Research Seminars @ Illinois

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Tailored for undergraduate researchers, this calendar is a curated list of research seminars at the University of Illinois. Explore the diverse world of research and expand your knowledge through engaging sessions designed to inspire and enlighten.

To have your events added or removed from this calendar, please contact OUR at ugresearch@illinois.edu

PChem Faculty Candidate: Dr. Ulrich Lorenz, EPFL, "Microsecond Time-Resolved Cryo-EM"

Event Type
Seminar/Symposium
Sponsor
Prof. Zaida Ann Luthey Schulten
Location
2021 Chemistry Annex, 601 S. Mathews Ave, Room 1024
Date
Jan 17, 2025   10:00 - 11:30 am  
Contact
Randy Prince
E-Mail
rlprince@illinois.edu
Phone
217-333-2540
Views
59
Originating Calendar
Chemistry - Physical Chemistry Seminars

While cryo-electron microscopy (cryo-EM) is rapidly gaining in popularity, its time resolution is frequently insufficient to directly observe proteins in action, leaving our understanding of these nanoscale machines fundamentally incomplete. My group has recently introduced a novel approach to time-resolved cryo-EM that improves its time resolution by about 3 orders of magnitude. Our method involves melting a cryo sample with a laser beam, which allows dynamics of the embedded particles to occur in liquid once a suitable stimulus is provided. While the dynamics occur, the heating laser is switched off at a well-defined point in time, causing the sample to rapidly recool, so that it vitrifies. The particles are thus trapped in their transient configurations, in which they can subsequently be imaged. We demonstrate that our approach affords a time resolution of 5 µs or better. Moreover, near-atomic resolution reconstructions can be obtained from revitrified samples, showing that the revitrification process leaves the protein structure intact. Finally, I will present a microsecond time-resolved pH jump experiment, in which we observe the dynamics of the capsid of CCMV, an icosahedral plant virus. These results highlight the potential of our method to fundamentally advance our understanding of protein function through direct observation of the dynamics involved

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