Related Experiment Video
Updated: Dec 23, 2025

Achieving Efficient Fragment Screening at XChem Facility at Diamond Light Source
Published on: May 29, 2021
Crystal-C: A Computational Tool for Refinement of Open Search Results
Hui-Yin Chang1, Andy T Kong1, Felipe da Veiga Leprevost1
1Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, United States.
Crystal-C is a new computational tool that removes artifacts from open search results in shotgun proteomics. This improves the detection of true post-translational modifications by simplifying data analysis.
Area of Science:
- Proteomics
- Mass Spectrometry
- Computational Biology
Background:
- Shotgun proteomics with LC-MS identifies post-translational modifications (PTMs).
- Open search strategies in proteomics increase the detection of PTMs and chemical modifications.
- Artifacts like missed cleavages and chimeric spectra can be mistaken for true modifications in open search results.
Purpose of the Study:
- To develop a computational tool, Crystal-C, for detecting and removing artifacts from open search results in shotgun proteomics.
- To enhance the accuracy and interpretability of PTM analysis using open search data.
Main Methods:
- Development of the Crystal-C computational tool.
- Application of Crystal-C to analyze shotgun proteomics data.
- Evaluation of Crystal-C's performance in identifying and removing artifacts.
Main Results:
- Crystal-C effectively detects and removes artifacts from open search data.
- The number of artifacts in typical shotgun proteomics datasets is relatively small.
- Removal of artifacts simplifies mass shift histogram interpretation.
Conclusions:
- Crystal-C improves the reliability of open search in proteomics.
- The tool enhances the ability to identify true post-translational and chemical modifications.
- Crystal-C facilitates more accurate downstream analysis and discovery in proteomics research.
Related Concept Videos
Crystal Growth: Principles of Crystallization
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Recrystallization: Solid–Solution Equilibria
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
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...
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...

