uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Indications of radiation damage in ferredoxin microcrystals using high-intensity X-FEL beams
Show others and affiliations
2015 (English)In: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 22, no 2, 225-238 p.Article in journal (Refereed) Published
Abstract [en]

Proteins that contain metal cofactors are expected to be highly radiation sensitive since the degree of X-ray absorption correlates with the presence of high-atomic-number elements and X-ray energy. To explore the effects of local damage in serial femtosecond crystallography (SFX), Clostridium ferredoxin was used as a model system. The protein contains two [4Fe–4S] clusters that serve as sensitive probes for radiation-induced electronic and structural changes. High-dose room-temperature SFX datasets were collected at the Linac Coherent Light Source of ferredoxin microcrystals. Difference electron density maps calculated from high-dose SFX and synchrotron data show peaks at the iron positions of the clusters, indicative of decrease of atomic scattering factors due to ionization. The electron density of the two [4Fe–4S] clusters differs in the FEL data, but not in the synchrotron data. Since the clusters differ in their detailed architecture, this observation is suggestive of an influence of the molecular bonding and geometry on the atomic displacement dynamics following initial photoionization. The experiments are complemented by plasma code calculations.

Place, publisher, year, edition, pages
2015. Vol. 22, no 2, 225-238 p.
Keyword [en]
free-electron laser, SFX, serial femtosecond crystallography, radiation damage, protein crystallography, metalloprotein
National Category
Structural Biology
Identifiers
URN: urn:nbn:se:uu:diva-245011DOI: 10.1107/S1600577515002349ISI: 000350641100004OAI: oai:DiVA.org:uu-245011DiVA: diva2:790248
Available from: 2015-02-23 Created: 2015-02-23 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Ultrafast Structural and Electron Dynamics in Soft Matter Exposed to Intense X-ray Pulses
Open this publication in new window or tab >>Ultrafast Structural and Electron Dynamics in Soft Matter Exposed to Intense X-ray Pulses
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Investigations of soft matter using ultrashort high intensity pulses have been made possible through the advent of X-ray free-electrons lasers. The last decade has seen the development of a new type of protein crystallography where femtosecond dynamics can be studied, and single particle imaging with atomic resolution is on the horizon. The pulses are so intense that any sample quickly turns into a plasma. This thesis studies the ultrafast transition from soft matter to warm dense matter, and the implications for structural determination of proteins.                   

We use non-thermal plasma simulations to predict ultrafast structural and electron dynamics. Changes in atomic form factors due to the electronic state, and displacement as a function of temperature, are used to predict Bragg signal intensity in protein nanocrystals. The damage processes started by the pulse will gate the diffracted signal within the pulse duration, suggesting that long pulses are useful to study protein structure. This illustrates diffraction-before-destruction in crystallography.

The effect from a varying temporal photon distribution within a pulse is also investigated. A well-defined initial front determines the quality of the diffracted signal. At lower intensities, the temporal shape of the X-ray pulse will affect the overall signal strength; at high intensities the signal level will be strongly dependent on the resolution.

Water is routinely used to deliver biological samples into the X-ray beam. Structural dynamics in water exposed to intense X-rays were investigated with simulations and experiments. Using pulses of different duration, we found that non-thermal heating will affect the water structure on a time scale longer than 25 fs but shorter than 75 fs. Modeling suggests that a loss of long-range coordination of the solvation shells accounts for the observed decrease in scattering signal.

The feasibility of using X-ray emission from plasma as an indicator for hits in serial diffraction experiments is studied. Specific line emission from sulfur at high X-ray energies is suitable for distinguishing spectral features from proteins, compared to emission from delivery liquids. We find that plasma emission continues long after the femtosecond pulse has ended, suggesting that spectrum-during-destruction could reveal information complementary to diffraction.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. 78 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1592
Keyword
X-ray free-electron laser; Serial Femtosecond Crystallography; Radiation Damage; Plasma Simulations; Ultrafast Lasers; X-ray Imaging; Diffraction Theory; Ultrafast Phenomena; Hit Detection; Plasma Emission Spectra; Serial Femtosecond Crystallography; Protein Structure; Protein Crystallography; Metalloprotein; Non-thermal Heating; Water; Ferredoxin; NLTE Simulation; XFEL; FEL; SFX
National Category
Biophysics
Research subject
Physics with specialization in Biophysics
Identifiers
urn:nbn:se:uu:diva-331936 (URN)978-91-513-0134-1 (ISBN)
Public defence
2017-12-15, Polhemssalen, Lägerhyddsvägen 1, Uppsala, 09:15 (English)
Opponent
Supervisors
Funder
Swedish Foundation for Strategic Research , ICA10-0090Swedish Research Council, 2013-3940The Swedish Foundation for International Cooperation in Research and Higher Education (STINT)
Available from: 2017-11-22 Created: 2017-10-25 Last updated: 2017-11-22

Open Access in DiVA

No full text

Other links

Publisher's full texthttp://dx.doi.org/10.1107/S1600577515002349

Authority records BETA

Jönsson, H. OlofTimneanu, NicusorCaleman, Carl

Search in DiVA

By author/editor
Jönsson, H. OlofTimneanu, NicusorCaleman, Carl
By organisation
Molecular and condensed matter physics
In the same journal
Journal of Synchrotron Radiation
Structural Biology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 651 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf