Ultrathin Liquid Cells for Microsecond Time-Resolved Cryo-EM

Area of Science:

• Structural Biology
• Biophysics

Background:

• Time-resolved cryo-electron microscopy (cryo-EM) aims to visualize proteins in action.
• Current limitations restrict observations to tens of microseconds due to sample instability under laser irradiation.

Purpose of the Study:

• To extend the observation window for microsecond time-resolved cryo-EM.
• To improve the spatial resolution and particle orientation in cryo-EM studies.
• To investigate protein dynamics and conformational changes at higher temporal resolutions.

Main Methods:

• Developed a method using ultrathin silicon dioxide membranes to encapsulate cryo samples.
• Implemented laser-induced temperature jumps to initiate protein dynamics.
• Applied microsecond time-resolved cryo-EM to analyze the 50S ribosomal subunit.

Main Results:

• Extended the observation window for time-resolved cryo-EM by an order of magnitude.
• Achieved near-atomic spatial resolution reconstructions.
• Eliminated preferred particle orientation issues.
• Gained new insights into the L1 stalk conformational landscape of the 50S ribosomal subunit.

Conclusions:

• Ultrathin silicon dioxide membranes significantly enhance microsecond time-resolved cryo-EM capabilities.
• This technique bridges the gap towards millisecond timescale observations.
• The method provides a powerful tool for studying dynamic biological processes at high resolution.