2020-01-10 11:00 ~ 2020-01-10 12:00
地點: 生化所209室
主講人: Dr. Jörg Standfuss
主講人背景: 瑞士保羅謝爾研究所生物與化學研究所副主任
演講主持人: 蔡明道特聘研究員
演講摘要:
X-ray free electron lasers offer exciting new opportunities to study the structural dynamics of light-sensitive proteins by time-resolved serial crystallography. It is now possible to determine whole series of structural snapshots at high spatial resolution and at precise time delays after activation to assemble them into flipbook-like movies of proteins in action. Based on our studies of the light-driven proton pump bacteriorhodopsin (bR), I will outline the possibilities but also the challenges that have to be overcome before we can routinely study atomic rearrangements in proteins at ambient temperature and in real time. One of the current bottlenecks is that access to X-ray lasers will remain scarce for the foreseeable future. To allow experiments at synchrotron sources, we have adapted high viscosity injector systems to carry out routine room-temperature serial millisecond crystallography at the Swiss Light Source (SLS) (1, 2). First pilot experiments at the Swiss Free Electron Laser (SwissFEL) highlight the importance of careful sample preparation to make the most of the new femtosecond X-ray laser sources. Molecular movies of structural changes prepared from 42 structural snapshots ranging from the femtosecond to the millisecond regime allowed us to study energy capture and proton transfer steps in bR with astounding detail (2-4). The sequential rearrangements throughout the bR photocycle follow the basic predictions of an alternate access model and provide a template to understand the principal transport steps in other membrane pumps. In the remaining time, I will describe our progress in using SwissFEL to resolve the structural dynamics of a light-driven cation pump and a visual G protein-coupled receptor. References 1. Weinert T, et al. (2017) Serial millisecond crystallography for routine room-temperature structure determination at synchrotrons. Nature Communications 8(1):542. 2. Weinert T, et al. (2019) Proton uptake mechanism in bacteriorhodopsin captured by serial synchrotron crystallography. Science 365(6448):61–65. 3. Nogly P, et al. (2018) Retinal isomerization in bacteriorhodopsin captured by a femtosecond X-ray laser. Science aat0094 :10.1126–science.aat0094. 4. Nango E, et al. (2016) A three-dimensional movie of structural changes in bacteriorhodopsin. Science 354(6319):1552–1557. -Dr. Jörg Standfuss
洽詢人員: 劉小姐
洽詢電話: 02-27855696#2061
洽詢信箱: liukchun@gate.sinica.edu.tw
中央研究院 生物化學研究所
