1
|
Abstract
The cell is a crowded space where large biomolecules and metabolites are in continuous motion. Great strides have been made in in vitro studies of protein dynamics, folding, and protein-protein interactions, and much new data are emerging of how they differ in the cell. In this Perspective, we highlight the current progress in atomistic modeling of in-cell environments, both bacteria and mammals, with emphasis on classical all-atom molecular dynamics simulations. These simulations have been recently used to capture and characterize functional and non-functional protein-protein interactions, protein folding dynamics of small proteins with varied topologies, and dynamics of metabolites. We further discuss the challenges and efforts for updating modern force fields critical to the progress of cellular environment simulations. We also briefly summarize developments in relevant state-of-the-art experimental techniques. As computational and experimental methodologies continue to progress and produce more directly comparable data, we are poised to capture the complex atomistic picture of the cell.
Collapse
Affiliation(s)
- Premila P Samuel Russell
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Sepehr Alaeen
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Taras V Pogorelov
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- School of Chemical Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- National Center for Supercomputing Applications, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
2
|
Guest TW, Bean R, Kammering R, van Riessen G, Mancuso AP, Abbey B. A phenomenological model of the X-ray pulse statistics of a high-repetition-rate X-ray free-electron laser. IUCrJ 2023; 10:708-719. [PMID: 37782462 PMCID: PMC10619450 DOI: 10.1107/s2052252523008242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/19/2023] [Indexed: 10/03/2023]
Abstract
Many coherent imaging applications that utilize ultrafast X-ray free-electron laser (XFEL) radiation pulses are highly sensitive to fluctuations in the shot-to-shot statistical properties of the source. Understanding and modelling these fluctuations are key to successful experiment planning and necessary to maximize the potential of XFEL facilities. Current models of XFEL radiation and their shot-to-shot statistics are based on theoretical descriptions of the source and are limited in their ability to capture the shot-to-shot intensity fluctuations observed experimentally. The lack of accurate temporal statistics in simulations that utilize these models is a significant barrier to optimizing and interpreting data from XFEL coherent diffraction experiments. Presented here is a phenomenological model of XFEL radiation that is capable of capturing the shot-to-shot statistics observed experimentally using a simple time-dependent approximation of the pulse wavefront. The model is applied to reproduce non-stationary shot-to-shot intensity fluctuations observed at the European XFEL, whilst accurately representing the single-shot properties predicted by FEL theory. Compared with previous models, this approach provides a simple, robust and computationally inexpensive method of generating statistical representations of XFEL radiation.
Collapse
Affiliation(s)
- Trey W. Guest
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3086, Australia
- Department of Mathematical and Physical Sciences, School of Engineering, Computing and Mathematical Sciences, La Trobe University, Bundoora, VIC 3086, Australia
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Richard Bean
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Raimund Kammering
- Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607 Hamburg, Germany
| | - Grant van Riessen
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3086, Australia
- Department of Mathematical and Physical Sciences, School of Engineering, Computing and Mathematical Sciences, La Trobe University, Bundoora, VIC 3086, Australia
| | - Adrian P. Mancuso
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3086, Australia
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Brian Abbey
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3086, Australia
- Department of Mathematical and Physical Sciences, School of Engineering, Computing and Mathematical Sciences, La Trobe University, Bundoora, VIC 3086, Australia
| |
Collapse
|
3
|
E J, Stransky M, Shen Z, Jurek Z, Fortmann-Grote C, Bean R, Santra R, Ziaja B, Mancuso AP. Water layer and radiation damage effects on the orientation recovery of proteins in single-particle imaging at an X-ray free-electron laser. Sci Rep 2023; 13:16359. [PMID: 37773512 PMCID: PMC10541445 DOI: 10.1038/s41598-023-43298-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/21/2023] [Indexed: 10/01/2023] Open
Abstract
The noise caused by sample heterogeneity (including sample solvent) has been identified as one of the determinant factors for a successful X-ray single-particle imaging experiment. It influences both the radiation damage process that occurs during illumination as well as the scattering patterns captured by the detector. Here, we investigate the impact of water layer thickness and radiation damage on orientation recovery from diffraction patterns of the nitrogenase iron protein. Orientation recovery is a critical step for single-particle imaging. It enables to sort a set of diffraction patterns scattered by identical particles placed at unknown orientations and assemble them into a 3D reciprocal space volume. The recovery quality is characterized by a "disconcurrence" metric. Our results show that while a water layer mitigates protein damage, the noise generated by the scattering from it can introduce challenges for orientation recovery and is anticipated to cause problems in the phase retrieval process to extract the desired protein structure. Compared to these disadvantageous effects due to the thick water layer, the effects of radiation damage on the orientation recovery are relatively small. Therefore, minimizing the amount of residual sample solvent should be considered a crucial step in improving the fidelity and resolution of X-ray single-particle imaging experiments.
Collapse
Affiliation(s)
- Juncheng E
- European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany.
| | - Michal Stransky
- European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany
- Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342, Kraków, Poland
| | - Zhou Shen
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Zoltan Jurek
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761, Hamburg, Germany
| | | | - Richard Bean
- European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany
| | - Robin Santra
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761, Hamburg, Germany
- Department of Physics, Universität Hamburg, Notkestr. 9-11, 22607, Hamburg, Germany
| | - Beata Ziaja
- Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342, Kraków, Poland
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Adrian P Mancuso
- European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany.
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK.
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| |
Collapse
|
4
|
Nakano M, Miyashita O, Tama F. Molecular size dependence on achievable resolution from XFEL single-particle 3D reconstruction. Struct Dyn 2023; 10:024101. [PMID: 36942031 PMCID: PMC10024609 DOI: 10.1063/4.0000175] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/16/2023] [Indexed: 05/03/2023]
Abstract
Single-particle analysis using x-ray free-electron lasers (XFELs) is a novel method for obtaining structural information of samples in a state close to nature. In particular, it is suitable for observing the inner structure of large biomolecules by taking advantage of the high transmittance of x-rays. However, systematic studies on the resolution achievable for large molecules are lacking. In this study, the molecular size dependence of the resolution of a three-dimensional (3D) structure resulting from XFEL single-particle reconstruction is evaluated using synthetic data. Evidently, 3D structures of larger molecules can be restored with higher detail (defined relative to the molecular sizes) than smaller ones; however, reconstruction with high absolute resolution (defined in nm-1) is challenging. Our results provide useful information for the experimental design of 3D structure reconstruction using coherent x-ray diffraction patterns of single-particles.
Collapse
Affiliation(s)
- Miki Nakano
- RIKEN Center for Computational Science, 6-7-1, Minatojima-minami-machi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Osamu Miyashita
- RIKEN Center for Computational Science, 6-7-1, Minatojima-minami-machi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | | |
Collapse
|
5
|
E J, Kim Y, Bielecki J, Sikorski M, de Wijn R, Fortmann-Grote C, Sztuk-Dambietz J, Koliyadu JCP, Letrun R, Kirkwood HJ, Sato T, Bean R, Mancuso AP, Kim C. Expected resolution limits of x-ray free-electron laser single-particle imaging for realistic source and detector properties. Struct Dyn 2022; 9:064101. [PMID: 36411869 PMCID: PMC9675053 DOI: 10.1063/4.0000169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/31/2022] [Indexed: 05/15/2023]
Abstract
The unprecedented intensity of x-ray free-electron laser sources has enabled single-particle x-ray diffraction imaging (SPI) of various biological specimens in both two-dimensional projection and three dimensions (3D). The potential of studying protein dynamics in their native conditions, without crystallization or chemical staining, has encouraged researchers to aim for increasingly higher resolutions with this technique. The currently achievable resolution of SPI is limited to the sub-10 nanometer range, mainly due to background effects, such as instrumental noise and parasitic scattering from the carrier gas used for sample delivery. Recent theoretical studies have quantified the effects of x-ray pulse parameters, as well as the required number of diffraction patterns to achieve a certain resolution, in a 3D reconstruction, although the effects of detector noise and the random particle orientation in each diffraction snapshot were not taken into account. In this work, we show these shortcomings and address limitations on achievable image resolution imposed by the adaptive gain integrating pixel detector noise.
Collapse
Affiliation(s)
- Juncheng E
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Y. Kim
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - J. Bielecki
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - M. Sikorski
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - R. de Wijn
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | | | - R. Letrun
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - T. Sato
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - R. Bean
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - C. Kim
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Author to whom correspondence should be addressed:
| |
Collapse
|