Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Li, Chufeng, Schmidt, Kevin, Spence, John C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Crystallographic Association 2015
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
_version_ 1782409967530147840
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
work_keys_str_mv AT lichufeng datacollectionstrategiesfortimeresolvedxrayfreeelectronlaserdiffractionand2colormethods
AT schmidtkevin datacollectionstrategiesfortimeresolvedxrayfreeelectronlaserdiffractionand2colormethods
AT spencejohnc datacollectionstrategiesfortimeresolvedxrayfreeelectronlaserdiffractionand2colormethods