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Golczak A, Prukała D, Sikorska E, Gierszewski M, Cherkas V, Kwiatek D, Kubiak A, Varma N, Pędziński T, Murphree S, Cibulka R, Mrówczyńska L, Kolanowski JL, Sikorski M. Tetramethylalloxazines as efficient singlet oxygen photosensitizers and potential redox-sensitive agents. Sci Rep 2023; 13:13426. [PMID: 37591918 PMCID: PMC10435492 DOI: 10.1038/s41598-023-40536-4] [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: 06/23/2023] [Accepted: 08/12/2023] [Indexed: 08/19/2023] Open
Abstract
Tetramethylalloxazines (TMeAll) have been found to have a high quantum yield of singlet oxygen generation when used as photosensitizers. Their electronic structure and transition energies (S0 → Si, S0 → Ti, T1 → Ti) were calculated using DFT and TD-DFT methods and compared to experimental absorption spectra. Generally, TMeAll display an energy diagram similar to other derivatives belonging to the alloxazine class of compounds, namely π,π* transitions are accompanied by closely located n,π* transitions. Photophysical data such as quantum yields of fluorescence, fluorescence lifetimes, and nonradiative rate constants were also studied in methanol (MeOH), acetonitrile (ACN), and 1,2-dichloroethane (DCE). The transient absorption spectra were also analyzed. To assess cytotoxicity of new compounds, a hemolytic assay was performed using human red blood cells (RBC) in vitro. Subsequently, fluorescence lifetime imaging experiments (FLIM) were performed on RBC under physiological and oxidative stress conditions alone or in the presence of TMeAll allowing for pinpointing changes caused by those compounds on the intracellular environment of these cells.
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Affiliation(s)
- Anna Golczak
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland
| | - Dorota Prukała
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland
| | - Ewa Sikorska
- Poznań University of Economics and Business, Al. Niepodległości 10, 61-875, Poznan, Poland
| | - Mateusz Gierszewski
- Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614, Poznan, Poland
| | - Volodymyr Cherkas
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Dorota Kwiatek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Adam Kubiak
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland
| | - Naisargi Varma
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland
| | - Tomasz Pędziński
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland
| | - Shaun Murphree
- Department of Chemistry, Allegheny College, 520 N. Main Street, Meadville, PA, USA
| | - Radek Cibulka
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technicka 5, 16628, Prague 6, Czech Republic.
| | - Lucyna Mrówczyńska
- Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznan, Poland.
| | - Jacek Lukasz Kolanowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
| | - Marek Sikorski
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland.
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2
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Curtolo F, Arantes GM. Molecular properties and tautomeric equilibria of isolated flavins. J Comput Chem 2022; 43:1561-1572. [PMID: 35778728 DOI: 10.1002/jcc.26957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/09/2022] [Indexed: 11/05/2022]
Abstract
Flavins are employed as redox cofactors and chromophores in a plethora of flavoenzymes. Their versatility is an outcome of intrinsic molecular properties of the isoalloxazine ring modulated by the protein scaffold and surrounding solvent. Thus, an investigation of isolated flavins with high-level electronic-structure methods and with error assessment of the calculated properties will contribute to building better models of flavin reactivity. Here, we benchmarked ground-state properties such as electron affinity, gas-phase basicity, dipole moment, torsion energy, and tautomer stability for lumiflavins in all biologically relevant oxidation and charge states. Overall, multiconfigurational effects are small and chemical accuracy is achieved by coupled-cluster treatments of energetic properties. Augmented basis sets and extrapolations to the complete basis-set limit are necessary for consistent agreement with experimental energetics. Among DFT functionals tested, M06-2X shows the best performance for most properties, except gas-phase basicity, in which M06 and CAM-B3LYP perform better. Moreover, dipole moments of radical flavins show large deviations for all functionals studied. Tautomers with noncanonical protonation states are significantly populated at normal temperatures, adding to the complexity of modeling flavins. These results will guide future computational studies of flavoproteins and flavin chemistry by indicating the limitations of electronic-structure methodologies and the contributions of multiple tautomeric states.
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Affiliation(s)
- Felipe Curtolo
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Guilherme M Arantes
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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3
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Foja R, Walter A, Jandl C, Thyrhaug E, Hauer J, Storch G. Reduced Molecular Flavins as Single-Electron Reductants after Photoexcitation. J Am Chem Soc 2022; 144:4721-4726. [PMID: 35259294 DOI: 10.1021/jacs.1c13285] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Flavoenzymes mediate a multitude of chemical reactions and are catalytically active both in different oxidation states and in covalent adducts with reagents. The transfer of such reactivity to the organic laboratory using simplified molecular flavins is highly desirable, and such applications in (photo)oxidation reactions are already established. However, molecular flavins have not been used for the reduction of organic substrates yet, although this activity is known and well-studied for DNA photolyase enzymes. We report a catalytic method using reduced molecular flavins as photoreductants and γ-terpinene as a sacrificial reductant. Additionally, we present our design for air-stable, reduced flavin catalysts, which is based on a conformational bias strategy and circumvents the otherwise rapid reduction of O2 from air. Using our catalytic strategy, we were able to replace superstoichiometric amounts of the rare-earth reductant SmI2 in a 5-exo-trig cyclization of substituted barbituric acid derivatives. Such flavin-catalyzed reductions are anticipated to be beneficial for other transformations as well and their straightforward synthesis indicates future use in stereo- as well as site-selective transformations.
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Affiliation(s)
- Richard Foja
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Alexandra Walter
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Christian Jandl
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Erling Thyrhaug
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Jürgen Hauer
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Golo Storch
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
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4
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Dozova N, Lacombat F, Lombard M, Hamdane D, Plaza P. Ultrafast dynamics of fully reduced flavin in catalytic structures of thymidylate synthase ThyX. Phys Chem Chem Phys 2021; 23:22692-22702. [PMID: 34605505 DOI: 10.1039/d1cp03379d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thymidylate is a vital DNA precursor synthesized by thymidylate synthases. ThyX is a flavin-dependent thymidylate synthase found in several human pathogens and absent in humans, which makes it a potential target for antimicrobial drugs. This enzyme methylates the 2'-deoxyuridine 5'-monophosphate (dUMP) to 2'-deoxythymidine 5'-monophosphate (dTMP) using a reduced flavin adenine dinucleotide (FADH-) as prosthetic group and (6R)-N5,N10-methylene-5,6,7,8-tetrahydrofolate (CH2THF) as a methylene donor. Recently, it was shown that ThyX-catalyzed reaction is a complex process wherein FADH- promotes both methylene transfer and reduction of the transferred methylene into a methyl group. Here, we studied the dynamic and photophysics of FADH- bound to ThyX, in several substrate-binding states (no substrate, in the presence of dUMP or folate or both) by femtosecond transient absorption spectroscopy. This methodology provides valuable information about the ground-state configuration of the isoalloxazine moiety of FADH- and the rigidity of its local environment, through spectra shape and excited-state lifetime parameters. In the absence of substrate, the environment of FADH- in ThyX is only mildly more constrained than that of free FADH- in solution. The addition of dUMP however narrows the distribution of ground-state configurations and increases the constraints on the butterfly bending motion in the excited state. Folate binding results in the selection of new ground-state configurations, presumably located at a greater distance from the conical intersection where excited-state decay occurs. When both substrates are present, the ground-state configuration appears on the contrary rather limited to a geometry close to the conical intersection, which explains the relatively fast excited-state decay (100 ps on the average), even if the environment of the isoalloxazine is densely packed. Hence, although the environment of the flavin is dramatically constrained, FADH- retains a dynamic necessary to shuttle carbon from folate to dUMP. Our study demonstrates the high sensitivity of FADH- photophysics to the constraints exerted by its immediate surroundings.
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Affiliation(s)
- Nadia Dozova
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - Fabien Lacombat
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - Murielle Lombard
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège de France, Sorbonne Université, 75005 Paris, France.
| | - Djemel Hamdane
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège de France, Sorbonne Université, 75005 Paris, France.
| | - Pascal Plaza
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
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Pakiari AH, Salarhaji M, Abdollahi T, Safapour M. The redox potential of flavin derivatives as a mediator in biosensors. J Mol Model 2021; 27:96. [PMID: 33641033 DOI: 10.1007/s00894-020-04650-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 12/16/2020] [Indexed: 11/28/2022]
Abstract
The two-electron reduction potential for a set of 393 flavin derivatives is presented in this article. These derivatives are substituted flavin on carbon 6, 7, 8, and 9 by coinage transition metals (Cu, Ag, and Au) and conjugated double bond hydrocarbons; and both groups are examined with and without functional groups such as OH, Cl, CH3, COOH, and NO2. In order to show the validity of the results, the reduction potential of human life molecules, which have experimental values, such as flavin adenine dinucleotide (FAD) and riboflavin (vitamin B2) is calculated. The experimental value for FAD is - 0.22 V, while the obtained theoretical value is - 0.21 V, and the corresponding values for riboflavin are - 0.18 and - 0.19 V, respectively. Theoretical calculations have been carried out by DFT procedure with a 6-31+G** basis set and BLYP xc-functional for coinage transition metals substitution, and MPW1PW9 xc-functionals for conjugated double bond hydrocarbon substitution. Both xc-functionals are chosen by the DFT calibration procedure.
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Affiliation(s)
- A H Pakiari
- Chemistry Department, College of Sciences, Shiraz University, Shiraz, 7194684795, Iran.
| | - M Salarhaji
- Chemistry Department, College of Sciences, Shiraz University, Shiraz, 7194684795, Iran
| | - T Abdollahi
- Young Researchers and Elite Club, Bushehr Branch, Islamic Azad University, Bushehr, 75149-44141, Iran
| | - M Safapour
- Chemistry Department, College of Sciences, Shiraz University, Shiraz, 7194684795, Iran
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Setser JW, Heemstra JR, Walsh CT, Drennan CL. Crystallographic evidence of drastic conformational changes in the active site of a flavin-dependent N-hydroxylase. Biochemistry 2014; 53:6063-77. [PMID: 25184411 PMCID: PMC4179590 DOI: 10.1021/bi500655q] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
![]()
The soil actinomycete Kutzneria sp. 744 produces
a class of highly decorated hexadepsipeptides, which represent a new
chemical scaffold that has both antimicrobial and antifungal properties.
These natural products, known as kutznerides, are created via nonribosomal
peptide synthesis using various derivatized amino acids. The piperazic
acid moiety contained in the kutzneride scaffold, which is vital for
its antibiotic activity, has been shown to derive from the hydroxylated
product of l-ornithine, l-N5-hydroxyornithine. The production of this hydroxylated species
is catalyzed by the action of an FAD- and NAD(P)H-dependent N-hydroxylase known as KtzI. We have been able to structurally
characterize KtzI in several states along its catalytic trajectory,
and by pairing these snapshots with the biochemical and structural
data already available for this enzyme class, we propose a structurally
based reaction mechanism that includes novel conformational changes
of both the protein backbone and the flavin cofactor. Further, we
were able to recapitulate these conformational changes in the protein
crystal, displaying their chemical competence. Our series of structures,
with corroborating biochemical and spectroscopic data collected by
us and others, affords mechanistic insight into this relatively new
class of flavin-dependent hydroxylases and adds another layer to the
complexity of flavoenzymes.
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Affiliation(s)
- Jeremy W Setser
- Department of Chemistry, ‡Department of Biology, and §Howard Hughes Medical Institute, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Langer J, Günther A, Seidenbecher S, Berden G, Oomens J, Dopfer O. Probing protonation sites of isolated flavins using IR spectroscopy: from lumichrome to the cofactor flavin mononucleotide. Chemphyschem 2014; 15:2550-62. [PMID: 24895155 DOI: 10.1002/cphc.201402146] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Indexed: 11/06/2022]
Abstract
Infrared spectra of the isolated protonated flavin molecules lumichrome, lumiflavin, riboflavin (vitamin B2), and the biologically important cofactor flavin mononucleotide are measured in the fingerprint region (600-1850 cm(-1)) by means of IR multiple-photon dissociation (IRMPD) spectroscopy. Using density functional theory calculations, the geometries, relative energies, and linear IR absorption spectra of several low-energy isomers are calculated. Comparison of the calculated IR spectra with the measured IRMPD spectra reveals that the N10 substituent on the isoalloxazine ring influences the protonation site of the flavin. Lumichrome, with a hydrogen substituent, is only stable as the N1-protonated tautomer and protonates at N5 of the pyrazine ring. The presence of the ribityl unit in riboflavin leads to protonation at N1 of the pyrimidinedione moiety, and methyl substitution in lumiflavin stabilizes the tautomer that is protonated at O2. In contrast, flavin mononucleotide exists as both the O2- and N1-protonated tautomers. The frequencies and relative intensities of the two C=O stretch vibrations in protonated flavins serve as reliable indicators for their protonation site.
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Affiliation(s)
- Judith Langer
- Technische Universität Berlin, Institut für Optik und Atomare Physik, Hardenbergstraße 36, D-10623 Berlin (Germany); Current address: Parque Tecnologico de San Sebastian, Paseo Miramon 182, Edif C, 20009 San Sebastian (Spain)
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8
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Prukala D, Khmelinskii I, Koput J, Gierszewski M, Pędziński T, Sikorski M. Photophysics, excited-state double-proton transfer and hydrogen-bonding properties of 5-deazaalloxazines. Photochem Photobiol 2014; 90:972-88. [PMID: 24816028 DOI: 10.1111/php.12289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 05/06/2014] [Indexed: 11/30/2022]
Abstract
The photophysical properties of 5-deazaalloxazine and 1,3-dimethyl-5-deazaalloxazine were studied in different solvents. These compounds have higher values of fluorescence quantum yields and longer fluorescence lifetimes, compared to those obtained for their alloxazine analogs. Electronic structure and S0 -Si transitions were investigated using the ab initio methods [MP2, CIS(D), EOM-CCSD] with the correlation-consistent basis sets. Also the time-dependent density functional theory (TD-DFT) has been employed. The lowest singlet excited states of 5-deazaalloxazine and 1,3-dimethyl-5-deazaalloxazine are predicted to have the π, π* character, whereas similar alloxazines have two close-lying π, π* and n, π* transitions. Experimental steady-state and time-resolved spectral studies indicate formation of an isoalloxazinic excited state via excited-state double-proton transfer (ESDPT) catalyzed by an acetic acid molecule that forms a hydrogen bond complex with the 5-deazaalloxazine molecule. Solvatochromism of both 5-deazaalloxazine and its 1,3-dimethyl substituted derivative was analyzed using the Kamlet-Taft scale and four-parameter Catalán solvent scale. The most significant result of our studies is that the both scales show a strong influence of solvent acidity (hydrogen bond donating ability) on the emission properties of these compounds, indicating the importance of intermolecular solute-solvent hydrogen-bonding interactions in their excited state.
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Affiliation(s)
- Dorota Prukala
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Poznań, Poland
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9
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Abstract
(1)H-, (11)B-, (13)C-, (15)N-, (17)O-, (19)F-, and (31)P-NMR chemical shifts of flavocoenzymes and derivatives of it, as well as of alloxazines and isoalloxazinium salts, from NMR experiments performed under various experimental conditions (e.g., dependence of the chemical shifts on temperature, concentration, solvent polarity, and pH) are reported. Also solid-state (13)C- and (15)N-NMR experiments are described revealing the anisotropic values of corresponding chemical shifts. These data, in combination with a number of coupling constants, led to a detailed description of the electronic structure of oxidized and reduced flavins. The data also demonstrate that the structure of oxidized flavin can assume a configuration deviating from coplanarity, depending on substitutions in the isoalloxazine ring, while that of reduced flavin exhibits several configurations, from almost planar to quite bended. The complexes formed between oxidized flavin and metal ions or organic molecules revealed three coordination sites with metal ions (depending on the chemical nature of the ion), and specific interactions between the pyrimidine moiety of flavin and organic molecules, mimicking specific interactions between apoflavoproteins and their coenzymes. Most NMR studies on flavoproteins were performed using (13)C- and (15)N-substituted coenzymes, either specifically enriched in the pterin moiety of flavin or uniformly labeled flavins. The chemical shifts of free flavins are used as a guide in the interpretation of the chemical shifts observed in flavoproteins. Although the hydrogen-bonding pattern in oxidized and reduced flavoproteins varies considerably, no correlation is obvious between these patterns and the corresponding redox potentials. In all reduced flavoproteins the N(1)H group of the flavocoenzyme is deprotonated, an exception is thioredoxin reductase. Three-dimensional structures of only a few flavoproteins, mostly belonging to the family of flavodoxins, have been solved. Also the kinetics of unfolding and refolding of flavodoxins has been investigated by NMR techniques. In addition, (31)P-NMR data of all so far studied flavoproteins and some (19)F-NMR spectra are discussed.
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Affiliation(s)
- Franz Müller
- , Wylstrasse 13, CH-6052, Hergiswil, Switzerland,
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Spectroscopy and Photophysics of Monomethyl-Substituted Derivatives of 5-Deazaalloxazine and 10-Ethyl-5-Deaza-Isoalloxazine. J Fluoresc 2013; 24:505-21. [PMID: 24272639 DOI: 10.1007/s10895-013-1320-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 11/07/2013] [Indexed: 11/27/2022]
Abstract
Steady-state and time-resolved spectra were used to describe the singlet and triplet states of 8-methyl-5-deazaalloxazine (8-Me-5-DAll), 9-methyl-5-deazaalloxazine (9-Me-5-DAll) and 10-ethyl-5-deaza-isoalloxazine (10-Et-5-DIAll). Solvatochromic properties were described using different polarity scales, including Δf and the four-parameter scale proposed by Catalán. The results indicate that the Catalán scale shows a strong influence of solvent acidity (hydrogen-bond donating ability) on the emission properties of 8-Me-5-DAll and 9-Me-5-DAll. These results indicate the importance of intermolecular solute-solvent hydrogen-bonding interactions in the excited state of these compounds. Contrary to deazaalloxazines, solvent acidity affects the absorption spectra of 10-Et-5-DIAll. Fluorescence lifetimes and quantum yields and also transient absorption spectra were determined for all of the compounds studied. Electronic structure and S(0)-S(i), S(0)-T(i ), T(1)-T(i) transitions energies and oscillator strengths were calculated using the TD-DFT methods. Theoretical calculations were compared to experimental data.
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Iida H, Mizoguchi T, Oh SD, Yashima E. Redox-triggered switching of helical chirality of poly(phenylacetylene)s bearing riboflavin pendants. Polym Chem 2010. [DOI: 10.1039/c0py00044b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Electronic structure and spectral properties of selected trimethyl-alloxazines: Combined experimental and DFT study. Chem Phys 2009. [DOI: 10.1016/j.chemphys.2009.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Sikorski M, Prukała D, Insińska-Rak M, Khmelinskii I, Worrall DR, Williams SL, Hernando J, Bourdelande JL, Koput J, Sikorska E. Spectroscopy and photophysics of dimethyl-substituted alloxazines. J Photochem Photobiol A Chem 2008. [DOI: 10.1016/j.jphotochem.2008.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Kao YT, Saxena C, He TF, Guo L, Wang L, Sancar A, Zhong D. Ultrafast dynamics of flavins in five redox states. J Am Chem Soc 2008; 130:13132-9. [PMID: 18767842 DOI: 10.1021/ja8045469] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report here our systematic studies of excited-state dynamics of two common flavin molecules, FMN and FAD, in five redox states--oxidized form, neutral and anionic semiquinones, and neutral and anionic fully reduced hydroquinones--in solution and in inert protein environments with femtosecond resolution. Using protein environments, we were able to stabilize two semiquinone radicals and thus observed their weak emission spectra. Significantly, we observed a strong correlation between their excited-state dynamics and the planarity of their flavin isoalloxazine ring. For a bent ring structure, we observed ultrafast dynamics from a few to hundreds of picoseconds and strong excitation-wavelength dependence of emission spectra, indicating deactivation during relaxation. A butterfly bending motion is invoked to get access to conical intersection(s) to facilitate deactivation. These states include the anionic semiquinone radical and fully reduced neutral and anionic hydroquinones in solution. In a planar configuration, flavins have a long lifetime of nanoseconds, except for the stacked conformation of FAD, where intramolecular electron transfer between the ring and the adenine moiety in 5-9 ps as well as subsequent charge recombination in 30-40 ps were observed. These observed distinct dynamics, controlled by the flavin ring flexibility, are fundamental to flavoenzyme's functions, as observed in photolyase with a planar structure to lengthen the lifetime to maximize DNA repair efficiency and in insect type 1 cryptochrome with a flexible structure to vary the excited-state deactivation to modulate the functional channel.
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Affiliation(s)
- Ya-Ting Kao
- Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210, USA
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15
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16
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Zenichowski K, Gothe M, Saalfrank P. Exciting flavins: Absorption spectra and spin–orbit coupling in light–oxygen–voltage (LOV) domains. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2007.02.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Hasegawa JY, Bureekaew S, Nakatsuji H. SAC-CI theoretical study on the excited states of lumiflavin: Structure, excitation spectrum, and solvation effect. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2007.01.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Choe YK, Nagase S, Nishimoto K. Theoretical study of the electronic spectra of oxidized and reduced states of lumiflavin and its derivative. J Comput Chem 2007; 28:727-39. [PMID: 17226839 DOI: 10.1002/jcc.20533] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Time-dependent density functional theory has been applied to investigate the electronic absorption spectrum of oxidized and reduced lumiflavin and its derivative, 8-NH(2)-lumiflavin. The calculations allow the authors to explain the origin of the difference in spectral features between oxidized and reduced states of lumiflavin. For the reduced lumiflavin, a reasonable assignment of the experimental spectrum has been made for the first time. Furthermore, the results obtained reveal that the NH(2) group plays a critical role in shaping the spectral features of 8-NH(2)-lumiflavin, and offer a reasonable explanation for the spectral changes upon substituting the NH(2) group for the CH(3) group of lumiflavin.
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Affiliation(s)
- Yoong-Kee Choe
- Research Institute for Computational Sciences (RICS), National Institute of Advanced Industrial Science and Technology (AIST), Centeral-2, Umezono 1-1-1, Tsukuba 305-8578, Japan.
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Bonazzola C, Gordillo G. Electrochemistry of lumiflavin adsorbed at mercury acidic aqueous solution interface. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2006.07.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Koder RL, Walsh JD, Pometun MS, Dutton PL, Wittebort RJ, Miller AF. 15N solid-state NMR provides a sensitive probe of oxidized flavin reactive sites. J Am Chem Soc 2006; 128:15200-8. [PMID: 17117871 PMCID: PMC5993988 DOI: 10.1021/ja0648817] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Flavins are central to the reactivity of a wide variety of enzymes and electron transport proteins. There is great interest in understanding the basis for the different reactivities displayed by flavins in different protein contexts. We propose solid-state nuclear magnetic resonance (SS-NMR) as a tool for directly observing reactive positions of the flavin ring and thereby obtaining information on their frontier orbitals. We now report the SS-NMR signals of the redox-active nitrogens N1 and N5, as well as that of N3. The chemical shift tensor of N5 is over 720 ppm wide, in accordance with the predictions of theory and our calculations. The signal of N3 can be distinguished on the basis of coupling to 1H absent for N1 and N5, as well as the shift tensor span of only 170 ppm, consistent with N3's lower aromaticity and lack of a nonbonding lone pair. The isotropic shifts and spans of N5 and N1 reflect two opposite extremes of the chemical shift range for "pyridine-type" N's, consistent with their electrophilic and nucleophilic chemical reactivities, respectively. Upon flavin reduction, N5's chemical shift tensor contracts dramatically to a span of less than 110 ppm, and the isotropic chemical shift changes by approximately 300 ppm. Both are consistent with loss of N5's nonbonding lone pair and decreased aromaticity, and illustrate the responsiveness of the 15N chemical shift principal values to electronic structure. Thus. 15N chemical shift principal values promise to be valuable tools for understanding electronic differences that underlie variations in flavin reactivity, as well as the reactivities of other heterocyclic cofactors.
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Affiliation(s)
- Ronald L. Koder
- Department of Chemistry, University of Kentucky, Lexington KY 40506-0055
- Department of Biochemistry and Biophysics, The Johnson Research Foundation, University of Pennsylvania, Philadelphia, PA 19104
| | - Joseph D. Walsh
- Department of Chemistry, University of Kentucky, Lexington KY 40506-0055
| | - Maxim S. Pometun
- Department of Chemistry, University of Louisville, Louisville KY 40292
| | - P. Leslie Dutton
- Department of Biochemistry and Biophysics, The Johnson Research Foundation, University of Pennsylvania, Philadelphia, PA 19104
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Merino G, Vela A, Heine T. Description of Electron Delocalization via the Analysis of Molecular Fields. Chem Rev 2005; 105:3812-41. [PMID: 16218568 DOI: 10.1021/cr030086p] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel Merino
- Institut für Physikalische Chemie und Elektrochemie, TU Dresden, D-01062 Dresden, Germany.
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Sikorska E, Khmelinskii I, Komasa A, Koput J, Ferreira LF, Herance JR, Bourdelande JL, Williams SL, Worrall DR, Insińska-Rak M, Sikorski M. Spectroscopy and photophysics of flavin related compounds: Riboflavin and iso-(6,7)-riboflavin. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.03.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Sikorska E, Herance JR, Bourdelande JL, Khmelinskii IV, Williams SL, Worrall DR, Nowacka G, Komasa A, Sikorski M. Spectroscopy and photophysics of flavin-related compounds: 3-ethyl-lumiflavin. J Photochem Photobiol A Chem 2005. [DOI: 10.1016/j.jphotochem.2004.08.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lindén AA, Hermanns N, Ott S, Krüger L, Bäckvall JE. Preparation and Redox Properties ofN,N,N-1,3,5-Trialkylated Flavin Derivatives and Their Activity as Redox Catalysts. Chemistry 2004; 11:112-9. [PMID: 15532052 DOI: 10.1002/chem.200400540] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Eight different flavin derivatives have been synthesized and the electronic effects of substituents in various positions on the flavin redox chemistry were investigated. The redox potentials of the flavins, determined by cyclic voltammetry, correlated with their efficiency as catalysts in the H2O2 oxidation of methyl p-tolyl sulfide. Introduction of electron-withdrawing groups increased the stability of the reduced catalyst precursor.
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Affiliation(s)
- Auri A Lindén
- Department of Organic Chemistry, Stockholm University, 106 91 Stockholm, Sweden
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Sikorska E, Khmelinskii IV, Koput J, Sikorski M. Electronic structure of lumiflavin and its analogues in their ground and excited states. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.theochem.2004.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sikorska E, Khmelinskii IV, Bourdelande JL, Bednarek A, Williams SL, Patel M, Worrall DR, Koput J, Sikorski M. Spectroscopy and photophysics of mono methyl-substituted alloxazines. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2004.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Sikorska E, Khmelinskii IV, Prukała W, Williams SL, Patel M, Worrall DR, Bourdelande JL, Koput J, Sikorski M. Spectroscopy and Photophysics of Lumiflavins and Lumichromes. J Phys Chem A 2004. [DOI: 10.1021/jp037048u] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ewa Sikorska
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Igor V. Khmelinskii
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Wiesław Prukała
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Siân L. Williams
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Manisha Patel
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - David R. Worrall
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Jose L. Bourdelande
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Jacek Koput
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Marek Sikorski
- Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland, Universidade do Algarve, FCT, Campus de Gambelas, Faro 8000-117, Portugal, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland, Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK, and Unitat de Química Orgànica, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
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