Time-resolved serial femtosecond crystallography reveals early structural changes in channelrhodopsin

X線自由電子レーザーを用いて、光照射によるチャネルロドプシンの構造変化の過程を捉えることに成功. 京都大学プレスリリース. 2021-03-26.Channelrhodopsins (ChRs) are microbial light-gated ion channels utilized in optogenetics to control neural activity with light . Light absorption causes retinal chromophore isomerization and subsequent protein conformational changes visualized as optically distinguished intermediates, coupled with channel opening and closing. However, the detailed molecular events underlying channel gating remain unknown. We performed time-resolved serial femtosecond crystallographic analyses of ChR by using an X-ray free electron laser, which revealed conformational changes following photoactivation. The isomerized retinal adopts a twisted conformation and shifts toward the putative internal proton donor residues, consequently inducing an outward shift of TM3, as well as a local deformation in TM7. These early conformational changes in the pore-forming helices should be the triggers that lead to opening of the ion conducting pore

Wide Area Ray-Launching for Pilot Pollution Analyses using Adaptive Object Selection

Abstract: We propose a new method of ray-launching estimation for high-speed and highly accurate analysis of pilot pollution, which often occurs in the upper floors of high-rise buildings. Our method simulates radio signals that reach from distant base stations much faster than a conventional raylaunching method. The mechanism of the fast calculation is due to an adaptive object selection approach, which excludes objects that have limited effects on a radio environment in the upper floors of high-rise buildings. It is confirmed that our method can make a calculation more than 20 times faster than a conventional ray-launching method with almost the same accuracy for the case with high base station antennas

Terfenadine induces thymocyte apoptosis via mitochondrial pathway

NRC publication: Ye