1
|
Riegerová P, Horváth M, Šebesta F, Sýkora J, Šulc M, Vlček A. Single-step Purification and Characterization of Pseudomonas aeruginosa Azurin. Protein Expr Purif 2024:106566. [PMID: 39128594 DOI: 10.1016/j.pep.2024.106566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/30/2024] [Accepted: 08/06/2024] [Indexed: 08/13/2024]
Abstract
Azurin is a small periplasmic blue copper protein found in bacterial strains such as Pseudomonas and Alcaligenes where it facilitates denitrification. Azurin is extensively studied for its ability to mediate electron-transfer processes, but it has also sparked interest of the pharmaceutical community as a potential antimicrobial or anticancer agent. Here we offer a novel approach for expression and single-step purification of azurin in Escherichia coli with high yields and optimal metalation. A fusion tag strategy using an N-terminal GST tag was employed to obtain pure protein without requiring any additional purification steps. After the on-column cleavage by HRV 3C Protease, azurin is collected and additionally incubated with copper sulphate to ensure sufficient metalation. UV-VIS absorption, mass spectroscopy, and circular dichroism analysis all validated the effective production of azurin, appropriate protein folding and the development of an active site with an associated cofactor. MD simulations verified that incorporation of the N-terminal GPLGS segment does not affect azurin structure. In addition, the biological activity of azurin was tested in HeLa cells.
Collapse
Affiliation(s)
- Petra Riegerová
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, 182 23, Prague, Czech Republic.
| | - Matej Horváth
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, 182 23, Prague, Czech Republic; Department of Cell Biology, Charles University, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Filip Šebesta
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, 182 23, Prague, Czech Republic; Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - Jan Sýkora
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, 182 23, Prague, Czech Republic
| | - Miroslav Šulc
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, CZ-12843 Prague 2, Czech Republic
| | - Antonín Vlček
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, 182 23, Prague, Czech Republic; Queen Mary University of London, Department of Chemistry, Mile End Road, London E1 4NS, United Kingdom.
| |
Collapse
|
2
|
Melčák M, Šebesta F, Heyda J, Gray HB, Záliš S, Vlček A. Tryptophan to Tryptophan Hole Hopping in an Azurin Construct. J Phys Chem B 2024; 128:96-108. [PMID: 38145895 PMCID: PMC10788906 DOI: 10.1021/acs.jpcb.3c06568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/18/2023] [Accepted: 11/30/2023] [Indexed: 12/27/2023]
Abstract
Electron transfer (ET) between neutral and cationic tryptophan residues in the azurin construct [ReI(H126)(CO)3(dmp)](W124)(W122)CuI (dmp = 4,7-Me2-1,10-phenanthroline) was investigated by Born-Oppenheimer quantum-mechanics/molecular mechanics/molecular dynamics (QM/MM/MD) simulations. We focused on W124•+ ← W122 ET, which is the middle step of the photochemical hole-hopping process *ReII(CO)3(dmp•-) ← W124 ← W122 ← CuI, where sequential hopping amounts to nearly 10,000-fold acceleration over single-step tunneling (ACS Cent. Sci. 2019, 5, 192-200). In accordance with experiments, UKS-DFT QM/MM/MD simulations identified forward and reverse steps of W124•+ ↔ W122 ET equilibrium, as well as back ET ReI(CO)3(dmp•-) → W124•+ that restores *ReII(CO)3(dmp•-). Strong electronic coupling between the two indoles (≥40 meV in the crossing region) makes the productive W124•+ ← W122 ET adiabatic. Energies of the two redox states are driven to degeneracy by fluctuations of the electrostatic potential at the two indoles, mainly caused by water solvation, with contributions from the protein dynamics in the W122 vicinity. ET probability depends on the orientation of Re(CO)3(dmp) relative to W124 and its rotation diminishes the hopping yield. Comparison with hole hopping in natural systems reveals structural and dynamics factors that are important for designing efficient hole-hopping processes.
Collapse
Affiliation(s)
- Martin Melčák
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- Department
of Physical Chemistry, University of Chemistry
and Technology Prague, Technická 5, CZ-166 28 Prague, Czech Republic
| | - Filip Šebesta
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- Department
of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Prague, Czech Republic
| | - Jan Heyda
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- Department
of Physical Chemistry, University of Chemistry
and Technology Prague, Technická 5, CZ-166 28 Prague, Czech Republic
| | - Harry B. Gray
- Beckman
Institute, California Institute of Technology, Pasadena, California 91125, United States
| | - Stanislav Záliš
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, CZ-182 23 Prague, Czech Republic
| | - Antonín Vlček
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- Department
of Chemistry, Queen Mary University of London, London E1 4NS, U.K.
| |
Collapse
|
3
|
Dumont R, Dowdell J, Song J, Li J, Wang S, Kang W, Li B. Control of charge transport in electronically active systems towards integrated biomolecular circuits (IbC). J Mater Chem B 2023; 11:8302-8314. [PMID: 37464922 DOI: 10.1039/d3tb00701d] [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: 07/20/2023]
Abstract
The miniaturization of traditional silicon-based electronics will soon reach its limitation as quantum tunneling and heat become serious problems at the several-nanometer scale. Crafting integrated circuits via self-assembly of electronically active molecules using a "bottom-up" paradigm provides a potential solution to these technological challenges. In particular, integrated biomolecular circuits (IbC) offer promising advantages to achieve this goal, as nature offers countless examples of functionalities entailed by self-assembly and examples of controlling charge transport at the molecular level within the self-assembled structures. To this end, the review summarizes the progress in understanding how charge transport is regulated in biosystems and the key redox-active amino acids that enable the charge transport. In addition, charge transport mechanisms at different length scales are also reviewed, offering key insights for controlling charge transport in IbC in the future.
Collapse
Affiliation(s)
- Ryan Dumont
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| | - Juwaan Dowdell
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| | - Jisoo Song
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| | - Jiani Li
- State Key Laboratory of Fine Chemicals, Frontiers Science Centre for Smart Materials Oriented Chemical Engineering, School of Bioengineering, Dalian University of Technology, Dalian, China.
| | - Suwan Wang
- State Key Laboratory of Fine Chemicals, Frontiers Science Centre for Smart Materials Oriented Chemical Engineering, School of Bioengineering, Dalian University of Technology, Dalian, China.
| | - Wei Kang
- State Key Laboratory of Fine Chemicals, Frontiers Science Centre for Smart Materials Oriented Chemical Engineering, School of Bioengineering, Dalian University of Technology, Dalian, China.
- Ningbo Institute of Dalian University of Technology, Ningbo, China
| | - Bo Li
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| |
Collapse
|
4
|
Maqboul I. Profiling charge transport: A new computational approach. Int J Biol Macromol 2023; 237:124065. [PMID: 36948333 DOI: 10.1016/j.ijbiomac.2023.124065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/12/2023] [Accepted: 03/13/2023] [Indexed: 03/24/2023]
Abstract
To maintain life, charge transfer processes must be efficient to allow electrons to migrate across distances as large as 30-50 Å within a timescale from picoseconds to milliseconds, and the free-energy cost should not exceed one electron volt. By employing local ionization and local affinity energies, we calculated the pathway for electron and electron-hole transport, respectively. The pathway is then used to calculate both the driving force and the activation energy. The electronic coupling is calculated using configuration interaction procedure. When the charge acceptor is not known, as in oxidative stress, the charge transport terminals are found using Monte-Carlo simulation. These parameters were used to calculate the rate described by Marcus theory. Our approach has been elaborately explained using the famous androstane example and then applied to two proteins: electron transport in azurin protein and hole-hopping migration route from the heme center of cytochrome c peroxidase to its surface. This model gives an effective method to calculate the charge transport pathway and the free-energy profile within 0.1 eV from the experimental measurements and electronic coupling within 3 meV.
Collapse
Affiliation(s)
- Ibrahim Maqboul
- Computer Chemistry Center (CCC), Department of Chemistry and Pharmacy, Faculty of Sciences, Friedrich-Alexander-University, Erlangen, Germany; Computer Chemistry Center (CCC), Department of Chemistry and Pharmacy, Faculty of Sciences, Friedrich-Alexander-University, Nägelsbachstraße 25, 91052 Erlangen, Germany..
| |
Collapse
|
5
|
Bacellar C, Rouxel JR, Ingle RA, Mancini GF, Kinschel D, Cannelli O, Zhao Y, Cirelli C, Knopp G, Szlachetko J, Lima FA, Menzi S, Ozerov D, Pamfilidis G, Kubicek K, Khakhulin D, Gawelda W, Rodriguez-Fernandez A, Biednov M, Bressler C, Arrell CA, Johnson PJM, Milne CJ, Chergui M. Ultrafast Energy Transfer from Photoexcited Tryptophan to the Haem in Cytochrome c. J Phys Chem Lett 2023; 14:2425-2432. [PMID: 36862109 DOI: 10.1021/acs.jpclett.3c00218] [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: 06/18/2023]
Abstract
We report femtosecond Fe K-edge absorption (XAS) and nonresonant X-ray emission (XES) spectra of ferric cytochrome C (Cyt c) upon excitation of the haem (>300 nm) or mixed excitation of the haem and tryptophan (<300 nm). The XAS and XES transients obtained in both excitation energy ranges show no evidence for electron transfer processes between photoexcited tryptophan (Trp) and the haem, but rather an ultrafast energy transfer, in agreement with previous ultrafast optical fluorescence and transient absorption studies. The reported (J. Phys. Chem. B 2011, 115 (46), 13723-13730) decay times of Trp fluorescence in ferrous (∼350 fs) and ferric (∼700 fs) Cyt c are among the shortest ever reported for Trp in a protein. The observed time scales cannot be rationalized in terms of Förster or Dexter energy transfer mechanisms and call for a more thorough theoretical investigation.
Collapse
Affiliation(s)
- Camila Bacellar
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
- SwissFEL, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Jérémy R Rouxel
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
- Univ Lyon, UJM-Saint-Etienne, CNRS, Graduate School Optics Institute, Laboratoire Hubert Curien, UMR 5516, Saint-Etienne F-42023, France
| | - Rebecca A Ingle
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Giulia F Mancini
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
- 2Laboratory for Ultrafast X-ray and Electron Microscopy, Department of Physics, University of Pavia, Via Agostino Bassi 6, 27100 Pavia PV, Italy
| | - Dominik Kinschel
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
| | - Oliviero Cannelli
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
| | - Yang Zhao
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
| | - Claudio Cirelli
- SwissFEL, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Gregor Knopp
- SwissFEL, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Jakub Szlachetko
- SOLARIS National Synchrotron Radiation Centre, Jagiellonian University, 30-392 Kraków, Poland
| | | | - Samuel Menzi
- SwissFEL, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Dmitry Ozerov
- SwissFEL, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | | | | | | | - Wojciech Gawelda
- European XFEL, Holzkoppel 4, D-22869 Schenefeld, Germany
- Faculty of Physics, Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, Poland
- Departamento de Química, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IMDEA Nanociencia, Calle Faraday 9, 28049 Madrid, Spain
| | | | - Mykola Biednov
- European XFEL, Holzkoppel 4, D-22869 Schenefeld, Germany
| | | | | | | | - Christopher J Milne
- SwissFEL, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
- European XFEL, Holzkoppel 4, D-22869 Schenefeld, Germany
| | - Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide (LSU), ISIC and Lausanne Centre for Ultrafast Science (LACUS), CH-1015 Lausanne, Switzerland
| |
Collapse
|
6
|
Šrut A, Mai S, Sazanovich IV, Heyda J, Vlček A, González L, Záliš S. Nonadiabatic excited-state dynamics of ReCl(CO) 3(bpy) in two different solvents. Phys Chem Chem Phys 2022; 24:25864-25877. [PMID: 36279148 DOI: 10.1039/d2cp02981b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We present a study of excited-states relaxation of the complex ReCl(CO)3(bpy) (bpy = 2,2-bipyridine) using a nonadiabatic TD-DFT dynamics on spin-mixed potential energy surfaces in explicit acetonitrile (ACN) and dimethylsulfoxide (DMSO) solutions up to 800 fs. ReCl(CO)3(bpy) belongs to a group of important photosensitizers which show ultrafast biexponential subpicosecond fluorescence decay kinetics. The choice of solvents was motivated by the different excited-state relaxation dynamics observed in subpicosecond time-resolved IR (TRIR) experiments. Simulations of intersystem crossing (ISC) showed the development of spin-mixed states in both solvents. Transformation of time-dependent populations of spin-mixed states enabled to monitor the temporal evolution of individual singlet and triplet states, fitting of bi-exponential decay kinetics, and simulating the time-resolved fluorescence spectra that show only minor differences between the two solvents. Analysis of structural relaxation and solvent reorganization employing time-resolved proximal distribution functions pointed to the factors influencing the fluorescence decay time constants. Nonadiabatic dynamics simulations of time-evolution of electronic, molecular, and solvent structures emerge as a powerful technique to interpret time-resolved spectroscopic data and ultrafast photochemical reactivity.
Collapse
Affiliation(s)
- Adam Šrut
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 23 Prague, Czech Republic.
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, 166 28 Prague, Czech Republic.
| | - Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
| | - Igor V Sazanovich
- Central Laser Facility, Research Complex at Harwell, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire, OX11 0QX, UK
| | - Jan Heyda
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 23 Prague, Czech Republic.
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, 166 28 Prague, Czech Republic.
| | - Antonín Vlček
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 23 Prague, Czech Republic.
- Department of Chemistry, Queen Mary University of London, London, E1 4NS, UK
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
| | - Stanislav Záliš
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 23 Prague, Czech Republic.
| |
Collapse
|
7
|
Mitra S, Ainavarapu SRK, Dasgupta J. Long-Range Charge Delocalization Mediates the Ultrafast Ligand-to-Metal Charge Transfer Dynamics at the Cu 2+-Active Site in Azurin. J Phys Chem B 2022; 126:5390-5399. [PMID: 35797135 DOI: 10.1021/acs.jpcb.2c01427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The blue color metalloprotein in azurin has traditionally been attributed to the intense cysteine-to-Cu2+ ligand-to-metal charge transfer transition centered at 628 nm. Although resonance Raman measurements of the Cu2+ active site have implied that the LMCT transition electronically couples to the protein scaffold well beyond its primary metal-ligand coordination shell, the structural extent of this electronic coupling and visualization of the protein-mediated charge transfer dynamics have remained elusive. Here, using femtosecond broadband transient absorption and impulsive Raman spectroscopy, we provide direct evidence for a rapid relaxation between two distinct charge transfer states, having different spatial delocalization, within ∼300 fs followed by recombination of charges in subpicosecond time scales. We invoke the formation of a protein-centered radical cation, possibly Trp48 or a Phe residue, within 100 fs substantiating the long-range electronic coupling for the first time beyond the traditional copper active site. The Raman spectra of the excited CT state show the presence of protein-centric vibrations along with the vibrational modes assigned to the copper active site. Our results demonstrate a large delocalization length scale of the initially populated CT state, thereby highlighting the possibility of exploiting azurin photochemistry for energy conversion techniques.
Collapse
Affiliation(s)
- Soumyajit Mitra
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | | | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| |
Collapse
|
8
|
Kontkanen OV, Biriukov D, Futera Z. Reorganization Free Energy of Copper Proteins in Solution, in Vacuum, and on Metal Surfaces. J Chem Phys 2022; 156:175101. [DOI: 10.1063/5.0085141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Metalloproteins, known to efficiently transfer electronic charge in biological systems, recently found their utilization in nanobiotechnological devices where the protein is placed into direct contact with metal surfaces. The feasibility of oxidation/reduction of the protein redox sites is affected by the reorganization free energies, one of the key parameters determining the transfer rates. While their values have been measured and computed for proteins in their native environments, i.e., in aqueous solution, the reorganization free energies of dry proteins or proteins adsorbed to metal surfaces remain unknown. Here, we investigate the redox properties of blue copper protein azurin, a prototypical redox-active metalloprotein previously probed by various experimental techniques both in solution and on metal/vacuum interfaces. We used a hybrid QM/MM computational technique based on DFT to explore protein dynamics, flexibility, and corresponding reorganization free energies in aqueous solution, vacuum, and on vacuum gold interfaces. Somewhat surprisingly, the reorganization free energy only slightly decreases when azurin is dried because the loss of the hydration shell leads to larger flexibility of the protein near its redox site. At the vacuum gold surfaces, the energetics of the structure relaxation depends on the adsorption geometry, however, significant reduction of the reorganization free energy was not observed. These findings have important consequences for the charge transport mechanism in vacuum devices, showing that the free energy barriers for protein oxidation remain significant even under ultra-high vacuum conditions.
Collapse
Affiliation(s)
| | - Denys Biriukov
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences, Czech Republic
| | - Zdenek Futera
- University of South Bohemia in Ceske Budejovice Faculty of Science, Czech Republic
| |
Collapse
|
9
|
Fedoretz-Maxwell BP, Shin CH, MacNeil GA, Worrall LJ, Park R, Strynadka NCJ, Walsby CJ, Warren JJ. The Impact of Second Coordination Sphere Methionine-Aromatic Interactions in Copper Proteins. Inorg Chem 2022; 61:5563-5571. [DOI: 10.1021/acs.inorgchem.2c00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brooklyn P. Fedoretz-Maxwell
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Catherine H. Shin
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Gregory A. MacNeil
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Liam J. Worrall
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Rachel Park
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Natalie C. J. Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Charles J. Walsby
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Jeffrey J. Warren
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| |
Collapse
|
10
|
Brink A, Jacobs FJF, Helliwell JR. Trends in coordination of rhenium organometallic complexes in the Protein Data Bank. IUCRJ 2022; 9:180-193. [PMID: 35371500 PMCID: PMC8895017 DOI: 10.1107/s2052252522000665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
Radiopharmaceutical development has similar overall characteristics to any biomedical drug development requiring a compound's stability, aqueous solubility and selectivity to a specific disease site. However, organometallic complexes containing 188/186Re or 99mTc involve a d-block transition-metal radioactive isotope and therefore bring additional factors such as metal oxidation states, isotope purity and half life into play. This topical review is focused on the development of radiopharmaceuticals containing the radioisotopes of rhenium and technetium and, therefore, on the occurrence of these organometallic complexes in protein structures in the Worldwide Protein Data Bank (wwPDB). The purpose of incorporating the group 7 transition metals of rhenium/technetium in the protein and the reasons for study by protein crystallography are described, as certain PDB studies were not aimed at drug development. Technetium is used as a medical diagnostic agent and involves the 99mTc isotope which decays to release gamma radiation, thereby employed for its use in gamma imaging. Due to the periodic relationship among group 7 transition metals, the coordination chemistry of rhenium is similar (but not identical) to that of technetium. The types of reactions the potential model radiopharmaceutical would prefer to partake in, and by extension knowing which proteins and biomolecules the compound would react with in vivo, are needed. Crystallography studies, both small molecule and macromolecular, are a key aspect in understanding chemical coordination. Analyses of bonding modes, coordination to particular residues and crystallization conditions are presented. In our Forward look as a concluding summary of this topical review, the question we ask is: what is the best way for this field to progress?
Collapse
Affiliation(s)
- Alice Brink
- Chemistry Department, University of the Free State, Nelson Mandela Drive, Bloemfontein, South Africa
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, United Kingdom
| | - Francois J. F. Jacobs
- Chemistry Department, University of the Free State, Nelson Mandela Drive, Bloemfontein, South Africa
| | - John R. Helliwell
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, United Kingdom
| |
Collapse
|
11
|
López-Ortiz M, Zamora RA, Giannotti MI, Hu C, Croce R, Gorostiza P. Distance and Potential Dependence of Charge Transport Through the Reaction Center of Individual Photosynthetic Complexes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2104366. [PMID: 34874621 DOI: 10.1002/smll.202104366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/11/2021] [Indexed: 06/13/2023]
Abstract
Charge separation and transport through the reaction center of photosystem I (PSI) is an essential part of the photosynthetic electron transport chain. A strategy is developed to immobilize and orient PSI complexes on gold electrodes allowing to probe the complex's electron acceptor side, the chlorophyll special pair P700. Electrochemical scanning tunneling microscopy (ECSTM) imaging and current-distance spectroscopy of single protein complex shows lateral size in agreement with its known dimensions, and a PSI apparent height that depends on the probe potential revealing a gating effect in protein conductance. In current-distance spectroscopy, it is observed that the distance-decay constant of the current between PSI and the ECSTM probe depends on the sample and probe electrode potentials. The longest charge exchange distance (lowest distance-decay constant β) is observed at sample potential 0 mV/SSC (SSC: reference electrode silver/silver chloride) and probe potential 400 mV/SSC. These potentials correspond to hole injection into an electronic state that is available in the absence of illumination. It is proposed that a pair of tryptophan residues located at the interface between P700 and the solution and known to support the hydrophobic recognition of the PSI redox partner plastocyanin, may have an additional role as hole exchange mediator in charge transport through PSI.
Collapse
Affiliation(s)
- Manuel López-Ortiz
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
| | - Ricardo A Zamora
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
| | - Marina Inés Giannotti
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1-11, Barcelona, 08028, Spain
| | - Chen Hu
- Biophysics of PhotosynthesisDepartment of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Roberta Croce
- Biophysics of PhotosynthesisDepartment of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, 08010, Spain
| |
Collapse
|
12
|
Gray HB, Winkler JR. Functional and protective hole hopping in metalloenzymes. Chem Sci 2021; 12:13988-14003. [PMID: 34760183 PMCID: PMC8565380 DOI: 10.1039/d1sc04286f] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/20/2021] [Indexed: 01/19/2023] Open
Abstract
Electrons can tunnel through proteins in microseconds with a modest release of free energy over distances in the 15 to 20 Å range. To span greater distances, or to move faster, multiple charge transfers (hops) are required. When one of the reactants is a strong oxidant, it is convenient to consider the movement of a positively charged "hole" in a direction opposite to that of the electron. Hole hopping along chains of tryptophan (Trp) and tyrosine (Tyr) residues is a critical function in several metalloenzymes that generate high-potential intermediates by reactions with O2 or H2O2, or by activation with visible light. Examination of the protein structural database revealed that Tyr/Trp chains are common protein structural elements, particularly among enzymes that react with O2 and H2O2. In many cases these chains may serve a protective role in metalloenzymes by deactivating high-potential reactive intermediates formed in uncoupled catalytic turnover.
Collapse
Affiliation(s)
- Harry B Gray
- Beckman Institute, California Institute of Technology 1200 E California Boulevard Pasadena CA 19925 USA
| | - Jay R Winkler
- Beckman Institute, California Institute of Technology 1200 E California Boulevard Pasadena CA 19925 USA
| |
Collapse
|
13
|
Abstract
Hole hopping through tryptophan/tyrosine chains enables rapid unidirectional charge transport over long distances. We have elucidated structural and dynamical factors controlling hopping speed and efficiency in two modified azurin constructs that include a rhenium(I) sensitizer, Re(His)(CO)3(dmp)+, and one or two tryptophans (W1, W2). Experimental kinetics investigations showed that the two closely spaced (3 to 4 Å) intervening tryptophans dramatically accelerated long-range electron transfer (ET) from CuI to the photoexcited sensitizer. In our theoretical work, we found that time-dependent density-functional theory (TDDFT) quantum mechanics/molecular mechanics/molecular dynamics (QM/MM/MD) trajectories of low-lying triplet excited states of ReI(His)(CO)3(dmp)+-W1(-W2) exhibited crossings between sensitizer-localized (*Re) and charge-separated [ReI(His)(CO)3(dmp•-)/(W1 •+ or W2 •+)] (CS1 or CS2) states. Our analysis revealed that the distances, angles, and mutual orientations of ET-active cofactors fluctuate in a relatively narrow range in which the cofactors are strongly coupled, enabling adiabatic ET. Water-dominated electrostatic field fluctuations bring *Re and CS1 states to a crossing where *Re(CO)3(dmp)+←W1 ET occurs, and CS1 becomes the lowest triplet state. ET is promoted by solvation dynamics around *Re(CO)3(dmp)+(W1); and CS1 is stabilized by Re(dmp•-)/W1 •+ electron/hole interaction and enhanced W1 •+ solvation. The second hop, W1 •+←W2, is facilitated by water fluctuations near the W1/W2 unit, taking place when the electrostatic potential at W2 drops well below that at W1 •+ Insufficient solvation and reorganization around W2 make W1 •+←W2 ET endergonic, shifting the equilibrium toward W1 •+ and decreasing the charge-separation yield. We suggest that multiscale TDDFT/MM/MD is a suitable technique to model the simultaneous evolution of photogenerated excited-state manifolds.
Collapse
|
14
|
Jung SM, Lee J, Song WJ. Design of artificial metalloenzymes with multiple inorganic elements: The more the merrier. J Inorg Biochem 2021; 223:111552. [PMID: 34332336 DOI: 10.1016/j.jinorgbio.2021.111552] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/21/2021] [Accepted: 07/15/2021] [Indexed: 11/27/2022]
Abstract
A large fraction of metalloenzymes harbors multiple metal-centers that are electronically and/or functionally arranged within their proteinaceous environments. To explore the orchestration of inorganic and biochemical components and to develop bioinorganic catalysts and materials, we have described selected examples of artificial metalloproteins having multiple metallocofactors that were grouped depending on their initial protein scaffolds, the nature of introduced inorganic moieties, and the method used to propagate the number of metal ions within a protein. They demonstrated that diverse inorganic moieties can be selectively grafted and modulated in protein environments, providing a retrosynthetic bottom-up approach in the design of versatile and proficient biocatalysts and biomimetic model systems to explore fundamental questions in bioinorganic chemistry.
Collapse
Affiliation(s)
- Se-Min Jung
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jaehee Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Woon Ju Song
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| |
Collapse
|
15
|
Natali M, Amati A, Demitri N, Iengo E. Photoinduced Electron vs. Concerted Proton Electron Transfer Pathways in Sn IV (l-Tryptophanato) 2 Porphyrin Conjugates. Chemistry 2021; 27:7872-7881. [PMID: 33780047 PMCID: PMC8252543 DOI: 10.1002/chem.202005487] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Indexed: 01/01/2023]
Abstract
Aromatic amino acids such as l‐tyrosine and l‐tryptophan are deployed in natural systems to mediate electron transfer (ET) reactions. While tyrosine oxidation is always coupled to deprotonation (proton‐coupled electron‐transfer, PCET), both ET‐only and PCET pathways can occur in the case of the tryptophan residue. In the present work, two novel conjugates 1 and 2, based on a SnIV tetraphenylporphyrin and SnIV octaethylporphyrin, respectively, as the chromophore/electron acceptor and l‐tryptophan as electron/proton donor, have been prepared and thoroughly characterized by a combination of different techniques including single crystal X‐ray analysis. The photophysical investigation of 1 and 2 in CH2Cl2 in the presence of pyrrolidine as a base shows that different quenching mechanisms are operating upon visible‐light excitation of the porphyrin component, namely photoinduced electron transfer and concerted proton electron transfer (CPET), depending on the chromophore identity and spin multiplicity of the excited state. The results are compared with those previously described for metal‐mediated analogues featuring SnIV porphyrin chromophores and l‐tyrosine as the redox active amino acid and well illustrate the peculiar role of l‐tryptophan with respect to PCET.
Collapse
Affiliation(s)
- Mirco Natali
- Department of Chemical, Pharmaceutical and Agricultural Sciences (DOCPAS), University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy.,Centro Interuniversitario per la Conversione Chimica dell'Energia Solare (SolarChem), sez. di Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy
| | - Agnese Amati
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127, Trieste, Italy.,Current address: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Nicola Demitri
- Electra-Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Elisabetta Iengo
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127, Trieste, Italy
| |
Collapse
|
16
|
Futera Z. Amino-acid interactions with the Au(111) surface: adsorption, band alignment, and interfacial electronic coupling. Phys Chem Chem Phys 2021; 23:10257-10266. [PMID: 33899874 DOI: 10.1039/d1cp00218j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The charge transport properties of biological molecules like peptides and proteins are intensively studied for the great flexibility, redox-state variability, long-range efficiency, and biocompatibility of potential bioelectronic applications. Yet, the electronic interactions of biomolecules with solid metal surfaces, determining the conductivities of the biomolecular junctions, are hard to predict and usually unavailable. Here, we present accurate adsorption structures and energies, electronic band alignment, and interfacial electronic coupling data for all 20 natural amino acids computed using the DFT+Σ scheme based on the vdW-DF and OT-RSH functionals. For comparison, data obtained using the popular PBE functional are provided as well. Tryptophan, compared to other amino acids, is shown to be distinctly exceptional in terms of the electronic properties related to charge transport. Its high adsorption energy, frontier-orbital levels aligned relatively close to the Fermi energy of gold and strong interfacial electronic coupling make it an ideal candidate for facilitating charge transfer on such heterogeneous interfaces. Although the amino acids in peptides and proteins are affected by the structural interactions hindering their contact with the surface, knowledge of the single-molecule surface interactions is necessary for a detailed understanding of such structural effects and tuning of potential applications.
Collapse
Affiliation(s)
- Zdenek Futera
- Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic.
| |
Collapse
|
17
|
Stout MJ, Skelton BW, Sobolev AN, Raiteri P, Massi M, Simpson PV. Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazol-2-ylidene Ligands. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00381] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew J. Stout
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley 6102, Perth, Western Australia, Australia
| | - Brian W. Skelton
- School of Molecular Sciences and CMCA, the University of Western Australia, 35 Stirling Highway, 6009 Perth, Western Australia, Australia
| | - Alexandre N. Sobolev
- School of Molecular Sciences and CMCA, the University of Western Australia, 35 Stirling Highway, 6009 Perth, Western Australia, Australia
| | - Paolo Raiteri
- Curtin Institute for Computation and School of Life and Molecular Sciences, Curtin University, Kent Street, Bentley 6102, Perth, Western Australia, Australia
| | - Massimiliano Massi
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley 6102, Perth, Western Australia, Australia
| | - Peter V. Simpson
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley 6102, Perth, Western Australia, Australia
| |
Collapse
|
18
|
Olloqui-Sariego JL, Zakharova GS, Poloznikov AA, Calvente JJ, Hushpulian DM, Gorton L, Andreu R. Influence of tryptophan mutation on the direct electron transfer of immobilized tobacco peroxidase. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.136465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Tyson KJ, Davis AN, Norris JL, Bartolotti LJ, Hvastkovs EG, Offenbacher AR. Impact of Local Electrostatics on the Redox Properties of Tryptophan Radicals in Azurin: Implications for Redox-Active Tryptophans in Proton-Coupled Electron Transfer. J Phys Chem Lett 2020; 11:2408-2413. [PMID: 32134666 DOI: 10.1021/acs.jpclett.0c00614] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tyrosine and tryptophan play critical roles in facilitating proton-coupled electron transfer (PCET) processes essential to life. The local protein environment is anticipated to modulate the thermodynamics of amino acid radicals to achieve controlled, unidirectional PCET. Herein, square-wave voltammetry was employed to investigate the electrostatic effects on the redox properties of tryptophan in two variants of the protein azurin. Each variant contains a single redox-active tryptophan, W48 or W108, in a unique and buried protein environment. These tryptophan residues exhibit reversible square-wave voltammograms. A Pourbaix plot, representing the reduction potentials versus pH, is presented for the non-H-bonded W48, which has potentials comparable to those of tryptophan in solution. The reduction potentials of W108 are seen to be increased by more than 100 mV across the same pH range. Molecular dynamics shows that, despite its buried indole ring, the N-H of W108 hydrogen bonds with a water cluster, while W48 is completely excluded from interactions with water or polar groups. These redox properties provide insight into the role of the protein in tuning the reactivity of tryptophan radicals, a requirement for controlled biological PCET.
Collapse
Affiliation(s)
- Kristin J Tyson
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Amanda N Davis
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Jessica L Norris
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Libero J Bartolotti
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Eli G Hvastkovs
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Adam R Offenbacher
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| |
Collapse
|
20
|
Mai S, Menger MFSJ, Marazzi M, Stolba DL, Monari A, González L. Competing ultrafast photoinduced electron transfer and intersystem crossing of [Re(CO) 3 (Dmp)(His124)(Trp122)] + in Pseudomonas aeruginosa azurin: a nonadiabatic dynamics study. Theor Chem Acc 2020; 139:65. [PMID: 32214889 PMCID: PMC7078154 DOI: 10.1007/s00214-020-2555-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 01/20/2020] [Indexed: 12/28/2022]
Abstract
We present a computational study of sub-picosecond nonadiabatic dynamics in a rhenium complex coupled electronically to a tryptophan (Trp) side chain of Pseudomonas aeruginosa azurin, a prototypical protein used in the study of electron transfer in proteins. To gain a comprehensive understanding of the photoinduced processes in this system, we have carried out vertical excitation calculations at the TDDFT level of theory as well as nonadiabatic dynamics simulations using the surface hopping including arbitrary couplings (SHARC) method coupled to potential energy surfaces represented with a linear vibronic coupling model. The results show that the initial photoexcitation populates both singlet metal-to-ligand charge transfer (MLCT) and singlet charge-separated (CS) states, where in the latter an electron was transferred from the Trp amino acid to the complex. Subsequently, a complex mechanism of simultaneous intersystem crossing and electron transfer leads to the sub-picosecond population of triplet MLCT and triplet CS states. These results confirm the assignment of the sub-ps time constants of previous experimental studies and constitute the first computational evidence for the ultrafast formation of the charge-separated states in Re-sensitized azurin.
Collapse
Affiliation(s)
- Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
- Present Address: Photonics Institute, Vienna University of Technology, Gußhausstr. 27–29, 1040 Vienna, Austria
| | - Maximilian F. S. J. Menger
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
- Present Address: Zernike Institute for Advanced Materials, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Marco Marazzi
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Universidad de Alcalá, Ctra. Madrid-Barcelona Km. 33,600, 28871 Alcalá de Henares, Madrid Spain
- Chemical Research Institute “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28871 Alcalá de Henares, Madrid Spain
| | - Dario L. Stolba
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Antonio Monari
- Université de Lorraine and CNRS, LPTC UMR, 7019 Nancy, France
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| |
Collapse
|
21
|
Pospíšil P, Sýkora J, Takematsu K, Hof M, Gray HB, Vlček A. Light-Induced Nanosecond Relaxation Dynamics of Rhenium-Labeled Pseudomonas aeruginosa Azurins. J Phys Chem B 2020; 124:788-797. [PMID: 31935093 DOI: 10.1021/acs.jpcb.9b10802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Time-resolved phosphorescence spectra of Re(CO)3(dmp)+ and Re(CO)3(phen)+ chromophores (dmp = 4,7-dimethyl-1,10-phenanthroline, phen = 1,10-phenanthroline) bound to surface histidines (H83, H124, and H126) of Pseudomonas aeruginosa azurin mutants exhibit dynamic band maxima shifts to lower wavenumbers following 3-exponential kinetics with 1-5 and 20-100 ns major phases and a 1.1-2.5 μs minor (5-16%) phase. Observation of slow relaxation components was made possible by using an organometallic Re chromophore as a probe whose long phosphorescence lifetime extends the observation window up to ∼3 μs. Integrated emission-band areas also decay with 2- or 3-exponential kinetics; the faster decay phase(s) is relaxation-related, whereas the slowest one [360-680 ns (dmp); 90-140 ns (phen)] arises mainly from population decay. As a result of shifting bands, the emission intensity decay kinetics depend on the detection wavelength. Detailed kinetics analyses and comparisons with band-shift dynamics are needed to disentangle relaxation and population decay kinetics if they occur on comparable timescales. The dynamic phosphorescence Stokes shift in Re-azurins is caused by relaxation motions of the solvent, the protein, and solvated amino acid side chains at the Re binding site in response to chromophore electronic excitation. Comparing relaxation and decay kinetics of Re(dmp)124K122CuII and Re(dmp)124W122CuII suggests that electron transfer (ET) and relaxation motions in the W122 mutant are coupled. It follows that nanosecond and faster photo-induced ET steps in azurins (and likely other redox proteins) occur from unrelaxed systems; importantly, these reactions can be driven (or hindered) by structural and solvational dynamics.
Collapse
Affiliation(s)
- Petr Pospíšil
- J. Heyrovský Institute of Physical Chemistry , Czech Academy of Sciences , Dolejškova 3 , CZ-182 23 Prague , Czech Republic
| | - Jan Sýkora
- J. Heyrovský Institute of Physical Chemistry , Czech Academy of Sciences , Dolejškova 3 , CZ-182 23 Prague , Czech Republic
| | - Kana Takematsu
- Department of Chemistry , Bowdoin College , Brunswick , Maine 04011 , United States
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry , Czech Academy of Sciences , Dolejškova 3 , CZ-182 23 Prague , Czech Republic
| | - Harry B Gray
- Beckman Institute , California Institute of Technology , Pasadena , California 91125 , United States
| | - Antonín Vlček
- J. Heyrovský Institute of Physical Chemistry , Czech Academy of Sciences , Dolejškova 3 , CZ-182 23 Prague , Czech Republic.,School of Biological and Chemical Sciences , Queen Mary University of London , Mile End Road , E1 4NS London , U.K
| |
Collapse
|
22
|
Yee EF, Dzikovski B, Crane BR. Tuning Radical Relay Residues by Proton Management Rescues Protein Electron Hopping. J Am Chem Soc 2019; 141:17571-17587. [PMID: 31603693 DOI: 10.1021/jacs.9b05715] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Transient tyrosine and tryptophan radicals play key roles in the electron transfer (ET) reactions of photosystem (PS) II, ribonucleotide reductase (RNR), photolyase, and many other proteins. However, Tyr and Trp are not functionally interchangeable, and the factors controlling their reactivity are often unclear. Cytochrome c peroxidase (CcP) employs a Trp191•+ radical to oxidize reduced cytochrome c (Cc). Although a Tyr191 replacement also forms a stable radical, it does not support rapid ET from Cc. Here we probe the redox properties of CcP Y191 by non-natural amino acid substitution, altering the ET driving force and manipulating the protic environment of Y191. Higher potential fluorotyrosine residues increase ET rates marginally, but only addition of a hydrogen bond donor to Tyr191• (via Leu232His or Glu) substantially alters activity by increasing the ET rate by nearly 30-fold. ESR and ESEEM spectroscopies, crystallography, and pH-dependent ET kinetics provide strong evidence for hydrogen bond formation to Y191• by His232/Glu232. Rate measurements and rapid freeze quench ESR spectroscopy further reveal differences in radical propagation and Cc oxidation that support an increased Y191• formal potential of ∼200 mV in the presence of E232. Hence, Y191 inactivity results from a potential drop owing to Y191•+ deprotonation. Incorporation of a well-positioned base to accept and donate back a hydrogen bond upshifts the Tyr• potential into a range where it can effectively oxidize Cc. These findings have implications for the YZ/YD radicals of PS II, hole-hopping in RNR and cryptochrome, and engineering proteins for long-range ET reactions.
Collapse
Affiliation(s)
- Estella F Yee
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Boris Dzikovski
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States.,National Biomedical Center for Advanced ESR Technologies (ACERT) , Cornell University , Ithaca , New York 14850 , United States
| | - Brian R Crane
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| |
Collapse
|
23
|
Mosberger M, Probst B, Spingler B, Alberto R. Influence of Hetero-Biaryl Ligands on the Photo-Electrochemical Properties of [ReI
NCS(N∩
N)(CO)3
]-Type Photosensitizers. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900652] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Mathias Mosberger
- Department of Chemistry; University of Zürich; Winterthurerstrasse 190 Zürich Suisse
| | - Benjamin Probst
- Department of Chemistry; University of Zürich; Winterthurerstrasse 190 Zürich Suisse
| | - Bernhard Spingler
- Department of Chemistry; University of Zürich; Winterthurerstrasse 190 Zürich Suisse
| | - Roger Alberto
- Department of Chemistry; University of Zürich; Winterthurerstrasse 190 Zürich Suisse
| |
Collapse
|
24
|
Abstract
After presenting the basic theoretical models of excitation energy transfer and charge transfer, I describe some of the novel experimental methods used to probe them. Finally, I discuss recent results concerning ultrafast energy and charge transfer in biological systems, in chemical systems and in photovoltaics based on sensitized transition metal oxides.
Collapse
Affiliation(s)
- Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Lausanne Centre for Ultrafast Science (LACUS), FSB, Station 6, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
25
|
Tazhigulov RN, Gayvert JR, Wei M, Bravaya KB. eMap: A Web Application for Identifying and Visualizing Electron or Hole Hopping Pathways in Proteins. J Phys Chem B 2019; 123:6946-6951. [DOI: 10.1021/acs.jpcb.9b04816] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ruslan N. Tazhigulov
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - James R. Gayvert
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Melissa Wei
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Ksenia B. Bravaya
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| |
Collapse
|
26
|
Takematsu K, Pospíšil P, Pižl M, Towrie M, Heyda J, Záliš S, Kaiser JT, Winkler JR, Gray HB, Vlček A. Hole Hopping Across a Protein-Protein Interface. J Phys Chem B 2019; 123:1578-1591. [PMID: 30673250 PMCID: PMC6384139 DOI: 10.1021/acs.jpcb.8b11982] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have investigated photoinduced hole hopping in a Pseudomonas aeruginosa azurin mutant Re126WWCuI, where two adjacent tryptophan residues (W124 and W122) are inserted between the CuI center and a Re photosensitizer coordinated to a H126 imidazole (Re = ReI(H126)(CO)3(dmp)+, dmp = 4,7-dimethyl-1,10-phenanthroline). Optical excitation of this mutant in aqueous media (≤40 μM) triggers 70 ns electron transport over 23 Å, yielding a long-lived (120 μs) ReI(H126)(CO)3(dmp•-)WWCuII product. The Re126FWCuI mutant (F124, W122) is not redox-active under these conditions. Upon increasing the concentration to 0.2-2 mM, {Re126WWCuI}2 and {Re126FWCuI}2 are formed with the dmp ligand of the Re photooxidant of one molecule in close contact (3.8 Å) with the W122' indole on the neighboring chain. In addition, {Re126WWCuI}2 contains an interfacial tryptophan quadruplex of four indoles (3.3-3.7 Å apart). In both mutants, dimerization opens an intermolecular W122' → //*Re ET channel (// denotes the protein interface, *Re is the optically excited sensitizer). Excited-state relaxation and ET occur together in two steps (time constants of ∼600 ps and ∼8 ns) that lead to a charge-separated state containing a Re(H126)(CO)3(dmp•-)//(W122•+)' unit; then (CuI)' is oxidized intramolecularly (60-90 ns) by (W122•+)', forming ReI(H126)(CO)3(dmp•-)WWCuI//(CuII)'. The photocycle is closed by ∼1.6 μs ReI(H126)(CO)3(dmp•-) → //(CuII)' back ET that occurs over 12 Å, in contrast to the 23 Å, 120 μs step in Re126WWCuI. Importantly, dimerization makes Re126FWCuI photoreactive and, as in the case of {Re126WWCuI}2, channels the photoproduced "hole" to the molecule that was not initially photoexcited, thereby shortening the lifetime of ReI(H126)(CO)3(dmp•-)//CuII. Although two adjacent W124 and W122 indoles dramatically enhance CuI → *Re intramolecular multistep ET, the tryptophan quadruplex in {Re126WWCuI}2 does not accelerate intermolecular electron transport; instead, it acts as a hole storage and crossover unit between inter- and intramolecular ET pathways. Irradiation of {Re126WWCuII}2 or {Re126FWCuII}2 also triggers intermolecular W122' → //*Re ET, and the Re(H126)(CO)3(dmp•-)//(W122•+)' charge-separated state decays to the ground state by ∼50 ns ReI(H126)(CO)3(dmp•-)+ → //(W122•+)' intermolecular charge recombination. Our findings shed light on the factors that control interfacial hole/electron hopping in protein complexes and on the role of aromatic amino acids in accelerating long-range electron transport.
Collapse
Affiliation(s)
- Kana Takematsu
- Department of Chemistry, Bowdoin College, Brunswick, ME 04011, USA
| | - Petr Pospíšil
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
| | - Martin Pižl
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- University of Chemistry and Technology, Prague, Technická 5, CZ-166 28 Prague, Czech Republic
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire, OX11 0FA, UK
| | - Jan Heyda
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- University of Chemistry and Technology, Prague, Technická 5, CZ-166 28 Prague, Czech Republic
| | - Stanislav Záliš
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
| | - Jens T. Kaiser
- Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jay R. Winkler
- Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Harry B. Gray
- Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Antonín Vlček
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague, Czech Republic
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London E1 4NS, United Kingdom
| |
Collapse
|