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Lafiosca P, Gómez S, Giovannini T, Cappelli C. Absorption Properties of Large Complex Molecular Systems: The DFTB/Fluctuating Charge Approach. J Chem Theory Comput 2022; 18:1765-1779. [PMID: 35184553 PMCID: PMC8908768 DOI: 10.1021/acs.jctc.1c01066] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
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We report on the
first formulation of a novel polarizable QM/MM
approach, where the density functional tight binding (DFTB) is coupled
to the fluctuating charge (FQ) force field. The resulting method (DFTB/FQ)
is then extended to the linear response within the TD-DFTB framework
and challenged to study absorption spectra of large condensed-phase
systems.
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Affiliation(s)
- Piero Lafiosca
- Scuola Normale Superiore, Classe di Scienze, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Sara Gómez
- Scuola Normale Superiore, Classe di Scienze, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Tommaso Giovannini
- Scuola Normale Superiore, Classe di Scienze, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Chiara Cappelli
- Scuola Normale Superiore, Classe di Scienze, Piazza dei Cavalieri 7, 56126 Pisa, Italy
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2
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Soorkia S, Jouvet C, Grégoire G. UV Photoinduced Dynamics of Conformer-Resolved Aromatic Peptides. Chem Rev 2019; 120:3296-3327. [DOI: 10.1021/acs.chemrev.9b00316] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Satchin Soorkia
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Christophe Jouvet
- CNRS, Aix Marseille Université, PIIM UMR 7345, 13397, Marseille, France
| | - Gilles Grégoire
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
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3
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Sahu P, Ali SM, Shenoy KT, Mohan S. Structure, Dynamics, and Adsorption of Charged Guest within the Nanocavity of Polymer-Functionalized Neutral Macrocyclic Host. ACS APPLIED MATERIALS & INTERFACES 2018; 10:20968-20982. [PMID: 29847905 DOI: 10.1021/acsami.8b03874] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Host-guest encapsulation has been widely applied for purification and seizing of the metal ions. Macrocyclic crown ethers are one of the most popular hosts in the field of host-guest chemistry, which on functionalization with polymers are employed as an effective adsorbent. In spite of their vast applications, the microscopic information about their sensing mechanism toward cations/molecules is very scarce. Therefore, the present study is focused on the molecular insights of ion-exchange mechanism within the cavity of crown ether-functionalized polymers using molecular dynamics (MD) simulations. This present study investigates the molecular-level events of chloromethylated polystyrene (CMPS) bearing dibenzo-18-crown-6 (DB18C6) in the aqueous and acidic environment, which has been found to be particularly successful in sensing of various alkali and alkali earth metal ions. A strategy has been envisaged to design a crown ether-based functionalized polymeric resin, which exhibits good match of properties with the in-house-synthesized resin. The MD studies well capture the experimentally observed Langmuir-type adsorption isotherms of Li+ ions on crown ether-grafted polymer resins. The presence of acid reduces the adsorption of Li+ ions due to the competition with H3O+ ions. In addition, the results revealed that the "adsorption in crown cavity" follows a dual residence time function. To the best of our knowledge, this is the first report on the adsorption isotherm of functionalized crown ether using MD simulations. The structure and dynamics of binding sites were explored using radial distribution functions and diffusion coefficients. All of these effects have been studied for different Li+-ion concentrations, acid concentrations, and counterions as well as different lengths of polymer chains and degrees of polymerization. Overall, the present study provides insights into and quantitative information about adsorption on the CMPS-DB18C6 resin, which might be useful in myriads of host-guest-based adsorption experiments.
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Affiliation(s)
- Pooja Sahu
- Bhabha Atomic Research Center , Mumbai 400085 , Maharashtra , India
- Homi Bhabha National Institute , Mumbai 400094 , Maharashtra , India
| | - Sk Musharaf Ali
- Bhabha Atomic Research Center , Mumbai 400085 , Maharashtra , India
- Homi Bhabha National Institute , Mumbai 400094 , Maharashtra , India
| | | | - Sadhana Mohan
- Bhabha Atomic Research Center , Mumbai 400085 , Maharashtra , India
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4
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Hansen K, Skinnerup Byskov C, Nielsen SB. Energy flow in peptides after UV photoexcitation of backbone linkages. Phys Chem Chem Phys 2018; 19:19640-19645. [PMID: 28474727 DOI: 10.1039/c7cp01768e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We report on the dissociation channels after UV photoexcitation of peptide cations tagged with 18-crown-6 ether (CE). The model peptides chosen for study were singly protonated (Ala)n-Pro (n = 1, 2, 3) and Pro-Pro (Ala = alanine, Pro = proline) that all contain at least one tertiary amide group with high absorption cross section at 210 nm (5.90 eV). Statistical dissociation was identified from the loss of CE, a process occuring remotely from the initial site of excitation, and therefore requiring flow of energy to the ammonium group where the CE is bound. However, homolytic breakage of the peptide backbone at the site of excitation is competitive, resulting in so-called a radical cations. Density functional theory calculations of dissociation energies were done on the simplest system [Ala-Pro + H+](CE) and found to be 1.87 eV for CE loss and 3.29 eV for the formation of a+(CE) and x. These numbers were used to calculate statistical branching ratios for the dissociation processes based on detailed balance. After the absorption of two 210 nm photons (according to power-dependence measurements), the branching ratio between the two channels is calculated to be less than 10-4, far below the observed ratio of 0.65. Hence both statistical and non-statistical dissociation contribute to dissociation of these photoexcited peptides.
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Affiliation(s)
- Klavs Hansen
- Tianjin International Center of Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, P. R. China.
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5
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Noble JA, Dedonder-Lardeux C, Mascetti J, Jouvet C. Electronic Spectroscopy of Protonated 1-Aminopyrene in a Cold Ion Trap. Chem Asian J 2017; 12:1523-1531. [DOI: 10.1002/asia.201700327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/31/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Jennifer Anna Noble
- Institut des Sciences Moléculaires (ISM, UMR 5255); Université de Bordeaux and CNRS; 351 Cours de la Libération F-33405 Talence France
| | - Claude Dedonder-Lardeux
- CNRS, Aix-Marseille Université, PIIM UMR 7345; Avenue Escadrille Normandie-Niémen 13397 Marseille Cedex 20 France
| | - Joëlle Mascetti
- Institut des Sciences Moléculaires (ISM, UMR 5255); Université de Bordeaux and CNRS; 351 Cours de la Libération F-33405 Talence France
| | - Christophe Jouvet
- CNRS, Aix-Marseille Université, PIIM UMR 7345; Avenue Escadrille Normandie-Niémen 13397 Marseille Cedex 20 France
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6
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Byskov CS, Jensen F, Jørgensen TJD, Nielsen SB. On the photostability of peptides after selective photoexcitation of the backbone: prompt versus slow dissociation. Phys Chem Chem Phys 2015; 16:15831-8. [PMID: 24945849 DOI: 10.1039/c4cp02015d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vulnerability of biomolecules to ultraviolet radiation is intimately linked to deexcitation pathways: photostability requires fast internal conversion to the electronic ground state, but also intramolecular vibrational redistribution and cooling on a time scale faster than dissociation. Here we present a protocol to disentangle slow and non-hazardous statistical dissociation from prompt cleavage of peptide bonds by 210 nm light based on experiments on protonated peptides isolated in vacuo and tagged by 18-crown-6 ether (CE). The weakest link in the system is between the charged site and CE, which is remote from the initial site of excitation. Hence loss of CE serves as direct proof that energy has reached the charge-site end, leaving the backbone intact. Our work demonstrates that excitation of tertiary amide moieties (proline linkages) results in both prompt dissociation and statistical dissociation after energy randomisation over all vibrational degrees of freedom.
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7
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Nielsen SB, Nielsen MB, Rubio A. Spectroscopy of nitrophenolates in vacuo: effect of spacer, configuration, and microsolvation on the charge-transfer excitation energy. Acc Chem Res 2014; 47:1417-25. [PMID: 24673172 DOI: 10.1021/ar500025h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a charge-transfer (CT) transition, electron density moves from one end of the molecule (donor) to the other end (acceptor). This type of transition is of paramount importance in nature, for example, in photosynthesis, and it governs the excitation of several protein biochromophores and luminophores such as the oxyluciferin anion that accounts for light emission from fireflies. Both transition energy and oscillator strength are linked to the coupling between the donor and acceptor groups: The weaker the coupling, the smaller the excitation energy. But a weak coupling necessarily also causes a low oscillator strength possibly preventing direct excitation (basically zero probability in the noncoupling case). The coupling is determined by the actual spacer between the two groups, and whether the spacer acts as an insulator or a conductor. However, it can be difficult or even impossible to distinguish the effect of the spacer from that of local solvent molecules that often cause large solvent shifts due to different ground-state and excited-state stabilization. This calls for gas-phase spectroscopy experiments where absorption by the isolated molecule is identified to unequivocally establish the intrinsic molecular properties with no perturbations from a microenvironment. From such insight, the effect of a protein microenvironment on the CT excited state can be deduced. In this Account, we review our results over the last 5 years from mass spectroscopy experiments using specially designed apparatus on several charged donor-acceptor ions that are based on the nitrophenolate moiety and π-extended derivatives, which are textbook examples of donor-acceptor chromophores. The phenolate oxygen is the donor, and the nitro group is the acceptor. The choice of this system is also based on the fact that phenolate is a common structural motif of biochromophores and luminophores, for example, it is a constituent of the oxyluciferin anion. A presentation of the setups used for gas-phase ion spectroscopy in Aarhus is given, and we address issues of whether double bonds or triple bonds best convey electronic coupling between the phenolate oxygen and the nitro group, the significance of separating the donor and acceptor spatially, the influence of cross-conjugation versus linear conjugation, and along this line ortho versus meta versus para configuration, and not least the effect of a single solvent molecule (water, methanol, or acetonitrile). From systematic studies, a clear picture has emerged that has been supported by high-level calculations of electronically excited states. Our work shows that CC2 coupled-cluster calculations of vertical excitation energies are within 0.2 eV of experimental band maxima, and importantly, that the theoretical method is excellent in predicting the relative order of excitation energies of a series of nitrophenolates. Finally, we discuss future challenges such as following the change in absorption as a function of the number of solvent molecules and when gradually approaching the bulk limit.
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Affiliation(s)
- Steen Brøndsted Nielsen
- Department
of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Mogens Brøndsted Nielsen
- Department of Chemistry & Center for Exploitation of Solar Energy, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
| | - Angel Rubio
- NanoBio Spectroscopy
Group and ETSF Centre for Scientific Development, Centro Mixto CSICUPV/EHU
“Fisica de Materiales”, University of the Basque Country
UPV/EHU Centro Joxe Mari Korta, Avenida
de Tolosa, 72, E-20018 Donostia-San Sebastian, Spain
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8
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Støchkel K, Hansen CN, Houmøller J, Nielsen LM, Anggara K, Linares M, Norman P, Nogueira F, Maltsev OV, Hintermann L, Nielsen SB, Naumov P, Milne BF. On the Influence of Water on the Electronic Structure of Firefly Oxyluciferin Anions from Absorption Spectroscopy of Bare and Monohydrated Ions in Vacuo. J Am Chem Soc 2013; 135:6485-93. [DOI: 10.1021/ja311400t] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kristian Støchkel
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C,
Denmark
| | | | - Jørgen Houmøller
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C,
Denmark
| | | | - Kelvin Anggara
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C,
Denmark
| | - Mathieu Linares
- Division of Computational
Physics,
Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
| | - Patrick Norman
- Division of Computational
Physics,
Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
| | - Fernando Nogueira
- Centre for Computational Physics,
Department of Physics, University of Coimbra, Rua Larga, 3004-516 Coimbra, Portugal
| | - Oleg V. Maltsev
- Department Chemie, Technische Universität München, Lichtenbergstrasse
4, 85748 Garching bei München, Germany
| | - Lukas Hintermann
- Department Chemie, Technische Universität München, Lichtenbergstrasse
4, 85748 Garching bei München, Germany
| | - Steen Brøndsted Nielsen
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C,
Denmark
| | - Panče Naumov
- New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
- Institute for Chemical Research and
the Hakubi Center for Advanced Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Bruce F. Milne
- Centre for Computational Physics,
Department of Physics, University of Coimbra, Rua Larga, 3004-516 Coimbra, Portugal
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9
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Dehon C, Soorkia S, Pedrazzani M, Jouvet C, Barat M, Fayeton JA, Lucas B. Photofragmentation at 263 nm of small peptides containing tyrosine: the role of the charge transfer on CO. Phys Chem Chem Phys 2013; 15:8779-88. [DOI: 10.1039/c3cp50720c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Aravind G, Klærke B, Rajput J, Toker Y, Andersen LH, Bochenkova AV, Antoine R, Lemoine J, Racaud A, Dugourd P. Photodissociation pathways and lifetimes of protonated peptides and their dimers. J Chem Phys 2012; 136:014307. [PMID: 22239781 DOI: 10.1063/1.3671943] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Photodissociation lifetimes and fragment channels of gas-phase, protonated YA(n) (n = 1,2) peptides and their dimers were measured with 266 nm photons. The protonated monomers were found to have a fast dissociation channel with an exponential lifetime of ~200 ns while the protonated dimers show an additional slow dissociation component with a lifetime of ~2 μs. Laser power dependence measurements enabled us to ascribe the fast channel in the monomer and the slow channel in the dimer to a one-photon process, whereas the fast dimer channel is from a two-photon process. The slow (1 photon) dissociation channel in the dimer was found to result in cleavage of the H-bonds after energy transfer through these H-bonds. In general, the dissociation of these protonated peptides is non-prompt and the decay time was found to increase with the size of the peptides. Quantum RRKM calculations of the microcanonical rate constants also confirmed a statistical nature of the photodissociation processes in the dipeptide monomers and dimers. The classical RRKM expression gives a rate constant as an analytical function of the number of active vibrational modes in the system, estimated separately on the basis of the equipartition theorem. It demonstrates encouraging results in predicting fragmentation lifetimes of protonated peptides. Finally, we present the first experimental evidence for a photo-induced conversion of tyrosine-containing peptides into monocyclic aromatic hydrocarbon along with a formamide molecule both found in space.
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Affiliation(s)
- G Aravind
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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11
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Calvert CR, Belshaw L, Duffy MJ, Kelly O, King RB, Smyth AG, Kelly TJ, Costello JT, Timson DJ, Bryan WA, Kierspel T, Rice P, Turcu ICE, Cacho CM, Springate E, Williams ID, Greenwood JB. LIAD-fs scheme for studies of ultrafast laser interactions with gas phase biomolecules. Phys Chem Chem Phys 2012; 14:6289-97. [PMID: 22322861 DOI: 10.1039/c2cp23840c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Laser induced acoustic desorption (LIAD) has been used for the first time to study the parent ion production and fragmentation mechanisms of a biological molecule in an intense femtosecond (fs) laser field. The photoacoustic shock wave generated in the analyte substrate (thin Ta foil) has been simulated using the hydrodynamic HYADES code, and the full LIAD process has been experimentally characterised as a function of the desorption UV-laser pulse parameters. Observed neutral plumes of densities >10(9) cm(-3) which are free from solvent or matrix contamination demonstrate the suitability and potential of the source for studying ultrafast dynamics in the gas phase using fs laser pulses. Results obtained with phenylalanine show that through manipulation of fundamental femtosecond laser parameters (such as pulse length, intensity and wavelength), energy deposition within the molecule can be controlled to allow enhancement of parent ion production or generation of characteristic fragmentation patterns. In particular by reducing the pulse length to a timescale equivalent to the fastest vibrational periods in the molecule, we demonstrate how fragmentation of the molecule can be minimised whilst maintaining a high ionisation efficiency.
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Affiliation(s)
- C R Calvert
- Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Northern Ireland
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12
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Kelly O, Calvert CR, Greenwood JB, Zettergren H, Nielsen SB, Wyer JA. Effects of charge location on the absorptions and lifetimes of protonated tyrosine peptides in vacuo. J Phys Chem A 2012; 116:1701-9. [PMID: 22268622 DOI: 10.1021/jp208578w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nearby charges affect the electronic energy levels of chromophores, with the extent of the effect being determined by the magnitude of the charge and degree of charge-chromophore separation. The molecular configuration dictates the charge-chromophore distance. Hence, in this study, we aim to assess how the location of the charge influences the absorption of a set of model protonated and diprotonated peptide ions, and whether spectral differences are large enough to be identified. The studied ions were the dipeptide YK, the tripeptide KYK (Y = tyrosine; K = lysine) and their complexes with 18-crown-6-ether (CE). The CE targets the ammonium group by forming internal ionic hydrogen bonds and limits the folding of the peptide. In the tripeptide, the distance between the chromophore and the backbone ammonium is enlarged relative to that in the dipeptide. Experiments were performed in an electrostatic ion storage ring using a tunable laser system, and action spectra based on lifetime measurements were obtained in the range from 210 to 310 nm. The spectra are all quite similar though there seems to be some changes in the absorption band between 210 and 250 nm, while in the lower energy band all ions had a maximum absorption at ~275 nm. Lifetimes after photoexcitation were found to shorten upon protonation and lengthen upon CE complexation, in accordance with the increased number of degrees of freedom and an increase in activation energies for dissociation as the mobile proton model is no longer operative.
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Affiliation(s)
- Orla Kelly
- Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN, UK
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13
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Antoine R, Dugourd P. Visible and ultraviolet spectroscopy of gas phase protein ions. Phys Chem Chem Phys 2011; 13:16494-509. [PMID: 21811728 DOI: 10.1039/c1cp21531k] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Optical spectroscopy has contributed enormously to our knowledge of the structure and dynamics of atoms and molecules and is now emerging as a cornerstone of the gas phase methods available for investigating biomolecular ions. This article focuses on the UV and visible spectroscopy of peptide and protein ions stored in ion traps, with emphasis placed on recent results obtained on protein polyanions, by electron photodetachment experiments. We show that among a large number of possible de-excitation pathways, the relaxation of biomolecular polyanions is mainly achieved by electron emission following photo-excitation in electronically excited states. Electron photodetachment is a fast process that occurs prior to relaxation on vibrational degrees of freedom. Electron photodetachment yield can then be used to record gas phase action spectra for systems as large as entire proteins, without the limitation of system size that would arise from energy redistribution on numerous modes and prevent fragmentation after the absorption of a photon. The optical activity of proteins in the near UV is directly related to the electronic structure and optical absorption of aromatic amino acids (Trp, Phe and Tyr). UV spectra for peptides and proteins containing neutral, deprotonated and radical aromatic amino acids were recorded. They displayed strong bathochromic shifts. In particular, the results outline the privileged role played by open shell ions in molecular spectroscopy which, in the case of biomolecules, is directly related to their reactivity and biological functions. The optical shifts observed are sufficient to provide unambiguous fingerprints of the electronic structure of chromophores without the requirement of theoretical calculations. They constitute benchmarks for calculating the absorption spectra of chromophores embedded in entire proteins and could be used in the future to study biochemical processes in the gas phase involving charge transfer in aromatic amino acids, such as in the mediation of electron transfer or redox reactions. We then addressed the important question of the sensitivity of protein optical spectra to the intrinsic properties of protein ions, including conformation, charge state, etc., and to environmental factors. We report optical spectra for different charge states of insulin, for ubiquitin starting from native and denaturated solutions, and for apo-myoglobin protein. All these spectra are compared critically to spectra recorded in solution, in order to assess solvent effects. We also report the spectra of peptides complexed with metal cations and show that complexation gives rise to new optical transitions related to charge transfer types of excitation. The perspectives of this work include integrative approaches where UV-Vis spectroscopy could, for example, be combined with ion mobility spectrometry and high level calculations for protein structural characterization. It could also be used in spectroscopy to probe biological processes in the gas phase, with different light sources including VUV radiation (to probe different types of excitations) and ultra short pulses with time and phase modulation (to probe and control the dynamics of de-excitation or charge transfer events), and with the derivatization of proteins with chromophores to modulate their optical properties. We also envision that photo-excitation will play an important role in the future to produce intermediates with new chemical and reactive properties. Another promising route is to conduct activated electron photodetachment dissociation experiments.
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Kirketerp MBS, Petersen MÅ, Wanko M, Zettergren H, Rubio A, Nielsen MB, Nielsen SB. Double-Bond versus Triple-Bond Bridges: Does it Matter for the Charge-Transfer Absorption by Donor-Acceptor Chromophores? Chemphyschem 2010; 11:2495-8. [DOI: 10.1002/cphc.201000464] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Ehlerding A, Wyer JA, Zettergren H, Kirketerp MBS, Nielsen SB. UV Photodissociation of Protonated Gly-Trp and Trp-Gly Dipeptides and Their Complexes with Crown Ether in an Electrostatic Ion Storage Ring. J Phys Chem A 2009; 114:299-303. [DOI: 10.1021/jp9086317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Anneli Ehlerding
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Jean Ann Wyer
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Henning Zettergren
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | | | - Steen Brøndsted Nielsen
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark
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