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Kabir M, Ghosh P, Gozem S. Electronic Structure Methods for Simulating Flavin's Spectroscopy and Photophysics: Comparison of Multi-reference, TD-DFT, and Single-Reference Wave Function Methods. J Phys Chem B 2024; 128:7545-7557. [PMID: 39074870 PMCID: PMC11317985 DOI: 10.1021/acs.jpcb.4c03748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/14/2024] [Accepted: 07/22/2024] [Indexed: 07/31/2024]
Abstract
The use of flavins and flavoproteins in photocatalytic, sensing, and biotechnological applications has led to a growing interest in computationally modeling the excited-state electronic structure and photophysics of flavin. However, there is limited consensus regarding which computational methods are appropriate for modeling flavin's photophysics. We compare the energies of low-lying excited states of flavin computed with time-dependent density functional theory (TD-DFT), equation-of-motion coupled cluster (EOM-EE-CCSD), scaled opposite-spin configuration interaction [SOS-CIS(D)], multiconfiguration pair-density functional theory (MC-PDFT), and several multireference perturbation theory (MR-PT2) methods. In the first part, we focus on excitation energies of the first singlet excited state (S1) of five different redox and protonation states of flavin, with the goal of finding a suitable active space for MR-PT2 calculations. In the second part, we construct two sets of one-dimensional potential energy surfaces connecting the S0 and S1 equilibrium geometries (S0-S1 path) and the S1 (π,π*) and S2 (n,π*) equilibrium geometries (S1-S2 path). The first path therefore follows a Franck-Condon active mode of flavin while the second path maps crossings points between low-lying singlet and triplet states in flavin. We discuss the similarities and differences in the TD-DFT, EOM-EE-CCSD, SOS-CIS(D), MC-PDFT and MR-PT2 energy profiles along these paths. We find that (TD-)DFT methods are suitable for applications such as simulating the spectra of flavins but are inconsistent with several other methods when used for some geometry optimizations and when describing the energetics of dark (n,π*) states. MR-PT2 methods show promise for the simulation of flavin's low-lying excited states, but the selection of orbitals for the active space and the number of roots used for state averaging must be done carefully to avoid artifacts. Some properties, such as the intersystem crossing geometry and energy between the S1 (π,π*) and T2 (n,π*) states, may require additional benchmarking before they can be determined quantitatively.
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Affiliation(s)
- Mohammad
Pabel Kabir
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Paulami Ghosh
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
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2
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Kurle-Tucholski P, Wiebeler C, Köhler L, Qin R, Zhao Z, Šimėnas M, Pöppl A, Matysik J. Red Shift in the Absorption Spectrum of Phototropin LOV1 upon the Formation of a Semiquinone Radical: Reconstructing the Orbital Architecture. J Phys Chem B 2024; 128:4344-4353. [PMID: 38688080 PMCID: PMC11089501 DOI: 10.1021/acs.jpcb.4c00397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/22/2024] [Accepted: 04/17/2024] [Indexed: 05/02/2024]
Abstract
Flavin mononucleotide (FMN) is a ubiquitous blue-light pigment due to its ability to drive one- and two-electron transfer reactions. In both light-oxygen-voltage (LOV) domains of phototropin from the green algae Chlamydomonas reinhardtii, FMN is noncovalently bound. In the LOV1 cysteine-to-serine mutant (C57S), light-induced electron transfer from a nearby tryptophan occurs, and a transient spin-correlated radical pair (SCRP) is formed. Within this photocycle, nuclear hyperpolarization is created by the solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) effect. In a side reaction, a stable protonated semiquinone radical (FMNH·) forms undergoing a significant bathochromic shift of the first electronic transition from 445 to 591 nm. The incorporation of phototropin LOV1-C57S into an amorphous trehalose matrix, stabilizing the radical, allows for application of various magnetic resonance experiments at ambient temperatures, which are combined with quantum-chemical calculations. As a result, the bathochromic shift of the first absorption band is explained by lifting the degeneracy of the molecular orbital energy levels for electrons with alpha and beta spins in FMNH· due to the additional electron.
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Affiliation(s)
- Patrick Kurle-Tucholski
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstraße
3, D-04103 Leipzig, Germany
| | - Christian Wiebeler
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstraße
3, D-04103 Leipzig, Germany
- Institut
für Physik, Universität Augsburg, Universitätsstraße 1, D-86159 Augsburg, Germany
| | - Lisa Köhler
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstraße
3, D-04103 Leipzig, Germany
| | - Ruonan Qin
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstraße
3, D-04103 Leipzig, Germany
| | - Ziyue Zhao
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstraße
3, D-04103 Leipzig, Germany
| | - Mantas Šimėnas
- Faculty
of Physics, Vilnius University, Sauletekio 3, LT-10257 Vilnius, Lithuania
| | - Andreas Pöppl
- Felix
Bloch Institute for Solid State Physics, Universität Leipzig, Linnéstraße 5, D-04103, Leipzig, Germany
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstraße
3, D-04103 Leipzig, Germany
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3
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Le DPN, Hastings G, Gozem S. How Aqueous Solvation Impacts the Frequencies and Intensities of Infrared Absorption Bands in Flavin: The Quest for a Suitable Solvent Model. Molecules 2024; 29:520. [PMID: 38276598 PMCID: PMC10818357 DOI: 10.3390/molecules29020520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
FTIR spectroscopy accompanied by quantum chemical simulations can reveal important information about molecular structure and intermolecular interactions in the condensed phase. Simulations typically account for the solvent either through cluster quantum mechanical (QM) models, polarizable continuum models (PCM), or hybrid quantum mechanical/molecular mechanical (QM/MM) models. Recently, we studied the effect of aqueous solvent interactions on the vibrational frequencies of lumiflavin, a minimal flavin model, using cluster QM and PCM models. Those models successfully reproduced the relative frequencies of four prominent stretching modes of flavin's isoalloxazine ring in the diagnostic 1450-1750 cm-1 range but poorly reproduced the relative band intensities. Here, we extend our studies on this system and account for solvation through a series of increasingly sophisticated models. Only by combining elements of QM clusters, QM/MM, and PCM approaches do we obtain an improved agreement with the experiment. The study sheds light more generally on factors that can impact the computed frequencies and intensities of IR bands in solution.
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Affiliation(s)
- D. P. Ngan Le
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA; (D.P.N.L.); (G.H.)
| | - Gary Hastings
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA; (D.P.N.L.); (G.H.)
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
| | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA; (D.P.N.L.); (G.H.)
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4
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Wang J, Liu Y. Vibrationally resolved absorption and fluorescence spectra of flavins: A theoretical simulation in the gas phase. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202200243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jinyu Wang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry Beijing Normal University Beijing China
| | - Ya‐Jun Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry Beijing Normal University Beijing China
- Center for Advanced Materials Research Beijing Normal University Zhuhai China
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5
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Understanding flavin electronic structure and spectra. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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6
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Götze JP, Anders F, Petry S, Felix Witte J, Lokstein H. Spectral Characterization of the Main Pigments in the Plant Photosynthetic Apparatus by Theory and Experiment. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Khan E, Shukla A, Al-Hanafi MAS, Tandon P, Vangala VR. Structural insights, spectral and H-bond analyses, of nitrofurantoin-phenazine cocrystal and comparison of its chemical reactivity with other nitrofurantoin cocrystals. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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8
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Kar RK, Chasen S, Mroginski MA, Miller AF. Tuning the Quantum Chemical Properties of Flavins via Modification at C8. J Phys Chem B 2021; 125:12654-12669. [PMID: 34784473 DOI: 10.1021/acs.jpcb.1c07306] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Flavins are central to countless enzymes but display different reactivities depending on their environments. This is understood to reflect modulation of the flavin electronic structure. To understand changes in orbital natures, energies, and correlation over the ring system, we begin by comparing seven flavin variants differing at C8, exploiting their different electronic spectra to validate quantum chemical calculations. Ground state calculations replicate a Hammett trend and reveal the significance of the flavin π-system. Comparison of higher-level theories establishes CC2 and ACD(2) as methods of choice for characterization of electronic transitions. Charge transfer character and electron correlation prove responsive to the identity of the substituent at C8. Indeed, bond length alternation analysis demonstrates extensive conjugation and delocalization from the C8 position throughout the ring system. Moreover, we succeed in replicating a particularly challenging UV/Vis spectrum by implementing hybrid QM/MM in explicit solvents. Our calculations reveal that the presence of nonbonding lone pairs correlates with the change in the UV/Vis spectrum observed when the 8-methyl is replaced by NH2, OH, or SH. Thus, our computations offer routes to understanding the spectra of flavins with different modifications. This is a first step toward understanding how the same is accomplished by different binding environments.
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Affiliation(s)
- Rajiv K Kar
- Faculty II-Mathematics and Natural Sciences, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Sam Chasen
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Maria-Andrea Mroginski
- Faculty II-Mathematics and Natural Sciences, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Anne-Frances Miller
- Faculty II-Mathematics and Natural Sciences, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany.,Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
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9
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Dratch BD, Orozco-Gonzalez Y, Gadda G, Gozem S. Ionic Atmosphere Effect on the Absorption Spectrum of a Flavoprotein: A Reminder to Consider Solution Ions. J Phys Chem Lett 2021; 12:8384-8396. [PMID: 34435784 DOI: 10.1021/acs.jpclett.1c02173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This study utilizes the FMN-dependent NADH:quinone oxidoreductase from Pseudomonas aeruginosa PAO1 to investigate the effect of introducing an active site negative charge on the flavin absorption spectrum both in the absence and presence of a long-range electrostatic potential coming from solution ions. There were no observed changes in the flavin UV-visible spectrum when an active site tyrosine (Y277) becomes deprotonated in vitro. These results could only be reproduced computationally using average solvent electrostatic configuration (ASEC) QM/MM simulations that include both positive and negative solution ions. The same calculations performed with minimal ions to neutralize the total protein charge predicted that deprotonating Y277 would significantly alter the flavin absorption spectrum. Analyzing the distribution of solution ions indicated that the ions reorganize around the protein surface upon Y277 deprotonation to cancel the effect of the tyrosinate on the flavin absorption spectrum. Additional biochemical experiments were performed to test this hypothesis.
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Affiliation(s)
- Benjamin D Dratch
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | | | - Giovanni Gadda
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
- Department of Biology, Georgia State University, Atlanta, Georgia 30302, United States
- Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia 30302, United States
| | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
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10
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Gozem S, Krylov AI. The
ezSpectra
suite: An easy‐to‐use toolkit for spectroscopy modeling. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1546] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Samer Gozem
- Department of Chemistry Georgia State University Atlanta Georgia USA
| | - Anna I. Krylov
- Department of Chemistry University of Southern California Los Angeles California USA
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11
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Müller D, Dopfer O. Interaction of Alkali Ions with Flavins: Infrared and Optical Spectra of Metal–Riboflavin Complexes. J Phys Chem A 2021; 125:3146-3158. [DOI: 10.1021/acs.jpca.1c01846] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- David Müller
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany
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12
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Yusuf TL, Akintemi EO, Olagboye S, Tolufashe GF. Investigating the biological actions of some Schiff bases using density functional theory study. PHYSICAL SCIENCES REVIEWS 2021. [DOI: 10.1515/psr-2019-0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Schiff base ligands have wide varieties of application in several fields. One of which is the biological actions they possess such as anti-fungal, anti-bacterial, anti-malarial, and anti-viral characteristics. In this study, some synthesized phenylimino-based Schiff bases were investigated using density functional theory (DFT) to unravel their biological descriptors. The gas-phase quantum chemical calculation was done on the Schiff base 3-((E)-(phenylimino)methyl)benzene-1,2-diol and other synthesized analogues to evaluate their reactivity and stability properties including the substituent effect on the basic molecule. The Coulomb-attenuating method (CAM-B3LYP) functional was employed for the theoretical calculations. The Nuclear Magnetic Resonance (NMR), Fourier Transform-Infrared (FT-IR), Ultraviolet/visible spectroscopies calculated agrees with the experimental values. The obtained charge transfer and electronic features provide useful information regarding the active sites for biological application in the compounds.
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Affiliation(s)
- Tunde L. Yusuf
- Department of Chemistry , Ekiti State University , Ado-Ekiti , Nigeria
- Department of Chemical Science , University of Johannesburg , Johannesburg , South Africa
| | - Eric O. Akintemi
- Department of Physical Sciences , Wesley University , P.M.B. 507 , Ondo Town , Ondo State , Nigeria
| | - Sulaimon Olagboye
- Department of Chemistry , Ekiti State University , Ado-Ekiti , Nigeria
| | - Gideon F. Tolufashe
- Department of Chemistry & Biochemistry, Faculty of Sciences , University of Porto , 4169-007 Porto , Portugal
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13
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Duan HD, Mohamed-Raseek N, Miller AF. Spectroscopic evidence for direct flavin-flavin contact in a bifurcating electron transfer flavoprotein. J Biol Chem 2020; 295:12618-12634. [PMID: 32661195 DOI: 10.1074/jbc.ra120.013174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/10/2020] [Indexed: 12/15/2022] Open
Abstract
A remarkable charge transfer (CT) band is described in the bifurcating electron transfer flavoprotein (Bf-ETF) from Rhodopseudomonas palustris (RpaETF). RpaETF contains two FADs that play contrasting roles in electron bifurcation. The Bf-FAD accepts electrons pairwise from NADH, directs one to a lower-reduction midpoint potential (E°) carrier, and the other to the higher-E° electron transfer FAD (ET-FAD). Previous work noted that a CT band at 726 nm formed when ET-FAD was reduced and Bf-FAD was oxidized, suggesting that both flavins participate. However, existing crystal structures place them too far apart to interact directly. We present biochemical experiments addressing this conundrum and elucidating the nature of this CT species. We observed that RpaETF missing either FAD lacked the 726 nm band. Site-directed mutagenesis near either FAD produced altered yields of the CT species, supporting involvement of both flavins. The residue substitutions did not alter the absorption maximum of the signal, ruling out contributions from residue orbitals. Instead, we propose that the residue identities modulate the population of a protein conformation that brings the ET-flavin and Bf-flavin into direct contact, explaining the 726 nm band based on a CT complex of reduced ET-FAD and oxidized Bf-FAD. This is corroborated by persistence of the 726 nm species during gentle protein denaturation and simple density functional theory calculations of flavin dimers. Although such a CT complex has been demonstrated for free flavins, this is the first observation of such, to our knowledge, in an enzyme. Thus, Bf-ETFs may optimize electron transfer efficiency by enabling direct flavin-flavin contact.
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Affiliation(s)
- H Diessel Duan
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
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14
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Andrikopoulos PC, Liu Y, Picchiotti A, Lenngren N, Kloz M, Chaudhari AS, Precek M, Rebarz M, Andreasson J, Hajdu J, Schneider B, Fuertes G. Femtosecond-to-nanosecond dynamics of flavin mononucleotide monitored by stimulated Raman spectroscopy and simulations. Phys Chem Chem Phys 2020; 22:6538-6552. [PMID: 31994556 DOI: 10.1039/c9cp04918e] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Flavin mononucleotide (FMN) belongs to the large family of flavins, ubiquitous yellow-coloured biological chromophores that contain an isoalloxazine ring system. As a cofactor in flavoproteins, it is found in various enzymes and photosensory receptors, like those featuring the light-oxygen-voltage (LOV) domain. The photocycle of FMN is triggered by blue light and proceeds via a cascade of intermediate states. In this work, we have studied isolated FMN in an aqueous solution in order to elucidate the intrinsic electronic and vibrational changes of the chromophore upon excitation. The ultrafast transitions of excited FMN were monitored through the joint use of femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption spectroscopy encompassing a time window between 0 ps and 6 ns with 50 fs time resolution. Global analysis of the obtained transient visible absorption and transient Raman spectra in combination with extensive quantum chemistry calculations identified unambiguously the singlet and triplet FMN populations and addressed solvent dynamics effects. The good agreement between the experimental and theoretical spectra facilitated the assignment of electronic transitions and vibrations. Our results represent the first steps towards more complex experiments aimed at tracking structural changes of FMN embedded in light-inducible proteins upon photoexcitation.
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Affiliation(s)
- Prokopis C Andrikopoulos
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czech Republic.
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15
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Mondal P, Schwinn K, Huix-Rotllant M. Impact of the redox state of flavin chromophores on the UV–vis spectra, redox and acidity constants and electron affinities. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2019.112164] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Khan E, Shukla A, Jhariya AN, Tandon P, Vangala VR. Nitrofurantoin-melamine monohydrate (cocrystal hydrate): Probing the role of H-bonding on the structure and properties using quantum chemical calculations and vibrational spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 221:117170. [PMID: 31158769 DOI: 10.1016/j.saa.2019.117170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/30/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
Cocrystal monohydrate of nitrofurantoin (NF) with melamine (MELA) has been studied as NF is an antibacterial drug used for the treatment of urinary tract infections. The structure of nitrofurantoin-melamine-monohydrate (NF-MELA-H2O) is characterized by FT-IR and FT-Raman spectroscopy. The energies and vibrational frequencies of the optimized structures calculated using quantum chemical calculations. Supported by normal coordinate analyses and potential energy distributions (PEDs), the complete vibrational assignments recommended for the observed fundamentals of cocrystal hydrate. With the aim of inclusion of all the H-bond interactions, dimer of NF-MELA-H2O has been studied as only two molecules of cocrystal hydrate are present in the unit cell. By the study of dimeric model consistent assignment of the FT-IR and FT-Raman spectrum obtained. H-bonds are of essential importance in an extensive range of molecular sciences. The vibrational analyses depict existence of H-bonding (O-H⋯N) between water O-H and pyridyl N atom of MELA in both monomer and dimer. To probe the strength and nature of H-bonding in monomer and dimer, topological parameters such as electron density (ρBCP), Laplacian of electron density (∇2ρBCP), total electron energy density (HBCP) and H-bond energy (EHB) at bond critical points (BCP) are evaluated by quantum theory of atoms in molecules (QTAIM). Natural bond orbitals (NBOs) analyses are carried out to study especially the intra and intermolecular H-bonding and their second order stabilization energy (E(2)). The value of HOMO-LUMO energy band gap for NF-MELA-H2O (monomer and dimer both) is less than NF, showing more chemical reactivity for NF-MELA-H2O. Chemical reactivity has been described with the assistance of electronic descriptors. Global electrophilicity index (ω = 7.3992 eV) shows that NF-MELA-H2O behaves as a strong electrophile than NF. The local reactivity descriptors analyses such as Fukui functions, local softnesses and electrophilicity indices performed to determine the reactive sites within NF-MELA-H2O. In MEP map of NF-MELA (monomer and dimer) electronegative regions are about NO2 and C=O group of NF, although the electropositive regions are around NH2, N-H group and H2O molecule. Molar refractivity (MR) value of NF-MELA-H2O (monomer and dimer) lies within the range set by Lipinski's modified rules. This study could set as an example to study the H-bond interactions in pharmaceutical cocrystals.
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Affiliation(s)
- Eram Khan
- Department of Physics, University of Lucknow, Lucknow 226 007, Uttar Pradesh, India
| | - Anuradha Shukla
- Department of Physics, University of Lucknow, Lucknow 226 007, Uttar Pradesh, India
| | - Aditya N Jhariya
- Centre for Pharmaceutical Engineering Science and School of Pharmacy and Medical Sciences, University of Bradford, Bradford, West Yorkshire BD7 1DP, United Kingdom
| | - Poonam Tandon
- Department of Physics, University of Lucknow, Lucknow 226 007, Uttar Pradesh, India.
| | - Venu R Vangala
- Centre for Pharmaceutical Engineering Science and School of Pharmacy and Medical Sciences, University of Bradford, Bradford, West Yorkshire BD7 1DP, United Kingdom.
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17
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Mohamed-Raseek N, Duan HD, Hildebrandt P, Mroginski MA, Miller AF. Spectroscopic, thermodynamic and computational evidence of the locations of the FADs in the nitrogen fixation-associated electron transfer flavoprotein. Chem Sci 2019; 10:7762-7772. [PMID: 31588324 PMCID: PMC6764259 DOI: 10.1039/c9sc00942f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 06/24/2019] [Indexed: 01/15/2023] Open
Abstract
Flavin-based electron bifurcation allows enzymes to redistribute energy among electrons by coupling endergonic and exergonic electron transfer reactions. Diverse bifurcating enzymes employ a two-flavin electron transfer flavoprotein (ETF) that accepts hydride from NADH at a flavin (the so-called bifurcating FAD, Bf-FAD). The Bf-FAD passes one electron exergonically to a second flavin thereby assuming a reactive semiquinone state able to reduce ferredoxin or flavodoxin semiquinone. The flavin that accepts one electron and passes it on via exergonic electron transfer is known as the electron transfer FAD (ET-FAD) and is believed to correspond to the single FAD present in canonical ETFs, in domain II. The Bf-FAD is believed to be the one that is unique to bifurcating ETFs, bound between domains I and III. This very reasonable model has yet to be challenged experimentally. Herein we used site-directed mutagenesis to disrupt FAD binding to the presumed Bf site between domains I and III, in the Bf-ETF from Rhodopseudomonas palustris (RpaETF). The resulting protein contained only 0.80 ± 0.05 FAD, plus 1.21 ± 0.04 bound AMP as in canonical ETFs. The flavin was not subject to reduction by NADH, confirming absence of Bf-FAD. The retained FAD displayed visible circular dichroism (CD) similar to that of the ET-FAD of RpaETF. Likewise, the mutant underwent two sequential one-electron reductions forming and then consuming anionic semiquinone, reproducing the reactivity of the ET-FAD. These data confirm that the retained FAD in domain II corresponds the ET-FAD. Quantum chemical calculations of the absorbance and CD spectra of each of WT RpaETF's two flavins reproduced the observed differences between their CD and absorbance signatures. The calculations for the flavin bound in domain II agreed better with the spectra of the ET-flavin, and those calculated based on the flavin between domains I and III agreed better with spectra of the Bf-flavin. Thus calculations independently confirm the locations of each flavin. We conclude that the site in domain II harbours the ET-FAD whereas the mutated site between domains I and III is the Bf-FAD site, confirming the accepted model by two different tests.
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Affiliation(s)
- Nishya Mohamed-Raseek
- Dept. Chemistry , University of Kentucky , 505 Rose Street , Lexington , KY 40506-0055 , USA .
| | - H Diessel Duan
- Dept. Chemistry , University of Kentucky , 505 Rose Street , Lexington , KY 40506-0055 , USA .
| | - Peter Hildebrandt
- Max Volmer Laboratorum für Biophysikalische Chemie , Technische Universität - Berlin , Sekr. PC 14, 135 Straße des 17. Juni , 10623 Berlin , Germany
| | - Maria Andrea Mroginski
- Max Volmer Laboratorum für Biophysikalische Chemie , Technische Universität - Berlin , Sekr. PC 14, 135 Straße des 17. Juni , 10623 Berlin , Germany
| | - Anne-Frances Miller
- Dept. Chemistry , University of Kentucky , 505 Rose Street , Lexington , KY 40506-0055 , USA .
- Max Volmer Laboratorum für Biophysikalische Chemie , Technische Universität - Berlin , Sekr. PC 14, 135 Straße des 17. Juni , 10623 Berlin , Germany
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18
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Structural and Reactivity Analyses of Nitrofurantoin–4-dimethylaminopyridine Salt Using Spectroscopic and Density Functional Theory Calculations. CRYSTALS 2019. [DOI: 10.3390/cryst9080413] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pharmaceutical salt, nitrofurantoin–4-dimethylaminopyridine (NF-DMAP), along with its native components NF and DMAP are scrutinized by FT-IR and FT-Raman spectroscopy along with density functional theory so that an insight into the H-bond patterns in the respective crystalline lattices can be gained. Two different functionals, B3LYP and wB97X-D, have been used to compare the theoretical results. The FT-IR spectra obtained for NF-DMAP and NF clearly validate the presence of C33–H34⋅⋅⋅O4 and N23–H24⋅⋅⋅N9 hydrogen bonds by shifting in the stretching vibration of –NH and –CH group of DMAP+ towards the lower wavenumber side. To explore the significance of hydrogen bonding, quantum theory of atoms in molecules (QTAIM) has been employed, and the findings suggest that the N23–H24⋅⋅⋅N9 bond is a strong intermolecular hydrogen bond. The decrement in the HOMO-LUMO gap, which is calculated from NF → NF-DMAP, reveals that the active pharmaceutical ingredient is chemically less reactive compared to the salt. The electrophilicity index (ω) profiles for NF and DMAP confirms that NF is acting as electron acceptor while DMAP acts as electron donor. The reactive sites of the salt are plotted by molecular electrostatic potential (MEP) surface and calculated using local reactivity descriptors.
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19
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Su D, Kabir MP, Orozco-Gonzalez Y, Gozem S, Gadda G. Fluorescence Properties of Flavin Semiquinone Radicals in Nitronate Monooxygenase. Chembiochem 2019; 20:1646-1652. [PMID: 30748074 DOI: 10.1002/cbic.201900016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Indexed: 11/09/2022]
Abstract
Fluorescent cofactors like flavins can be exploited to probe their local environment with spatial and temporal resolution. Although the fluorescence properties of the oxidized and two-electron-reduced states of flavins have been studied extensively, this is not the case for the one-electron-reduced state. Both the neutral and anionic semiquinones have proven particularly challenging to examine, as they are unstable in solution and are transient, short-lived species in many catalytic cycles. Here, we report that the nitronate monooxygenase (NMO) from Pseudomonas aeruginosa PAO1 is capable of stabilizing both semiquinone forms anaerobically for hours, thus enabling us to study their spectroscopy in a constant protein environment. We found that in the active site of NMO, the anionic semiquinone exhibits no fluorescence, whereas the neutral semiquinone radical shows a relatively strong fluorescence, with a behavior that violates the Kasha-Vavilov rule. These fluorescence properties are discussed in the context of time-dependent density functional theory calculations, which reveal low-lying dark states in both systems.
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Affiliation(s)
- Dan Su
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Mohammad Pabel Kabir
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Yoelvis Orozco-Gonzalez
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Samer Gozem
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Giovanni Gadda
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA.,Department of Biology, Georgia State University, 100 Piedmond Ave., Atlanta, GA, 30303, USA.,Center for Diagnostics and Therapeutics, Georgia State University, P.O. Box 5090, Atlanta, GA, 30303, USA.,Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA, 30302, USA
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20
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Kabir MP, Orozco-Gonzalez Y, Gozem S. Electronic spectra of flavin in different redox and protonation states: a computational perspective on the effect of the electrostatic environment. Phys Chem Chem Phys 2019; 21:16526-16537. [DOI: 10.1039/c9cp02230a] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This study discusses how UV/vis absorption spectra of flavin in different redox and protonation states are shifted by the nearby electrostatic microenvironment.
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Affiliation(s)
| | | | - Samer Gozem
- Department of Chemistry
- Georgia State University
- Atlanta
- USA
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21
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Kar RK, Borin VA, Ding Y, Matysik J, Schapiro I. Spectroscopic Properties of Lumiflavin: A Quantum Chemical Study. Photochem Photobiol 2018; 95:662-674. [DOI: 10.1111/php.13023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/05/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Rajiv Kumar Kar
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry Hebrew University of Jerusalem Jerusalem Israel
| | - Veniamin A. Borin
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry Hebrew University of Jerusalem Jerusalem Israel
| | - Yonghong Ding
- Institute of Analytical Chemistry University of Leipzig Leipzig Germany
| | - Jörg Matysik
- Institute of Analytical Chemistry University of Leipzig Leipzig Germany
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry Hebrew University of Jerusalem Jerusalem Israel
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22
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Pandey J, Prajapati P, Srivastava A, Tandon P, Sinha K, Ayala AP, Bansal AK. Spectroscopic and molecular structure (monomeric and dimeric model) investigation of Febuxostat: A combined experimental and theoretical study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 203:1-12. [PMID: 29852375 DOI: 10.1016/j.saa.2018.05.074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/20/2018] [Indexed: 06/08/2023]
Abstract
Febuxostat (FXT) is a urate-lowering drug and xanthine oxidase inhibitor which is used for the treatment of hyperuricemia and gout caused by increased levels of uric acid in the blood (hyperuricemia). The present study aims to provide deeper knowledge of the structural, vibrational spectroscopic and physiochemical properties of FXT based on monomeric and dimeric model with the aid of combination of experimental and computational methods. The conformational analysis of form Q has been done to predict the possible structure of unknown form A. Vibrational spectra of form A and Q has been compared to get an idea of hydrogen bonding interactions of form A. A computational study of FXT has been executed at different level (B3LYP, M06-2X, WB97XD) of theory and 6-31 G (d, p) basis set for dimeric model to elucidate the nature of intermolecular hydrogen bond. The red shift observed in the stretching modes of OH, CO groups and blue shift in stretching mode of CN group in experimental as well as in theoretical spectra explains the involvement of these groups in intermolecular hydrogen bonding. NBO analysis shows that change in electron density (ED) in the lone pair orbital to σ* antibonding orbital (LP1 (N39) → σ* (O3-H38)) with maximum value of E(2) energy confirms the presence of hydrogen bond (N39⋯H38-O3) leading to dimer formation. Study of topological parameters was executed for dimer using Bader's atoms in molecules (AIM) theory predicting the partially covalent nature of hydrogen bonds present in the molecule. The study of molecular electrostatic potential surface (MEPS) map ascertains that the CO, CN group are prone to electrophilic attack and OH group is active towards nucleophilic attack. The lower energy band gap and higher value of softness of dimeric model of FXT indicates its more reactivity, polarisability than monomeric model. The local reactivity descriptors predict the order of reactive sites towards electrophilic, nucleophilic and radical attack. An investigation made to determine the ligand protein interaction of FXT through docking with different molecular targets reveals the inhibitive as well as antibacterial nature of FXT.
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Affiliation(s)
- Jaya Pandey
- Department of Physics, University of Lucknow, Lucknow 226007, India
| | - Preeti Prajapati
- Department of Physics, University of Lucknow, Lucknow 226007, India
| | | | - Poonam Tandon
- Department of Physics, University of Lucknow, Lucknow 226007, India.
| | - Kirti Sinha
- Department of Physics, University of Lucknow, Lucknow 226007, India
| | - Alejandro P Ayala
- Departamento de Fisica, Universidade Federal do Ceará, C.P. 6030, 60.455-900 Fortaleza, CE, Brazil
| | - Arvind K Bansal
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab 160062, India
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23
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Aranda D, Cerezo J, Pescitelli G, Avila Ferrer FJ, Soto J, Santoro F. A computational study of the vibrationally-resolved electronic circular dichroism spectra of single-chain transoid and cisoid oligothiophenes in chiral conformations. Phys Chem Chem Phys 2018; 20:21864-21880. [PMID: 30105334 DOI: 10.1039/c8cp03482f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We simulate the vibronic profile of the electronic circular dichroism (ECD) spectra of oligothiophenes in cisoid and transoid chiral arrangements. We consider oligomers of different lengths, from two to fifteen units, and investigate extensively how the ECD spectral shapes depend on the inter-ring torsions. In general, the molecular structures we consider are not stationary points of the ground state potential energy surface. Therefore, in order to perform vibronic calculations, we present a new computational protocol able to define reduced-dimensionality models where the effect of the off-equilibrium modes is removed. This is done adopting a description of the vibrational motions in curvilinear internal coordinates, and vertical harmonic models coupled with an iterative application of projectors to define energy Hessians, and therefore effective normal modes, in the space complementary to the one of the off-equilibrium coordinates. Although we consider both Franck-Condon and Herzberg-Teller contributions, the results show that transoid twisted ribbons always give rise to monosignated ECD spectra, while bi-signated and multi-signated spectra are expected for cisoid helices. These findings are explained on the basis of the different transition strengths of the lowest electronic states imparted by the different spatial arrangement, that is almost linear for transoid structures and more globular for cisoid ones. We predicted the chiroptical response of a large number of possible molecular arrangements. These data are employed to critically discuss the experimental ECD of polythiophenes in different experimental conditions, forming either aggregates or host-guest complexes. The method here proposed to perform vibronic calculations in reduced-dimensionality models is of general applicability and its potential interest goes beyond the practical application presented here.
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Affiliation(s)
- Daniel Aranda
- Department of Physical Chemistry, Faculty of Science, University of Málaga, E-29071-Málaga, Spain
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24
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Giacomozzi L, Kjær C, Langeland Knudsen J, Andersen LH, Brøndsted Nielsen S, Stockett MH. Absorption and luminescence spectroscopy of mass-selected flavin adenine dinucleotide mono-anions. J Chem Phys 2018; 148:214309. [PMID: 29884035 DOI: 10.1063/1.5024028] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We report the absorption profile of isolated Flavin Adenine Dinucleotide (FAD) mono-anions recorded using photo-induced dissociation action spectroscopy. In this charge state, one of the phosphoric acid groups is deprotonated and the chromophore itself is in its neutral oxidized state. These measurements cover the first four optical transitions of FAD with excitation energies from 2.3 to 6.0 eV (210-550 nm). The S0 → S2 transition is strongly blue shifted relative to aqueous solution, supporting the view that this transition has a significant charge-transfer character. The remaining bands are close to their solution-phase positions. This confirms that the large discrepancy between quantum chemical calculations of vertical transition energies and solution-phase band maxima cannot be explained by solvent effects. We also report the luminescence spectrum of FAD mono-anions in vacuo. The gas-phase Stokes shift for S1 is 3000 cm-1, which is considerably larger than any previously reported for other molecular ions and consistent with a significant displacement of the ground and excited state potential energy surfaces. Consideration of the vibronic structure is thus essential for simulating the absorption and luminescence spectra of flavins.
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Affiliation(s)
- L Giacomozzi
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - C Kjær
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | - L H Andersen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | - M H Stockett
- Department of Physics, Stockholm University, Stockholm, Sweden
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25
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Bai Y, Lv X, Liu Z, Guo T, Li J. Synthesis, spectral and DFT study of 5-butyl-3,9-difluoro-5 H -benzimidazo[1,2- a ]benzimidazole. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.08.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Lincke K, Langeland J, Madsen AØ, Kiefer HV, Skov L, Gruber E, Mikkelsen KV, Andersen LH, Nielsen MB. Elucidation of the intrinsic optical properties of hydrogen-bonded and protonated flavin chromophores by photodissociation action spectroscopy. Phys Chem Chem Phys 2018; 20:28678-28684. [DOI: 10.1039/c8cp05368e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The intrinsic optical properties of the flavin chromophore when engaged in hydrogen bonding or being protonated were elucidated by photo-induced action spectroscopy and computations.
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Affiliation(s)
- Kasper Lincke
- Department of Chemistry, University of Copenhagen
- DK-2100 Copenhagen Ø
- Denmark
| | - Jeppe Langeland
- Department of Physics and Astronomy, Aarhus University
- DK-8000 Aarhus C
- Denmark
| | | | - Hjalte V. Kiefer
- Department of Physics and Astronomy, Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Louise Skov
- Department of Chemistry, University of Copenhagen
- DK-2100 Copenhagen Ø
- Denmark
| | - Elisabeth Gruber
- Department of Physics and Astronomy, Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Kurt V. Mikkelsen
- Department of Chemistry, University of Copenhagen
- DK-2100 Copenhagen Ø
- Denmark
| | - Lars H. Andersen
- Department of Physics and Astronomy, Aarhus University
- DK-8000 Aarhus C
- Denmark
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27
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Li SL, Truhlar DG. Franck-Condon Models for Simulating the Band Shape of Electronic Absorption Spectra. J Chem Theory Comput 2017; 13:2823-2830. [PMID: 28489367 DOI: 10.1021/acs.jctc.7b00325] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Band shape is an essential ingredient in the simulation of electronic absorption spectra. The excitation of multiple series of vibrational levels during an electronic excitation is a main contributor to band shapes. Here we present two simple models based on the Franck-Condon displaced-harmonic-oscillator model. The models are both derived from the time-dependent formulation of electronic spectroscopy. They assume that the transition dipoles do not depend on geometry and that the potential energy surfaces are locally quadratic; one model is second order in time and is called LQ2, and the other is third order in time and is called LQ3. These models are suitable for simulating the unresolved vibronic band shapes of electronic spectra that involve many vibrational modes. The models are straightforward and can be easily applied to simulate absorption spectra that are composed of many electronic transitions. As compared to carrying out molecular dynamics simulations, they require relatively few electronic structure calculations, and the additional cost for constructing the spectra is negligible. Therefore, the models are suitable for simulating the spectra of complex systems such as transition-metal complexes.
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Affiliation(s)
- Shaohong L Li
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455, United States
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28
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Zutterman F, Liégeois V, Champagne B. Simulation of the UV/Visible Absorption Spectra of Fluorescent Protein Chromophore Models. CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201700002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Freddy Zutterman
- Laboratoire de Chimie Théorique, Unité de Chimie-Physique Théorique et Structurale; Université de Namur; rue de Bruxelles, 61 B-5000 Namur Belgium
| | - Vincent Liégeois
- Laboratoire de Chimie Théorique, Unité de Chimie-Physique Théorique et Structurale; Université de Namur; rue de Bruxelles, 61 B-5000 Namur Belgium
| | - Benoît Champagne
- Laboratoire de Chimie Théorique, Unité de Chimie-Physique Théorique et Structurale; Université de Namur; rue de Bruxelles, 61 B-5000 Namur Belgium
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29
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Staniszewska M, Kupfer S, Łabuda M, Guthmuller J. Theoretical Assessment of Excited State Gradients and Resonance Raman Intensities for the Azobenzene Molecule. J Chem Theory Comput 2017; 13:1263-1274. [PMID: 28118003 DOI: 10.1021/acs.jctc.6b00966] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The ground state geometries and vibrational frequencies as well as the excitation energies and excited state gradients of the S1(nπ*) and S2(ππ*) states of trans- and cis-azobenzene are investigated by several DFT methods, namely B3LYP, PBE, M06-2X, CAM-B3LYP, and ωB97X. Excited state properties and in particular gradients are also assessed using the wave function based methods EOM-CCSD and RASPT2/RASSCF. Comparison with experimental data shows that the B3LYP functional gives the most accurate results for the ground state geometry and vibrational frequencies. The analysis of the vertical excitation energies reveals that the RASPT2 approach provides the most accurate excitation energies with deviations of the order of 0.1 eV. Among the TDDFT methods, the CAM-B3LYP functional shows the best performance on the excitation energies. By assessing the excited state gradients with respect to the reference RASPT2 data, the most accurate gradients are obtained with B3LYP, whereas other functionals as well as the EOM-CCSD and RASSCF calculations give less consistent results. Overall, despite the tendency of B3LYP to underestimate the excitation energies, this functional provides the most balanced description of both ground and excited state properties for both isomers of azobenzene in the Franck-Condon region.
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Affiliation(s)
- Magdalena Staniszewska
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Stephan Kupfer
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07-743 Jena, Germany
| | - Marta Łabuda
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Julien Guthmuller
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland
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30
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Stauch T, Dreuw A. Advances in Quantum Mechanochemistry: Electronic Structure Methods and Force Analysis. Chem Rev 2016; 116:14137-14180. [PMID: 27767298 DOI: 10.1021/acs.chemrev.6b00458] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In quantum mechanochemistry, quantum chemical methods are used to describe molecules under the influence of an external force. The calculation of geometries, energies, transition states, reaction rates, and spectroscopic properties of molecules on the force-modified potential energy surfaces is the key to gain an in-depth understanding of mechanochemical processes at the molecular level. In this review, we present recent advances in the field of quantum mechanochemistry and introduce the quantum chemical methods used to calculate the properties of molecules under an external force. We place special emphasis on quantum chemical force analysis tools, which can be used to identify the mechanochemically relevant degrees of freedom in a deformed molecule, and spotlight selected applications of quantum mechanochemical methods to point out their synergistic relationship with experiments.
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Affiliation(s)
- Tim Stauch
- Interdisciplinary Center for Scientific Computing , Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing , Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
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31
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Tapavicza E, Furche F, Sundholm D. Importance of Vibronic Effects in the UV-Vis Spectrum of the 7,7,8,8-Tetracyanoquinodimethane Anion. J Chem Theory Comput 2016; 12:5058-5066. [PMID: 27585186 DOI: 10.1021/acs.jctc.6b00720] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a computational method for simulating vibronic absorption spectra in the ultraviolet-visible (UV-vis) range and apply it to the 7,7,8,8-tetracyanoquinodimethane anion (TCNQ-), which has been used as a ligand in black absorbers. Gaussian broadening of vertical electronic excitation energies of TCNQ- from linear-response time-dependent density functional theory produces only one band, which is qualitatively incorrect. Thus, the harmonic vibrational modes of the two lowest doublet states were computed, and the vibronic UV-vis spectrum was simulated using the displaced harmonic oscillator approximation, the frequency-shifted harmonic oscillator approximation, and the full Duschinsky formalism. An efficient real-time generating function method was implemented to avoid the exponential complexity of conventional Franck-Condon approaches to vibronic spectra. The obtained UV-vis spectra for TCNQ- agree well with experiment; the Duschinsky rotation is found to have only a minor effect on the spectrum. Born-Oppenheimer molecular dynamics simulations combined with calculations of the electronic excitation energies for a large number of molecular structures were also used for simulating the UV-vis spectrum. The Born-Oppenheimer molecular dynamics simulations yield a broadening of the energetically lowest peak in the absorption spectrum, but additional vibrational bands present in the experimental and simulated quantum harmonic oscillator spectra are not observed in the molecular dynamics simulations. Our results underline the importance of vibronic effects for the UV-vis spectrum of TCNQ-, and they establish an efficient method for obtaining vibronic spectra using a combination of linear-response time-dependent density functional theory and a real-time generating function approach.
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Affiliation(s)
- Enrico Tapavicza
- Department of Chemistry and Biochemistry, California State University, Long Beach , 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine , 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - Dage Sundholm
- Department of Chemistry, University of Helsinki , P. O. Box 55 (A. I. Virtanens plats 1), FI-00014 Helsinki, Finland
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32
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Cerezo J, Santoro F. Revisiting Vertical Models To Simulate the Line Shape of Electronic Spectra Adopting Cartesian and Internal Coordinates. J Chem Theory Comput 2016; 12:4970-4985. [PMID: 27586086 DOI: 10.1021/acs.jctc.6b00442] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Vertical models for the simulation of spectroscopic line shapes expand the potential energy surface (PES) of the final state around the equilibrium geometry of the initial state. These models provide, in principle, a better approximation of the region of the band maximum. At variance, adiabatic models expand each PES around its own minimum. In the harmonic approximation, when the minimum energy structures of the two electronic states are connected by large structural displacements, adiabatic models can breakdown and are outperformed by vertical models. However, the practical application of vertical models faces the issues related to the necessity to perform a frequency analysis at a nonstationary point. In this contribution we revisit vertical models in harmonic approximation adopting both Cartesian (x) and valence internal curvilinear coordinates (s). We show that when x coordinates are used, the vibrational analysis at nonstationary points leads to a deficient description of low-frequency modes, for which spurious imaginary frequencies may even appear. This issue is solved when s coordinates are adopted. It is however necessary to account for the second derivative of s with respect to x, which here we compute analytically. We compare the performance of the vertical model in the s-frame with respect to adiabatic models and previously proposed vertical models in x- or Q1-frame, where Q1 are the normal coordinates of the initial state computed as combination of Cartesian coordinates. We show that for rigid molecules the vertical approach in the s-frame provides a description of the final state very close to the adiabatic picture. For sizable displacements it is a solid alternative to adiabatic models, and it is not affected by the issues of vertical models in x- and Q1-frames, which mainly arise when temperature effects are included. In principle the G matrix depends on s, and this creates nonorthogonality problems of the Duschinsky matrix connecting the normal modes of initial and final states in adiabatic approaches. We highlight that such a dependence of G on s is also an issue in vertical models, due to the necessity to approximate the kinetic term in the Hamiltonian when setting up the so-called GF problem. When large structural differences exist between the initial and the final-state minima, the changes in the G matrix can become too large to be disregarded.
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Affiliation(s)
- Javier Cerezo
- Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale delle Richerche (ICCOM-CNR) , Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Fabrizio Santoro
- Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale delle Richerche (ICCOM-CNR) , Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Italy
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33
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Baiardi A, Bloino J, Barone V. General formulation of vibronic spectroscopy in internal coordinates. J Chem Phys 2016; 144:084114. [PMID: 26931688 DOI: 10.1063/1.4942165] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Our general platform integrating time-independent and time-dependent evaluations of vibronic effects at the harmonic level for different kinds of absorption and emission one-photon, conventional and chiral spectroscopies has been extended to support various sets of internal coordinates. Thanks to the implementation of analytical first and second derivatives of different internal coordinates with respect to cartesian ones, both vertical and adiabatic models are available, with the inclusion of mode mixing and, possibly, Herzberg-Teller contributions. Furthermore, all supported non-redundant sets of coordinates are built from a fully automatized algorithm using only a primitive redundant set derived from a bond order-based molecular topology. Together with conventional stretching, bending, and torsion coordinates, the availability of additional coordinates (including linear and out-of-plane bendings) allows a proper treatment of specific systems, including, for instance, inter-molecular hydrogen bridges. A number of case studies are analysed, showing that cartesian and internal coordinates are nearly equivalent for semi-rigid systems not experiencing significant geometry distortions between initial and final electronic states. At variance, delocalized (possibly weighted) internal coordinates become much more effective than their cartesian counterparts for flexible systems and/or in the presence of significant geometry distortions accompanying electronic transitions.
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Affiliation(s)
- Alberto Baiardi
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Julien Bloino
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), UOS di Pisa, Area della Ricerca CNR, Via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
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Davari MD, Kopka B, Wingen M, Bocola M, Drepper T, Jaeger KE, Schwaneberg U, Krauss U. Photophysics of the LOV-Based Fluorescent Protein Variant iLOV-Q489K Determined by Simulation and Experiment. J Phys Chem B 2016; 120:3344-52. [DOI: 10.1021/acs.jpcb.6b01512] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Mehdi D. Davari
- Lehrstuhl
für Biotechnologie, RWTH Aachen University, 52056 Aachen, Germany
| | - Benita Kopka
- Institut
für Molekulare Enzymtechnologie, Heinrich Heine University
Düsseldorf, Forschungszentrum Jülich, 52426 Jülich, Germany
| | - Marcus Wingen
- Institut
für Molekulare Enzymtechnologie, Heinrich Heine University
Düsseldorf, Forschungszentrum Jülich, 52426 Jülich, Germany
| | - Marco Bocola
- Lehrstuhl
für Biotechnologie, RWTH Aachen University, 52056 Aachen, Germany
| | - Thomas Drepper
- Institut
für Molekulare Enzymtechnologie, Heinrich Heine University
Düsseldorf, Forschungszentrum Jülich, 52426 Jülich, Germany
| | - Karl-Erich Jaeger
- Institut
für Molekulare Enzymtechnologie, Heinrich Heine University
Düsseldorf, Forschungszentrum Jülich, 52426 Jülich, Germany
- Institut
für Bio- und Geowissenschaften, IBG-1, Biotechnologie, Forschungszentrum Jülich, 52426 Jülich, Germany
| | - Ulrich Schwaneberg
- Lehrstuhl
für Biotechnologie, RWTH Aachen University, 52056 Aachen, Germany
- DWI-Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52056, Aachen, Germany
| | - Ulrich Krauss
- Institut
für Molekulare Enzymtechnologie, Heinrich Heine University
Düsseldorf, Forschungszentrum Jülich, 52426 Jülich, Germany
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35
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Liu Y, Cerezo J, Santoro F, Rizzo A, Lin N, Zhao X. Theoretical investigation of the broad one-photon absorption line-shape of a flexible symmetric carbazole derivative. Phys Chem Chem Phys 2016; 18:22889-905. [DOI: 10.1039/c6cp04162k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The one-photon absorption spectrum of a carbazole derivative has been studied by employing density functional response theory combined with a mixed quantum/classical approach to simulate the spectral shape.
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Affiliation(s)
- Yanli Liu
- State Key Laboratory of Crystal Materials
- Shandong University
- 250100 Jinan
- P. R. China
- CNR – Consiglio Nazionale delle Ricerche
| | - Javier Cerezo
- CNR – Consiglio Nazionale delle Ricerche
- Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR)
- I-56124 Pisa
- Italy
| | - Fabrizio Santoro
- CNR – Consiglio Nazionale delle Ricerche
- Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR)
- I-56124 Pisa
- Italy
| | - Antonio Rizzo
- CNR – Consiglio Nazionale delle Ricerche
- Istituto per i Processi Chimico Fisici (IPCF-CNR)
- I-56124 Pisa
- Italy
| | - Na Lin
- State Key Laboratory of Crystal Materials
- Shandong University
- 250100 Jinan
- P. R. China
| | - Xian Zhao
- State Key Laboratory of Crystal Materials
- Shandong University
- 250100 Jinan
- P. R. China
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36
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Jun Y. Time-Dependent Density Functional Theory Study of Low-Lying Absorption and Fluorescence Band Shapes for Phenylene-Containing Oligoacenes. J Phys Chem A 2015; 119:12706-14. [DOI: 10.1021/acs.jpca.5b09788] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ye Jun
- Institute of High Performance Computing, Agency for Science, Technology
and Research, 1 Fusionopolis
Way, #16-16 Connexis North, Singapore 138632, Singapore
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37
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Falklöf O, Durbeej B, Norman P. Inter-Excited-State Phosphorescence in the Four-Component Relativistic Kohn–Sham Approximation: A Case Study on Lumiflavin. J Phys Chem A 2015; 119:11911-21. [DOI: 10.1021/acs.jpca.5b08908] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Olle Falklöf
- Division of Theoretical
Chemistry, IFM, Linköping University, SE-581 83 Linköping, Sweden
| | - Bo Durbeej
- Division of Theoretical
Chemistry, IFM, Linköping University, SE-581 83 Linköping, Sweden
| | - Patrick Norman
- Division of Theoretical
Chemistry, IFM, Linköping University, SE-581 83 Linköping, Sweden
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38
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Mathes T, Götze JP. A proposal for a dipole-generated BLUF domain mechanism. Front Mol Biosci 2015; 2:62. [PMID: 26579529 PMCID: PMC4630285 DOI: 10.3389/fmolb.2015.00062] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 10/12/2015] [Indexed: 11/25/2022] Open
Abstract
The resting and signaling structures of the blue-light sensing using flavin (BLUF) photoreceptor domains are still controversially debated due to differences in the molecular models obtained by crystal and NMR structures. Photocycles for the given preferred structural framework have been established, but a unifying picture combining experiment and theory remains elusive. We summarize present work on the AppA BLUF domain from both experiment and theory. We focus on IR and UV/vis spectra, and to what extent theory was able to reproduce experimental data and predict the structural changes upon formation of the signaling state. We find that the experimental observables can be theoretically reproduced employing any structural model, as long as the orientation of the signaling essential Gln63 and its tautomer state are a choice of the modeler. We also observe that few approaches are comparative, e.g., by considering all structures in the same context. Based on recent experimental findings and a few basic calculations, we suggest the possibility for a BLUF activation mechanism that only relies on electron transfer and its effect on the local electrostatics, not requiring an associated proton transfer. In this regard, we investigate the impact of dispersion correction on the interaction energies arising from weakly bound amino acids.
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Affiliation(s)
- Tilo Mathes
- Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Netherlands ; Institut für Biologie/Experimentelle Biophysik, Humboldt Universität zu Berlin Berlin, Germany
| | - Jan P Götze
- School of Chemistry, University of St Andrews St Andrews, UK
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Baiardi A, Bloino J, Barone V. Accurate Simulation of Resonance-Raman Spectra of Flexible Molecules: An Internal Coordinates Approach. J Chem Theory Comput 2015; 11:3267-80. [DOI: 10.1021/acs.jctc.5b00241] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Alberto Baiardi
- Scuola Normale Superiore, Piazza
dei Cavalieri 7, I-56126 Pisa, Italy
| | - Julien Bloino
- Scuola Normale Superiore, Piazza
dei Cavalieri 7, I-56126 Pisa, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), UOS di Pisa, Area della Ricerca CNR, Via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza
dei Cavalieri 7, I-56126 Pisa, Italy
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40
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Mewes JM, You ZQ, Wormit M, Kriesche T, Herbert JM, Dreuw A. Experimental Benchmark Data and Systematic Evaluation of Two a Posteriori, Polarizable-Continuum Corrections for Vertical Excitation Energies in Solution. J Phys Chem A 2015; 119:5446-64. [DOI: 10.1021/jp511163y] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jan-Michael Mewes
- Interdisciplinary
Center for Scientific Computing, Ruprechts-Karls University, Im Neuenheimer
Feld 368, 69120 Heidelberg, Germany
| | - Zhi-Qiang You
- Department
of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Michael Wormit
- Interdisciplinary
Center for Scientific Computing, Ruprechts-Karls University, Im Neuenheimer
Feld 368, 69120 Heidelberg, Germany
| | - Thomas Kriesche
- Institute
for Physical Chemistry, Ruprechts-Karls University, 69120 Heidelberg, Germany
| | - John M. Herbert
- Department
of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andreas Dreuw
- Interdisciplinary
Center for Scientific Computing, Ruprechts-Karls University, Im Neuenheimer
Feld 368, 69120 Heidelberg, Germany
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