scholarly journals X-ray Laue diffraction from crystals of xylose isomerase.

1988 ◽  
Vol 85 (1) ◽  
pp. 112-115 ◽  
Author(s):  
G. K. Farber ◽  
P. Machin ◽  
S. C. Almo ◽  
G. A. Petsko ◽  
J. Hajdu
Author(s):  
Ali Abboud ◽  
Ali AlHassan ◽  
Benjamin Dönges ◽  
Jean Sebastian Micha ◽  
Robert Hartmann ◽  
...  

2011 ◽  
Vol 44 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Catherine Dejoie ◽  
Martin Kunz ◽  
Nobumichi Tamura ◽  
Colin Bousige ◽  
Kai Chen ◽  
...  

Although the spectrum originating from a superconducting bending magnet is quasi-continuous, it shows important intensity variations through its spectral range. A method to determine the incident energy-dependent flux variation based on the comparison between observed intensities and the calculated intensities of a well known structure (calcite) is presented here. It is found that the measured flux is highly sensitive to the use of correct Debye–Waller factors for the atoms of the standard crystal. By using the measured flux curve, it was possible to unambiguously index the Laue diffraction pattern of a trigonal crystal structure in its hexagonal setting. This is a crucial but difficult first step for the determination of strain and stress in materials with this symmetry, such as quartz, Mg, Ti, Znetc.


1984 ◽  
Vol 259 (5) ◽  
pp. 3230-3236 ◽  
Author(s):  
H L Carrell ◽  
B H Rubin ◽  
T J Hurley ◽  
J P Glusker

1973 ◽  
Vol 19 (1) ◽  
pp. 319-330 ◽  
Author(s):  
A. N. Gureev ◽  
G. I. Gudzenko ◽  
L. I. Datsenko ◽  
V. B. Molodkin
Keyword(s):  

2019 ◽  
Vol 26 (4) ◽  
pp. 931-944 ◽  
Author(s):  
Helena Taberman ◽  
Charles S. Bury ◽  
Mark J. van der Woerd ◽  
Edward H. Snell ◽  
Elspeth F. Garman

Xylose isomerase (XI) is an industrially important metalloprotein studied for decades. Its reaction mechanism has been postulated to involve movement of the catalytic metal cofactor to several different conformations. Here, a dose-dependent approach was used to investigate the radiation damage effects on XI and their potential influence on the reaction mechanism interpreted from the X-ray derived structures. Radiation damage is still one of the major challenges for X-ray diffraction experiments and causes both global and site-specific damage. In this study, consecutive high-resolution data sets from a single XI crystal from the same wedge were collected at 100 K and the progression of radiation damage was tracked over increasing dose (0.13–3.88 MGy). The catalytic metal and its surrounding amino acid environment experience a build-up of free radicals, and the results show radiation-damage-induced structural perturbations ranging from an absolute metal positional shift to specific residue motions in the active site. The apparent metal movement is an artefact of global damage and the resulting unit-cell expansion, but residue motion appears to be driven by the dose. Understanding and identifying radiation-induced damage is an important factor in accurately interpreting the biological conclusions being drawn.


A transiently stable intermediate in trypsin catalysis, guanidinobenzoyl-Ser-195 trypsin, can be trapped and then released by control of the pH in crystals of the enzyme. This effect has been investigated by static and dynamic white-beam Laue crystallography. Comparison of structures determined before and immediately after a pH jump reveals the nature of concerted changes that accompany activation of the enzyme. Careful analysis of the results of several structure determinations gives information about the reliability of Laue results in general. A study of multiple exposures taken under differing conditions of beam intensity, crystal quality, and temperature revealed information about ways to control damage of specimens by the X-ray beam.


2013 ◽  
Vol 110 (11) ◽  
Author(s):  
A. J. Comley ◽  
B. R. Maddox ◽  
R. E. Rudd ◽  
S. T. Prisbrey ◽  
J. A. Hawreliak ◽  
...  

1994 ◽  
Vol 27 (1) ◽  
pp. 13-19 ◽  
Author(s):  
W. Zhou ◽  
R. Wang ◽  
J. Gui ◽  
J. Zhao ◽  
J. Jiang

Author(s):  
A. M. Afanas'ev ◽  
R. M. Imamov ◽  
E. Kh. Mukhamedzhanov ◽  
A. N. Chuzo

A simple relation has been established between the Fourier component of the probability density P(z) of photoelectron emission from different depths of a crystal and the angular dependence of the emission of photoelectrons formed in inclined X-ray Laue diffraction, which for the first time permitted the use of a direct method for the reconstruction of the P(z) function. Accurate measurements of the angular dependence of photoelectron emission were carried out on a silicon single crystal with diffraction of Cu Kα radiation for different energy ranges. Photoelectrons were recorded by a proportional gas counter specially designed for the energy analysis of photoelectrons under inclined Laue diffraction conditions. The laws predicted by the theory have been fully confirmed, and the corresponding P(z) functions have been obtained.


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