Related Experiment Videos
The "speed limit" for macromolecular crystal growth
Renee J Arias1, Jens T Kaiser1, Douglas C Rees1,2
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, 91125.
Protein Science : a Publication of the Protein Society
|July 30, 2018
Summary
A simple model shows macromolecular crystal growth is limited by diffusion. This suggests micron-sized crystals can form rapidly, enabling enzyme studies with advanced imaging techniques.
Area of Science:
- Crystallography
- Biophysics
- Biochemistry
Background:
- Macromolecular crystallization is crucial for structural biology.
- Understanding crystal growth kinetics is essential for optimizing crystal size and quality.
- Current methods may not yield crystals suitable for advanced imaging techniques.
Purpose of the Study:
- To develop and validate a model for diffusion-limited crystal growth.
- To determine the upper limit of crystal growth rates.
- To explore the implications for crystallizing enzymes for structural studies.
Main Methods:
- A simple "diffusion-to-capture" model was employed.
- The model's prediction of linear area increase over time was tested.
- Lysozyme crystal growth rates were monitored experimentally.
Main Results:
- The diffusion-to-capture model accurately predicts linear crystal area increase over time under diffusion-limited conditions.
- Experimental validation using lysozyme crystals confirmed the model's predictions.
- The model indicates that micron-sized crystals can form in approximately 1 second.
Conclusions:
- Crystal growth rate is limited by mass transfer (diffusion) from solution.
- Rapid formation of micron-sized crystals is achievable under diffusion-limited conditions.
- This rapid crystallization is compatible with enzyme turnover times and enables trapping of intermediate states using X-ray Free Electron Lasers and micro-electron diffraction.