Chemical physics

Biology

Materials science

Cryo-electron microscopy

Computer science

Plunger

Nanotechnology

Molecular machine

Composite material

Chemistry

Biological system

Biophysics

Optoelectronics

Journal of Structural Biology

Proteins are dynamic molecules that can undergo rapid conformational rearrangements in response to stimuli. These structural changes are often critical to protein function, and thus elucidating time-dependent conformational landscapes has been a long-standing goal of structural biology. To harness the power of single particle cryo-EM methods to enable ‘time-resolved’ structure determination, we have developed a light-coupled cryo-plunger that pairs flash-photolysis of caged ligands with rapid sample vitrification. The ‘flash-plunger’ consists of a high-power ultraviolet LED coupled with focusing optics and a motorized linear actuator, enabling the user to immobilize protein targets in vitreous ice within a programmable time window – as short as tens of milliseconds – after stimulus delivery. The flash-plunger is a simple, inexpensive and flexible tool to explore short-lived conformational states previously unobtainable by conventional sample preparation methods.

Light-coupled cryo-plunger for time-resolved cryo-EM