1
|
Young ID, Mendez D, Poon BK, Blaschke JP, Wittwer F, Wall ME, Sauter NK. Interpreting macromolecular diffraction through simulation. Methods Enzymol 2023; 688:195-222. [PMID: 37748827 DOI: 10.1016/bs.mie.2023.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
This chapter discusses the use of diffraction simulators to improve experimental outcomes in macromolecular crystallography, in particular for future experiments aimed at diffuse scattering. Consequential decisions for upcoming data collection include the selection of either a synchrotron or free electron laser X-ray source, rotation geometry or serial crystallography, and fiber-coupled area detector technology vs. pixel-array detectors. The hope is that simulators will provide insights to make these choices with greater confidence. Simulation software, especially those packages focused on physics-based calculation of the diffraction, can help to predict the location, size, shape, and profile of Bragg spots and diffuse patterns in terms of an underlying physical model, including assumptions about the crystal's mosaic structure, and therefore can point to potential issues with data analysis in the early planning stages. Also, once the data are collected, simulation may offer a pathway to improve the measurement of diffraction, especially with weak data, and might help to treat problematic cases such as overlapping patterns.
Collapse
Affiliation(s)
- Iris D Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Derek Mendez
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, United States
| | - Billy K Poon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Johannes P Blaschke
- National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Felix Wittwer
- National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Michael E Wall
- Computer, Computational and Statistical Sciences Division, Los Alamos, NM, United States
| | - Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
| |
Collapse
|
2
|
Suzuki R, Baba S, Mizuno N, Hasegawa K, Koizumi H, Kojima K, Kumasaka T, Tachibana M. Radiation-induced defects in protein crystals observed by X-ray topography. ACTA CRYSTALLOGRAPHICA SECTION D STRUCTURAL BIOLOGY 2022; 78:196-203. [DOI: 10.1107/s205979832101281x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 12/01/2021] [Indexed: 11/10/2022]
Abstract
The characterization of crystal defects induced by irradiation, such as X-rays, charged particles and neutrons, is important for understanding radiation damage and the associated generation of defects. Radiation damage to protein crystals has been measured using various methods. Until now, these methods have focused on decreased diffraction intensity, volume expansion of unit cells and specific damage to side chains. Here, the direct observation of specific crystal defects, such as dislocations, induced by X-ray irradiation of protein crystals at room temperature is reported. Dislocations are induced even by low absorbed doses of X-ray irradiation. This study revealed that for the same total absorbed dose, the formation of defects appears to critically depend on the dose rate. The relationship between dislocation energy and dose energy was analyzed based on dislocation theory associated with elasticity theory for crystalline materials. This demonstration of the crystal defects induced by X-ray irradiation could help to understand the underlying mechanisms of X-ray-induced radiation damage.
Collapse
|
3
|
Atakisi H, Conger L, Moreau DW, Thorne RE. Resolution and dose dependence of radiation damage in biomolecular systems. IUCRJ 2019; 6:1040-1053. [PMID: 31709060 PMCID: PMC6830208 DOI: 10.1107/s2052252519008777] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/19/2019] [Indexed: 05/30/2023]
Abstract
The local Fourier-space relation between diffracted intensity I, diffraction wavevector q and dose D, , is key to probing and understanding radiation damage by X-rays and energetic particles in both diffraction and imaging experiments. The models used in protein crystallography for the last 50 years provide good fits to experimental I(q) versus nominal dose data, but have unclear physical significance. More recently, a fit to diffraction and imaging experiments suggested that the maximum tolerable dose varies as q -1 or linearly with resolution. Here, it is shown that crystallographic data have been strongly perturbed by the effects of spatially nonuniform crystal irradiation and diffraction during data collection. Reanalysis shows that these data are consistent with a purely exponential local dose dependence, = I 0(q)exp[-D/D e(q)], where D e(q) ∝ q α with α ≃ 1.7. A physics-based model for radiation damage, in which damage events occurring at random locations within a sample each cause energy deposition and blurring of the electron density within a small volume, predicts this exponential variation with dose for all q values and a decay exponent α ≃ 2 in two and three dimensions, roughly consistent with both diffraction and imaging experiments over more than two orders of magnitude in resolution. The B-factor model used to account for radiation damage in crystallographic scaling programs is consistent with α = 2, but may not accurately capture the dose dependencies of structure factors under typical nonuniform illumination conditions. The strong q dependence of radiation-induced diffraction decays implies that the previously proposed 20-30 MGy dose limit for protein crystallography should be replaced by a resolution-dependent dose limit that, for atomic resolution data sets, will be much smaller. The results suggest that the physics underlying basic experimental trends in radiation damage at T ≃ 100 K is straightforward and universal. Deviations of the local I(q, D) from strictly exponential behavior may provide mechanistic insights, especially into the radiation-damage processes responsible for the greatly increased radiation sensitivity observed at T ≃ 300 K.
Collapse
Affiliation(s)
- Hakan Atakisi
- Physics Department, Cornell University, Ithaca, NY 14853, USA
| | | | - David W. Moreau
- Physics Department, Cornell University, Ithaca, NY 14853, USA
| | | |
Collapse
|
5
|
Coughlan HD, Darmanin C, Kirkwood HJ, Phillips NW, Hoxley D, Clark JN, Vine DJ, Hofmann F, Harder RJ, Maxey E, Abbey B. Bragg coherent diffraction imaging and metrics for radiation damage in protein micro-crystallography. JOURNAL OF SYNCHROTRON RADIATION 2017; 24:83-94. [PMID: 28009549 PMCID: PMC5182022 DOI: 10.1107/s1600577516017525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/01/2016] [Indexed: 05/09/2023]
Abstract
The proliferation of extremely intense synchrotron sources has enabled ever higher-resolution structures to be obtained using data collected from smaller and often more imperfect biological crystals (Helliwell, 1984). Synchrotron beamlines now exist that are capable of measuring data from single crystals that are just a few micrometres in size. This provides renewed motivation to study and understand the radiation damage behaviour of small protein crystals. Reciprocal-space mapping and Bragg coherent diffractive imaging experiments have been performed on cryo-cooled microcrystals of hen egg-white lysozyme as they undergo radiation damage. Several well established metrics, such as intensity-loss and lattice expansion, are applied to the diffraction data and the results are compared with several new metrics that can be extracted from the coherent imaging experiments. Individually some of these metrics are inconclusive. However, combining metrics, the results suggest that radiation damage behaviour in protein micro-crystals differs from that of larger protein crystals and may allow them to continue to diffract for longer. A possible mechanism to account for these observations is proposed.
Collapse
Affiliation(s)
- H. D. Coughlan
- ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
- CSIRO Manufacturing Flagship, Parkville 3052, Australia
| | - C. Darmanin
- ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - H. J. Kirkwood
- ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - N. W. Phillips
- ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
- CSIRO Manufacturing Flagship, Parkville 3052, Australia
| | - D. Hoxley
- ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| | - J. N. Clark
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Center for Free-Electron Laser Science (CFEL), Deutsches Elektronensynchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - D. J. Vine
- Advanced Light Source, Berkeley Lab, Berkeley, CA 94720, USA
| | - F. Hofmann
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - R. J. Harder
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - E. Maxey
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - B. Abbey
- ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia
| |
Collapse
|