Related Experiment Video
Updated: Jul 10, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Estimates of the twinning fraction for macromolecular crystals using statistical models accounting for experimental
Vladimir Y Lunin1, Natalia L Lunina, Manfred W Baumstark
1Institute of Mathematical Problems of Biology, Russian Academy of Sciences, Pushchino 142290, Russia.
Abstract:
An advanced statistical model is suggested that is designed to estimate the twinning fraction in merohedrally (or pseudo-merohedrally) twinned crystals. The model takes experimental errors of the measured intensities into account and is adapted to the accuracy of a particular X-ray experiment through the standard deviations of the reflection intensities. The theoretical probability distributions for the improved model are calculated using a Monte Carlo-type simulation procedure. The use of different statistical criteria (including likelihood) to estimate the optimal twinning-fraction value is discussed. The improved model enables better agreement of theoretical and observed cumulative distribution functions to be obtained and produces twinning-fraction estimates that are closer to the refined values in comparison to the conventional model, which disregards experimental errors. The results of the two approaches converge when applied to selected subsets of measured intensities of high accuracy.
More Related Videos
11:48Microfluidic Chips for In Situ Crystal X-ray Diffraction and In Situ Dynamic Light Scattering for Serial Crystallography
Published on: April 24, 2018
10:45Crystallization and Structural Determination of an Enzyme:Substrate Complex by Serial Crystallography in a Versatile Microfluidic Chip
Published on: March 20, 2021
Related Concept Videos
Determination of Crystal Structures
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Imperfections in Crystal Structure: Stoichiometric Point Defects
Imperfections in Crystal Structure: Non-Stoichiometric Defects