Related Experiment Video
Updated: Jan 4, 2026

Optimization of Crystal Growth for Neutron Macromolecular Crystallography
Published on: March 13, 2021
Solvent flows, conformation changes and lattice reordering in a cold protein crystal
David W Moreau1, Hakan Atakisi1, Robert E Thorne1
1Physics Department, Cornell University, Ithaca, NY 14853, USA.
Cooling protein crystals causes unit-cell contraction and solvent expulsion, increasing mosaicity. Subsequent solvent re-entry and conformational changes at low temperatures reduce mosaicity, highlighting the role of solvent dynamics in protein crystal behavior.
Area of Science:
- Crystallography
- Structural Biology
- Biophysics
Background:
- Protein crystal cooling can induce unit-cell contraction and solvent redistribution.
- Solvent outflow from unit cells has been hypothesized to increase crystal mosaicity.
- Understanding these dynamic processes is crucial for variable-temperature crystallography.
Purpose of the Study:
- To investigate the dynamic response of apoferritin crystals to abrupt cooling.
- To elucidate the relationship between solvent flow, conformational changes, and crystal mosaicity.
- To explore the feasibility of studying cold denaturation mechanisms at low temperatures.
Main Methods:
- Variable-temperature X-ray crystallography of apoferritin crystals.
- Monitoring unit-cell parameters, solvent-cavity volumes, and crystal mosaicity.
- Observing temperature-dependent structural relaxations over time.
Main Results:
- Abrupt cooling of apoferritin crystals to 220-260 K caused unit-cell contraction and increased mosaicity due to solvent outflow.
- Over 10-200 seconds, unit-cell and solvent-cavity volumes expanded, with solvent re-entering the crystal.
- This reordering led to decreased mosaicity and B-factor, associated with large-scale conformational changes.
Conclusions:
- Increased mosaicity upon cooling results from solvent flow and incomplete protein conformational relaxation.
- Time-dependent solvent dynamics play a critical role in variable-temperature crystallographic studies.
- These findings enable the study of cold denaturation mechanisms in protein crystals near 200 K.
More Related Videos
Related Concept Videos
Recrystallization: Solid–Solution Equilibria
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...
Structures of Solids
Phase Transitions: Melting and Freezing
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Solution Equilibrium and Saturation

