulsed-source experiments. To advance existing software, this article demonstrates the use of machine learning to refine peak locations, predict peak shapes and yield more accurate integrated intensities when applied to whole data sets from a protein crystal. The artificial neural network, based on the U-Net architecture commonly used for image segmentation, is trained using about 100 000 simulated training peaks derived from strong peaks. After 100 training epochs (a round of training over the whole data set broken into smaller batches), training converges and achieves a Dice coefficient of around 65%, in contrast to just 15% for negative control data sets. Integrating whole peak sets using the neural network yields improved intensity statistics compared with other integration methods, including k-nearest neighbours. These results demonstrate, for the first time, that neural networks can learn peak shapes and be used to integrate Bragg peaks. It is expected that integration using neural networks can be further developed to increase the quality of neutron, electron and X-ray crystallography data.
Collapse
Affiliation(s)
- Brendan Sullivan
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Rick Archibald
- Computer Science and Mathematics Division, Computing and Computational Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Jahaun Azadmanesh
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, Nebraska 68198, USA
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, 985870 Nebraska Medical Center, Omaha, Nebraska 68198, USA
| | - Venu Gopal Vandavasi
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Patricia S. Langan
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Leighton Coates
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Vickie Lynch
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Paul Langan
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| |
Collapse
|
24
|
Langan PS, Vandavasi VG, Sullivan B, Harp J, Weiss K, Coates L. Crystallization of a potassium ion channel and X-ray and neutron data collection. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2019; 75:435-438. [PMID: 31204690 DOI: 10.1107/s2053230x19006630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/08/2019] [Indexed: 11/10/2022]
Abstract
The mechanism by which potassium ions are transported through ion channels is currently being investigated by several groups using many different techniques. Clarification of the location of water molecules during transport is central to understanding how these integral membrane proteins function. Neutrons have a unique sensitivity to both hydrogen and potassium, rendering neutron crystallography capable of distinguishing waters from K+ ions. Here, the collection of a complete neutron data set from a potassium ion channel to a resolution of 3.55 Å using the Macromolecular Neutron Diffractometer (MaNDi) is reported. A room-temperature X-ray data set was also collected from the same crystal to a resolution of 2.50 Å. Upon further refinement, these results will help to further clarify the ion/water population within the selectivity filter of potassium ion channels.
Collapse
Affiliation(s)
- Patricia S Langan
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Venu Gopal Vandavasi
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Brendan Sullivan
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Joel Harp
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Kevin Weiss
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Leighton Coates
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| |
Collapse
|
25
|
Sullivan B, Langan PS, Archibald R, Coates L, Vadavasi VG, Lynch V. Volumetric Segmentation via Neural Networks Improves Neutron Crystallography Data Analysis. IEEE/ACM INTERNATIONAL SYMPOSIUM ON CLUSTER, CLOUD AND GRID COMPUTING. IEEE/ACM INTERNATIONAL SYMPOSIUM ON CLUSTER, CLOUD, AND GRID COMPUTING 2019; 2019:549-555. [PMID: 31886471 PMCID: PMC6934264 DOI: 10.1109/ccgrid.2019.00070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Crystallography is the powerhouse technique for molecular structure determination, with applications in fields ranging from energy storage to drug design. Accurate structure determination, however, relies partly on determining the precise locations and integrated intensities of Bragg peaks in the resulting data. Here, we describe a method for Bragg peak integration that is accomplished using neural networks. The network is based on a U-Net and identifies peaks in three-dimensional reciprocal space through segmentation, allowing prediction of the full 3D peak shape from noisy data that is commonly difficult to process. The procedure for generating appropriate training sets is detailed. Trained networks achieve Dice coefficients of 0.82 and mean IoUs of 0.69. Carrying out integration over entire datasets, it is demonstrated that integrating neural network-predicted peaks results in improved intensity statistics. Furthermore, using a second dataset, the possibility of transfer learning between datasets is shown. Given the ubiquity and growing complexity of crystallography, we anticipate integration by machine learning to play an increasingly important role across the physical sciences. These early results demonstrate the applicability of deep learning techniques for integrating crystallography data and suggest a possible role in the next generation of crystallography experiments.
Collapse
Affiliation(s)
- Brendan Sullivan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Patricia S Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Rick Archibald
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Venu Gopal Vadavasi
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Vickie Lynch
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| |
Collapse
|
26
|
The Neutron Macromolecular Crystallography Instruments at Oak Ridge National Laboratory: Advances, Challenges, and Opportunities. CRYSTALS 2018. [DOI: 10.3390/cryst8100388] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The IMAGINE and MaNDi instruments, located at Oak Ridge National Laboratory High Flux Isotope Reactor and Spallation Neutron Source, respectively, are powerful tools for determining the positions of hydrogen atoms in biological macromolecules and their ligands, orienting water molecules, and for differentiating chemical states in macromolecular structures. The possibility to model hydrogen and deuterium atoms in neutron structures arises from the strong interaction of neutrons with the nuclei of these isotopes. Positions can be unambiguously assigned from diffraction studies at the 1.5–2.5 Å resolutions, which are typical for protein crystals. Neutrons have the additional benefit for structural biology of not inducing radiation damage to protein crystals, which can be critical in the study of metalloproteins. Here we review the specifications of the IMAGINE and MaNDi beamlines and illustrate their complementarity. IMAGINE is suitable for crystals with unit cell edges up to 150 Å using a quasi-Laue technique, whereas MaNDi provides neutron crystallography resources for large unit cell samples with unit cell edges up to 300 Å using the time of flight (TOF) Laue technique. The microbial culture and crystal growth facilities which support the IMAGINE and MaNDi user programs are also described.
Collapse
|