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23 results on '"Agathangelou, Damianos"'

1. Sub-picosecond C$=$C bond photo-isomerization: evidence for the role of excited state mixing

Author

Agathangelou, Damianos, Roy, Partha Pratim, del Carmen Marín, María, Ferré, Nicolas, Olivucci, Massimo, Buckup, Tiago, Léonard, Jérémie, and Haacke, Stefan

Subjects
Photo-isomerisation, Retinal proteins, Chromophore–protein coupling, Non-adiabatic dynamics, Photo-sensory proteins, Charge transfer state, Physics, QC1-999
Abstract

Sub-picosecond photo-isomerization is the major primary process of energy conversion in retinal proteins and has as such been in the focus of extensive theoretical and experimental work over the past decades. In this review article, we revisit the long-standing question as to how the protein tunes the isomerization speed and quantum yield. We focus on our recent contributions to this field, which underscore the concept of a delicate mixing of reactive and non-reactive excited states, as a result of steric properties and electrostatic interactions with the protein environment. Further avenues and new approaches are outlined which hold promise for advancing our understanding of these intimately coupled chromophore–protein systems.

Published
2021
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2. Phase-Modulated Rapid-Scanning Fluorescence-Detected Two-Dimensional Electronic Spectroscopy

Author

Agathangelou, Damianos, Javed, Ariba, Sessa, Francesco, Solinas, Xavier, Joffre, Manuel, and Ogilvie, Jennifer P.

Subjects
Physics - Optics, Condensed Matter - Other Condensed Matter, Physics - Chemical Physics
Abstract

We present a rapid-scanning approach to fluorescence-detected two-dimensional electronic spectroscopy that combines acousto-optic phase-modulation with digital lock-in detection. The approach shifts the signal detection window to suppress 1/f laser noise and enables interferometric tracking of the time delays to allow for correction of spectral phase distortions and accurate phasing of the data. This use of digital lock-in detection enables acquisition of linear and nonlinear signals of interest in a single measurement. We demonstrate the method on a laser dye, measuring the linear fluorescence excitation spectrum, as well as rephasing, non-rephasing and absorptive fluorescence-detected two-dimensional electronic spectra.

Published
2021
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5. Sub-picosecond C=C bond photo-isomerization: Evidence for the role of excited state mixing

Author

Agathangelou, Damianos, Pratim, Partha, del Carmen Marín, María, Ferré, Nicolas, Olivucci, Massimo, Buckup, Tiago, Léonard, Jérémie, Haacke, Stefan, Haacke, Stefan, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Universität Heidelberg, Department of Biotechnology Chemistry and Pharmacy (University of Siena), University of Siena, Institut de Chimie Radicalaire (ICR), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Chimica, Università degli Studi di Siena = University of Siena (UNISI), and Universität Heidelberg [Heidelberg]

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.PHYS.PHYS-CHEM-PH] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Published
2020

6. Engineering the vibrational coherence of vision into a synthetic molecular device

Author

Gueye, Moussa, Manathunga, Madushanka, Agathangelou, Damianos, Orozco, Yoelvis, Paolino, Marco, Fusi, Stefania, Haacke, Stefan, Olivucci, Massimo, Leónard, Jérémie, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Department of Chemistry, Bowling Green State University, and Dipartimento di Biotechnologie, Chimica e Farmacia, Università di Siena

Subjects
Genetics and Molecular Biology (all), Rhodopsin, Alkylation, Light, Science, Biochemistry, Vibration, Article, Physics and Astronomy (all), Biomimetic Materials, Physics::Atomic and Molecular Clusters, Animals, Humans, Pyrroles, Physics::Chemical Physics, lcsh:Science, Vision, Ocular, ComputingMilieux_MISCELLANEOUS, Quantitative Biology::Biomolecules, Spectrum Analysis, Chemistry (all), Optical Devices, Chemical Engineering, Photochemical Processes, Indans, Retinaldehyde, Quantum Theory, lcsh:Q, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Biochemistry, Genetics and Molecular Biology (all)
Abstract

The light-induced double-bond isomerization of the visual pigment rhodopsin operates a molecular-level optomechanical energy transduction, which triggers a crucial protein structure change. In fact, rhodopsin isomerization occurs according to a unique, ultrafast mechanism that preserves mode-specific vibrational coherence all the way from the reactant excited state to the primary photoproduct ground state. The engineering of such an energy-funnelling function in synthetic compounds would pave the way towards biomimetic molecular machines capable of achieving optimum light-to-mechanical energy conversion. Here we use resonance and off-resonance vibrational coherence spectroscopy to demonstrate that a rhodopsin-like isomerization operates in a biomimetic molecular switch in solution. Furthermore, by using quantum chemical simulations, we show why the observed coherent nuclear motion critically depends on minor chemical modifications capable to induce specific geometric and electronic effects. This finding provides a strategy for engineering vibrationally coherent motions in other synthetic systems., The ultrafast, vibrationally coherent photoisomerization of rhodopsin is a model of efficient photomechanical energy conversion at the molecular scale. Here, the authors demonstrate a similar photoreaction in synthetic compounds, unraveling the underlying mechanism and discussing its implications.

Published
2018

8. Anabena sensory rhodospin : l'impact de mutations sur la dynamique ultra-rapide de la photo-isomerization

Author

Agathangelou, Damianos, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg, and Stefan Haacke

Subjects
Isomerization, Lasers, Proteins, Two dimensional electronic spectroscopy, Excited state lifetime, Protéines, Durée de vie excitée, Vibrational modes, Isomérisation, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Modes de vibration, Spectroscopie d'absorption transitoire, Transient absorption spectroscopy, Spectroscopie électronique bidimensionnelle, Mutations
Abstract

ASR, is a photoreceptor protein that binds the protonated Schiff base of retinal in two ground state conformations. The particular protein consists a model system where the effect of the protein environment on the isomerization dynamics of the two isomers can be investigated. In this thesis an extended study on point mutated proteins is presented where the variable is the protein environment. The results show significant differences between the two isomers excited state lifetimes with the shorter or longer lifetimes commented in terms of Sl/S2 electronic mixing. Supplementary, the experimental development of a Transient absorption spectrometer (T.A) and a Two-dimensional electronic spectroscopy setup (2DES) operating in the NIR and UV-Vis spectral range respectively are described. The 2DES spectrometer is based on translating wedges made out of birefringent material producing two collinear phase-locked pulses with sub-I Ofs duration. The interferometric precision on controlling the delay between the two pump pulses allows to perform 2DES measurements on systems absorbing in the 360-430 nm range allowing to resolve the excitation process spectrally.; ASR, est une protéine photo réceptrice qui lie la base protonée de la rétine de Schiff dans deux conformations de l'état fondamental. La protéine particulière consiste en un système modèle dans lequel I'effet de l'environnement protéique sur la dynamique d'isomérisation des deux isomères peut être étudié. Dans cette thèse, une étude approfondie sur les protéines mutées ponctuellement est présentée, où la variable est l'environnement protéique. Les résultats montrent des différences significatives entre les durées de vie des états excités des deux isomères et les durées de vie plus courtes ou plus longues commentées en termes de mélange électronique Sl/S2. En complément, le développement expérimental d'un spectromètre à absorption transitoire (T.A) et d'un dispositif de spectroscopie électronique bidimensionnelle (2DES) fonctionnant respectivement dans les domaines spectral NIR et UV-Vis. Avec cette configuration, deux impulsions colinéaires à verrouillage de phase d'une durée inférieure à 10fs sont générées, où. la précision interférométrique sur le contrôle du retard entre les deux impulsions de pompe permet d'effectuer des mesures 2DES.

Published
2019

9. Anabaena Sensory Rhodopsin : effect of mutations on the ultrafast photo-isomerization dynamics

Author

Agathangelou, Damianos, STAR, ABES, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, and Stefan Haacke

Subjects
Isomerization, Lasers, Proteins, Two dimensional electronic spectroscopy, Excited state lifetime, Protéines, Durée de vie excitée, Vibrational modes, Isomérisation, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Modes de vibration, [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry, Spectroscopie d'absorption transitoire, Transient absorption spectroscopy, Spectroscopie électronique bidimensionnelle, Mutations
Abstract

ASR, is a photoreceptor protein that binds the protonated Schiff base of retinal in two ground state conformations. The particular protein consists a model system where the effect of the protein environment on the isomerization dynamics of the two isomers can be investigated. In this thesis an extended study on point mutated proteins is presented where the variable is the protein environment. The results show significant differences between the two isomers excited state lifetimes with the shorter or longer lifetimes commented in terms of Sl/S2 electronic mixing. Supplementary, the experimental development of a Transient absorption spectrometer (T.A) and a Two-dimensional electronic spectroscopy setup (2DES) operating in the NIR and UV-Vis spectral range respectively are described. The 2DES spectrometer is based on translating wedges made out of birefringent material producing two collinear phase-locked pulses with sub-I Ofs duration. The interferometric precision on controlling the delay between the two pump pulses allows to perform 2DES measurements on systems absorbing in the 360-430 nm range allowing to resolve the excitation process spectrally., ASR, est une protéine photo réceptrice qui lie la base protonée de la rétine de Schiff dans deux conformations de l'état fondamental. La protéine particulière consiste en un système modèle dans lequel I'effet de l'environnement protéique sur la dynamique d'isomérisation des deux isomères peut être étudié. Dans cette thèse, une étude approfondie sur les protéines mutées ponctuellement est présentée, où la variable est l'environnement protéique. Les résultats montrent des différences significatives entre les durées de vie des états excités des deux isomères et les durées de vie plus courtes ou plus longues commentées en termes de mélange électronique Sl/S2. En complément, le développement expérimental d'un spectromètre à absorption transitoire (T.A) et d'un dispositif de spectroscopie électronique bidimensionnelle (2DES) fonctionnant respectivement dans les domaines spectral NIR et UV-Vis. Avec cette configuration, deux impulsions colinéaires à verrouillage de phase d'une durée inférieure à 10fs sont générées, où. la précision interférométrique sur le contrôle du retard entre les deux impulsions de pompe permet d'effectuer des mesures 2DES.

Published
2019

13. Fluorescence Enhancement of a Microbial Rhodopsin via Electronic Reprogramming

Author

Marín, María del Carmen, primary, Agathangelou, Damianos, additional, Orozco-Gonzalez, Yoelvis, additional, Valentini, Alessio, additional, Kato, Yoshitaka, additional, Abe-Yoshizumi, Rei, additional, Kandori, Hideki, additional, Choi, Ahreum, additional, Jung, Kwang-Hwan, additional, Haacke, Stefan, additional, and Olivucci, Massimo, additional

Published
2018
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17. An Average Solvent Electrostatic Configuration Protocol for QM/MM Free Energy Optimization: Implementation and Application to Rhodopsin Systems

Author

Orozco-Gonzalez, Yoelvis, primary, Manathunga, Madushanka, additional, Marín, María del Carmen, additional, Agathangelou, Damianos, additional, Jung, Kwang-Hwan, additional, Melaccio, Federico, additional, Ferré, Nicolas, additional, Haacke, Stefan, additional, Coutinho, Kaline, additional, Canuto, Sylvio, additional, and Olivucci, Massimo, additional

Published
2017
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21. High sensitivity fluorescence up-conversion spectroscopy of 3MLCT emission of metal-organic complexes.

Author

Liu, Li, Agathangelou, Damianos, Roland, Thomas, Crégut, Olivier, Duchanois, Thibaud, Beley, Marc, Léonard, Jérémie, Gros, Philippe, Haacke, Stefan, Cerullo, G., Ogilvie, J., Kärtner, F., Khalil, M., and Li, R.

Subjects
*FLUORESCENCE spectroscopy, *METAL-organic frameworks, *TRIPLET state (Quantum mechanics), *DYNAMIC range (Acoustics), *SIGNAL-to-noise ratio
Abstract

We demonstrate the implementation of a broadband fluorescence up-conversion set-up with high signal-to-noise ratio and dynamic range allowing for the detection of weak luminescence from triplet states in Fe(II) NHC complexes. Based on the experimentally determined radiative rates and the emission spectra, these states have dominant MLCT character. [ABSTRACT FROM AUTHOR]

Published
2019
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