1
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Rogers DM, Do H, Hirst JD. An Improved Diabatization Scheme for Computing the Electronic Circular Dichroism of Proteins. J Phys Chem B 2024; 128:7350-7361. [PMID: 39034688 DOI: 10.1021/acs.jpcb.4c02582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
We advance the quality of first-principles calculations of protein electronic circular dichroism (CD) through an amelioration of a key deficiency of a previous procedure that involved diabatization of electronic states on the amide chromophore (to obtain interamide couplings) in a β-strand conformation of a diamide. This yields substantially improved calculated far-ultraviolet (far-UV) electronic circular dichroism (CD) spectra for β-sheet conformations. The interamide couplings from the diabatization procedure for 13 secondary structural elements (13 diamide structures) are applied to compute the CD spectra for seven example proteins: myoglobin (α helix), jacalin (β strand), concanavalin A (β type I), elastase (β type II), papain (α + β), 310-helix bundle (310-helix) and snow flea antifreeze protein (polyproline). In all cases, except concanavalin A and papain, the CD spectra computed using the interamide couplings from the diabatization procedure yield improved agreement with experiment with respect to previous first-principles calculations.
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Affiliation(s)
- David M Rogers
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Hainam Do
- Department of Chemical and Environmental Engineering and Key Laboratory of Carbonaceous Waste Processing and Process Intensification Research of Zhejiang Province, University of Nottingham Ningbo China, Ningbo 315100, China
- New Materials Institute, University of Nottingham Ningbo China, Ningbo 315042, China
| | - Jonathan D Hirst
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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2
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Zhang Q, Wang B, Zhang Y, Yang J, Deng B, Ding B, Zhong D. Probing Intermolecular Interactions of Amyloidogenic Fragments of SOD1 by Site-Specific Tryptophan and Its Noncanonical Derivative. J Phys Chem B 2021; 125:13088-13098. [PMID: 34812635 DOI: 10.1021/acs.jpcb.1c07175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Transient amyloid intermediates are likely to be cytotoxic and play an essential role in amyloid-associated neurodegenerative diseases. Characterization of their structural and dynamic evolution is the key to elucidating the molecular mechanism of amyloid formation. Here, combining circular dichroism (CD), exciton couplet theory, and Fourier transform infrared spectroscopy with site-specific tryptophan (Trp) and its noncanonical derivative 5-cyano-tryptochan (Trp5CN), we developed a method to monitor strand-to-strand tertiary and sheet-to-sheet quaternary interactions in the aggregation cascades of an amyloidogenic fragment from protein SOD128-38 (with the sequence KVKVWGSIKGL). We found that the exciton couplet generated from the Bb band of Trp can be used as a probe for side chain interactions. Its sensitivity can be further improved by four times with the incorporation of Trp5CN. We further observed a red-shift of ∼2 cm-1 and a broadening of ∼2 cm-1 in the IR band generated from the CN stretch during the aggregation, which we attributed to the transition from a corkscrew-like structure to a cross-linked intermediate phase. We show here that the integration of optical methods with unique aromatic side chain-related probes is able to elucidate amyloid intermolecular interactions and even capture elusive transient intermediates on and off the amyloid assembling pathway.
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Affiliation(s)
- Qin Zhang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bingyao Wang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yifei Zhang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jie Yang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bodan Deng
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bei Ding
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dongping Zhong
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.,Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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3
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Sun Q, Zhai Y, Wang W, Gan N, Zhang S, Suo Z, Li H. Molecular recognition patterns between vitamin B12 and human serum albumin explored through STD-NMR and spectroscopic methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 258:119828. [PMID: 33930850 DOI: 10.1016/j.saa.2021.119828] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 04/09/2021] [Accepted: 04/10/2021] [Indexed: 06/12/2023]
Abstract
Ligand-receptor molecular recognitionis the basis of biological process. The Saturation Transfer Difference-NMR (STD-NMR) technique has been recently used to gain qualitative and quantitative information about physiological interactions at atomic-resolution. The molecular recognition patterns between Vitamin B12 (VB12) and human serum albumin (HSA) were investigated by STD-NMR supplemented by other spectroscopies and molecular docking. STD-NMR delivered a complete picture that the substituent groups on the tetrapyrrole ring of VB12 interacted with site III of HSA through binding epitope mapping and competitive probe experiments. STD-NMR and fluorescence results proved the moderate binding capability of VB12 and clarified a static, spontaneous, and temperature-sensitive binding mechanism. 3D-fluorencence, FT-IR and circular dichroism spectra showed a compact protein structure by interacting with VB12. Size distribution and surface hydrophobicity showed the surface properties changes of HSA caused by the binding of VB12. Computer simulation confirmed the recognition mode in theory and was compared with experiments. This work is beneficial for understanding the safety and biological action of VB12, and will attract researchers interested in NMR technology.
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Affiliation(s)
- Qiaomei Sun
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Yuanming Zhai
- Analytical & Testing Center, Sichuan University, Chengdu 610064, China.
| | - Wenjing Wang
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Na Gan
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Shuangshuang Zhang
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Zili Suo
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Hui Li
- School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
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4
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Castelletto V, Seitsonen J, Ruokolainen J, Barnett SA, Sandu C, Hamley IW. Self-Assembly of Angiotensin-Converting Enzyme Inhibitors Captopril and Lisinopril and Their Crystal Structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9170-9178. [PMID: 34292730 PMCID: PMC8397397 DOI: 10.1021/acs.langmuir.1c01340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The peptide angiotensin-converting enzyme inhibitors captopril and lisinopril are unexpectedly shown to exhibit critical aggregation concentration (CAC) behavior through measurements of surface tension, electrical conductivity, and dye probe fluorescence. These three measurements provide similar values for the CAC, and there is also evidence from circular dichroism spectroscopy for a possible conformational change in the peptides at the same concentration. Cryogenic transmission electron microscopy indicates the formation of micelle-like aggregates above the CAC, which can thus be considered a critical micelle concentration, and the formation of aggregates with a hydrodynamic radius of ∼6-7 nm is also evidenced by dynamic light scattering. We also used synchrotron radiation X-ray diffraction to determine the single-crystal structure of captopril and lisinopril. Our results improve the accuracy of previous data reported in the literature, obtained using conventional X-ray sources. We also studied the structure of aqueous solutions containing captopril or lisinopril at high concentrations. The aggregation may be driven by intermolecular interactions between the proline moiety of captopril molecules or between the phenylalanine moiety of lisinopril molecules.
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Affiliation(s)
| | - Jani Seitsonen
- Nanomicroscopy
Center, Aalto University, Puumiehenkuja 2, Espoo FIN-02150, Finland
| | - Janne Ruokolainen
- Nanomicroscopy
Center, Aalto University, Puumiehenkuja 2, Espoo FIN-02150, Finland
| | - Sarah A. Barnett
- Diamond
Light Source, Harwell Science and Innovation
Campus, Fermi Avenue, Didcot OX11 0DE, U.K.
| | - Callum Sandu
- Department
of Chemistry, University of Reading, Reading RG6 6AD, U.K.
| | - Ian W. Hamley
- Department
of Chemistry, University of Reading, Reading RG6 6AD, U.K.
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5
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Segatta F, Rogers DM, Dyer NT, Guest EE, Li Z, Do H, Nenov A, Garavelli M, Hirst JD. Near-Ultraviolet Circular Dichroism and Two-Dimensional Spectroscopy of Polypeptides. Molecules 2021; 26:E396. [PMID: 33451152 PMCID: PMC7828623 DOI: 10.3390/molecules26020396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/18/2022] Open
Abstract
A fully quantitative theory of the relationship between protein conformation and optical spectroscopy would facilitate deeper insights into biophysical and simulation studies of protein dynamics and folding. In contrast to intense bands in the far-ultraviolet, near-UV bands are much weaker and have been challenging to compute theoretically. We report some advances in the accuracy of calculations in the near-UV, which were realised through the consideration of the vibrational structure of the electronic transitions of aromatic side chains.
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Affiliation(s)
- Francesco Segatta
- Dipartimento di Chimica Industriale “Toso Montanari”, Universita’ degli Studi di Bologna, Viale del Risorgimento, 4, I-40136 Bologna, Italy; (F.S.); (A.N.); (M.G.)
| | - David M. Rogers
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (D.M.R.); (N.T.D.); (E.E.G.)
| | - Naomi T. Dyer
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (D.M.R.); (N.T.D.); (E.E.G.)
| | - Ellen E. Guest
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (D.M.R.); (N.T.D.); (E.E.G.)
| | - Zhuo Li
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China;
| | - Hainam Do
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
- New Materials Institute, University of Nottingham Ningbo China, Ningbo 315042, China;
| | - Artur Nenov
- Dipartimento di Chimica Industriale “Toso Montanari”, Universita’ degli Studi di Bologna, Viale del Risorgimento, 4, I-40136 Bologna, Italy; (F.S.); (A.N.); (M.G.)
| | - Marco Garavelli
- Dipartimento di Chimica Industriale “Toso Montanari”, Universita’ degli Studi di Bologna, Viale del Risorgimento, 4, I-40136 Bologna, Italy; (F.S.); (A.N.); (M.G.)
| | - Jonathan D. Hirst
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (D.M.R.); (N.T.D.); (E.E.G.)
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6
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Begušić T, Vaníček J. On-the-fly ab initio semiclassical evaluation of third-order response functions for two-dimensional electronic spectroscopy. J Chem Phys 2020; 153:184110. [DOI: 10.1063/5.0031216] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Tomislav Begušić
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jiří Vaníček
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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7
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Rogers DM, Jasim SB, Dyer NT, Auvray F, Réfrégiers M, Hirst JD. Electronic Circular Dichroism Spectroscopy of Proteins. Chem 2019. [DOI: 10.1016/j.chempr.2019.07.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Lischka H, Nachtigallová D, Aquino AJA, Szalay PG, Plasser F, Machado FBC, Barbatti M. Multireference Approaches for Excited States of Molecules. Chem Rev 2018; 118:7293-7361. [DOI: 10.1021/acs.chemrev.8b00244] [Citation(s) in RCA: 197] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hans Lischka
- School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, P.R. China
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
| | - Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry v.v.i., The Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, 78371 Olomouc, Czech Republic
| | - Adélia J. A. Aquino
- School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, P.R. China
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
- Institute for Soil Research, University of Natural Resources and Life Sciences Vienna, Peter-Jordan-Strasse 82, A-1190 Vienna, Austria
| | - Péter G. Szalay
- ELTE Eötvös Loránd University, Laboratory of Theoretical Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
| | - Felix Plasser
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
- Department of Chemistry, Loughborough University, Leicestershire LE11 3TU, United Kingdom
| | - Francisco B. C. Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 12228-900, São Paulo, Brazil
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9
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Jasim SB, Li Z, Guest EE, Hirst JD. DichroCalc: Improvements in Computing Protein Circular Dichroism Spectroscopy in the Near-Ultraviolet. J Mol Biol 2018; 430:2196-2202. [DOI: 10.1016/j.jmb.2017.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/24/2017] [Accepted: 12/10/2017] [Indexed: 12/13/2022]
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10
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Li Z, Hirst JD. Quantitative first principles calculations of protein circular dichroism in the near-ultraviolet. Chem Sci 2017; 8:4318-4333. [PMID: 29163925 PMCID: PMC5637123 DOI: 10.1039/c7sc00586e] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 03/23/2017] [Indexed: 11/30/2022] Open
Abstract
Vibrational structure in the near-UV circular dichroism (CD) spectra of proteins is an important source of information on protein conformation and can be exploited to study structure and folding. A fully quantitative theory of the relationship between protein conformation and optical spectroscopy would facilitate deeper interpretation of and insight into biophysical and simulation studies of protein dynamics and folding. We have developed new models of the aromatic side chain chromophores toluene, p-cresol and 3-methylindole, which incorporate ab initio calculations of the Franck-Condon effect into first principles calculations of CD using an exciton approach. The near-UV CD spectra of 40 proteins are calculated with the new parameter set and the correlation between the computed and the experimental intensity from 270 to 290 nm is much improved. The contribution of individual chromophores to the CD spectra has been calculated for several mutants and in many cases helps rationalize changes in their experimental spectra. Considering conformational flexibility by using families of NMR structures leads to further improvements for some proteins and illustrates an informative level of sensitivity to side chain conformation. In several cases, the near-UV CD calculations can distinguish the native protein structure from a set of computer-generated misfolded decoy structures.
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Affiliation(s)
- Zhuo Li
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , UK .
| | - Jonathan D Hirst
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , UK .
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11
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Nenov A, Mukamel S, Garavelli M, Rivalta I. Two-Dimensional Electronic Spectroscopy of Benzene, Phenol, and Their Dimer: An Efficient First-Principles Simulation Protocol. J Chem Theory Comput 2016; 11:3755-71. [PMID: 26574458 DOI: 10.1021/acs.jctc.5b00443] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
First-principles simulations of two-dimensional electronic spectroscopy in the ultraviolet region (2DUV) require computationally demanding multiconfigurational approaches that can resolve doubly excited and charge transfer states, the spectroscopic fingerprints of coupled UV-active chromophores. Here, we propose an efficient approach to reduce the computational cost of accurate simulations of 2DUV spectra of benzene, phenol, and their dimer (i.e., the minimal models for studying electronic coupling of UV-chromophores in proteins). We first establish the multiconfigurational recipe with the highest accuracy by comparison with experimental data, providing reference gas-phase transition energies and dipole moments that can be used to construct exciton Hamiltonians involving high-lying excited states. We show that by reducing the active spaces and the number of configuration state functions within restricted active space schemes, the computational cost can be significantly decreased without loss of accuracy in predicting 2DUV spectra. The proposed recipe has been successfully tested on a realistic model proteic system in water. Accounting for line broadening due to thermal and solvent-induced fluctuations allows for direct comparison with experiments.
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Affiliation(s)
- Artur Nenov
- Dipartimento di Chimica "G. Ciamician", Università di Bologna , Via F. Selmi 2, 40126 Bologna, Italy
| | - Shaul Mukamel
- Department of Chemistry, University of California , Irvine, California 92697-2025, United States
| | - Marco Garavelli
- Dipartimento di Chimica "G. Ciamician", Università di Bologna , Via F. Selmi 2, 40126 Bologna, Italy.,Université de Lyon , CNRS, Laboratoire de Chimie, École Normale Supérieure de Lyon, UMR 5182, 46 Allée d'Italie, 69364 Lyon, Cedex 07, France
| | - Ivan Rivalta
- Université de Lyon , CNRS, Laboratoire de Chimie, École Normale Supérieure de Lyon, UMR 5182, 46 Allée d'Italie, 69364 Lyon, Cedex 07, France
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12
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Bortolotti A, Wong YH, Korsholm SS, Bahring NHB, Bobone S, Tayyab S, van de Weert M, Stella L. On the purported “backbone fluorescence” in protein three-dimensional fluorescence spectra. RSC Adv 2016. [DOI: 10.1039/c6ra23426g] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A peak in 3D-fluorescence spectra of proteins, often assigned to backbone emission, is shown to be due to aromatic residues.
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Affiliation(s)
- Annalisa Bortolotti
- Dipartimento di Scienze e Tecnologie Chimiche
- Università di Roma Tor Vergata
- 00133 Rome
- Italy
| | - Yin How Wong
- Biomolecular Research Group
- Biochemistry Program
- Institute of Biological Sciences
- Faculty of Science
- University of Malaya
| | - Stine S. Korsholm
- Department of Pharmacy
- Faculty of Health and Medical Sciences
- University of Copenhagen
- 2100 Copenhagen
- Denmark
| | - Noor Hafizan B. Bahring
- Biomolecular Research Group
- Biochemistry Program
- Institute of Biological Sciences
- Faculty of Science
- University of Malaya
| | - Sara Bobone
- Dipartimento di Scienze e Tecnologie Chimiche
- Università di Roma Tor Vergata
- 00133 Rome
- Italy
| | - Saad Tayyab
- Biomolecular Research Group
- Biochemistry Program
- Institute of Biological Sciences
- Faculty of Science
- University of Malaya
| | - Marco van de Weert
- Department of Pharmacy
- Faculty of Health and Medical Sciences
- University of Copenhagen
- 2100 Copenhagen
- Denmark
| | - Lorenzo Stella
- Dipartimento di Scienze e Tecnologie Chimiche
- Università di Roma Tor Vergata
- 00133 Rome
- Italy
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13
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Nenov A, Beccara S, Rivalta I, Cerullo G, Mukamel S, Garavelli M. Tracking conformational dynamics of polypeptides by nonlinear electronic spectroscopy of aromatic residues: a first-principles simulation study. Chemphyschem 2014; 15:3282-90. [PMID: 25145908 DOI: 10.1002/cphc.201402374] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Indexed: 11/06/2022]
Abstract
The ability of nonlinear electronic spectroscopy to track folding/unfolding processes of proteins in solution by monitoring aromatic interactions is investigated by first-principles simulations of two-dimensional (2D) electronic spectra of a model peptide. A dominant reaction pathway approach is employed to determine the unfolding pathway of a tetrapeptide, which connects the initial folded configuration with stacked aromatic side chains and the final unfolded state with distant noninteracting aromatic residues. The π-stacking and excitonic coupling effects are included through ab initio simulations based on multiconfigurational methods within a hybrid quantum mechanics/molecular mechanics scheme. It is shown that linear absorption spectroscopy in the ultraviolet (UV) region is unable to resolve the unstacking dynamics characterized by the three-step process: T-shaped→twisted offset stacking→unstacking. Conversely, pump-probe spectroscopy can be used to resolve aromatic interactions by probing in the visible region, the excited-state absorptions (ESAs) that involve charge-transfer states. 2D UV spectroscopy offers the highest sensitivity to the unfolding process, by providing the disentanglement of ESA signals belonging to different aromatic chromophores and high correlation between the conformational dynamics and the quartic splitting.
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Affiliation(s)
- Artur Nenov
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, V. F. Selmi 2, 40126 Bologna (Italy).
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14
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Fornander LH, Feng B, Beke-Somfai T, Nordén B. UV Transition Moments of Tyrosine. J Phys Chem B 2014; 118:9247-57. [DOI: 10.1021/jp5065352] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Louise H. Fornander
- Department of Chemical and
Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Bobo Feng
- Department of Chemical and
Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Tamás Beke-Somfai
- Department of Chemical and
Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Bengt Nordén
- Department of Chemical and
Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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15
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Nenov A, Rivalta I, Mukamel S, Garavelli M. Bidimensional electronic spectroscopy on indole in gas phase and in water from first principles. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.03.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Meloni SL, Matsika S. Theoretical studies of the excited states of p-cyanophenylalanine and comparisons with the natural amino acids phenylalanine and tyrosine. Theor Chem Acc 2014. [DOI: 10.1007/s00214-014-1497-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Do H, Deeth RJ, Besley NA. Computational study of the structure and electronic circular dichroism spectroscopy of blue copper proteins. J Phys Chem B 2013; 117:8105-12. [PMID: 23773120 DOI: 10.1021/jp404107j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The calculation of the electronic circular dichroism (CD) spectra of the oxidized form of the blue copper proteins plastocyanin and cucumber basic protein and the relationship between the observed spectral features and the structure of the active site of the protein is investigated. Excitation energies and transition strengths are computed using multireference configuration interaction, and it is shown that computed spectra based on coordinates from the crystal structure or a single structure optimized in quantum mechanics/molecular mechanics (QM/MM) or ligand field molecular mechanics (LFMM) are qualitatively incorrect. In particular, the rotational strength of the ligand to metal charge transfer band is predicted to be too small or have the incorrect sign. By considering calculations on active site models with modified structures, it is shown that the intensity of this band is sensitive to the nonplanarity of the histidine and cysteine ligands coordinated to copper. Calculation of the ultraviolet absorption and CD spectra based upon averaging over many structures drawn from a LFMM molecular dynamics simulation are in good agreement with experiment, and superior to analogous calculations based upon structures from a classical molecular dynamics simulation. This provides evidence that the LFMM force field provides an accurate description of the molecular dynamics of these proteins.
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Affiliation(s)
- Hainam Do
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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18
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Karabencheva-Christova TG, Carlsson U, Balali-Mood K, Black GW, Christov CZ. Conformational effects on the circular dichroism of Human Carbonic Anhydrase II: a multilevel computational study. PLoS One 2013; 8:e56874. [PMID: 23526922 PMCID: PMC3582176 DOI: 10.1371/journal.pone.0056874] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 01/15/2013] [Indexed: 11/25/2022] Open
Abstract
Circular Dichroism (CD) spectroscopy is a powerful method for investigating conformational changes in proteins and therefore has numerous applications in structural and molecular biology. Here a computational investigation of the CD spectrum of the Human Carbonic Anhydrase II (HCAII), with main focus on the near-UV CD spectra of the wild-type enzyme and it seven tryptophan mutant forms, is presented and compared to experimental studies. Multilevel computational methods (Molecular Dynamics, Semiempirical Quantum Mechanics, Time-Dependent Density Functional Theory) were applied in order to gain insight into the mechanisms of interaction between the aromatic chromophores within the protein environment and understand how the conformational flexibility of the protein influences these mechanisms. The analysis suggests that combining CD semi empirical calculations, crystal structures and molecular dynamics (MD) could help in achieving a better agreement between the computed and experimental protein spectra and provide some unique insight into the dynamic nature of the mechanisms of chromophore interactions.
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Affiliation(s)
- Tatyana G Karabencheva-Christova
- Department of Applied Sciences, School of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
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McMillan AW, Kier BL, Shu I, Byrne A, Andersen NH, Parson WW. Fluorescence of tryptophan in designed hairpin and Trp-cage miniproteins: measurements of fluorescence yields and calculations by quantum mechanical molecular dynamics simulations. J Phys Chem B 2013; 117:1790-809. [PMID: 23330783 PMCID: PMC3581364 DOI: 10.1021/jp3097378] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The quantum yield of tryptophan (Trp) fluorescence was measured in 30 designed miniproteins (17 β-hairpins and 13 Trp-cage peptides), each containing a single Trp residue. Measurements were made in D(2)O and H(2)O to distinguish between fluorescence quenching mechanisms involving electron and proton transfer in the hairpin peptides, and at two temperatures to check for effects of partial unfolding of the Trp-cage peptides. The extent of folding of all the peptides also was measured by NMR. The fluorescence yields ranged from 0.01 in some of the Trp-cage peptides to 0.27 in some hairpins. Fluorescence quenching was found to occur by electron transfer from the excited indole ring of the Trp to a backbone amide group or the protonated side chain of a nearby histidine, glutamate, aspartate, tyrosine, or cysteine residue. Ionized tyrosine side chains quenched strongly by resonance energy transfer or electron transfer to the excited indole ring. Hybrid classical/quantum mechanical molecular dynamics simulations were performed by a method that optimized induced electric dipoles separately for the ground and excited states in multiple π-π* and charge-transfer (CT) excitations. Twenty 0.5 ns trajectories in the tryptophan's lowest excited singlet π-π* state were run for each peptide, beginning by projections from trajectories in the ground state. Fluorescence quenching was correlated with the availability of a CT or exciton state that was strongly coupled to the π-π* state and that matched or fell below the π-π* state in energy. The fluorescence yields predicted by summing the calculated rates of charge and energy transfer are in good accord with the measured yields.
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Affiliation(s)
- Andrew W. McMillan
- Department of Biochemistry, Structure and Design, University of Washington, Seattle, WA 98195
- Program in Biological Physics, Structure and Design, University of Washington, Seattle, WA 98195
| | - Brandon L. Kier
- Department of Chemistry, Structure and Design, University of Washington, Seattle, WA 98195
- Program in Biological Physics, Structure and Design, University of Washington, Seattle, WA 98195
| | - Irene Shu
- Department of Chemistry, Structure and Design, University of Washington, Seattle, WA 98195
| | - Aimee Byrne
- Department of Chemistry, Structure and Design, University of Washington, Seattle, WA 98195
| | - Niels H. Andersen
- Department of Chemistry, Structure and Design, University of Washington, Seattle, WA 98195
- Program in Biological Physics, Structure and Design, University of Washington, Seattle, WA 98195
| | - William W. Parson
- Department of Biochemistry, Structure and Design, University of Washington, Seattle, WA 98195
- Program in Biological Physics, Structure and Design, University of Washington, Seattle, WA 98195
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20
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Gonçalves MB, Dreyer J, Lupieri P, Barrera-Patiño C, Ippoliti E, Webb MR, Corrie JET, Carloni P. Structural prediction of a rhodamine-based biosensor and comparison with biophysical data. Phys Chem Chem Phys 2013; 15:2177-83. [DOI: 10.1039/c2cp42396k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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21
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Rondi A, Bonacina L, Trisorio A, Hauri C, Wolf JP. Coherent manipulation of free amino acids fluorescence. Phys Chem Chem Phys 2012; 14:9317-22. [PMID: 22395710 DOI: 10.1039/c2cp23357f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Coherent manipulation of molecular wavepackets in biomolecules might contribute to the quest towards label-free cellular imaging and protein identification. We report the use of optimally tailored UV laser pulses in pump-probe depletion experiments that selectively enhance or decrease fluorescence between two aromatic amino acids: tryptophan (Trp) and tyrosine (Tyr). Selective fluorescence modulation is achieved with a contrast of ~35%. A neat modification of the time-dependent fluorescence depletion signal of Trp is observed, while the Tyr transient trace remains unchanged. The mechanism invoked for explaining the change of the depletion of Trp is a less efficient coupling between the fluorescing state and the higher non-radiative excited states by the optimally shaped pulse, than by the reference pulse.
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Affiliation(s)
- A Rondi
- GAP-Biophotonics, University of Geneva, 22 ch. de Pinchat, CH-1211 Geneva 4, Switzerland
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22
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Jiang J, Mukamel S. Two-dimensional near-ultraviolet spectroscopy of aromatic residues in amyloid fibrils: a first principles study. Phys Chem Chem Phys 2011; 13:2394-400. [PMID: 21132201 PMCID: PMC3141107 DOI: 10.1039/c0cp02047h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a first principles study of two dimensional electronic spectroscopy of aromatic side chain transitions in the 32-residue β-amyloid (Aβ(9-40)) fibrils in the near ultraviolet (250-300 nm). An efficient exciton Hamiltonian with electrostatic fluctuations (EHEF) algorithm is used to compute the electronic excitations in the presence of environmental fluctuations. The through-space inter- and intra-molecular interactions are calculated with high level quantum mechanics (QM) approaches, and interfaced with molecular mechanics (MM) simulations. Distinct two dimensional near ultraviolet (2DNUV) spectroscopic signatures are identified for different aromatic transitions, and the couplings between them. 2DNUV signals associated with the transition couplings are shown to be very sensitive to the change of residue-residue interactions induced by residue mutations. Our simulations suggest that 2DNUV spectra could provide a useful local probe for the structure and kinetics of fibrils.
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Affiliation(s)
- Jun Jiang
- Chemistry Department, University of California Irvine, USA
| | - Shaul Mukamel
- Chemistry Department, University of California Irvine, USA
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23
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Hamley IW, Nutt DR, Brown GD, Miravet JF, Escuder B, Rodríguez-Llansola F. Influence of the solvent on the self-assembly of a modified amyloid beta peptide fragment. II. NMR and computer simulation investigation. J Phys Chem B 2010; 114:940-51. [PMID: 20039666 DOI: 10.1021/jp906107p] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The conformation of a model peptide AAKLVFF based on a fragment of the amyloid beta peptide Abeta16-20, KLVFF, is investigated in methanol and water via solution NMR experiments and molecular dynamics computer simulations. In previous work, we have shown that AAKLVFF forms peptide nanotubes in methanol and twisted fibrils in water. Chemical shift measurements were used to investigate the solubility of the peptide as a function of concentration in methanol and water. This enabled the determination of critical aggregation concentrations. The solubility was lower in water. In dilute solution, diffusion coefficients revealed the presence of intermediate aggregates in concentrated solution, coexisting with NMR-silent larger aggregates, presumed to be beta-sheets. In water, diffusion coefficients did not change appreciably with concentration, indicating the presence mainly of monomers, coexisting with larger aggregates in more concentrated solution. Concentration-dependent chemical shift measurements indicated a folded conformation for the monomers/intermediate aggregates in dilute methanol, with unfolding at higher concentration. In water, an antiparallel arrangement of strands was indicated by certain ROESY peak correlations. The temperature-dependent solubility of AAKLVFF in methanol was well described by a van't Hoff analysis, providing a solubilization enthalpy and entropy. This pointed to the importance of solvophobic interactions in the self-assembly process. Molecular dynamics simulations constrained by NOE values from NMR suggested disordered reverse turn structures for the monomer, with an antiparallel twisted conformation for dimers. To model the beta-sheet structures formed at higher concentration, possible model arrangements of strands into beta-sheets with parallel and antiparallel configurations and different stacking sequences were used as the basis for MD simulations; two particular arrangements of antiparallel beta-sheets were found to be stable, one being linear and twisted and the other twisted in two directions. These structures were used to simulate circular dichroism spectra. The roles of aromatic stacking interactions and charge transfer effects were also examined. Simulated spectra were found to be similar to those observed experimentally (in water or methanol) which show a maximum at 215 or 218 nm due to pi-pi* interactions, when allowance is made for a 15-18 nm red-shift that may be due to light scattering effects.
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Affiliation(s)
- I W Hamley
- Department of Chemistry, University of Reading, Reading RG6 6AD, UK
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24
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Robinson D, Besley NA, O’Shea P, Hirst JD. Calculating the Fluorescence of 5-Hydroxytryptophan in Proteins. J Phys Chem B 2009; 113:14521-8. [DOI: 10.1021/jp9071108] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- David Robinson
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Paul O’Shea
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Jonathan D. Hirst
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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25
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Bulheller BM, Rodger A, Hicks MR, Dafforn TR, Serpell LC, Marshall KE, Bromley EHC, King PJS, Channon KJ, Woolfson DN, Hirst JD. Flow Linear Dichroism of Some Prototypical Proteins. J Am Chem Soc 2009; 131:13305-14. [DOI: 10.1021/ja902662e] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benjamin M. Bulheller
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Alison Rodger
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Matthew R. Hicks
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Timothy R. Dafforn
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Louise C. Serpell
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Karen E. Marshall
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Elizabeth H. C. Bromley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Patrick J. S. King
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Kevin J. Channon
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Derek N. Woolfson
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
| | - Jonathan D. Hirst
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., Department of Biochemistry, School of Life Sciences, University of Sussex, Falmer BN1 9QG, U.K., School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K., and Department of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
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26
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Conte AM, Ippoliti E, Del Sole R, Carloni P, Pulci O. Many-Body Perturbation Theory Extended to the Quantum Mechanics/Molecular Mechanics Approach: Application to Indole in Water Solution. J Chem Theory Comput 2009; 5:1822-8. [DOI: 10.1021/ct800528e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Adriano Mosca Conte
- NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita’ di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA—Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2−4, Trieste, Italy
| | - Emiliano Ippoliti
- NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita’ di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA—Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2−4, Trieste, Italy
| | - Rodolfo Del Sole
- NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita’ di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA—Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2−4, Trieste, Italy
| | - Paolo Carloni
- NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita’ di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA—Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2−4, Trieste, Italy
| | - Olivia Pulci
- NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita’ di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA—Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2−4, Trieste, Italy
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27
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Robinson D, Besley NA, Lunt EAM, O’Shea P, Hirst JD. Electronic Structure of 5-Hydroxyindole: From Gas Phase to Explicit Solvation. J Phys Chem B 2009; 113:2535-41. [DOI: 10.1021/jp808943d] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- David Robinson
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Elizabeth A. M. Lunt
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Paul O’Shea
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Jonathan D. Hirst
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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28
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29
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Miura M, Aoki Y. Ab initiotheory for treating local electron excitations in molecules and its performance for computing optical properties. J Comput Chem 2009; 30:2213-30. [DOI: 10.1002/jcc.21206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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Li Z, Abramavicius D, Mukamel S. Probing electron correlations in molecules by two-dimensional coherent optical spectroscopy. J Am Chem Soc 2008; 130:3509-15. [PMID: 18288841 PMCID: PMC2901111 DOI: 10.1021/ja0774414] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nonlinear optical signal generated in phenol by three femtosecond pulses with wavevectors k1, k2, and k3 in the phase-matching direction k1 + k2 - k3 is simulated. This two-dimensional coherent spectroscopy (2DCS) signal has a rich pattern containing information on double-excitation states. The signal vanishes for uncorrelated electrons due to interference among quantum pathways and, thus, provides direct signatures of correlated many-electron wavefunctions. This is illustrated by the very different 2DCS signals predicted by two levels of electronic structure calculations: state-averaged complete active space self-consistent field (SA-CASSCF) and multistate multiconfigurational second-order perturbation theory (MS-CASPT2).
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Affiliation(s)
| | | | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California 92697
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31
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Two Dimensional Electronic Correlation Spectroscopy of the npi* and pipi* Protein Backbone Transitions: A Simulation Study. Chem Phys 2007; 341:29-36. [PMID: 19011677 DOI: 10.1016/j.chemphys.2007.03.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The two dimensional (2D) photon echo spectrum of the amide ultraviolet (UV) bands of proteins are simulated. Two effective exciton Hamiltonian parameter sets developed by Woody and Hirst, which predict similar CD spectra, may be distinguished by their very different 2DUV spectra. These differences are enhanced in specific configurations of pulse polarizations which provide chirality-induced signals.
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32
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Miura M, Aoki Y, Champagne B. Assessment of time-dependent density functional schemes for computing the oscillator strengths of benzene, phenol, aniline, and fluorobenzene. J Chem Phys 2007; 127:084103. [PMID: 17764225 DOI: 10.1063/1.2761886] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In present study the relevance of using the time-dependent density functional theory (DFT) within the adiabatic approximation for computing oscillator strengths (f) is assessed using different LDA, GGA, and hybrid exchange-correlation (XC) functionals. In particular, we focus on the lowest-energy valence excitations, dominating the UV/visible absorption spectra and originating from benzenelike HOMO(pi)-->LUMO(pi(*)) transitions, of several aromatic molecules: benzene, phenol, aniline, and fluorobenzene. The TDDFT values are compared to both experimental results obtained from gas phase measurements and to results determined using several ab initio schemes: random phase approximation (RPA), configuration interaction single (CIS), and a series of linear response coupled-cluster calculations, CCS, CC2, and CCSD. In particular, the effect of the amount of Hartree-Fock (HF) exchange in the functional is highlighted, whereas a basis set investigation demonstrates the need of including diffuse functions. So, the hybrid XC functionals--and particularly BHandHLYP--provide f values in good agreement with the highly correlated CCSD scheme while these can be strongly underestimated using pure DFT functionals. These results also display systematic behaviors: (i) larger f and squares of the transition dipole moments (mid R:mumid R:(2)) are associated with larger excitation energies (DeltaE); (ii) these relationships present generally a linear character with R>0.9 in least-squares fit procedures; (iii) larger amounts of HF exchange in the XC functional lead to larger f, R:mumid R:(2), as well as DeltaE values; (iv) these increases in f, mid R:mumid R:(2), and DeltaE are related to increased HOMO-LUMO character; and (v) these relationships are, however, not universal since the linear regression parameters (the slopes and the intercepts at the origin) depend on the system under investigation as well as on the nature of the excited state.
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Affiliation(s)
- Masanori Miura
- Department of Material Sciences, Faculty of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
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33
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Abstract
Circular dichroism (CD) is an important technique in the structural characterisation of proteins, and especially for secondary structure determination. The CD of proteins can be calculated from first principles using the so-called matrix method, with an accuracy which is almost quantitative for helical proteins. Thus, for proteins of unknown structure, CD calculations and experimental data can be used in conjunction to aid structure analysis. Linear dichroism (LD) can be calculated using analogous methodology and has been used to establish the relative orientations of subunits in proteins and protein orientation in an environment such as a membrane. However, simple analysis of LD data is not possible, due to overlapping transitions. So coupling the calculations and experiment is an important strategy. In this paper, the use of LD for the determination of protein orientation and how these data can be interpreted with the aid of calculations, are discussed. We review methods for the calculation of CD spectra, focusing on semiempirical and ab initio parameter sets used in the matrix method. Lastly, a new web interface for online CD and LD calculation is presented.
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Affiliation(s)
- Benjamin M Bulheller
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK NG7 2RD
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34
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Lucas LH, Ersoy BA, Kueltzo LA, Joshi SB, Brandau DT, Thyagarajapuram N, Peek LJ, Middaugh CR. Probing protein structure and dynamics by second-derivative ultraviolet absorption analysis of cation-{pi} interactions. Protein Sci 2006; 15:2228-43. [PMID: 16963649 PMCID: PMC2242397 DOI: 10.1110/ps.062133706] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We describe an alternate approach for studying protein structure using the detection of ultraviolet (UV) absorbance peak shifts of aromatic amino acid side chains induced by the presence of salts. The method is based on the hypothesis that salt cations (Li+, Na+, and Cs+) of varying sizes can differentially diffuse through protein matrices and interact with benzyl, phenyl, and indole groups through cation-pi interactions. We have investigated the potential of this method to probe protein dynamics by measuring high resolution second-derivative UV spectra as a function of salt concentration for eight proteins of varying physical and chemical properties and the N-acetylated C-ethyl esterified amino acids to represent totally exposed side chains. We show that small shifts in the wavelength maxima for Phe, Tyr, and Trp in the presence of high salt concentrations can be reliably measured and that the magnitude and direction of the peak shifts are influenced by several factors, including protein size, charge, and the local environment and solvent accessibility of the aromatic groups. Evaluating the empirical UV spectral data in light of known protein structural information shows that probing cation-pi interactions in proteins reveals unique information about the influence of structure on aromatic side chain spectroscopic behavior.
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Affiliation(s)
- Laura H Lucas
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, USA
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Guthmuller J, Simon D. Linear and Nonlinear Optical Response of Aromatic Amino Acids: A Time-Dependent Density Functional Investigation. J Phys Chem A 2006; 110:9967-73. [PMID: 16898701 DOI: 10.1021/jp063053x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The linear and nonlinear optical responses of the three aromatic amino acids tryptophan, tyrosine, and phenylalanine have been investigated by time-dependent density functional theory. The effect of the peptidic chain on the polarizabilities and the first hyperpolarizabilities is addressed by substituting different groups to the chromophores indole, phenol, and benzene. The optimized structures are in very good agreement with the experimental results. Furthermore, the calculated polarizabilities are found to match well with the empirical results, showing the evolution obtained as the chain is lengthened. A systematic and constant increase of the polarizability is found, for the three chromophores, for the various chain lengths. The first hyperpolarizability is also noticeably modified by the chains, but the evolution of this quantity is found to be more dependent on the system considered. Finally, it is suggested that each of the three aromatic amino acids has a significant contribution to the nonlinear response of proteins.
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Affiliation(s)
- J Guthmuller
- Laboratoire de Spectrométrie ionique et moléculaire, Unité Mixte de Recherche 5579, Université Claude Bernard Lyon 1, and Centre National de la Recherche Scientifique, F-69622 Villeurbanne Cedex, France.
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Guthmuller J, Simon D. Water solvent effect on the first hyperpolarizability of p-nitrophenol and p-nitrophenylphosphate: A time-dependent density functional study. J Chem Phys 2006; 124:174502. [PMID: 16689578 DOI: 10.1063/1.2187490] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The first hyperpolarizabilities of p-nitrophenol and p-nitrophenylphosphate have been investigated in vacuum and in neutral aqueous solution by means of time-dependent density functional theory. The calculated excited states and hyperpolarizabilities obtained for these systems and for the molecules of phenol, nitrobenzene, and p-nitroaniline in vacuum match well with the experimental trends. The water solvent has been described by the conductorlike screening model and has been completed by water molecules interacting by hydrogen bonds with the solute. The results show a significant effect of the solvent on the first hyperpolarizability. In particular, the hyperpolarizability of p-nitrophenylphosphate (6.78 x 10(-30) esu) in vacuum is only 1.2 times larger than p-nitrophenol (5.63 x 10(-30) esu), whereas it is almost twice higher in aqueous environment, 12.6 x 10(-30) and 6.5 x 10(-30) esu, respectively. This difference in the nonlinear response in neutral water makes the p-nitrophenylphosphate substrate a suitable probe for measuring the activity of alkaline phosphatase enzymes.
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Affiliation(s)
- J Guthmuller
- Laboratoire de Spectrométrie Ionique et Moléculaire (UMR 5579), Université Claude Bernard Lyon 1 and CNRS, 43 Boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
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Oakley MT, Bulheller BM, Hirst JD. First-principles calculations of protein circular dichroism in the far-ultraviolet and beyond. Chirality 2006; 18:340-7. [PMID: 16557524 DOI: 10.1002/chir.20264] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Understanding the relationship between the amino acid sequence of a protein and its unique, compact three-dimensional structure is one of the grand challenges in molecular biophysics. One exciting approach to the protein-folding problem is fast time-resolved spectroscopy in the ultra-violet (UV). Time-resolved electronic circular dichroism (CD) spectroscopy offers resolution on a nanosecond (or faster) timescale, but does not provide the spatial resolution of techniques like X-ray crystallography or NMR. There is a need to underpin fast timescale spectroscopic studies of protein folding with a stronger theoretical foundation. We review some recent studies in this regard and briefly highlight how modern quantum chemical models of aromatic groups have improved the accuracy of calculations of protein CD spectra near-UV. On the other side of the far-UV, we describe calculations indicating that charge-transfer transitions are likely to be responsible for bands observed in the vacuum UV in protein CD.
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Affiliation(s)
- Mark T Oakley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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Dartigalongue T, Hache F. Calculation of the circular dichroism spectra of carbon monoxy- and deoxy myoglobin: Interpretation of a time-resolved circular dichroism experiment. J Chem Phys 2005; 123:184901. [PMID: 16292933 DOI: 10.1063/1.2041467] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A calculation of the circular dichroism (CD) spectra of carbon monoxy- and deoxy myoglobin is carried out in relation with a time-resolved CD experiment. The calculation is based on the polarizability theory and the parameters are adjusted to fit the experimental absorption and CD spectra. By performing the calculation for intermediate configurations of the protein, we are able to propose an explanation of the CD structure observed on a sub-100 ps time scale. The role of the proximal histidine is, in particular, clearly demonstrated in the first step of the myoglobin relaxation from its liganded to it deliganded form.
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Affiliation(s)
- Thibault Dartigalongue
- Laboratoire d'Optique et Biosciences-Centre National de la Recherche Scientifique-Institute National de la Sante et de la Recherche Medicale, Ecole Polytechnique, 91128 Palaiseau Cedex, France
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Abstract
Understanding the relationship between the amino acid sequence of a protein and its unique, compact 3D structure is one of the grand challenges in molecular biophysics. One particularly exciting approach is time-resolved electronic circular dichroism (CD) spectroscopy, which offers resolution on a nanosecond (or faster) time scale, although it does not provide the spatial resolution of techniques like X-ray crystallography or NMR. The thrust of our work is to underpin fast time scale spectroscopic studies of protein folding with a stronger theoretical foundation. Ultimately, we seek to use molecular dynamics simulations to study the influence of conformational dynamics and conformational transitions on the electronic CD spectra of proteins. We discuss how improved quantum chemical models of individual chromophores, including aromatic sidechains, can be incorporated into calculations of the electronic structure of proteins and their CD.
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Affiliation(s)
- David M Rogers
- School of Chemistry, University of Nottingham, University Park, Nottingham, United Kingdom
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