Search results for "PHOTOCYCLE"
showing 3 items of 3 documents
Femtosecond structural dynamics drives the trans/cis isomerization in photoactive yellow protein
2016
Many biological processes depend on detecting and responding to light. The response is often mediated by a structural change in a protein that begins when absorption of a photon causes isomerization of a chromophore bound to the protein. Pande et al. used x-ray pulses emitted by a free electron laser source to conduct time-resolved serial femtosecond crystallography in the time range of 100 fs to 3 ms. This allowed for the real-time tracking of the trans-cis isomerization of the chromophore in photoactive yellow protein and the associated structural changes in the protein.Science, this issue p. 725A variety of organisms have evolved mechanisms to detect and respond to light, in which the re…
Photocycle of Excitons in Nitrogen-Rich Carbon Nanodots: Implications for Photocatalysis and Photovoltaics
2020
Nitrogen-rich carbon nanodots have emerged as promising nanomaterials for a wide range of applications where a highly emissive and photoactive material with low toxicity and cost-effectiveness is required. One of their hallmarks is indeed a bright, tunable fluorescence of excitonic nature. Disentangling the origin of their optical absorption and fluorescence properties and uncovering relaxation channels and interactions with solvents are some of the most debated issues in the field. Uncovering these aspects is essential for targeted applications, especially in the fields of photocatalysis but also photovoltaics and optoelectronics. Here, we present dedicated transient absorption measurement…
Photoinduced changes in phytochromes studied by means of low temperature UV-Vis spectroscopy
2018
Phytochromes are a major family of red-light-sensing kinases that control diverse cellular functions in plants, bacteria and fungi. These proteins must relay structural signals from the sensory site over large distances to regulatory output domains. To accomplish this function, they undergo rather large structural changes from one state to another. The general aim of this work was to study these structural changes and possible protonation states of the photosensory core of the bacteriophytochrome from Deinococcus radiodurans in the intermediate states of the photoreaction, which became possible to observe under low temperatures. Moreover, it was interesting to investigate the role Serine272…