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Computer simulations of radiation damage in protein crystals; Simulationsrechnungen zu Strahlenschaeden an Proteinkristallen

Abstract

The achievable resolution and the quality of the dataset of an intensity data collection for structure analysis of protein crystals with X-rays is limited among other factors by radiation damage. The aim of this work is to obtain a better quantitative understanding of the radiation damage process in proteins. Since radiation damage is unavoidable it was intended to look for the optimum ratio between elastically scattered intensity and radiation damage. Using a Monte Carlo algorithm physical processes after an inelastic photon interaction are studied. The main radiation damage consists of ionizations of the atoms through the electron cascade following any inelastic photon interaction. Results of the method introduced in this investigation and results of an earlier theoretical studies of the influence of Auger-electron transport in diamond are in a good agreement. The dependence of the radiation damage as a function of the energy of the incident photon was studied by computer-aided simulations. The optimum energy range for diffraction experiments on the protein myoglobin is 10-40 keV. Studies of radiation damage as a function of crystal volume and shape revealed that very small plate or rod shaped crystals suffer less damage than crystals formed like a cube with the same volume.  More>>
Authors:
Publication Date:
Mar 15, 2007
Product Type:
Thesis/Dissertation
Report Number:
DESY-THESIS-2007-006
Resource Relation:
Other Information: TH: Diss.
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTALS; ALGORITHMS; IONIZATION; X-RAY DIFFRACTION; MYOGLOBIN; COMPUTERIZED SIMULATION; PHYSICAL RADIATION EFFECTS; MONTE CARLO METHOD; ELECTRON-ATOM COLLISIONS; CASCADE SHOWERS; PHOTON-MOLECULE COLLISIONS; AUGER EFFECT; ENERGY DEPENDENCE; KEV RANGE 10-100; CHARGED-PARTICLE TRANSPORT
OSTI ID:
20855538
Research Organizations:
Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Fachbereich 12 - Physik
Country of Origin:
Germany
Language:
German
Other Identifying Numbers:
Other: ISSN 1435-8085; TRN: DE07F4373
Availability:
Commercial reproduction prohibited; INIS; OSTI as DE20855538
Submitting Site:
DEN
Size:
177 pages
Announcement Date:
Apr 12, 2007

Citation Formats

Zehnder, M. Computer simulations of radiation damage in protein crystals; Simulationsrechnungen zu Strahlenschaeden an Proteinkristallen. Germany: N. p., 2007. Web.
Zehnder, M. Computer simulations of radiation damage in protein crystals; Simulationsrechnungen zu Strahlenschaeden an Proteinkristallen. Germany.
Zehnder, M. 2007. "Computer simulations of radiation damage in protein crystals; Simulationsrechnungen zu Strahlenschaeden an Proteinkristallen." Germany.
@misc{etde_20855538,
title = {Computer simulations of radiation damage in protein crystals; Simulationsrechnungen zu Strahlenschaeden an Proteinkristallen}
author = {Zehnder, M}
abstractNote = {The achievable resolution and the quality of the dataset of an intensity data collection for structure analysis of protein crystals with X-rays is limited among other factors by radiation damage. The aim of this work is to obtain a better quantitative understanding of the radiation damage process in proteins. Since radiation damage is unavoidable it was intended to look for the optimum ratio between elastically scattered intensity and radiation damage. Using a Monte Carlo algorithm physical processes after an inelastic photon interaction are studied. The main radiation damage consists of ionizations of the atoms through the electron cascade following any inelastic photon interaction. Results of the method introduced in this investigation and results of an earlier theoretical studies of the influence of Auger-electron transport in diamond are in a good agreement. The dependence of the radiation damage as a function of the energy of the incident photon was studied by computer-aided simulations. The optimum energy range for diffraction experiments on the protein myoglobin is 10-40 keV. Studies of radiation damage as a function of crystal volume and shape revealed that very small plate or rod shaped crystals suffer less damage than crystals formed like a cube with the same volume. Furthermore the influence of a few heavy atoms in the protein molecule on radiation damage was examined. Already two iron atoms in the unit cell of myoglobin increase radiation damage significantly. (orig.)}
place = {Germany}
year = {2007}
month = {Mar}
}