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Data collection strategies for time-resolved X-ray free-electron laser diffraction, and 2-color methods
We compare three schemes for time-resolved X-ray diffraction from protein nanocrystals using an X-ray free-electron laser. We find expressions for the errors in structure factor measurement using the Monte Carlo pump-probe method of data analysis with a liquid jet, the fixed sample pump-probe (gonio...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Crystallographic Association
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711652/ https://www.ncbi.nlm.nih.gov/pubmed/26798813 http://dx.doi.org/10.1063/1.4922433 |
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author | Li, Chufeng Schmidt, Kevin Spence, John C. |
author_facet | Li, Chufeng Schmidt, Kevin Spence, John C. |
author_sort | Li, Chufeng |
collection | PubMed |
description | We compare three schemes for time-resolved X-ray diffraction from protein nanocrystals using an X-ray free-electron laser. We find expressions for the errors in structure factor measurement using the Monte Carlo pump-probe method of data analysis with a liquid jet, the fixed sample pump-probe (goniometer) method (both diffract-and-destroy, and below the safe damage dose), and a proposed two-color method. Here, an optical pump pulse arrives between X-ray pulses of slightly different energies which hit the same nanocrystal, using a weak first X-ray pulse which does not damage the sample. (Radiation damage is outrun in the other cases.) This two-color method, in which separated Bragg spots are impressed on the same detector readout, eliminates stochastic fluctuations in crystal size, shape, and orientation and is found to require two orders of magnitude fewer diffraction patterns than the currently used Monte Carlo liquid jet method, for 1% accuracy. Expressions are given for errors in structure factor measurement for the four approaches, and detailed simulations provided for cathepsin B and IC3 crystals. While the error is independent of the number of shots for the dose-limited goniometer method, it falls off inversely as the square root of the number of shots for the two-color and Monte Carlo methods, with a much smaller pre-factor for the two-color mode, when the first shot is below the damage threshold. |
format | Online Article Text |
id | pubmed-4711652 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | American Crystallographic Association |
record_format | MEDLINE/PubMed |
spelling | pubmed-47116522016-01-21 Data collection strategies for time-resolved X-ray free-electron laser diffraction, and 2-color methods Li, Chufeng Schmidt, Kevin Spence, John C. Struct Dyn SPECIAL TOPIC: BIOLOGY WITH X-RAY LASERS 2 We compare three schemes for time-resolved X-ray diffraction from protein nanocrystals using an X-ray free-electron laser. We find expressions for the errors in structure factor measurement using the Monte Carlo pump-probe method of data analysis with a liquid jet, the fixed sample pump-probe (goniometer) method (both diffract-and-destroy, and below the safe damage dose), and a proposed two-color method. Here, an optical pump pulse arrives between X-ray pulses of slightly different energies which hit the same nanocrystal, using a weak first X-ray pulse which does not damage the sample. (Radiation damage is outrun in the other cases.) This two-color method, in which separated Bragg spots are impressed on the same detector readout, eliminates stochastic fluctuations in crystal size, shape, and orientation and is found to require two orders of magnitude fewer diffraction patterns than the currently used Monte Carlo liquid jet method, for 1% accuracy. Expressions are given for errors in structure factor measurement for the four approaches, and detailed simulations provided for cathepsin B and IC3 crystals. While the error is independent of the number of shots for the dose-limited goniometer method, it falls off inversely as the square root of the number of shots for the two-color and Monte Carlo methods, with a much smaller pre-factor for the two-color mode, when the first shot is below the damage threshold. American Crystallographic Association 2015-06-12 /pmc/articles/PMC4711652/ /pubmed/26798813 http://dx.doi.org/10.1063/1.4922433 Text en © 2015 Author(s). 2329-7778/2015/2(4)/041714/19 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. |
spellingShingle | SPECIAL TOPIC: BIOLOGY WITH X-RAY LASERS 2 Li, Chufeng Schmidt, Kevin Spence, John C. Data collection strategies for time-resolved X-ray free-electron laser diffraction, and 2-color methods |
title | Data collection strategies for time-resolved X-ray free-electron laser
diffraction, and 2-color methods |
title_full | Data collection strategies for time-resolved X-ray free-electron laser
diffraction, and 2-color methods |
title_fullStr | Data collection strategies for time-resolved X-ray free-electron laser
diffraction, and 2-color methods |
title_full_unstemmed | Data collection strategies for time-resolved X-ray free-electron laser
diffraction, and 2-color methods |
title_short | Data collection strategies for time-resolved X-ray free-electron laser
diffraction, and 2-color methods |
title_sort | data collection strategies for time-resolved x-ray free-electron laser
diffraction, and 2-color methods |
topic | SPECIAL TOPIC: BIOLOGY WITH X-RAY LASERS 2 |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711652/ https://www.ncbi.nlm.nih.gov/pubmed/26798813 http://dx.doi.org/10.1063/1.4922433 |
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