The Origin of Ultrafast Multiphasic Dynamics in Photoisomerization of Bacteriophytochrome.

ABSTRACT: Red-light bacteriophytochromes regulate many physiological functions through photoisomerization of a linear tetrapyrrole chromophore. In this work, we mapped out femtosecond-resolved fluorescence spectra of the excited Pr state and observed unique active-site relaxations on the picosecond time scale with unusual spectral tuning of rises on the blue side and decays on the red side of the emission. We also observed initial wavepacket dynamics in femtoseconds with two low-frequency modes of 38 and 181 cm^-1 as well as the intermediate product formation after isomerization in hundreds of picoseconds. With critical mutations at the active site, we observed similar dynamic patterns with different times for both relaxation and isomerization, consistent with the structural and chemical c

SUBMITTER: Wang D 

PROVIDER: S-EPMC8172095 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature