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Aleksandrov A, Bonvalet A, Müller P, Sorigué D, Beisson F, Antonucci L, Solinas X, Joffre M, Vos MH. Catalytic Mechanism of Fatty Acid Photodecarboxylase: On the Detection and Stability of the Initial Carbonyloxy Radical Intermediate. Angew Chem Int Ed Engl 2024; 63:e202401376. [PMID: 38466236 DOI: 10.1002/anie.202401376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/29/2024] [Accepted: 03/11/2024] [Indexed: 03/12/2024]
Abstract
In fatty acid photodecarboxylase (FAP), light-induced formation of the primary radical product RCOO⋅ from fatty acid RCOO- occurs in 300 ps, upon which CO2 is released quasi-immediately. Based on the hypothesis that aliphatic RCOO⋅ (spectroscopically uncharacterized because unstable) absorbs in the red similarly to aromatic carbonyloxy radicals such as 2,6-dichlorobenzoyloxy radical (DCB⋅), much longer-lived linear RCOO⋅ has been suggested recently. We performed quantum chemical reaction pathway and spectral calculations. These calculations are in line with the experimental DCB⋅ decarboxylation dynamics and spectral properties and show that in contrast to DCB⋅, aliphatic RCOO⋅ radicals a) decarboxylate with a very low energetic barrier and on the timescale of a few ps and b) exhibit little red absorption. A time-resolved infrared spectroscopy experiment confirms very rapid, ≪300 ps RCOO⋅ decarboxylation in FAP. We argue that this property is required for the observed high quantum yield of hydrocarbons formation by FAP.
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Affiliation(s)
- Alexey Aleksandrov
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Adeline Bonvalet
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Pavel Müller
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Damien Sorigué
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108, Saint-Paul-lez-Durance, France
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Fred Beisson
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108, Saint-Paul-lez-Durance, France
| | - Laura Antonucci
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Xavier Solinas
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Manuel Joffre
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Marten H Vos
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120, Palaiseau, France
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2
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Abstract
Dissection of multistep catalysis by a photoenzyme could inspire green chemistry applications.
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Affiliation(s)
- Marten H Vos
- Laboratoire d'Optique et Biosciences, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, École Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
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3
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Raics K, Pirisi K, Zhuang B, Fekete Z, Kis-Bicskei N, Pecsi I, Ujfalusi KP, Telek E, Li Y, Collado JT, Tonge PJ, Meech SR, Vos MH, Bodis E, Lukacs A. Photocycle alteration and increased enzymatic activity in genetically modified photoactivated adenylate cyclase OaPAC. J Biol Chem 2023; 299:105056. [PMID: 37468104 PMCID: PMC10448171 DOI: 10.1016/j.jbc.2023.105056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/30/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023] Open
Abstract
Photoactivated adenylate cyclases (PACs) are light activated enzymes that combine blue light sensing capacity with the ability to convert ATP to cAMP and pyrophosphate (PPi) in a light-dependent manner. In most of the known PACs blue light regulation is provided by a blue light sensing domain using flavin which undergoes a structural reorganization after blue-light absorption. This minor structural change then is translated toward the C-terminal of the protein, inducing a larger conformational change that results in the ATP conversion to cAMP. As cAMP is a key second messenger in numerous signal transduction pathways regulating various cellular functions, PACs are of great interest in optogenetic studies. The optimal optogenetic device must be "silent" in the dark and highly responsive upon light illumination. PAC from Oscillatoria acuminata is a very good candidate as its basal activity is very small in the dark and the conversion rates increase 20-fold upon light illumination. We studied the effect of replacing D67 to N, in the blue light using flavin domain. This mutation was found to accelerate the primary electron transfer process in the photosensing domain of the protein, as has been predicted. Furthermore, it resulted in a longer lived signaling state, which was formed with a lower quantum yield. Our studies show that the overall effects of the D67N mutation lead to a slightly higher conversion of ATP to cAMP, which points in the direction that by fine tuning the kinetic properties more responsive PACs and optogenetic devices can be generated.
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Affiliation(s)
- Katalin Raics
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | - Katalin Pirisi
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | - Bo Zhuang
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Palaiseau, France
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | | | - Ildiko Pecsi
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | | | - Elek Telek
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | - Yin Li
- Department of Physics, School of Physics and Materials Science, Nanchang University, Nanchang City, China
| | | | - Peter J Tonge
- Department of Chemistry, Stony Brook University, New York, USA
| | | | - Marten H Vos
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Palaiseau, France
| | - Emoke Bodis
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary.
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary.
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Diuba AV, Vygodina TV, Azarkina NV, Arutyunyan AM, Soulimane T, Vos MH, Konstantinov AA. Individual heme a and heme a 3 contributions to the Soret absorption spectrum of the reduced bovine cytochrome c oxidase. Biochim Biophys Acta Bioenerg 2023; 1864:148937. [PMID: 36403793 DOI: 10.1016/j.bbabio.2022.148937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 10/24/2022] [Accepted: 11/11/2022] [Indexed: 11/19/2022]
Abstract
Bovine cytochrome c oxidase (CcO) contains two hemes, a and a3, chemically identical but differing in coordination and spin state. The Soret absorption band of reduced aa3-type cytochrome c oxidase consists of overlapping bands of the hemes a2+ and a32+. It shows a peak at ∼444 nm and a distinct shoulder at ∼425 nm. However, attribution of individual spectral lineshapes to hemes a2+ and a32+ in the Soret is controversial. In the present work, we characterized spectral contributions of hemes a2+ and a32+ using two approaches. First, we reconstructed bovine CcO heme a2+ spectrum using a selective Ca2+-induced spectral shift of the heme a2+. Second, we investigated photobleaching of the reduced Thermus thermophilus ba3- and bovine aa3-oxidases in the Soret induced by femtosecond laser pulses in the Q-band. The resolved spectra show splitting of the electronic B0x-, B0y-transitions of both reduced hemes. The heme a2+ spectrum is shifted to the red relative to heme a32+ spectrum. The ∼425 nm shoulder is mostly attributed to heme a32+.
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Affiliation(s)
- Artem V Diuba
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld.40, Moscow 119992, Russia.
| | - Tatiana V Vygodina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld.40, Moscow 119992, Russia.
| | - Natalia V Azarkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld.40, Moscow 119992, Russia.
| | - Alexander M Arutyunyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld.40, Moscow 119992, Russia.
| | - Tewfik Soulimane
- Materials and Surface Science Institute, University of Limerick, V94 T9PX, Ireland.
| | - Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau 91120, France.
| | - Alexander A Konstantinov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld.40, Moscow 119992, Russia
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5
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Telek E, Raics K, Pirisi K, Kapronczai R, Bodis E, Pecsi I, Vos MH, Zhuang B, Lukacs A. The role of electron transfer in the enzymatic activity of a photoactivable adenylate cyclase. Biophys J 2023; 122:43a. [PMID: 36784254 DOI: 10.1016/j.bpj.2022.11.446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Elek Telek
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Katalin Raics
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Katalin Pirisi
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Robert Kapronczai
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Emoke Bodis
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Ildiko Pecsi
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Marten H Vos
- Laboratoire d'Optique et Biosciences, École Polytechnique, Palaiseau, France
| | - Bo Zhuang
- Laboratoire d'Optique et Biosciences, École Polytechnique, Palaiseau, France
| | - Andras Lukacs
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
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Zhuang B, Aleksandrov A, Seo D, Vos MH. Excited-State Properties of Fully Reduced Flavins in Ferredoxin-NADP + Oxidoreductase. J Phys Chem Lett 2023; 14:1096-1102. [PMID: 36700861 DOI: 10.1021/acs.jpclett.2c03741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The fully reduced flavin cofactor (FADred) in ferredoxin-NADP+ oxidoreductase (FNR) is a functional intermediate that displays different catalytic and steady-state spectral properties for enzymes from Bacillus subtilis (BsFNR), Chlorobaculum tepidum (CtFNR), and Rhodopseudomonas palustris (RpFNR). Using ultrafast spectroscopy, we reveal that at physiological pH, photoexcited FADred in BsFNR and RpFNR exhibits unprecedentedly fast decays (dominantly in 6 and 8 ps, respectively), whereas in CtFNR the decay is much slower (∼400 ps), as in other flavoproteins. Correlating these observations with the protonation states of FADred and the dynamic properties of the protein environment, we conclude that the excited state of neutral FADred can be intrinsically short-lived even in proteins, contrasting with the well-documented behavior of the anionic form that systematically displays markedly increased excited-state lifetime upon binding to proteins. This work provides new insight into the photochemistry of fully reduced flavins, which are emerging as functional initial states in bioengineered photocatalysts.
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Affiliation(s)
- Bo Zhuang
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
| | - Alexey Aleksandrov
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
| | - Daisuke Seo
- Division of Material Science, Graduate School of Natural Science and Technology, Kanazawa University, 920-1192 Kanazawa, Ishikawa, Japan
| | - Marten H Vos
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
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7
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Vos MH, Salman M, Liebl U. Early processes in heme-based CO-sensing proteins. Front Mol Biosci 2022; 9:1046412. [PMID: 36406263 PMCID: PMC9670170 DOI: 10.3389/fmolb.2022.1046412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
Carbon monoxide has been recognized relatively recently as signaling molecule, and only very few dedicated natural CO sensor proteins have been identified so far. These include in particular heme-based transcription factors: the bacterial sensor proteins CooA and RcoM. In these 6-coordinated systems, exchange between an internal protein residue and CO as a heme ligand in the sensor domain affects the properties of the DNA-binding domain. Using light to dissociate heme-ligand bonds can in principle initiate this switching process. We review the efforts to use this method to investigate early processes in ligand switching and signaling, with an emphasis on the CO-“trappingˮ properties of the heme cavity. These features are unusual for most heme proteins, but common for heme-based CO sensors.
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8
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Zhuang B, Vos MH, Aleksandrov A. Photochemical and Molecular Dynamics Studies of Halide Binding in Flavoenzyme Glucose Oxidase. Chembiochem 2022; 23:e202200227. [PMID: 35876386 DOI: 10.1002/cbic.202200227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/11/2022] [Indexed: 11/11/2022]
Abstract
Glucose oxidase (GOX), a characteristic flavoprotein oxidase with widespread industrial applications, binds fluoride (F - ) and chloride (Cl - ). We investigated binding properties of halide inhibitors of GOX through time-resolved spectral characterization of flavin-related photochemical processes and molecular dynamic simulations. Cl - and F - bind differently to the protein active site and have substantial but opposite effects on the population and decay of the flavin excited state. Cl - binds closer to the flavin, whose excited-state decays in <100 fs due to anion-π interactions. Such interactions appear absent in F - binding, which, however, significantly increases the active-site rigidity leading to more homogeneous, picosecond fluorescence decay kinetics. These findings are discussed in relation to the mechanism of halide inhibition of GOX by occupying the accommodation site of catalytic intermediates and increasing the active-site rigidity.
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Affiliation(s)
- Bo Zhuang
- Ecole Polytechnique, LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, FRANCE
| | - Marten H Vos
- CNRS UMR7645, Laboratory of Optics and Biosciences, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, FRANCE
| | - Alexey Aleksandrov
- Ecole Polytechnique, Laboratory of Optics and Biosciences, Department of Biology, rue du Saclay, 91128, Palaiseau, FRANCE
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9
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Zhuang B, Vos MH. Photoswitching Behavior of Flavin-Inhibitor Complex in a Nonphotocatalytic Flavoenzyme. J Am Chem Soc 2022; 144:11569-11573. [PMID: 35727223 DOI: 10.1021/jacs.2c04763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An unprecedented photoswitching phenomenon of flavin-inhibitor complexes in a flavoenzyme was revealed by femtosecond transient absorption spectroscopy. The vast majority of flavoenzymes, including monomeric sarcosine oxidase (MSOX), perform non-light-driven physiological functions. Yet, the participation of flavin cofactors in photoinduced electron transfer reactions is widespread. MSOX catalyzes the oxidative demethylation of sarcosine; methylthioacetate (MTA) is a substrate analog inhibitor that forms a complex with MSOX exhibiting intense absorption bands over the whole visible range due to flavin-MTA charge transfer (CT) interactions. Here, we demonstrate that upon excitation, these CT interactions vanish during a barrierless high quantum yield reaction in ∼300 fs. The initial complex subsequently geminately re-forms in a few nanoseconds near room temperature in a thermally activated way with an activation energy of 28 kJ/mol. We attribute this hitherto undocumented process to a well-defined photoinduced isomerization of MTA in the active site, as corroborated by experiments with the heavier ligand methylselenoacetate. Photoisomerization phenomena involving CT transitions may be further explored in photocatalytic and photoswitching applications of flavoenzymes.
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Affiliation(s)
- Bo Zhuang
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Marten H Vos
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
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10
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Kapetanaki SM, Fekete Z, Dorlet P, Vos MH, Liebl U, Lukacs A. Molecular insights into the role of heme in the transcriptional regulatory system AppA/PpsR. Biophys J 2022; 121:2135-2151. [PMID: 35488435 DOI: 10.1016/j.bpj.2022.04.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 03/07/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022] Open
Abstract
Heme has been shown to have a crucial role in the signal transduction mechanism of the facultative photoheterotrophic bacterium Rhodobacter sphaeroides. It interacts with the transcriptional regulatory complex AppA/PpsR in which AppA and PpsR function as the antirepressor and repressor, respectively of photosynthesis gene expression. The mechanism, however of this interaction remains incompletely understood. In this study, we combined EPR spectroscopy and FRET to demonstrate the ligation of heme in PpsR with a proposed cysteine residue. We show that heme binding in AppA affects the fluorescent properties of the dark-adapted state of the protein, suggesting a less constrained flavin environment compared to the absence of heme and the light-adapted state. We performed ultrafast transient absorption measurements in order to reveal potential differences in the dynamic processes in the full-length AppA and its heme-binding domain alone. Comparison of the CO-binding dynamics demonstrates a more open heme pocket in the holo-protein, qualitatively similar to what has been observed in the CO sensor RcoM-2, and suggests a communication path between the BLUF and SCHIC domains of AppA. We have also examined quantitatively, the affinity of PpsR to bind to individual DNA fragments of the puc promoter using fluorescence anisotropy assays. We conclude that oligomerization of PpsR is initially triggered by binding of one of the two DNA fragments and observe a ∼10-fold increase in the dissociation constant Kd for DNA binding upon heme binding to PpsR. Our study provides significant new insight at the molecular level on the regulatory role of heme that modulates the complex transcriptional regulation in R. sphaeroides and supports the two levels of heme signaling, via its binding to AppA and PpsR and via the sensing of gases like oxygen.
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Affiliation(s)
- Sofia M Kapetanaki
- Department of Biophysics, Medical School, University of Pécs, 7624 Pécs, Hungary; Szentagothai Research Center, University of Pecs, 7624 Pécs, Hungary.
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Pierre Dorlet
- Aix Marseille Univ, CNRS, BIP, IMM, Marseille, France
| | - Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pécs, 7624 Pécs, Hungary; Szentagothai Research Center, University of Pecs, 7624 Pécs, Hungary.
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11
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Abstract
Flavins are highly versatile redox-active and colored cofactors in a large variety of proteins. These do include photoenzymes and photoreceptors, although the vast majority performs non-light-driven physiological functions. Nevertheless, electron transfer between flavins and specific nearby amino acid residues (in particular tyrosine, tryptophan, and presumably histidine and arginine) takes place upon excitation of flavin in many flavoproteins. For oxidized flavoproteins these reactions potentially have a photoprotective role. In this Perspective, we outline work on the characterization of early reaction intermediates not only in the relatively well-studied resting oxidized forms but also in the fully reduced and the intrinsically unstable semireduced forms, where ultrafast photooxidation of flavin was recently demonstrated. Along different lines, flavoprotein-based novel photocatalysts for biotechnological applications are presently emerging, employing both substrate photooxidation and photoreduction strategies. Deep insight into the fundamental flavin photochemical reactions may help in guiding and optimizing their development and in the exploration of novel photocatalytic approaches.
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Affiliation(s)
- Bo Zhuang
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
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12
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Sorigué D, Hadjidemetriou K, Blangy S, Gotthard G, Bonvalet A, Coquelle N, Samire P, Aleksandrov A, Antonucci L, Benachir A, Boutet S, Byrdin M, Cammarata M, Carbajo S, Cuiné S, Doak RB, Foucar L, Gorel A, Grünbein M, Hartmann E, Hienerwadel R, Hilpert M, Kloos M, Lane TJ, Légeret B, Legrand P, Li-Beisson Y, Moulin SLY, Nurizzo D, Peltier G, Schirò G, Shoeman RL, Sliwa M, Solinas X, Zhuang B, Barends TRM, Colletier JP, Joffre M, Royant A, Berthomieu C, Weik M, Domratcheva T, Brettel K, Vos MH, Schlichting I, Arnoux P, Müller P, Beisson F. Mechanism and dynamics of fatty acid photodecarboxylase. Science 2021; 372:372/6538/eabd5687. [PMID: 33833098 DOI: 10.1126/science.abd5687] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 02/17/2021] [Indexed: 12/21/2022]
Abstract
Fatty acid photodecarboxylase (FAP) is a photoenzyme with potential green chemistry applications. By combining static, time-resolved, and cryotrapping spectroscopy and crystallography as well as computation, we characterized Chlorella variabilis FAP reaction intermediates on time scales from subpicoseconds to milliseconds. High-resolution crystal structures from synchrotron and free electron laser x-ray sources highlighted an unusual bent shape of the oxidized flavin chromophore. We demonstrate that decarboxylation occurs directly upon reduction of the excited flavin by the fatty acid substrate. Along with flavin reoxidation by the alkyl radical intermediate, a major fraction of the cleaved carbon dioxide unexpectedly transformed in 100 nanoseconds, most likely into bicarbonate. This reaction is orders of magnitude faster than in solution. Two strictly conserved residues, R451 and C432, are essential for substrate stabilization and functional charge transfer.
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Affiliation(s)
- D Sorigué
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - K Hadjidemetriou
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 38000 Grenoble, France
| | - S Blangy
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - G Gotthard
- European Synchrotron Radiation Facility, 38043 Grenoble, France
| | - A Bonvalet
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - N Coquelle
- Large-Scale Structures Group, Institut Laue Langevin, 38042 Grenoble Cedex 9, France
| | - P Samire
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - A Aleksandrov
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - L Antonucci
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - A Benachir
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - S Boutet
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - M Byrdin
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 38000 Grenoble, France
| | - M Cammarata
- Department of Physics, UMR UR1-CNRS 6251, University of Rennes 1, F-Rennes, France.
| | - S Carbajo
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - S Cuiné
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - R B Doak
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - L Foucar
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - A Gorel
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - M Grünbein
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - E Hartmann
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - R Hienerwadel
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - M Hilpert
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - M Kloos
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany.
| | - T J Lane
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - B Légeret
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - P Legrand
- Synchrotron SOLEIL. L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Y Li-Beisson
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - S L Y Moulin
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - D Nurizzo
- European Synchrotron Radiation Facility, 38043 Grenoble, France
| | - G Peltier
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - G Schirò
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 38000 Grenoble, France
| | - R L Shoeman
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - M Sliwa
- Univ. Lille, CNRS, UMR 8516, LASIRE, LAboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement, 59000 Lille, France
| | - X Solinas
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - B Zhuang
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - T R M Barends
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - J-P Colletier
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 38000 Grenoble, France
| | - M Joffre
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - A Royant
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 38000 Grenoble, France.,European Synchrotron Radiation Facility, 38043 Grenoble, France
| | - C Berthomieu
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France.
| | - M Weik
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 38000 Grenoble, France.
| | - T Domratcheva
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany. .,Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - K Brettel
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - M H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France.
| | - I Schlichting
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany.
| | - P Arnoux
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France.
| | - P Müller
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
| | - F Beisson
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France.
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13
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Zhuang B, Seo D, Aleksandrov A, Vos MH. Characterization of Light-Induced, Short-Lived Interacting Radicals in the Active Site of Flavoprotein Ferredoxin-NADP + Oxidoreductase. J Am Chem Soc 2021; 143:2757-2768. [PMID: 33591179 DOI: 10.1021/jacs.0c09627] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Radicals of flavin adenine dinucleotide (FAD), as well as tyrosine and tryptophan, are widely involved as key reactive intermediates during electron-transfer (ET) reactions in flavoproteins. Due to the high reactivity of these species and their corresponding short lifetime, characterization of these intermediates in functional processes of flavoproteins is usually challenging but can be achieved by ultrafast spectroscopic studies of light-activatable flavoproteins. In ferredoxin-NADP+ oxidoreductase from Bacillus subtilis (BsFNR), fluorescence of the FAD cofactor that very closely interacts with a neighboring tyrosine residue (Tyr50) is strongly quenched. Here we study short-lived photoproducts of this enzyme and its variants, with Tyr50 replaced by tryptophan or glycine. Using time-resolved fluorescence and absorption spectroscopies, we show that, upon the excitation of WT BsFNR, ultrafast ET from Tyr50 to the excited FAD cofactor occurs in ∼260 fs, an order of magnitude faster than the decay by charge recombination, facilitating the characterization of the reaction intermediates in the charge-separated state with respect to other recently studied systems. These studies are corroborated by experiments on the Y50W mutant protein, which yield photoproducts qualitatively similar to those observed in other tryptophan-bearing flavoproteins. By combining the experimental results with molecular dynamics simulations and quantum mechanics calculations, we investigate in detail the effects of protein environment and relaxations on the spectral properties of those radical intermediates and demonstrate that the spectral features of radical anionic FAD are highly sensitive to its environment, and in particular to the dynamics and nature of the counterions formed in the photoproducts. Altogether, comprehensive characterizations are provided for important radical intermediates that are generally involved in functional processes of flavoproteins.
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Affiliation(s)
- Bo Zhuang
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Daisuke Seo
- Division of Material Science, Graduate School of Natural Science and Technology, Kanazawa University, 920-1192 Kanazawa, Ishikawa, Japan
| | - Alexey Aleksandrov
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Marten H Vos
- LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
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14
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Pirisi K, Nag L, Fekete Z, Iuliano JN, Tolentino Collado J, Clark IP, Pécsi I, Sournia P, Liebl U, Greetham GM, Tonge PJ, Meech SR, Vos MH, Lukacs A. Identification of the vibrational marker of tyrosine cation radical using ultrafast transient infrared spectroscopy of flavoprotein systems. Photochem Photobiol Sci 2021; 20:369-378. [PMID: 33721272 DOI: 10.1007/s43630-021-00024-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/09/2021] [Indexed: 11/29/2022]
Abstract
Tryptophan and tyrosine radical intermediates play crucial roles in many biological charge transfer processes. Particularly in flavoprotein photochemistry, short-lived reaction intermediates can be studied by the complementary techniques of ultrafast visible and infrared spectroscopy. The spectral properties of tryptophan radical are well established, and the formation of neutral tyrosine radicals has been observed in many biological processes. However, only recently, the formation of a cation tyrosine radical was observed by transient visible spectroscopy in a few systems. Here, we assigned the infrared vibrational markers of the cationic and neutral tyrosine radical at 1483 and 1502 cm-1 (in deuterated buffer), respectively, in a variant of the bacterial methyl transferase TrmFO, and in the native glucose oxidase. In addition, we studied a mutant of AppABLUF blue-light sensor domain from Rhodobacter sphaeroides in which only a direct formation of the neutral radical was observed. Our studies highlight the exquisite sensitivity of transient infrared spectroscopy to low concentrations of specific radicals.
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Affiliation(s)
- Katalin Pirisi
- Department of Biophysics, Medical School, University of Pecs, Szigeti Str. 12, 7624, Pecs, Hungary
| | - Lipsa Nag
- Laboratoire d'Optique et Biosciences, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pecs, Szigeti Str. 12, 7624, Pecs, Hungary
| | - James N Iuliano
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794-3400, USA
| | | | - Ian P Clark
- Central Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, OX11 0QX, Oxon, UK
| | - Ildikó Pécsi
- Department of Biophysics, Medical School, University of Pecs, Szigeti Str. 12, 7624, Pecs, Hungary
| | - Pierre Sournia
- Laboratoire d'Optique et Biosciences, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Ursula Liebl
- Laboratoire d'Optique et Biosciences, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Gregory M Greetham
- Central Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, OX11 0QX, Oxon, UK
| | - Peter J Tonge
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794-3400, USA
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Marten H Vos
- Laboratoire d'Optique et Biosciences, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France.
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs, Szigeti Str. 12, 7624, Pecs, Hungary.
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15
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Vos MH, Salman M, Ramodiharilafy R, Liebl U. Fluorescent iron‑sulfur centers: Photochemistry of the PetA Rieske protein from Aquifex aeolicus. Biochim Biophys Acta Bioenerg 2021; 1862:148385. [PMID: 33516769 DOI: 10.1016/j.bbabio.2021.148385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 11/28/2022]
Abstract
Cytochrome bc1 complexes are energy-transducing enzymes and key components of respiratory electron chains. They contain Rieske 2Fe2S proteins that absorb very weakly in the visible absorption region compared to the heme cofactors of the cytochromes, but are known to yield photoproducts. Here, the photoreactions of isolated Rieske proteins from the hyperthermophilic bacterium Aquifex aeolicus are studied in two redox states using ultrafast transient fluorescence and absorption spectroscopy. We provide evidence, for the first time in iron‑sulfur proteins, of very weak fluorescence of the excited state, in the oxidized as well as the reduced state. The excited states of the oxidized and reduced forms decay in 1.5 ps and 30 ps, respectively. In both cases they give rise to product states with lifetimes beyond 1 ns, reflecting photo-reduction of oxidized centers as well as photo-oxidation of reduced centers. Potential reaction partners are discussed and studied using site-directed mutagenesis. For the reduced state, a nearby disulfide bridge is suggested as an electron acceptor. The resulting photoproducts in either state may play a role in photoactivation processes.
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Affiliation(s)
- Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France.
| | - Mayla Salman
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Rivo Ramodiharilafy
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
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16
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Karadi K, Kapetanaki SM, Raics K, Pecsi I, Kapronczai R, Fekete Z, Iuliano JN, Collado JT, Gil AA, Orban J, Nyitrai M, Greetham GM, Vos MH, Tonge PJ, Meech SR, Lukacs A. Functional dynamics of a single tryptophan residue in a BLUF protein revealed by fluorescence spectroscopy. Sci Rep 2020; 10:2061. [PMID: 32029866 PMCID: PMC7005313 DOI: 10.1038/s41598-020-59073-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/23/2020] [Indexed: 11/17/2022] Open
Abstract
Blue Light Using Flavin (BLUF) domains are increasingly being adopted for use in optogenetic constructs. Despite this, much remains to be resolved on the mechanism of their activation. The advent of unnatural amino acid mutagenesis opens up a new toolbox for the study of protein structural dynamics. The tryptophan analogue, 7-aza-Trp (7AW) was incorporated in the BLUF domain of the Activation of Photopigment and pucA (AppA) photoreceptor in order to investigate the functional dynamics of the crucial W104 residue during photoactivation of the protein. The 7-aza modification to Trp makes selective excitation possible using 310 nm excitation and 380 nm emission, separating the signals of interest from other Trp and Tyr residues. We used Förster energy transfer (FRET) between 7AW and the flavin to estimate the distance between Trp and flavin in both the light- and dark-adapted states in solution. Nanosecond fluorescence anisotropy decay and picosecond fluorescence lifetime measurements for the flavin revealed a rather dynamic picture for the tryptophan residue. In the dark-adapted state, the major population of W104 is pointing away from the flavin and can move freely, in contrast to previous results reported in the literature. Upon blue-light excitation, the dominant tryptophan population is reorganized, moves closer to the flavin occupying a rigidly bound state participating in the hydrogen-bond network around the flavin molecule.
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Affiliation(s)
- Kristof Karadi
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary.,Szentagothai Research Center, University of Pécs, 7624, Pécs, Hungary
| | - Sofia M Kapetanaki
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary.,Szentagothai Research Center, University of Pécs, 7624, Pécs, Hungary
| | - Katalin Raics
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - Ildiko Pecsi
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - Robert Kapronczai
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - James N Iuliano
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794-3400, USA
| | | | - Agnieszka A Gil
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794-3400, USA
| | - Jozsef Orban
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - Miklos Nyitrai
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary.,Szentagothai Research Center, University of Pécs, 7624, Pécs, Hungary
| | - Greg M Greetham
- Central Laser Facility, Harwell Science and Innovation Campus, Didcot, Oxfordshire, UK
| | - Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, Cedex, France
| | - Peter J Tonge
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794-3400, USA
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary. .,Szentagothai Research Center, University of Pécs, 7624, Pécs, Hungary.
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17
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Ferrante C, Batignani G, Pontecorvo E, Montemiglio LC, Vos MH, Scopigno T. Ultrafast Dynamics and Vibrational Relaxation in Six-Coordinate Heme Proteins Revealed by Femtosecond Stimulated Raman Spectroscopy. J Am Chem Soc 2020; 142:2285-2292. [PMID: 31917551 PMCID: PMC7735705 DOI: 10.1021/jacs.9b10560] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Identifying
the structural rearrangements during photoinduced reactions is a fundamental
challenge for understanding from a microscopic perspective the dynamics
underlying the functional mechanisms of heme proteins. Here, femtosecond
stimulated Raman spectroscopy is applied to follow the ultrafast evolution
of two different proteins, each bearing a six-coordinate heme with
two amino acid axial ligands. By exploiting the sensitivity of Raman
spectra to the structural configuration, we investigate the effects
of photolysis and the binding of amino acid residues in cytochrome c and neuroglobin. By comparing the system response for
different time delays and Raman pump resonances, we show how detailed
properties of atomic motions and energy redistribution can be unveiled.
In particular, we demonstrate substantially faster energy flow from
the dissociated heme to the protein moiety in cytochrome c, which we assign to the presence of covalent heme–protein
bonds.
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Affiliation(s)
- Carino Ferrante
- Center for Life Nano Science @Sapienza , Istituto Italiano di Tecnologia , Rome I-00161 , Italy
| | | | | | | | - Marten H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM , Institut Polytechnique de Paris , 91128 Palaiseau , France
| | - Tullio Scopigno
- Center for Life Nano Science @Sapienza , Istituto Italiano di Tecnologia , Rome I-00161 , Italy
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18
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Salman M, Villamil Franco C, Ramodiharilafy R, Liebl U, Vos MH. Interaction of the Full-Length Heme-Based CO Sensor Protein RcoM-2 with Ligands. Biochemistry 2019; 58:4028-4034. [PMID: 31502443 DOI: 10.1021/acs.biochem.9b00623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The heme-based and CO-responsive RcoM transcriptional regulators from Burkholderia xenovorans are known to display an extremely high affinity for CO while being insensitive to O2. We have quantitatively characterized the heme-CO interaction in full-length RcoM-2 and compared it with the isolated heme domain RcoMH-2 to establish the origin of these characteristics. Whereas the CO binding rates are similar to those of other heme-based sensor proteins, the dissociation rates are two to three orders of magnitude lower. The latter property is tuned by the yield of CO escape from the heme pocket after disruption of the heme-CO bond, as determined by ultrafast spectroscopy. For the full-length protein this yield is ∼0.5%, and for the isolated heme domain it is even lower, associated with correspondingly faster CO rebinding kinetics, leading to Kd values of 4 and 0.25 nM, respectively. These differences imply that the presence of the DNA-binding domain influences the ligand-binding properties of the heme domain, thus abolishing the observed quasi-irreversibility of CO binding to the isolated heme domain. RcoM-2 binds target DNA with high affinity (Kd < 2 nM) when CO is bound to the heme, and the presence of DNA also influences the heme-CO rebinding kinetics. The functional implications of our findings are discussed.
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Affiliation(s)
- Mayla Salman
- LOB, CNRS, INSERM, Ecole Polytechnique , Institut Polytechnique de Paris , 91128 Palaiseau , France
| | - Carolina Villamil Franco
- LOB, CNRS, INSERM, Ecole Polytechnique , Institut Polytechnique de Paris , 91128 Palaiseau , France
| | - Rivo Ramodiharilafy
- LOB, CNRS, INSERM, Ecole Polytechnique , Institut Polytechnique de Paris , 91128 Palaiseau , France
| | - Ursula Liebl
- LOB, CNRS, INSERM, Ecole Polytechnique , Institut Polytechnique de Paris , 91128 Palaiseau , France
| | - Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique , Institut Polytechnique de Paris , 91128 Palaiseau , France
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19
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Nag L, Lukacs A, Vos MH. Short-Lived Radical Intermediates in the Photochemistry of Glucose Oxidase. Chemphyschem 2019; 20:1793-1798. [PMID: 31081986 DOI: 10.1002/cphc.201900329] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/10/2019] [Indexed: 11/07/2022]
Abstract
Glucose oxidase is a flavoprotein that is relatively well-studied as a physico-chemical model system. The flavin cofactor is surrounded by several aromatic acid residues that can act as direct and indirect electron donors to photoexcited flavin. Yet, the identity of the photochemical product states is not well established. We present a detailed full spectral reinvestigation of this issue using femtosecond fluorescence and absorption spectroscopy. Based on a recent characterization of the unstable tyrosine cation radical TyrOH•+ , we now propose that the primary photoproduct involves this species, which was previously not considered. Formation of this product is followed by competing charge recombination and radical pair stabilization reactions that involve proton transfer and radical transfer to tryptophan. A minimal kinetic model is proposed, including a fraction of TyrOH.+ that is stabilized up to the tens of picoseconds timescale, suggesting a potential role of this species as intermediate in biochemical electron transfer reactions.
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Affiliation(s)
- Lipsa Nag
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs, Hungary
| | - Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France
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20
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Kapetanaki SM, Burton MJ, Basran J, Uragami C, Moody PCE, Mitcheson JS, Schmid R, Davies NW, Dorlet P, Vos MH, Storey NM, Raven E. A mechanism for CO regulation of ion channels. Nat Commun 2018; 9:907. [PMID: 29500353 PMCID: PMC5834611 DOI: 10.1038/s41467-018-03291-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/31/2018] [Indexed: 01/08/2023] Open
Abstract
Despite being highly toxic, carbon monoxide (CO) is also an essential intracellular signalling molecule. The mechanisms of CO-dependent cell signalling are poorly defined, but are likely to involve interactions with heme proteins. One such role for CO is in ion channel regulation. Here, we examine the interaction of CO with KATP channels. We find that CO activates KATP channels and that heme binding to a CXXHX16H motif on the SUR2A receptor is required for the CO-dependent increase in channel activity. Spectroscopic and kinetic data were used to quantify the interaction of CO with the ferrous heme-SUR2A complex. The results are significant because they directly connect CO-dependent regulation to a heme-binding event on the channel. We use this information to present molecular-level insight into the dynamic processes that control the interactions of CO with a heme-regulated channel protein, and we present a structural framework for understanding the complex interplay between heme and CO in ion channel regulation.
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Affiliation(s)
- Sofia M Kapetanaki
- Department of Chemistry and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 7RH, England
| | - Mark J Burton
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England
| | - Jaswir Basran
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England
| | - Chiasa Uragami
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Peter C E Moody
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England
| | - John S Mitcheson
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England
| | - Ralf Schmid
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England
| | - Noel W Davies
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England
| | - Pierre Dorlet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Marten H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay, 91128, Palaiseau Cedex, France
| | - Nina M Storey
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 9HN, England.
| | - Emma Raven
- Department of Chemistry and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, LE1 7RH, England.
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21
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Abstract
We present a full investigation of ultrafast light-induced events in the membraneous cytochrome bc1 complex by transient absorption spectroscopy. This energy-transducing complex harbors four redox-active components per monomer: heme c1, two 6-coordinate b-hemes and a [2Fe-2S] cluster. Using excitation of these components in different ratios under various excitation conditions, probing in the full visible range and under three well-defined redox conditions, we demonstrate that for all ferrous hemes of the complex photodissociation of axial ligands takes place and that they rebind in 5-7 ps, as in other 6-coordinate heme proteins, including cytoglobin, which is included as a reference in this study. By contrast, the signals are not consistent with photooxidation of the b hemes. This conclusion contrasts with a recent assessment based on a more limited data set. The binding kinetics of internal and external ligands are indicative of a rigid heme environment, consistent with the electron transfer function. We also report, for the first time, photoactivity of the very weakly absorbing iron-sulfur center. This yields the unexpected perspective of studying photochemistry, initiated by excitation of iron-sulfur clusters, in a range of protein complexes.
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Affiliation(s)
- Marten H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France.
| | | | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ursula Liebl
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France.
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22
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Nag L, Sournia P, Myllykallio H, Liebl U, Vos MH. Correction to “Identification of the TyrOH ●+ Radical Cation in the Flavoenzyme TrmFO”. J Am Chem Soc 2017; 139:15554. [DOI: 10.1021/jacs.7b10508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Abstract
Tyrosine (TyrOH) and tryptophan radicals play important roles as intermediates in biochemical charge-transfer reactions. Tryptophanyl radicals have been observed both in their protonated cation form and in their unprotonated neutral form, but to date, tyrosyl radicals have only been observed in their unprotonated form. With a genetically modified form of the flavoenzyme TrmFO as a suitable model system and using ultrafast fluorescence and absorption spectroscopy, we characterize its protonated precursor TyrOH•+, and we show this species to have a distinct visible absorption band and a transition moment that we suggest to lie close to the phenol symmetry axis. TyrOH•+ is formed in ∼1 ps by electron transfer to excited flavin and decays in ∼3 ps by charge recombination. These findings imply that TyrOH oxidation does not necessarily induce its concerted deprotonation. Our results will allow disentangling of photoproduct states in flavoproteins in often-encountered complex situations and more generally are important for understanding redox chains relying on tyrosyl intermediates.
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Affiliation(s)
- Lipsa Nag
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau 91128 Cedex, France
| | - Pierre Sournia
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau 91128 Cedex, France
| | - Hannu Myllykallio
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau 91128 Cedex, France
| | - Ursula Liebl
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau 91128 Cedex, France
| | - Marten H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay , Palaiseau 91128 Cedex, France
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24
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Vos MH, Reeder BJ, Daldal F, Liebl U. Correction: Ultrafast photochemistry of the bc 1 complex. Phys Chem Chem Phys 2017; 19:9320. [DOI: 10.1039/c7cp90057k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Ultrafast photochemistry of the bc1 complex’ by Marten H. Vos et al., Phys. Chem. Chem. Phys., 2017, 19, 6807–6813.
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Affiliation(s)
- Marten H. Vos
- LOB
- Ecole Polytechnique
- CNRS
- INSERM
- 91128 Palaiseau Cedex
| | | | - Fevzi Daldal
- Department of Biology
- University of Pennsylvania
- Philadelphia
- USA
| | - Ursula Liebl
- LOB
- Ecole Polytechnique
- CNRS
- INSERM
- 91128 Palaiseau Cedex
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25
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Bouzhir-Sima L, Motterlini R, Gross J, Vos MH, Liebl U. Unusual Dynamics of Ligand Binding to the Heme Domain of the Bacterial CO Sensor Protein RcoM-2. J Phys Chem B 2016; 120:10686-10694. [DOI: 10.1021/acs.jpcb.6b08160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Latifa Bouzhir-Sima
- LOB,
Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay, 91128 Palaiseau Cedex, France
| | - Roberto Motterlini
- Faculté
de Médicine, Université Paris-Est, Créteil 94000, France
- INSERM, U955, Equipe 12, Créteil 94000, France
| | - Julia Gross
- LOB,
Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay, 91128 Palaiseau Cedex, France
| | - Marten H. Vos
- LOB,
Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- LOB,
Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay, 91128 Palaiseau Cedex, France
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26
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Ferrante C, Pontecorvo E, Cerullo G, Vos MH, Scopigno T. Direct observation of subpicosecond vibrational dynamics in photoexcited myoglobin. Nat Chem 2016; 8:1137-1143. [PMID: 27874865 DOI: 10.1038/nchem.2569] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/09/2016] [Indexed: 11/10/2022]
Abstract
Determining the initial pathway for ultrafast energy redistribution within biomolecules is a challenge, and haem proteins, for which energy can be deposited locally in the haem moiety using short light pulses, are suitable model systems to address this issue. However, data acquired using existing experimental techniques that fail to combine sufficient structural sensitivity with adequate time resolution have resulted in alternative hypotheses concerning the interplay between energy flow among highly excited vibrational levels and potential concomitant electronic processes. By developing a femtosecond-stimulated Raman set-up, endowed with the necessary tunability to take advantage of different resonance conditions, here we visualize the temporal evolution of energy redistribution over different vibrational modes in myoglobin. We establish that the vibrational energy initially stored in the highly excited Franck-Condon manifold is transferred with different timescales into low- and high-frequency modes, prior to slow dissipation through the protein. These findings demonstrate that a newly proposed mechanism involving the population dynamics of specific vibrational modes settles the controversy on the existence of transient electronic intermediates.
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Affiliation(s)
- C Ferrante
- Dipartimento di Fisica, Università di Roma, La Sapienza, I-00185 Roma, Italy
| | - E Pontecorvo
- Dipartimento di Fisica, Università di Roma, La Sapienza, I-00185 Roma, Italy
| | - G Cerullo
- Istituto di Fotonica e Nanotecnologie (IFN-CNR), Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - M H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM, Université Paris-Saclay, 91128 Palaiseau Cedex, France
| | - T Scopigno
- Dipartimento di Fisica, Università di Roma, La Sapienza, I-00185 Roma, Italy.,Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
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27
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Krumova S, Todinova S, Tileva M, Bouzhir-Sima L, Vos MH, Liebl U, Taneva SG. Thermal stability and binding energetics of thymidylate synthase ThyX. Int J Biol Macromol 2016; 91:560-7. [PMID: 27268384 DOI: 10.1016/j.ijbiomac.2016.05.083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/20/2016] [Accepted: 05/23/2016] [Indexed: 10/21/2022]
Abstract
The bacterial thymidylate synthase ThyX is a multisubstrate flavoenzyme that takes part in the de novo synthesis of thymidylate in a variety of microorganisms. Herein we study the effect of FAD and dUMP binding on the thermal stability of wild type (WT) ThyX from the mesophilic Paramecium bursaria chlorella virus-1 (PBCV-1) and from the thermophilic bacterium Thermotoga maritima (TmThyX), and from two variants of TmThyX, Y91F and S88W, using differential scanning calorimetry. The energetics underlying these processes was characterized by isothermal titration calorimetry. The PBCV-1 protein is significantly less stable against the thermal challenge than the TmThyX WT. FAD exerted stabilizing effect greater for PBCV-1 than for TmThyX and for both mutants, whereas binding of dUMP to FAD-loaded proteins stabilized further only TmThyX. Different thermodynamic signatures describe the FAD binding to the WT ThyX proteins. While TmThyX binds FAD with a low μM binding affinity in a process characterized by a favorable entropy change, the assembly of PBCV-1 with FAD is governed by a large enthalpy change opposed by an unfavorable entropy change resulting in a relatively strong nM binding. An enthalpy-driven formation of a high affinity ternary ThyX/FAD/dUMP complex was observed only for TmThyX.
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Affiliation(s)
- Sashka Krumova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria
| | - Svetla Todinova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria
| | - Milena Tileva
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria
| | | | - Marten H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France
| | - Stefka G Taneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria.
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28
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Lambry JC, Stranava M, Lobato L, Martinkova M, Shimizu T, Liebl U, Vos MH. Ultrafast Spectroscopy Evidence for Picosecond Ligand Exchange at the Binding Site of a Heme Protein: Heme-Based Sensor YddV. J Phys Chem Lett 2016; 7:69-74. [PMID: 26651267 DOI: 10.1021/acs.jpclett.5b02517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
An important question for the functioning of heme proteins is whether different ligands present within the protein moiety can readily exchange with heme-bound ligands. Studying the dynamics of the heme domain of the Escherichia coli sensor protein YddV upon dissociation of NO from the ferric heme by ultrafast spectroscopy, we demonstrate that when the hydrophobic leucine residue in the distal heme pocket is mutated to glycine, in a substantial fraction of the protein water replaces NO as an internal ligand in as fast as ∼4 ps. This process, which is near-barrierless and occurs orders of magnitude faster than the corresponding process in myoglobin, corresponds to a ligand swap of NO with a water molecule present in the heme pocket, as corroborated by molecular dynamics simulations. Our findings provide important new insight into ligand exchange in heme proteins that functionally interact with different external ligands.
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Affiliation(s)
| | - Martin Stranava
- Department of Biochemistry, Faculty of Science, Charles University in Prague , Hlavova (Albertov) 2030/8, Prague 4, Czech Republic
| | - Laura Lobato
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France
| | - Marketa Martinkova
- Department of Biochemistry, Faculty of Science, Charles University in Prague , Hlavova (Albertov) 2030/8, Prague 4, Czech Republic
| | - Toru Shimizu
- Department of Biochemistry, Faculty of Science, Charles University in Prague , Hlavova (Albertov) 2030/8, Prague 4, Czech Republic
| | - Ursula Liebl
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France
| | - Marten H Vos
- LOB, Ecole Polytechnique, CNRS, INSERM, 91128 Palaiseau Cedex, France
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29
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Fojtikova V, Stranava M, Vos MH, Liebl U, Hranicek J, Kitanishi K, Shimizu T, Martinkova M. Kinetic Analysis of a Globin-Coupled Histidine Kinase, AfGcHK: Effects of the Heme Iron Complex, Response Regulator, and Metal Cations on Autophosphorylation Activity. Biochemistry 2015. [PMID: 26212354 DOI: 10.1021/acs.biochem.5b00517] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The globin-coupled histidine kinase, AfGcHK, is a part of the two-component signal transduction system from the soil bacterium Anaeromyxobacter sp. Fw109-5. Activation of its sensor domain significantly increases its autophosphorylation activity, which targets the His183 residue of its functional domain. The phosphate group of phosphorylated AfGcHK is then transferred to the cognate response regulator. We investigated the effects of selected variables on the autophosphorylation reaction's kinetics. The kcat values of the heme Fe(III)-OH(-), Fe(III)-cyanide, Fe(III)-imidazole, and Fe(II)-O2 bound active AfGcHK forms were 1.1-1.2 min(-1), and their Km(ATP) values were 18.9-35.4 μM. However, the active form bearing a CO-bound Fe(II) heme had a kcat of 1.0 min(-1) but a very high Km(ATP) value of 357 μM, suggesting that its active site structure differs strongly from the other active forms. The Fe(II) heme-bound inactive form had kcat and Km(ATP) values of 0.4 min(-1) and 78 μM, respectively, suggesting that its low activity reflects a low affinity for ATP relative to that of the Fe(III) form. The heme-free form exhibited low activity, with kcat and Km(ATP) values of 0.3 min(-1) and 33.6 μM, respectively, suggesting that the heme iron complex is essential for high catalytic activity. Overall, our results indicate that the coordination and oxidation state of the sensor domain heme iron profoundly affect the enzyme's catalytic activity because they modulate its ATP binding affinity and thus change its kcat/Km(ATP) value. The effects of the response regulator and different divalent metal cations on the autophosphorylation reaction are also discussed.
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Affiliation(s)
| | | | - Marten H Vos
- §Laboratoire d'Optique et Biosciences, INSERM U1182-CNRS UMR7645, Ecole Polytechnique, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- §Laboratoire d'Optique et Biosciences, INSERM U1182-CNRS UMR7645, Ecole Polytechnique, 91128 Palaiseau Cedex, France
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30
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Falvo C, Daniault L, Vieille T, Kemlin V, Lambry JC, Meier C, Vos MH, Bonvalet A, Joffre M. Ultrafast Dynamics of Carboxy-Hemoglobin: Two-Dimensional Infrared Spectroscopy Experiments and Simulations. J Phys Chem Lett 2015; 6:2216-2222. [PMID: 26266594 DOI: 10.1021/acs.jpclett.5b00811] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This Letter presents a comparison between experimental and simulated 2D mid-infrared spectra of carboxy-hemoglobin in the spectral region of the carbon monoxide stretching mode. The simulations rely on a fluctuating potential energy surface that includes both the effect of heme and the protein surroundings computed from molecular dynamics simulations. A very good agreement between theory and experiment is obtained with no adjustable parameters. The simulations show that the effect of the distal histidine through the hydrogen bond is strong and is directly responsible for the slow decay of the frequency-frequency correlation function on a 10 ps time scale. This study confirms that fluctuations in carboxy-hemoglobin are more inhomogeneous than those in the more frequently studied carboxy-myoglobin. The comparison between simulations and experiments brings valuable information on the complex relation between protein structure and spectral diffusion.
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Affiliation(s)
- Cyril Falvo
- †Institut des Sciences Moléculaires d'Orsay, Univ Paris-Sud, CNRS UMR 8214, 91405 Orsay, France
| | - Louis Daniault
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
| | - Thibault Vieille
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
| | - Vincent Kemlin
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
| | - Jean-Christophe Lambry
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
| | - Christoph Meier
- §Laboratoire Collisions Agrégats et Réactivité, IRSAMC, Université Paul Sabatier, CNRS UMR 5589, 31062 Toulouse, France
| | - Marten H Vos
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
| | - Adeline Bonvalet
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
| | - Manuel Joffre
- ‡Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR 7645, INSERM U1182, 91128 Palaiseau, France
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31
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Lobato L, Bouzhir-Sima L, Yamashita T, Wilson MT, Vos MH, Liebl U. Dynamics of the heme-binding bacterial gas-sensing dissimilative nitrate respiration regulator (DNR) and activation barriers for ligand binding and escape. J Biol Chem 2014; 289:26514-26524. [PMID: 25037216 DOI: 10.1074/jbc.m114.571398] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
DNR (dissimilative nitrate respiration regulator) is a heme-binding transcription factor that is involved in the regulation of denitrification in Pseudomonas aeruginosa. In the ferrous deoxy state, the heme is 6-coordinate; external NO and CO can replace an internal ligand. Using fluorescence anisotropy, we show that high-affinity sequence-specific DNA binding occurs only when the heme is nitrosylated, consistent with the proposed function of DNR as NO sensor and transcriptional activator. This role is moreover supported by the NO "trapping" properties revealed by ultrafast spectroscopy that are similar to those of other heme-based NO sensor proteins. Dissociated CO-heme pairs rebind in an essentially barrierless way. This process competes with migration out of the heme pocket. The latter process is thermally activated (Ea ∼ 7 kJ/mol). This result is compared with other heme proteins, including the homologous CO sensor/transcription factor CooA, variants of the 5-coordinate mycobacterial sensor DosT and the electron transfer protein cytochrome c. This comparison indicates that thermal activation of ligand escape from the heme pocket is specific for systems where an external ligand replaces an internal one. The origin of this finding and possible implications are discussed.
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Affiliation(s)
- Laura Lobato
- Laboratory for Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France,; INSERM U696, 91128 Palaiseau, France
| | - Latifa Bouzhir-Sima
- Laboratory for Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France,; INSERM U696, 91128 Palaiseau, France
| | - Taku Yamashita
- Laboratory of Analytical Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan, and
| | - Michael T Wilson
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester C04 3SQ, United Kingdom
| | - Marten H Vos
- Laboratory for Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France,; INSERM U696, 91128 Palaiseau, France,.
| | - Ursula Liebl
- Laboratory for Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France,; INSERM U696, 91128 Palaiseau, France,.
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Abstract
This chapter describes an experimental layout for time and spectrally resolved fluorescence measurements with femtosecond time resolution based on Kerr gating. The combination of data recorded using different Kerr media allows a temporal dynamic range from ~100 fs to several nanoseconds. Simultaneous analysis of multiple datasets is described.
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Affiliation(s)
- Sergey P Laptenok
- Laboratoire d'Optique et Biosciences, INSERM U696-CNRS UMR7645, Ecole Polytechnique, Palaiseau, France
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33
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Abstract
We present a new platform for the production and manipulation of microfluidic droplets in view of measuring the evolution of a chemical reaction. Contrary to existing approaches, our device uses gradients of confinement to produce a single drop on demand and guide it to a pre-determined location. In this way, two nanoliter drops containing different reagents can be placed in contact and merged together, in order to trigger a chemical reaction. The reaction rate is extracted from an analysis of the observed reaction-diffusion front. We show that the results obtained using this platform are in excellent agreement with stopped-flow measurements, while decreasing the sample consumption 5000 fold. We also show how the device operation can be parallelized in order to react an initial sample with a range of compounds or concentrations, on a single integrated chip. This integrated chip thus further reduces sample consumption while reducing the time required for the experimental runs from hours to minutes.
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Affiliation(s)
- Etienne Fradet
- Laboratoire d'Hydrodynamique (LadHyX) and Department of Mechanics, Ecole Polytechnique, CNRS, 91128, Palaiseau, France.
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Antonucci L, Bonvalet A, Solinas X, Jones MR, Vos MH, Joffre M. Arbitrary-detuning asynchronous optical sampling pump-probe spectroscopy of bacterial reaction centers. Opt Lett 2013; 38:3322-3324. [PMID: 23988946 DOI: 10.1364/ol.38.003322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A recently reported variant of asynchronous optical sampling compatible with arbitrary unstabilized laser repetition rates is applied to pump-probe spectroscopy. This makes possible the use of a 5.1 MHz chirped pulse oscillator as the pump laser, thus extending the available time window to almost 200 ns with a time resolution as good as about 320 fs. The method is illustrated with the measurement in a single experiment of the complete charge transfer dynamics of the reaction center from Rhodobacter sphaeroides.
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Affiliation(s)
- Laura Antonucci
- Laboratoire d’Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, 91128 Palaiseau, France
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Laptenok SP, Bouzhir-Sima L, Lambry JC, Myllykallio H, Liebl U, Vos MH. Ultrafast real-time visualization of active site flexibility of flavoenzyme thymidylate synthase ThyX. Proc Natl Acad Sci U S A 2013; 110:8924-9. [PMID: 23671075 PMCID: PMC3670337 DOI: 10.1073/pnas.1218729110] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In many bacteria the flavoenzyme thymidylate synthase ThyX produces the DNA nucleotide deoxythymidine monophosphate from dUMP, using methylenetetrahydrofolate as carbon donor and NADPH as hydride donor. Because all three substrates bind in close proximity to the catalytic flavin adenine dinucleotide group, substantial flexibility of the ThyX active site has been hypothesized. Using femtosecond time-resolved fluorescence spectroscopy, we have studied the conformational heterogeneity and the conformational interconversion dynamics in real time in ThyX from the hyperthermophilic bacterium Thermotoga maritima. The dynamics of electron transfer to excited flavin adenine dinucleotide from a neighboring tyrosine residue are used as a sensitive probe of the functional dynamics of the active site. The fluorescence decay spanned a full three orders of magnitude, demonstrating a very wide range of conformations. In particular, at physiological temperatures, multiple angstrom cofactor-residue displacements occur on the picoseconds timescale. These experimental findings are supported by molecular dynamics simulations. Binding of the dUMP substrate abolishes this flexibility and stabilizes the active site in a configuration where dUMP closely interacts with the flavin cofactor and very efficiently quenches fluorescence itself. Our results indicate a dynamic selected-fit mechanism where binding of the first substrate dUMP at high temperature stabilizes the enzyme in a configuration favorable for interaction with the second substrate NADPH, and more generally have important implications for the role of active site flexibility in enzymes interacting with multiple poly-atom substrates and products. Moreover, our data provide the basis for exploring the effect of inhibitor molecules on the active site dynamics of ThyX and other multisubstrate flavoenzymes.
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Affiliation(s)
- Sergey P. Laptenok
- Laboratory for Optics and Biosciences, Centre National de la Recherche Scientifique Ecole Polytechnique, 91128 Palaiseau, France; and
- Institut National de la Santé et de la Recherche Médicale U696, 91128 Palaiseau, France
| | - Latifa Bouzhir-Sima
- Laboratory for Optics and Biosciences, Centre National de la Recherche Scientifique Ecole Polytechnique, 91128 Palaiseau, France; and
- Institut National de la Santé et de la Recherche Médicale U696, 91128 Palaiseau, France
| | - Jean-Christophe Lambry
- Laboratory for Optics and Biosciences, Centre National de la Recherche Scientifique Ecole Polytechnique, 91128 Palaiseau, France; and
- Institut National de la Santé et de la Recherche Médicale U696, 91128 Palaiseau, France
| | - Hannu Myllykallio
- Laboratory for Optics and Biosciences, Centre National de la Recherche Scientifique Ecole Polytechnique, 91128 Palaiseau, France; and
- Institut National de la Santé et de la Recherche Médicale U696, 91128 Palaiseau, France
| | - Ursula Liebl
- Laboratory for Optics and Biosciences, Centre National de la Recherche Scientifique Ecole Polytechnique, 91128 Palaiseau, France; and
- Institut National de la Santé et de la Recherche Médicale U696, 91128 Palaiseau, France
| | - Marten H. Vos
- Laboratory for Optics and Biosciences, Centre National de la Recherche Scientifique Ecole Polytechnique, 91128 Palaiseau, France; and
- Institut National de la Santé et de la Recherche Médicale U696, 91128 Palaiseau, France
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Liebl U, Lambry JC, Vos MH. Primary processes in heme-based sensor proteins. Biochim Biophys Acta 2013; 1834:1684-92. [PMID: 23485911 DOI: 10.1016/j.bbapap.2013.02.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/08/2013] [Accepted: 02/16/2013] [Indexed: 12/22/2022]
Abstract
A wide and still rapidly increasing range of heme-based sensor proteins has been discovered over the last two decades. At the molecular level, these proteins function as bistable switches in which the catalytic activity of an enzymatic domain is altered mostly by binding or dissociation of small gaseous ligands (O2, NO or CO) to the heme in a sensor domain. The initial "signal" at the heme level is subsequently transmitted within the protein to the catalytic site, ultimately leading to adapted expression levels of specific proteins. Making use of the photolability of the heme-ligand bond that mimics thermal dissociation, early processes in this intra-protein signaling pathway can be followed using ultrafast optical spectroscopic techniques; they also occur on timescales accessible to molecular dynamics simulations. Experimental studies performed over the last decade on proteins including the sensors FixL (O2), CooA (CO) and soluble guanylate cyclase (NO) are reviewed with an emphasis on emerging general mechanisms. After heme-ligand bond breaking, the ligand can escape from the heme pocket and eventually from the protein, or rebind directly to the heme. Remarkably, in all sensor proteins the rebinding, specifically of the sensed ligand, is highly efficient. This "ligand trap" property possibly provides means to smoothen the effects of fast environmental fluctuations on the switching frequency. For 6-coordinate proteins, where exchange between an internal heme-bound residue and external gaseous ligands occurs, the study of early processes starting from the unliganded form indicates that mobility of the internal ligand may facilitate signal transfer. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.
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Affiliation(s)
- Ursula Liebl
- Laboratory for Optics and Biosciences, CNRS, Ecole Polytechnique, Palaiseau, France
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Abstract
Cardiolipin, a phospholipid specific to the mitochondrion, interacts with the small electron transfer heme protein cytochrome c through both electrostatic and hydrophobic interactions. Once in a complex with cardiolipin, cytochrome c has been shown to undergo a conformational change that leads to the rupture of the bond between the heme iron and the intrinsic sulfur ligand of a methionine residue and to enhance the peroxidatic properties of the protein considered important to its apoptotic activity. Here we report that the ferric cytochrome c/cardiolipin complex binds nitric oxide tightly through a multistep process in which the first step is the relatively slow displacement (5 s(-1)) from heme coordination of an intrinsic ligand that replaces methionine in the complex. Nanosecond photolysis of the nitrosyl adduct demonstrated that a fraction of the nitric oxide escapes from the heme pocket and subsequently recombines to the heme in second-order processes (k = 1.8 × 10(6) and 5.5 × 10(5) M(-1) s(-1)) that, under these conditions, were much faster than recombination of the intrinsic ligand with which they compete. Ultrafast (femtosecond) laser photolysis showed that the geminate recombination of nitric oxide to the heme occurred with time constants (τ = 22 and 72 ps) and that ~23% of the photolyzed nitric oxide escaped into the bulk phase. This high value for the escape fraction relative to other heme proteins indicates the open nature of the heme pocket in this complex. These results are summarized in a scheme and are discussed in terms of the possible modulation of the apoptotic activity of cytochrome c by nitric oxide.
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Affiliation(s)
- G Silkstone
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, C04 3SQ, UK.
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Creze C, Ligabue A, Laurent S, Lestini R, Laptenok SP, Khun J, Vos MH, Czjzek M, Myllykallio H, Flament D. Modulation of the Pyrococcus abyssi NucS endonuclease activity by replication clamp at functional and structural levels. J Biol Chem 2012; 287:15648-60. [PMID: 22431731 DOI: 10.1074/jbc.m112.346361] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pyrococcus abyssi NucS is the founding member of a new family of structure-specific DNA endonucleases that interact with the replication clamp proliferating cell nuclear antigen (PCNA). Using a combination of small angle x-ray scattering and surface plasmon resonance analyses, we demonstrate the formation of a stable complex in solution, in which one molecule of the PabNucS homodimer binds to the outside surface of the PabPCNA homotrimer. Using fluorescent labels, PCNA is shown to increase the binding affinity of NucS toward single-strand/double-strand junctions on 5' and 3' flaps, as well as to modulate the cleavage specificity on the branched DNA structures. Our results indicate that the presence of a single major contact between the PabNucS and PabPCNA proteins, together with the complex-induced DNA bending, facilitate conformational flexibility required for specific cleavage at the single-strand/double-strand DNA junction.
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Affiliation(s)
- Christophe Creze
- Ifremer, UMR6197, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
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Jasaitis A, Ouellet H, Lambry JC, Martin JL, Friedman JM, Guertin M, Vos MH. Ultrafast heme–ligand recombination in truncated hemoglobin HbO from Mycobacterium tuberculosis: A ligand cage. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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41
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Vos MH, Bouzhir-Sima L, Lambry JC, Luo H, Eaton-Rye JJ, Ioanoviciu A, Ortiz de Montellano PR, Liebl U. Ultrafast ligand dynamics in the heme-based GAF sensor domains of the histidine kinases DosS and DosT from Mycobacterium tuberculosis. Biochemistry 2012; 51:159-66. [PMID: 22142262 PMCID: PMC3254832 DOI: 10.1021/bi201467c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The transcriptional regulator DosR from M. tuberculosis plays a crucial role in the virulence to dormancy transition of the pathogen. DosR can be activated by DosT and DosS, two histidine kinases with heme-containing sensor GAF domains, capable of diatomic ligand binding. To investigate the initial processes occurring upon ligand dissociation, we performed ultrafast time-resolved absorption spectroscopy of the isolated sensor domains ligated with O(2), NO, and CO. The results reveal a relatively closed heme pocket for both proteins. For DosT the yield of O(2) escape from the heme pocket on the picoseconds time scale upon photodissociation was found to be very low (1.5%), similar to other heme-based oxygen sensor proteins, implying that this sensor acts as an effective O(2) trap. Remarkably, this yield is an order of magnitude higher in DosS (18%). For CO, by contrast, the fraction of CO rebinding within the heme pocket is higher in DosS. Experiments with mutant DosT sensor domains and molecular dynamics simulations indicate an important role in ligand discrimination of the distal tyrosine, present in both proteins, which forms a hydrogen bond with heme-bound O(2). We conclude that despite their similarity, DosT and DosS display ligand-specific different primary dynamics during the initial phases of intraprotein signaling. The distal tyrosine, present in both proteins, plays an important role in these processes.
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Affiliation(s)
- Marten H Vos
- Laboratory for Optics and Biosciences, CNRS Ecole Polytechnique, 91128 Palaiseau, France.
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Lechardeur D, Cesselin B, Liebl U, Vos MH, Fernandez A, Brun C, Gruss A, Gaudu P. Discovery of intracellular heme-binding protein HrtR, which controls heme efflux by the conserved HrtB-HrtA transporter in Lactococcus lactis. J Biol Chem 2011; 287:4752-8. [PMID: 22084241 DOI: 10.1074/jbc.m111.297531] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Most commensal and food bacteria lack heme biosynthesis genes. For several of these, the capture of environmental heme is a means of activating aerobic respiration metabolism. Our previous studies in the Gram-positive bacterium Lactococcus lactis showed that heme exposure strongly induced expression of a single operon, called here hrtRBA, encoding an ortholog of the conserved membrane hrt (heme-regulated transporter) and a unique transcriptional regulator that we named HrtR. We show that HrtR expressed as a fusion protein is a heme-binding protein. Heme iron interaction with HrtR is non-covalent, hexacoordinated, and involves two histidines, His-72 and His-149. HrtR specifically binds a 15-nt palindromic sequence in the hrtRBA promoter region, which is needed for hrtRBA repression. HrtR-DNA binding is abolished by heme addition, which activates expression of the HrtB-HrtA (HrtBA) transporter in vitro and in vivo. The use of HrtR as an intracellular heme sensor appears to be conserved among numerous commensal bacteria, in contrast with numerous Gram-positive pathogens that use an extracellular heme-sensing system, HssRS, to regulate hrt. Finally, we show for the first time that HrtBA permease controls heme toxicity by its direct and specific efflux. The use of an intracellular heme sensor to control heme efflux constitutes a novel paradigm for bacterial heme homeostasis.
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Nuernberger P, Lee KF, Bonvalet A, Bouzhir-Sima L, Lambry JC, Liebl U, Joffre M, Vos MH. Strong Ligand–Protein Interactions Revealed by Ultrafast Infrared Spectroscopy of CO in the Heme Pocket of the Oxygen Sensor FixL. J Am Chem Soc 2011; 133:17110-3. [DOI: 10.1021/ja204549n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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Groma GI, Colonna A, Martin JL, Vos MH. Vibrational motions associated with primary processes in bacteriorhodopsin studied by coherent infrared emission spectroscopy. Biophys J 2011; 100:1578-86. [PMID: 21402041 DOI: 10.1016/j.bpj.2011.02.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/01/2011] [Accepted: 02/04/2011] [Indexed: 11/18/2022] Open
Abstract
The primary energetic processes driving the functional proton pump of bacteriorhodopsin take place in the form of complex molecular dynamic events after excitation of the retinal chromophore into the Franck-Condon state. These early events include a strong electronic polarization, skeletal stretching, and all-trans-to-13-cis isomerization upon formation of the J intermediate. The effectiveness of the photoreaction is ensured by a conical intersection between the electronic excited and ground states, providing highly nonadiabatic coupling to nuclear motions. Here, we study real-time vibrational coherences associated with these motions by analyzing light-induced infrared emission from oriented purple membranes in the 750-1400 cm(-)(1) region. The experimental technique applied is based on second-order femtosecond difference frequency generation on macroscopically ordered samples that also yield information on phase and direction of the underlying motions. Concerted use of several analysis methods resulted in the isolation and characterization of seven different vibrational modes, assigned as C-C stretches, out-of-plane methyl rocks, and hydrogen out-of-plane wags, whereas no in-plane H rock was found. Based on their lifetimes and several other criteria, we deduce that the majority of the observed modes take place on the potential energy surface of the excited electronic state. In particular, the direction sensitivity provides experimental evidence for large intermediate distortions of the retinal plane during the excited-state isomerization process.
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Affiliation(s)
- Géza I Groma
- Laboratory for Optical Biosciences, Ecole Polytechnique, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Palaiseau, France.
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Abstract
The relationship between the thermodynamical and structural properties of photosynthetic reaction centers and kinetics and polarization of electric field-induced luminescence was studied. A general model is presented to describe the influence of an electric field on the individual electron transfer rate constants. Comparison of simulations with this model and experimental curves of Photosystem I electroluminescence showed that (a) at least three electrogenic electron transfer steps occur: P-700 to A(0)( approximately 30%), A(0) to A(1) ( approximately 50%), and A(1) to F(A)( approximately 20%), (b) the midpoint potential of A(1)/A-(1) is approximately - 0.81 V, and (c) the emission moments of the pigments make on average an angle of 67 degrees with the membrane normal. It is concluded that the analysis of electro-luminescence kinetics may be a powerful technique to obtain information on primary processes using relatively intact systems.
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Affiliation(s)
- M H Vos
- Department of Biophysics, Huygens Laboratory of the State University, 2300 RA Leiden, The Netherlands
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Rappaport F, Zhang J, Vos MH, Gennis RB, Borisov VB. Heme-heme and heme-ligand interactions in the di-heme oxygen-reducing site of cytochrome bd from Escherichia coli revealed by nanosecond absorption spectroscopy. Biochim Biophys Acta 2010; 1797:1657-64. [PMID: 20529691 DOI: 10.1016/j.bbabio.2010.05.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 05/12/2010] [Accepted: 05/15/2010] [Indexed: 01/07/2023]
Abstract
Cytochrome bd is a terminal quinol:O(2) oxidoreductase of respiratory chains of many bacteria. It contains three hemes, b(558), b(595), and d. The role of heme b(595) remains obscure. A CO photolysis/recombination study of the membranes of Escherichia coli containing either wild type cytochrome bd or inactive E445A mutant was performed using nanosecond absorption spectroscopy. We compared photoinduced changes of heme d-CO complex in one-electron-reduced, two-electron-reduced, and fully reduced states of cytochromes bd. The line shape of spectra of photodissociation of one-electron-reduced and two-electron-reduced enzymes is strikingly different from that of the fully reduced enzyme. The difference demonstrates that in the fully reduced enzyme photolysis of CO from heme d perturbs ferrous heme b(595) causing loss of an absorption band centered at 435 nm, thus supporting interactions between heme b(595) and heme d in the di-heme oxygen-reducing site, in agreement with previous works. Photolyzed CO recombines with the fully reduced enzyme monoexponentially with tau approximately 12 micros, whereas recombination of CO with one-electron-reduced cytochrome bd shows three kinetic phases, with tau approximately 14 ns, 14 micros, and 280 micros. The spectra of the absorption changes associated with these components are different in line shape. The 14 ns phase, absent in the fully reduced enzyme, reflects geminate recombination of CO with part of heme d. The 14-micros component reflects bimolecular recombination of CO with heme d and electron backflow from heme d to hemes b in approximately 4% of the enzyme population. The final, 280-micros component, reflects return of the electron from hemes b to heme d and bimolecular recombination of CO in that population. The fact that even in the two-electron-reduced enzyme, a nanosecond geminate recombination is observed, suggests that namely the redox state of heme b(595), and not that of heme b(558), controls the pathway(s) by which CO migrates between heme d and the medium.
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Affiliation(s)
- Fabrice Rappaport
- Institut de Biologie Physico-Chimique, Unite Mixte de Recherche 7141 CNRS, Universite Paris 6, 13 Rue Pierre et Marie Curie, 75005 Paris, France
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Silkstone G, Kapetanaki SM, Husu I, Vos MH, Wilson MT. Nitric oxide binds to the proximal heme coordination site of the ferrocytochrome c/cardiolipin complex: formation mechanism and dynamics. J Biol Chem 2010; 285:19785-92. [PMID: 20395293 DOI: 10.1074/jbc.m109.067736] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian mitochondrial cytochrome c interacts with cardiolipin to form a complex (cyt. c/CL) important in apoptosis. Here we show that this interaction leads to structural changes in ferrocytochrome c that leads to an open coordinate site on the central iron, resulting from the dissociation of the intrinsic methionine residue, where NO can rapidly bind (k = 1.2 x 10(7) m(-1) s(-1)). Accompanying NO binding, the proximal histidine dissociates leaving the heme pentacoordinate, in contrast to the hexacoordinate nitrosyl adducts of native ferrocytochrome c or of the protein in which the coordinating methionine is removed by chemical modification or mutation. We present the results of stopped-flow and photolysis experiments that show that following initial NO binding to the heme, there ensues an unusually complex set of kinetic steps. The spectral changes associated with these kinetic transitions, together with their dependence on NO concentration, have been determined and lead us to conclude that NO binding to cyt. c/CL takes place via an overall scheme comparable to that described for cytochrome c' and guanylate cyclase, the final product being one in which NO resides on the proximal side of the heme. In addition, novel features not observed before in other heme proteins forming pentacoordinate nitrosyl species, include a high yield of NO escape after dissociation, rapid (<1 ms) dissociation of proximal histidine upon NO binding and its very fast binding (60 ps) after NO dissociation, and the formation of a hexacoordinate intermediate. These features all point at a remarkable mobility of the proximal heme environment induced by cardiolipin.
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Affiliation(s)
- Gary Silkstone
- Department of Biological Sciences, Wivenhoe Park, University of Essex, Colchester CO4 3SQ, United Kingdom
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Byrdin M, Lukacs A, Thiagarajan V, Eker APM, Brettel K, Vos MH. Quantum Yield Measurements of Short-Lived Photoactivation Intermediates in DNA Photolyase: Toward a Detailed Understanding of the Triple Tryptophan Electron Transfer Chain. J Phys Chem A 2009; 114:3207-14. [DOI: 10.1021/jp9093589] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin Byrdin
- CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogène, Gif sur Yvette, F-91191, France, CNRS, URA2096, Gif sur Yvette, F-91191, France, Laboratoire d’Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France, INSERM U696, F-91128 Palaiseau, France, and Department of Cell Biology and Genetics, Medical Genetics Centre, Erasmus University Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Andras Lukacs
- CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogène, Gif sur Yvette, F-91191, France, CNRS, URA2096, Gif sur Yvette, F-91191, France, Laboratoire d’Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France, INSERM U696, F-91128 Palaiseau, France, and Department of Cell Biology and Genetics, Medical Genetics Centre, Erasmus University Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Viruthachalam Thiagarajan
- CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogène, Gif sur Yvette, F-91191, France, CNRS, URA2096, Gif sur Yvette, F-91191, France, Laboratoire d’Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France, INSERM U696, F-91128 Palaiseau, France, and Department of Cell Biology and Genetics, Medical Genetics Centre, Erasmus University Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - André P. M. Eker
- CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogène, Gif sur Yvette, F-91191, France, CNRS, URA2096, Gif sur Yvette, F-91191, France, Laboratoire d’Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France, INSERM U696, F-91128 Palaiseau, France, and Department of Cell Biology and Genetics, Medical Genetics Centre, Erasmus University Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Klaus Brettel
- CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogène, Gif sur Yvette, F-91191, France, CNRS, URA2096, Gif sur Yvette, F-91191, France, Laboratoire d’Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France, INSERM U696, F-91128 Palaiseau, France, and Department of Cell Biology and Genetics, Medical Genetics Centre, Erasmus University Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Marten H. Vos
- CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogène, Gif sur Yvette, F-91191, France, CNRS, URA2096, Gif sur Yvette, F-91191, France, Laboratoire d’Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France, INSERM U696, F-91128 Palaiseau, France, and Department of Cell Biology and Genetics, Medical Genetics Centre, Erasmus University Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
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Lechauve C, Bouzhir-Sima L, Yamashita T, Marden MC, Vos MH, Liebl U, Kiger L. Heme ligand binding properties and intradimer interactions in the full-length sensor protein dos from Escherichia coli and its isolated heme domain. J Biol Chem 2009; 284:36146-36159. [PMID: 19864414 DOI: 10.1074/jbc.m109.066811] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dos from Escherichia coli is a bacterial gas sensor protein comprising a heme-containing gas sensor domain and a phosphodiesterase catalytic domain. Using a combination of static light scattering and gel filtration experiments, we established that, as are many other sensor proteins, the full-length protein is dimeric. The full-length dimer (association constant <10 nm) is more stable than the dimeric heme domain (association constant approximately 1 mum), and the dimer interface presumably includes both sensor and catalytic domains. Ultrafast spectroscopic studies showed little influence of the catalytic domain on kinetic processes in the direct vicinity of the heme. By contrast, the properties of ligand (CO and O(2)) binding to the heme in the sensor domain, occurring on a microsecond to second time scale, were found to be influenced by (i) the presence of the catalytic domain, (ii) the dimerization state, and in dimers, (iii) the ligation state of the other subunit. These results imply allosteric interactions within dimers. Steady-state titrations demonstrated marked cooperativity in oxygen binding to both the full-length protein and the isolated heme domain, a feature not reported to date for any dimeric sensor protein. Analysis of a variety of time-resolved experiments showed that Met-95 plays a major role in the intradimer interactions. The intrinsic binding and dissociation rates of Met-95 to the heme were modulated approximately 10-fold by intradimer and sensor-catalytic domain interactions. Dimerization effects were also observed for cyanide binding to the ferric heme domains, suggesting a similar role for Met-95 in ferric proteins.
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Affiliation(s)
| | - Latifa Bouzhir-Sima
- Laboratory of Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France; INSERM U696, 91228 Palaiseau, France
| | - Taku Yamashita
- Laboratory of Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France; INSERM U696, 91228 Palaiseau, France
| | - Michael C Marden
- INSERM U779, Universités Paris VI et XI, 94276 Le Kremlin-Bicêtre, France
| | - Marten H Vos
- Laboratory of Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France; INSERM U696, 91228 Palaiseau, France.
| | - Ursula Liebl
- Laboratory of Optics and Biosciences, CNRS, Ecole Polytechnique, 91128 Palaiseau, France; INSERM U696, 91228 Palaiseau, France
| | - Laurent Kiger
- INSERM U779, Universités Paris VI et XI, 94276 Le Kremlin-Bicêtre, France.
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Nuernberger P, Lee KF, Bonvalet A, Polack T, Vos MH, Alexandrou A, Joffre M. Suppression of perturbed free-induction decay and noise in experimental ultrafast pump-probe data. Opt Lett 2009; 34:3226-3228. [PMID: 19838281 DOI: 10.1364/ol.34.003226] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We apply a Fourier filtering technique for the global removal of coherent contributions, like perturbed free-induction decay, and noise, to experimental pump-probe spectra. A further filtering scheme gains access to spectra otherwise only recordable by scanning the probe's center frequency with adjustable spectral resolution. These methods cleanse pump-probe data and allow improved visualization and simpler analysis of the contained dynamics. We demonstrate these filters using visible pump/mid-infrared probe spectroscopy of ligand dissociation in carboxyhemoglobin.
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