Automated electron microscopy for evaluating two-dimensional crystallization of membrane proteins

Area of Science:

• Structural Biology
• Biophysics
• Biochemistry

Background:

• Membrane proteins are vital cellular components and drug targets.
• Determining membrane protein structures is challenging.
• Electron microscopy of 2D crystals offers visualization in native environments but is underutilized.

Purpose of the Study:

• To develop a high-throughput system for screening 2D crystallization conditions of membrane proteins.
• To enhance the efficiency of electron crystallography for structural genomics.

Main Methods:

• A robotic system (SCARA and Cartesian robots) was developed for automated sample loading into a JEOL 1230 electron microscope.
• The microscope holder and airlock were modified for robotic control.
• A custom computer program integrated with Leginon software enabled automated imaging of individual samples.
• Images were stored in the Sesame laboratory information management system.

Main Results:

• Successful implementation of an automated electron microscopy system for screening 2D crystallization.
• Demonstrated feasibility of high-throughput imaging for membrane protein crystallization trials.
• Integration of robotics, microscopy software, and a database for efficient data management.

Conclusions:

• The developed automated system significantly improves the throughput of electron crystallography screening.
• This advancement facilitates the structure determination of membrane proteins, aiding drug discovery efforts.
• The system increases the likelihood of obtaining well-ordered crystals for atomic resolution analysis.