We report a transient signature in the near-UV absorption of rhodopsin 2 (KR2), which spans from the femtosecond up to the millisecond time scale. The signature rises with the all- to 13- isomerization of retinal and decays with the reisomerization to all- in the late photocycle, making it a promising marker band for retinal configuration. Hybrid quantum mechanics/molecular mechanics simulations show that the near-UV absorption signal corresponds to an S → S and/or an S → S transition, which is present in all photointermediates. These transitions exhibit a negligible spectral shift by the altering protein environment, in contrast to the main absorption band. This is rationalized by the extension of the transition densities that omits the Schiff base nitrogen. Further characterization and first steps into possible optogenetic applications were performed with near-UV quenching experiments of an induced photostationary state, yielding an ultrafast regeneration of the parent state of KR2.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.1c01436 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dissociation of adsorbates electronic energy transfer from aromatic thin films.
Phys Chem Chem Phys
January 2025
Department of Physics, University of Northern BC, Canada.
Photofragment translational spectroscopy has been used to characterize the energetics and the cross sections for photodissociation of CHI and CFI adsorbed on thin films of a variety of aromatic molecules, initiated by near-UV light. Thin films (nominally 10 monolayers) of benzene, five substituted benzenes and two naphthalenes have been employed to study systematic changes in the photochemical activity. Illumination of these systems with 248 nm light is found to result in a dissociation process for the CHI and CFI mediated by initial absorption in the aromatic thin film, followed by electronic energy transfer (EET) to the dissociating species.
View Article and Find Full Text PDFDivalent Intermediates in Lanthanide-Based Photocatalysts: Spectroscopic Characterization and Reactivity.
Inorg Chem
December 2024
Department of Chemistry, Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden.
The reduction of stable trivalent lanthanide species (Ln(III)) by the excited states of organic chromophores is the basis of photocatalytic divalent lanthanide-mediated reduction reactions. While indirect evidence of the photochemical formation of the reactive Ln(II) species is abundant, direct spectroscopic evidence of their presence is scarce. Here, nine chromophores with absorptions covering the near UV and visible ranges were systematically investigated in the presence of Ln(III) ions to evaluate their ability to reduce Eu(III) upon excitation with visible light to the catalytically active Eu(II) species.
View Article and Find Full Text PDFIncarcerating bismuth nanoparticles into a thiol-laced metal-organic framework for electro and photocatalysis.
Mater Horiz
December 2024
Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Republic of Singapore.
Article Synopsis
- * The incorporation of Bi nanoparticles is facilitated by thiol groups, which help bind bismuth precursors and control nanoparticle growth, leading to a composite structure with enhanced catalytic properties.
- * The BiNP@Zr-DMBD-1 composite exhibited high efficiency for CO electroreduction and showed effective degradation of methylene blue dye under blue LED light, demonstrating its potential for various catalytic applications.
Acridone Derivatives for Near-UV Radical Polymerization: One-Component Type II vs. Multicomponent Behaviors.
Molecules
October 2024
CNRS, IS2M UMR 7361, Université de Haute-Alsace, F-68100 Mulhouse, France.
In this work, two novel acridone-based photoinitiators were designed and synthesized for the free radical polymerization of acrylates with a light-emitting diode emitting at 405 nm. These acridone derivatives were employed as mono-component Type II photoinitiators and as multicomponent photoinitiating systems in the presence of an iodonium salt or an amine synergist (EDB) in which they achieved excellent polymerization initiating abilities and high final conversions of the acrylate group. Photoinitiation mechanisms through which reactive species are produced were investigated employing different complementary techniques including steady-state photolysis, steady-state fluorescence, cyclic voltammetry, UV-visible absorption spectroscopy, and electron spin resonance spectroscopy.
View Article and Find Full Text PDFNovel Eu-Doped Glasses in the MoO-WO-LaO-BO System: Preparation, Structure and Photoluminescent Properties.
Molecules
October 2024
Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188, Japan.
Novel multicomponent glasses with nominal compositions of (50-x)MoO:xWO:25LaO:25BO, x = 0, 10, 20, 30, 40, 50 mol% doped with 3 mol % EuO were prepared using a conventional melt-quenching method. Their structure, thermal behavior and luminescent properties were investigated by Raman spectroscopy, differential thermal analysis and photoluminescence spectroscopy. The optical properties of the glasses were investigated by UV-vis absorption spectroscopy and a determination of the refractive index.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!