1
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Li P, Bera S, Kumar-Saxena S, Pecht I, Sheves M, Cahen D, Selzer Y. Electron transport through two interacting channels in Azurin-based solid-state junctions. Proc Natl Acad Sci U S A 2024; 121:e2405156121. [PMID: 39110736 PMCID: PMC11331140 DOI: 10.1073/pnas.2405156121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 07/12/2024] [Indexed: 08/21/2024] Open
Abstract
The fundamental question of "what is the transport path of electrons through proteins?" initially introduced while studying long-range electron transfer between localized redox centers in proteins in vivo is also highly relevant to the transport properties of solid-state, dry metal-protein-metal junctions. Here, we report conductance measurements of such junctions, Au-(Azurin monolayer ensemble)-Bismuth (Bi) ones, with well-defined nanopore geometry and ~103 proteins/pore. Our results can be understood as follows. (1) Transport is via two interacting conducting channels, characterized by different spatial and time scales. The slow and spatially localized channel is associated with the Cu center of Azurin and the fast delocalized one with the protein's polypeptide matrix. Transport via the slow channel is by a sequential (noncoherent) process and in the second one by direct, off-resonant tunneling. (2) The two channels are capacitively coupled. Thus, with a change in charge occupation of the weakly coupled (metal center) channel, the broad energy level manifold, responsible for off-resonance tunneling, shifts, relative to the electrodes' Fermi levels. In this process, the off-resonance (fast) channel dominates transport, and the slow (redox) channel, while contributing only negligibly directly, significantly affects transport by intramolecular gating.
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Affiliation(s)
- Ping’an Li
- Department of Chemical Physics, School of Chemistry, Tel Aviv University, Tel Aviv69978, Israel
| | - Sudipta Bera
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot76100, Israel
| | - Shailendra Kumar-Saxena
- Department of Physics and Nanotechnology, College of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur603203, Tamil Nadu, India
| | - Israel Pecht
- Department of Regenerative Biology and Immunology, Weizmann Institute of Science, Rehovot76100, Israel
| | - Mordechai Sheves
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot76100, Israel
| | - David Cahen
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot76100, Israel
| | - Yoram Selzer
- Department of Chemical Physics, School of Chemistry, Tel Aviv University, Tel Aviv69978, Israel
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2
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Roldán-Piñero C, Romero-Muñiz C, Díez-Pérez I, Vilhena JG, Pérez R, Cuevas JC, Zotti LA. Efficient Electron Hopping Transport through Azurin-Based Junctions. J Phys Chem Lett 2023; 14:11242-11249. [PMID: 38059566 PMCID: PMC10726356 DOI: 10.1021/acs.jpclett.3c02702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 12/08/2023]
Abstract
We conducted a theoretical study of electron transport through junctions of the blue-copper azurin from Pseudomonas aeruginosa. We found that single-site hopping can lead to either higher or lower current values compared to fully coherent transport. This depends on the structural details of the junctions as well as the alignment of the protein orbitals. Moreover, we show how the asymmetry of the IV curves can be affected by the position of the tip in the junction and that, under specific conditions, such a hopping mechanism is consistent with a fairly low temperature dependence of the current. Finally, we show that increasing the number of hopping sites leads to higher hopping currents. Our findings, from fully quantum calculations, provide deep insight to help guide the interpretation of experimental IV curves on highly complex systems.
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Affiliation(s)
- Carlos Roldán-Piñero
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Carlos Romero-Muñiz
- Departamento
de Física de la Materia Condensada, Universidad de Sevilla, PO Box 1065, 41080 Sevilla, Spain
| | - Ismael Díez-Pérez
- Department
of Chemistry, Faculty of Natural & Mathematical Sciences, King’s College London, Britannia House, 7 Trinity Street, London SE1 1DB, U.K.
| | - J. G. Vilhena
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - Rubén Pérez
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - Juan Carlos Cuevas
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - Linda A. Zotti
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
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3
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Kılıç M, Diamantis P, Johnson SK, Toth O, Rothlisberger U. Redox-Based Defect Detection in Packed DNA: Insights from Hybrid Quantum Mechanical/Molecular Mechanics Molecular Dynamics Simulations. J Chem Theory Comput 2023; 19:8434-8445. [PMID: 37963372 PMCID: PMC10687876 DOI: 10.1021/acs.jctc.3c01013] [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: 09/15/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 11/16/2023]
Abstract
The impact of an 8-oxoguanine (8oxoG) defect on the redox properties of DNA within the nucleosome core particle (NCP) was investigated employing hybrid quantum mechanical/molecular mechanics (QM/MM) molecular dynamics simulations of native and 8oxoG-containing NCP systems with an explicit representation of a biologically relevant environment. Two distinct NCP positions with varying solvent accessibility were considered for 8oxoG insertion. In both cases, it is found that the presence of 8oxoG drastically decreases the redox free energy of oxidation by roughly 1 eV, which is very similar to what was recently reported for free native and 8oxoG-containing DNA. In contrast, the effect of 8oxoG on the reorganization free energy is even smaller for packed DNA (decrease of 0.13 and 0.01 eV for defect-free and defect-containing systems, respectively) compared to the one for free DNA (0.25 eV), consistent with the increased rigidity of the NCP as compared to free DNA. Furthermore, the presence of an 8oxoG defect does not yield any significant changes in the packed DNA structure. Such a conclusion favors the idea that in the case of chromatin, defect-induced changes in DNA redox chemistry can also be exploited to detect damaged bases via DNA-mediated hole transfer.
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Affiliation(s)
| | | | - Sophia K. Johnson
- Laboratory of Computational Chemistry
and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Oliver Toth
- Laboratory of Computational Chemistry
and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry
and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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4
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Cheng L, Li D, Mai BK, Bo Z, Cheng L, Liu P, Yang Y. Stereoselective amino acid synthesis by synergistic photoredox-pyridoxal radical biocatalysis. Science 2023; 381:444-451. [PMID: 37499030 PMCID: PMC10444520 DOI: 10.1126/science.adg2420] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 06/20/2023] [Indexed: 07/29/2023]
Abstract
Developing synthetically useful enzymatic reactions that are not known in biochemistry and organic chemistry is an important challenge in biocatalysis. Through the synergistic merger of photoredox catalysis and pyridoxal 5'-phosphate (PLP) biocatalysis, we developed a pyridoxal radical biocatalysis approach to prepare valuable noncanonical amino acids, including those bearing a stereochemical dyad or triad, without the need for protecting groups. Using engineered PLP enzymes, either enantiomeric product could be produced in a biocatalyst-controlled fashion. Synergistic photoredox-pyridoxal radical biocatalysis represents a powerful platform with which to discover previously unknown catalytic reactions and to tame radical intermediates for asymmetric catalysis.
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Affiliation(s)
- Lei Cheng
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Dian Li
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Zhiyu Bo
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Lida Cheng
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Yang Yang
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
- Biomolecular Science and Engineering (BMSE) Program, University of California Santa Barbara, Santa Barbara, California 93106, USA
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5
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Kontkanen OV, Biriukov D, Futera Z. Applicability of perturbed matrix method for charge transfer studies at bio/metallic interfaces: a case of azurin. Phys Chem Chem Phys 2023; 25:12479-12489. [PMID: 37097130 DOI: 10.1039/d3cp00197k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
As the field of nanoelectronics based on biomolecules such as peptides and proteins rapidly grows, there is a need for robust computational methods able to reliably predict charge transfer properties at bio/metallic interfaces. Traditionally, hybrid quantum-mechanical/molecular-mechanical techniques are employed for systems where the electron hopping transfer mechanism is applicable to determine physical parameters controlling the thermodynamics and kinetics of charge transfer processes. However, these approaches are limited by a relatively high computational cost when extensive sampling of a configurational space is required, like in the case of soft biomatter. For these applications, semi-empirical approaches such as the perturbed matrix method (PMM) have been developed and successfully used to study charge-transfer processes in biomolecules. Here, we explore the performance of PMM on prototypical redox-active protein azurin in various environments, from solution to vacuum interfaces with gold surfaces and protein junction. We systematically benchmarked the robustness and convergence of the method with respect to the quantum-centre size, size of the Hamiltonian, number of samples, and level of theory. We show that PMM can adequately capture all the trends associated with the structural and electronic changes related to azurin oxidation at bio/metallic interfaces.
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Affiliation(s)
- Outi Vilhelmiina Kontkanen
- Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic.
| | - Denys Biriukov
- Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic.
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, 16610 Prague 6, Czech Republic
| | - Zdenek Futera
- Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic.
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6
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Abstract
The theory of electron transfer reactions establishes the conceptual foundation for redox solution chemistry, electrochemistry, and bioenergetics. Electron and proton transfer across the cellular membrane provide all energy of life gained through natural photosynthesis and mitochondrial respiration. Rates of biological charge transfer set kinetic bottlenecks for biological energy storage. The main system-specific parameter determining the activation barrier for a single electron-transfer hop is the reorganization energy of the medium. Both harvesting of light energy in natural and artificial photosynthesis and efficient electron transport in biological energy chains require reduction of the reorganization energy to allow fast transitions. This review article discusses mechanisms by which small values of the reorganization energy are achieved in protein electron transfer and how similar mechanisms can operate in other media, such as nonpolar and ionic liquids. One of the major mechanisms of reorganization energy reduction is through non-Gibbsian (nonergodic) sampling of the medium configurations on the reaction time. A number of alternative mechanisms, such as electrowetting of active sites of proteins, give rise to non-parabolic free energy surfaces of electron transfer. These mechanisms, and nonequilibrium population of donor-acceptor vibrations, lead to a universal phenomenology of separation between the Stokes shift and variance reorganization energies of electron transfer.
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Affiliation(s)
- Dmitry V Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona 85287-1504, USA.
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7
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Di Rocco G, Ranieri A, Borsari M, Sola M, Bortolotti CA, Battistuzzi G. Assessing the Functional and Structural Stability of the Met80Ala Mutant of Cytochrome c in Dimethylsulfoxide. Molecules 2022; 27:molecules27175630. [PMID: 36080396 PMCID: PMC9458088 DOI: 10.3390/molecules27175630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/02/2022] Open
Abstract
The Met80Ala variant of yeast cytochrome c is known to possess electrocatalytic properties that are absent in the wild type form and that make it a promising candidate for biocatalysis and biosensing. The versatility of an enzyme is enhanced by the stability in mixed aqueous/organic solvents that would allow poorly water-soluble substrates to be targeted. In this work, we have evaluated the effect of dimethylsulfoxide (DMSO) on the functionality of the Met80Ala cytochrome c mutant, by investigating the thermodynamics and kinetics of electron transfer in mixed water/DMSO solutions up to 50% DMSO v/v. In parallel, we have monitored spectroscopically the retention of the main structural features in the same medium, focusing on both the overall protein structure and the heme center. We found that the organic solvent exerts only minor effects on the redox and structural properties of the mutant mostly as a result of the modification of the dielectric constant of the solvent. This would warrant proper functionality of this variant also under these potentially hostile experimental conditions, that differ from the physiological milieu of cytochrome c.
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Affiliation(s)
- Giulia Di Rocco
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Antonio Ranieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Marco Borsari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Marco Sola
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Carlo Augusto Bortolotti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
- Correspondence: (C.A.B.); (G.B.); Tel.: +39-0592058608 (C.A.B.); +39-059208639 (G.B.)
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
- Correspondence: (C.A.B.); (G.B.); Tel.: +39-0592058608 (C.A.B.); +39-059208639 (G.B.)
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8
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Sarhangi SM, Matyushov DV. Anomalously Small Reorganization Energy of the Half Redox Reaction of Azurin. J Phys Chem B 2022; 126:3000-3011. [DOI: 10.1021/acs.jpcb.2c00338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Setare M. Sarhangi
- Department of Physics, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287-1504, United States
| | - Dmitry V. Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287-1504, United States
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9
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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.
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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
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10
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Chen CG, Nardi AN, Amadei A, D’Abramo M. Theoretical Modeling of Redox Potentials of Biomolecules. Molecules 2022; 27:1077. [PMID: 35164342 PMCID: PMC8838479 DOI: 10.3390/molecules27031077] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/28/2022] Open
Abstract
The estimation of the redox potentials of biologically relevant systems by means of theoretical-computational approaches still represents a challenge. In fact, the size of these systems typically does not allow a full quantum-mechanical treatment needed to describe electron loss/gain in such a complex environment, where the redox process takes place. Therefore, a number of different theoretical strategies have been developed so far to make the calculation of the redox free energy feasible with current computational resources. In this review, we provide a survey of such theoretical-computational approaches used in this context, highlighting their physical principles and discussing their advantages and limitations. Several examples of these approaches applied to the estimation of the redox potentials of both proteins and nucleic acids are described and critically discussed. Finally, general considerations on the most promising strategies are reported.
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Affiliation(s)
- Cheng Giuseppe Chen
- Department of Chemistry, Sapienza University of Rome, 00185 Rome, Italy; (C.G.C.); (A.N.N.)
| | | | - Andrea Amadei
- Department of Chemical and Technological Sciences, Tor Vergata University, 00133 Rome, Italy;
| | - Marco D’Abramo
- Department of Chemistry, Sapienza University of Rome, 00185 Rome, Italy; (C.G.C.); (A.N.N.)
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11
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Acquisition of ionic copper by the bacterial outer membrane protein OprC through a novel binding site. PLoS Biol 2021; 19:e3001446. [PMID: 34762655 PMCID: PMC8610252 DOI: 10.1371/journal.pbio.3001446] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/23/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022] Open
Abstract
Copper, while toxic in excess, is an essential micronutrient in all kingdoms of life due to its essential role in the structure and function of many proteins. Proteins mediating ionic copper import have been characterised in detail for eukaryotes, but much less so for prokaryotes. In particular, it is still unclear whether and how gram-negative bacteria acquire ionic copper. Here, we show that Pseudomonas aeruginosa OprC is an outer membrane, TonB-dependent transporter that is conserved in many Proteobacteria and which mediates acquisition of both reduced and oxidised ionic copper via an unprecedented CxxxM-HxM metal binding site. Crystal structures of wild-type and mutant OprC variants with silver and copper suggest that acquisition of Cu(I) occurs via a surface-exposed “methionine track” leading towards the principal metal binding site. Together with whole-cell copper quantitation and quantitative proteomics in a murine lung infection model, our data identify OprC as an abundant component of bacterial copper biology that may enable copper acquisition under a wide range of conditions. How do Gram-negative bacteria acquire copper? This study shows that the outer membrane protein OprC from Pseudomonas aeruginosa is abundant during infection and mediates highly selective acquisition of both copper redox states via an extracellular "methionine track" and an unprecedented near-irreversible binding site.
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12
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Ramírez CS, Tolmie C, Opperman DJ, González PJ, Rivas MG, Brondino CD, Ferroni FM. Copper nitrite reductase from Sinorhizobium meliloti 2011: Crystal structure and interaction with the physiological versus a nonmetabolically related cupredoxin-like mediator. Protein Sci 2021; 30:2310-2323. [PMID: 34562300 DOI: 10.1002/pro.4195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/08/2022]
Abstract
We report the crystal structure of the copper-containing nitrite reductase (NirK) from the Gram-negative bacterium Sinorhizobium meliloti 2011 (Sm), together with complex structural alignment and docking studies with both non-cognate and the physiologically related pseudoazurins, SmPaz1 and SmPaz2, respectively. S. meliloti is a rhizobacterium used for the formulation of Medicago sativa bionoculants, and SmNirK plays a key role in this symbiosis through the denitrification pathway. The structure of SmNirK, solved at a resolution of 2.5 Å, showed a striking resemblance with the overall structure of the well-known Class I NirKs composed of two Greek key β-barrel domains. The activity of SmNirK is ~12% of the activity reported for classical NirKs, which could be attributed to several factors such as subtle structural differences in the secondary proton channel, solvent accessibility of the substrate channel, and that the denitrifying activity has to be finely regulated within the endosymbiont. In vitro kinetics performed in homogenous and heterogeneous media showed that both SmPaz1 and SmPaz2, which are coded in different regions of the genome, donate electrons to SmNirK with similar performance. Even though the energetics of the interprotein electron transfer (ET) process is not favorable with either electron donors, adduct formation mediated by conserved residues allows minimizing the distance between the copper centers involved in the interprotein ET process.
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Affiliation(s)
- Cintia Soledad Ramírez
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral (UNL). CONICET, Ciudad Universitaria, Santa Fe, Argentina
| | - Carmien Tolmie
- Department of Microbiology and Biochemistry, University of the Free State (UFS), Bloemfontein, South Africa
| | - Diederik Johannes Opperman
- Department of Microbiology and Biochemistry, University of the Free State (UFS), Bloemfontein, South Africa
| | - Pablo Javier González
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral (UNL). CONICET, Ciudad Universitaria, Santa Fe, Argentina
| | - María Gabriela Rivas
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral (UNL). CONICET, Ciudad Universitaria, Santa Fe, Argentina
| | - Carlos Dante Brondino
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral (UNL). CONICET, Ciudad Universitaria, Santa Fe, Argentina
| | - Felix Martín Ferroni
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral (UNL). CONICET, Ciudad Universitaria, Santa Fe, Argentina
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13
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Unravelling the Structure of the Tetrahedral Metal-Binding Site in METP3 through an Experimental and Computational Approach. Molecules 2021; 26:molecules26175221. [PMID: 34500655 PMCID: PMC8434281 DOI: 10.3390/molecules26175221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/17/2022] Open
Abstract
Understanding the structural determinants for metal ion coordination in metalloproteins is a fundamental issue for designing metal binding sites with predetermined geometry and activity. In order to achieve this, we report in this paper the design, synthesis and metal binding properties of METP3, a homodimer made up of a small peptide, which self assembles in the presence of tetrahedrally coordinating metal ions. METP3 was obtained through a redesign approach, starting from the previously developed METP molecule. The undecapeptide sequence of METP, which dimerizes to house a Cys4 tetrahedral binding site, was redesigned in order to accommodate a Cys2His2 site. The binding properties of METP3 were determined toward different metal ions. Successful assembly of METP3 with Co(II), Zn(II) and Cd(II), in the expected 2:1 stoichiometry and tetrahedral geometry was proven by UV-visible spectroscopy. CD measurements on both the free and metal-bound forms revealed that the metal coordination drives the peptide chain to fold into a turned conformation. Finally, NMR data of the Zn(II)-METP3 complex, together with a retrostructural analysis of the Cys-X-X-His motif in metalloproteins, allowed us to define the model structure. All the results establish the suitability of the short METP sequence for accommodating tetrahedral metal binding sites, regardless of the first coordination ligands.
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14
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Patel AY, Jonnalagadda KS, Paradis N, Vaden TD, Wu C, Caputo GA. Effects of Ionic Liquids on Metalloproteins. Molecules 2021; 26:514. [PMID: 33478102 PMCID: PMC7835893 DOI: 10.3390/molecules26020514] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/04/2021] [Accepted: 01/08/2021] [Indexed: 01/28/2023] Open
Abstract
In the past decade, innovative protein therapies and bio-similar industries have grown rapidly. Additionally, ionic liquids (ILs) have been an area of great interest and rapid development in industrial processes over a similar timeline. Therefore, there is a pressing need to understand the structure and function of proteins in novel environments with ILs. Understanding the short-term and long-term stability of protein molecules in IL formulations will be key to using ILs for protein technologies. Similarly, ILs have been investigated as part of therapeutic delivery systems and implicated in numerous studies in which ILs impact the activity and/or stability of protein molecules. Notably, many of the proteins used in industrial applications are involved in redox chemistry, and thus often contain metal ions or metal-associated cofactors. In this review article, we focus on the current understanding of protein structure-function relationship in the presence of ILs, specifically focusing on the effect of ILs on metal containing proteins.
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Affiliation(s)
- Aashka Y. Patel
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA; (A.Y.P.); (N.P.); (T.D.V.); (C.W.)
| | | | - Nicholas Paradis
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA; (A.Y.P.); (N.P.); (T.D.V.); (C.W.)
| | - Timothy D. Vaden
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA; (A.Y.P.); (N.P.); (T.D.V.); (C.W.)
| | - Chun Wu
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA; (A.Y.P.); (N.P.); (T.D.V.); (C.W.)
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ 08028, USA
| | - Gregory A. Caputo
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA; (A.Y.P.); (N.P.); (T.D.V.); (C.W.)
- Department of Molecular and Cellular Biosciences, Rowan University, Glassboro, NJ 08028, USA
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15
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Lancellotti L, Borsari M, Bellei M, Bonifacio A, Bortolotti CA, Di Rocco G, Ranieri A, Sola M, Battistuzzi G. Urea-induced denaturation of immobilized yeast iso-1 cytochrome c: Role of Met80 and Tyr67 in the thermodynamics of unfolding and promotion of pseudoperoxidase and nitrite reductase activities. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.137237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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16
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Diamantis P, Tavernelli I, Rothlisberger U. Redox Properties of Native and Damaged DNA from Mixed Quantum Mechanical/Molecular Mechanics Molecular Dynamics Simulations. J Chem Theory Comput 2020; 16:6690-6701. [PMID: 32926773 DOI: 10.1021/acs.jctc.0c00568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The redox properties of two large DNA fragments composed of 39 base pairs, differing only by an 8-oxoguanine (8oxoG) defect replacing a guanine (G), were investigated in physiological conditions using mixed quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulations. The quantum region of the native fragment comprised 3 G-C base pairs, while one G was replaced by an 8oxoG in the defect fragment. The calculated values for the redox free energy are 6.55 ± 0.28 eV and 5.62 ± 0.30 eV for the native and the 8oxoG-containing fragment, respectively. The respective estimates for the reorganization free energy are 1.25 ± 0.18 eV and 1.00 ± 0.18 eV. Both reactions follow the Marcus theory for electron transfer. The large difference in redox potential between the two fragments shows that replacement of a G by an 8oxoG renders the DNA more easily oxidizable. This finding is in agreement with the suggestion that DNA fragments containing an 8oxoG defect can act as sinks of oxidative damage that protect the rest of the genome from assault. In addition, the difference in redox potential between the native and the defect DNA fragment indicates that a charge transfer-based mechanism for the recognition of DNA defects might be feasible, in line with recent suggestions based on experimental observations.
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Affiliation(s)
- Polydefkis Diamantis
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
| | - Ivano Tavernelli
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
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17
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Szuster J, Zitare UA, Castro MA, Leguto AJ, Morgada MN, Vila AJ, Murgida DH. Cu A-based chimeric T1 copper sites allow for independent modulation of reorganization energy and reduction potential. Chem Sci 2020; 11:6193-6201. [PMID: 32953013 PMCID: PMC7480511 DOI: 10.1039/d0sc01620a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/01/2020] [Indexed: 01/19/2023] Open
Abstract
Attaining rational modulation of thermodynamic and kinetic redox parameters of metalloproteins is a key milestone towards the (re)design of proteins with new or improved redox functions. Here we report that implantation of ligand loops from natural T1 proteins into the scaffold of a CuA protein leads to a series of distorted T1-like sites that allow for independent modulation of reduction potentials (E°') and electron transfer reorganization energies (λ). On the one hand E°' values could be fine-tuned over 120 mV without affecting λ. On the other, λ values could be modulated by more than a factor of two while affecting E°' only by a few millivolts. These results are in sharp contrast to previous studies that used T1 cupredoxin folds, thus highlighting the importance of the protein scaffold in determining such parameters.
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Affiliation(s)
- Jonathan Szuster
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE, CONICET-UBA) , Argentina .
- Departamento de Química Inorgánica, Analítica y Química-Física , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Buenos Aires , Argentina
| | - Ulises A Zitare
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE, CONICET-UBA) , Argentina .
- Departamento de Química Inorgánica, Analítica y Química-Física , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Buenos Aires , Argentina
| | - María A Castro
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE, CONICET-UBA) , Argentina .
- Departamento de Química Inorgánica, Analítica y Química-Física , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Buenos Aires , Argentina
| | - Alcides J Leguto
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Argentina
- Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
| | - Marcos N Morgada
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Argentina
- Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Argentina
- Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
| | - Daniel H Murgida
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE, CONICET-UBA) , Argentina .
- Departamento de Química Inorgánica, Analítica y Química-Física , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Buenos Aires , Argentina
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18
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Zitare UA, Szuster J, Santalla MC, Morgada MN, Vila AJ, Murgida DH. Dynamical effects in metalloprotein heterogeneous electron transfer. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.136095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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19
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Martin DR, Dinpajooh M, Matyushov DV. Polarizability of the Active Site in Enzymatic Catalysis: Cytochrome c. J Phys Chem B 2019; 123:10691-10699. [DOI: 10.1021/acs.jpcb.9b09236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Mohammadhasan Dinpajooh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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20
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Affiliation(s)
- Dmitry V. Matyushov
- Department of Physics and School of Molecular Sciences, Arizona State University, PO Box 871504, Tempe, Arizona 85287-1504, United States
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21
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Tazhigulov RN, Gurunathan PK, Kim Y, Slipchenko LV, Bravaya KB. Polarizable embedding for simulating redox potentials of biomolecules. Phys Chem Chem Phys 2019; 21:11642-11650. [PMID: 31116217 PMCID: PMC6611676 DOI: 10.1039/c9cp01533g] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Redox reactions play a key role in various biological processes, including photosynthesis and respiration. Quantitative and predictive computational characterization of redox events is therefore highly desirable for enriching our knowledge on mechanistic features of biological redox-active macromolecules. Here, we present a computational protocol exploiting polarizable embedding hybrid quantum-classical approach and resulting in accurate estimates of redox potentials of biological macromolecules. A special attention is paid to fundamental aspects of the theoretical description such as the effects of environment polarization and of the long-range electrostatic interactions on the computed energetic parameters. Environment (protein and the solvent) polarization is shown to be crucial for accurate estimates of the redox potential: hybrid quantum-classical results with and without account for environment polarization differ by 1.4 V. Long-range electrostatic interactions are shown to contribute significantly to the computed redox potential value even at the distances far beyond the protein outer surface. The approach is tested on simulating reduction potential of cryptochrome 1 protein from Arabidopsis thaliana. The theoretical estimate (0.07 V) of the midpoint reduction potential is in good agreement with available experimental data (-0.15 V).
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Affiliation(s)
- Ruslan N Tazhigulov
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA.
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22
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Can multiscale simulations unravel the function of metallo-enzymes to improve knowledge-based drug discovery? Future Med Chem 2019; 11:771-791. [DOI: 10.4155/fmc-2018-0495] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Metallo-enzymes are a large class of biomolecules promoting specialized chemical reactions. Quantum-classical quantum mechanics/molecular mechanics molecular dynamics, describing the metal site at quantum mechanics level, while accounting for the rest of system at molecular mechanics level, has an accessible time-scale limited by its computational cost. Hence, it must be integrated with classical molecular dynamics and enhanced sampling simulations to disentangle the functions of metallo-enzymes. In this review, we provide an overview of these computational methods and their capabilities. In particular, we will focus on some systems such as CYP19A1 a Fe-dependent enzyme involved in estrogen biosynthesis, and on Mg2+-dependent DNA/RNA processing enzymes/ribozymes and the spliceosome, a protein-directed ribozyme. This information may guide the discovery of drug-like molecules and genetic manipulation tools.
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23
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Xu M, He X, Zhu T, Zhang JZH. A Fragment Quantum Mechanical Method for Metalloproteins. J Chem Theory Comput 2019; 15:1430-1439. [PMID: 30620584 DOI: 10.1021/acs.jctc.8b00966] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An accurate energy calculation of metalloprotein is of crucial importance and also a theoretical challenge. In this work, a metal molecular fractionation with conjugate caps (metal-MFCC) approach is developed for efficient linear-scaling quantum calculation of potential energy and atomic forces of metalloprotein. In this approach, the potential energy of a given protein is calculated by a linear combination of potential energies of the neighboring residues, two-body interaction energy between non-neighboring residues that are spatially in close contact and the potential energy of the metal binding group. The calculation of each fragment is embedded in a field of point charges representing the remaining protein environment. Numerical studies were carried out to check the performance of this method, and the calculated potential energies and atomic forces all show excellent agreement with the full system calculations at the M06-2X/6-31G(d) level. By combining the energy calculation with molecular dynamic simulation, we performed an ab initio structural optimization for a zinc finger protein with high efficiency. The present metal-MFCC approach is linear-scaling with a low prefactor and trivially parallelizable. The individual fragment typically contains about 50 atoms, and it is thus possible to be calculated at higher levels of the quantum chemistry method. This fragment method can be routinely applied to perform structural optimization and ab initio molecular dynamic simulation for metalloproteins of any size.
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Affiliation(s)
- Mingyuan Xu
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering , East China Normal University , Shanghai , 200062 , China
| | - Xiao He
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering , East China Normal University , Shanghai , 200062 , China.,NYU-ECNU Center for Computational Chemistry at NYU Shanghai , Shanghai , 200062 , China
| | - Tong Zhu
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering , East China Normal University , Shanghai , 200062 , China.,NYU-ECNU Center for Computational Chemistry at NYU Shanghai , Shanghai , 200062 , China
| | - John Z H Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering , East China Normal University , Shanghai , 200062 , China.,NYU-ECNU Center for Computational Chemistry at NYU Shanghai , Shanghai , 200062 , China.,Department of Chemistry , New York University , New York 10003 , United States
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24
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The Catalytic Mechanism of Steroidogenic Cytochromes P450 from All-Atom Simulations: Entwinement with Membrane Environment, Redox Partners, and Post-Transcriptional Regulation. Catalysts 2019. [DOI: 10.3390/catal9010081] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cytochromes P450 (CYP450s) promote the biosynthesis of steroid hormones with major impact on the onset of diseases such as breast and prostate cancers. By merging distinct functions into the same catalytic scaffold, steroidogenic CYP450s enhance complex chemical transformations with extreme efficiency and selectivity. Mammalian CYP450s and their redox partners are membrane-anchored proteins, dynamically associating to form functional machineries. Mounting evidence signifies that environmental factors are strictly intertwined with CYP450s catalysis. Atomic-level simulations have the potential to provide insights into the catalytic mechanism of steroidogenic CYP450s and on its regulation by environmental factors, furnishing information often inaccessible to experimental means. In this review, after an introduction of computational methods commonly employed to tackle these systems, we report the current knowledge on three steroidogenic CYP450s—CYP11A1, CYP17A1, and CYP19A1—endowed with multiple catalytic functions and critically involved in cancer onset. In particular, besides discussing their catalytic mechanisms, we highlight how the membrane environment contributes to (i) regulate ligand channeling through these enzymes, (ii) modulate their interactions with specific protein partners, (iii) mediate post-transcriptional regulation induced by phosphorylation. The results presented set the basis for developing novel therapeutic strategies aimed at fighting diseases originating from steroid metabolism dysfunction.
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25
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Shen L, Zeng X, Hu H, Hu X, Yang W. Accurate Quantum Mechanical/Molecular Mechanical Calculations of Reduction Potentials in Azurin Variants. J Chem Theory Comput 2018; 14:4948-4957. [PMID: 30040901 DOI: 10.1021/acs.jctc.8b00403] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Understanding the regulation mechanism and molecular determinants of the reduction potential of metalloprotein is a major challenge. An ab initio quantum mechanical/molecular mechanical (QM/MM) method combining the minimum free energy path (MFEP) and fractional number of electron (FNE) approaches has been developed in our group to simulate the redox processes of large systems. The FNE scheme provides an efficient unique description for the redox process, while the MFEP method provides improved conformational sampling on complex environments such as protein in the QM/MM calculations. The reduction potentials of wild-type and seven mutants of azurin, a type 1 copper metalloprotein, were simulated with the QM/MM-MFEP+FNE approach in this paper. A range of 350 mV for the variations of the reduction potentials of these azurin proteins was reproduced faithfully with relative errors around 20 mV. The correlation between structural interactions and reduction potentials observed in simulations provides in-depth insight into the regulation of reduction potentials, which potentially can also be very useful to the engineering of metalloprotein-based electrocatalysts in artificial photosynthesis. The excellent accuracy and efficiency of the QM/MM-MFEP+FNE approach demonstrate the potential for simulations of many electron transfer processes in condensed phases and biochemical systems.
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Affiliation(s)
- Lin Shen
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
| | - Xiancheng Zeng
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
| | - Hao Hu
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
| | - Xiangqian Hu
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
| | - Weitao Yang
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
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26
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Amadei A, Aschi M. Theoretical-computational modeling of charge transfer and intersystem crossing reactions in complex chemical systems. RSC Adv 2018; 8:27900-27918. [PMID: 35542751 PMCID: PMC9083445 DOI: 10.1039/c8ra03900c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/23/2018] [Indexed: 11/21/2022] Open
Abstract
In this paper we present a theoretical-computational methodology specifically aimed at describing processes involving internal conversion or intersystem crossing, from atomistic (semiclassical) simulations and, hence, very suitable for treating complex atomic-molecular systems. The core of the presented approach is the evaluation of the diabatic perturbed energy surfaces of a portion of the whole system, treated at the quantum level and therefore preventively selected, in semi-classical interaction with the atomic-molecular environment. Subsequently, the estimation of the coupling between the diabatic surfaces and the inclusion of the obtained observables within a properly designed kinetic model allows the reconstruction of the whole phenomenology directly comparable to the experimental (typically kinetic) data. Application to two systems has demonstrated that the proposed approach can represent a valuable tool, somewhat complementary to other methods based on explicit quantum-dynamical approaches, for the theoretical-computational investigations of large and complex atomic-molecular systems.
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Affiliation(s)
- Andrea Amadei
- Dipartimento di Scienze e Tecnologie Chimiche, Universita' di Roma 'Tor Vergata' Roma Italy +390672594905
| | - Massimiliano Aschi
- Dipartimento di Scienze Fisiche e Chimiche, Universita' di L'Aquila L'Aquila Italy +390862433775
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27
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Morzan UN, Alonso de Armiño DJ, Foglia NO, Ramírez F, González Lebrero MC, Scherlis DA, Estrin DA. Spectroscopy in Complex Environments from QM–MM Simulations. Chem Rev 2018; 118:4071-4113. [DOI: 10.1021/acs.chemrev.8b00026] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Uriel N. Morzan
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
| | - Diego J. Alonso de Armiño
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
| | - Nicolás O. Foglia
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
| | - Francisco Ramírez
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
| | - Mariano C. González Lebrero
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
| | - Damián A. Scherlis
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
| | - Darío A. Estrin
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina
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28
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Ruiz MP, Aragonès AC, Camarero N, Vilhena JG, Ortega M, Zotti LA, Pérez R, Cuevas JC, Gorostiza P, Díez-Pérez I. Bioengineering a Single-Protein Junction. J Am Chem Soc 2017; 139:15337-15346. [DOI: 10.1021/jacs.7b06130] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Marta P. Ruiz
- Departament of Materials Science and Physical Chemistry & Institute of Theoretical and Computational Chemistry (IQTCUB), University of Barcelona, Martí i Franquès, 1, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona
Institute of Science and Technology (BIST), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Centro Investigación Biomédica en Red (CIBER-BBN), Campus Río Ebro-Edificio
I+D, Poeta Mariano Esquillor s/n, 50018 Zaragoza, Spain
| | - Albert C. Aragonès
- Departament of Materials Science and Physical Chemistry & Institute of Theoretical and Computational Chemistry (IQTCUB), University of Barcelona, Martí i Franquès, 1, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona
Institute of Science and Technology (BIST), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Centro Investigación Biomédica en Red (CIBER-BBN), Campus Río Ebro-Edificio
I+D, Poeta Mariano Esquillor s/n, 50018 Zaragoza, Spain
| | - Nuria Camarero
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona
Institute of Science and Technology (BIST), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Centro Investigación Biomédica en Red (CIBER-BBN), Campus Río Ebro-Edificio
I+D, Poeta Mariano Esquillor s/n, 50018 Zaragoza, Spain
| | - J. G. Vilhena
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Department
of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Cantoblanco, Madrid, Spain
| | - Maria Ortega
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Linda A. Zotti
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Rubén Pérez
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Juan Carlos Cuevas
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona
Institute of Science and Technology (BIST), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Centro Investigación Biomédica en Red (CIBER-BBN), Campus Río Ebro-Edificio
I+D, Poeta Mariano Esquillor s/n, 50018 Zaragoza, Spain
- Catalan Institution for Research and Advanced Studies (ICREA)
| | - Ismael Díez-Pérez
- Departament of Materials Science and Physical Chemistry & Institute of Theoretical and Computational Chemistry (IQTCUB), University of Barcelona, Martí i Franquès, 1, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona
Institute of Science and Technology (BIST), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Centro Investigación Biomédica en Red (CIBER-BBN), Campus Río Ebro-Edificio
I+D, Poeta Mariano Esquillor s/n, 50018 Zaragoza, Spain
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29
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Fowler NJ, Blanford CF, Warwicker J, de Visser SP. Prediction of Reduction Potentials of Copper Proteins with Continuum Electrostatics and Density Functional Theory. Chemistry 2017; 23:15436-15445. [PMID: 28815759 PMCID: PMC5698706 DOI: 10.1002/chem.201702901] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Indexed: 12/20/2022]
Abstract
Blue copper proteins, such as azurin, show dramatic changes in Cu2+/Cu+ reduction potential upon mutation over the full physiological range. Hence, they have important functions in electron transfer and oxidation chemistry and have applications in industrial biotechnology. The details of what determines these reduction potential changes upon mutation are still unclear. Moreover, it has been difficult to model and predict the reduction potential of azurin mutants and currently no unique procedure or workflow pattern exists. Furthermore, high‐level computational methods can be accurate but are too time consuming for practical use. In this work, a novel approach for calculating reduction potentials of azurin mutants is shown, based on a combination of continuum electrostatics, density functional theory and empirical hydrophobicity factors. Our method accurately reproduces experimental reduction potential changes of 30 mutants with respect to wildtype within experimental error and highlights the factors contributing to the reduction potential change. Finally, reduction potentials are predicted for a series of 124 new mutants that have not yet been investigated experimentally. Several mutants are identified that are located well over 10 Å from the copper center that change the reduction potential by more than 85 mV. The work shows that secondary coordination sphere mutations mostly lead to long‐range electrostatic changes and hence can be modeled accurately with continuum electrostatics.
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Affiliation(s)
- Nicholas J Fowler
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Christopher F Blanford
- Manchester Institute of Biotechnology and School of Materials, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Jim Warwicker
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Sam P de Visser
- Manchester Institute of Biotechnology, and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
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30
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Zanetti Polzi L, Battistuzzi G, Borsari M, Pignataro M, Paltrinieri L, Daidone I, Bortolotti CA. Computational investigation of the electron transfer complex between neuroglobin and cytochrome c. Supramol Chem 2017. [DOI: 10.1080/10610278.2017.1377342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Laura Zanetti Polzi
- Department of Physical and Chemical Sciences, University of L’Aquila, L’Aquila, Italy
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Marco Borsari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Marcello Pignataro
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Licia Paltrinieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Isabella Daidone
- Department of Physical and Chemical Sciences, University of L’Aquila, L’Aquila, Italy
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31
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Bizzarri AR, Baldacchini C, Cannistraro S. Structure, Dynamics, and Electron Transfer of Azurin Bound to a Gold Electrode. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9190-9200. [PMID: 28789529 DOI: 10.1021/acs.langmuir.7b01102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Blue copper redox protein azurin (AZ) constitutes an ideal active element for building bionano-optoelectronic devices based on the intriguing interplay among its electron transfer (ET), vibrational, and optical properties. A full comprehension of its dynamical and functional behavior is required for efficient applications. Here, AZ bound to gold electrode via its disulfide bridge was investigated by a molecular dynamics simulation approach taking into account for gold electron polarization which provides a more realistic description of the protein-gold interaction. Upon binding to gold, AZ undergoes slight changes in its secondary structure with the preservation of the copper-containing active site structure. Binding of AZ to gold promotes new collective motions, with respect to free AZ, as evidenced by essential dynamics. Analysis of the ET from the AZ copper ion to the gold substrate, performed by the Pathways model, put into evidence the main residues and structural motifs of AZ involved in the ET paths. During the dynamical evolution of the bionanosystem, transient contacts between some lateral protein atoms and the gold substrate occurred; concomitantly, the opening of additional ET channels with much higher rates was registered. These results provide new and detailed insights on the dynamics and ET properties of the AZ-gold system, by also helping to rationalize some imaging and conductive experimental evidences and also to design new bionanodevices with tailored features.
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Affiliation(s)
- Anna Rita Bizzarri
- Biophysics & Nanoscience Centre, DEB, Università della Tuscia , Viterbo 01100, Italy
| | - Chiara Baldacchini
- Biophysics & Nanoscience Centre, DEB, Università della Tuscia , Viterbo 01100, Italy
- IBAF-CNR , Porano 05010, Italy
| | - Salvatore Cannistraro
- Biophysics & Nanoscience Centre, DEB, Università della Tuscia , Viterbo 01100, Italy
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32
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Abstract
Extensive simulations of cytochrome c in solution are performed to address the apparent contradiction between large reorganization energies of protein electron transfer typically reported by atomistic simulations and much smaller values produced by protein electrochemistry. The two sets of data are reconciled by deriving the activation barrier for electrochemical reaction in terms of an effective reorganization energy composed of half the Stokes shift (characterizing the medium polarization in response to electron transfer) and the variance reorganization energy (characterizing the breadth of electrostatic fluctuations). This effective reorganization energy is much smaller than each of the two components contributing to it and is fully consistent with electrochemical measurements. Calculations in the range of temperatures between 280 and 360 K combine long, classical molecular dynamics simulations with quantum calculations of the protein active site. The results agree with the Arrhenius plots for the reaction rates and with cyclic voltammetry of cytochrome c immobilized on self-assembled monolayers. Small effective reorganization energy, and the resulting small activation barrier, is a general phenomenology of protein electron transfer allowing fast electron transport within biological energy chains.
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Affiliation(s)
- Salman S Seyedi
- Department of Physics, Arizona State University , P.O. Box 871504, Tempe, Arizona 85287-1504, United States
| | - Morteza M Waskasi
- School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287-1604, United States
| | - Dmitry V Matyushov
- Department of Physics, Arizona State University , P.O. Box 871504, Tempe, Arizona 85287-1504, United States.,School of Molecular Sciences, Arizona State University , P.O. Box 871604, Tempe, Arizona 85287-1604, United States
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33
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Nakano H, Sato H. Introducing the mean field approximation to CDFT/MMpol method: Statistically converged equilibrium and nonequilibrium free energy calculation for electron transfer reactions in condensed phases. J Chem Phys 2017; 146:154101. [DOI: 10.1063/1.4979895] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Hiroshi Nakano
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
- Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
- Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Japan
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34
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Peltzer RM, Eisenstein O, Nova A, Cascella M. How Solvent Dynamics Controls the Schlenk Equilibrium of Grignard Reagents: A Computational Study of CH3MgCl in Tetrahydrofuran. J Phys Chem B 2017; 121:4226-4237. [DOI: 10.1021/acs.jpcb.7b02716] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Raphael M. Peltzer
- Department
of Chemistry and Centre for Theoretical and Computational Chemistry
(CTCC), University of Oslo, Postbox 1033 Blindern, 0315 Oslo, Norway
| | - Odile Eisenstein
- Department
of Chemistry and Centre for Theoretical and Computational Chemistry
(CTCC), University of Oslo, Postbox 1033 Blindern, 0315 Oslo, Norway
- Institut
Charles Gerhardt, UMR 5253 CNRS-Université de Montpellier, Université de Montpellier, cc 1501, Place E. Bataillon, 34095 Montpellier, France
| | - Ainara Nova
- Department
of Chemistry and Centre for Theoretical and Computational Chemistry
(CTCC), University of Oslo, Postbox 1033 Blindern, 0315 Oslo, Norway
| | - Michele Cascella
- Department
of Chemistry and Centre for Theoretical and Computational Chemistry
(CTCC), University of Oslo, Postbox 1033 Blindern, 0315 Oslo, Norway
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35
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Warshel A, Bora RP. Perspective: Defining and quantifying the role of dynamics in enzyme catalysis. J Chem Phys 2017; 144:180901. [PMID: 27179464 DOI: 10.1063/1.4947037] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Enzymes control chemical reactions that are key to life processes, and allow them to take place on the time scale needed for synchronization between the relevant reaction cycles. In addition to general interest in their biological roles, these proteins present a fundamental scientific puzzle, since the origin of their tremendous catalytic power is still unclear. While many different hypotheses have been put forward to rationalize this, one of the proposals that has become particularly popular in recent years is the idea that dynamical effects contribute to catalysis. Here, we present a critical review of the dynamical idea, considering all reasonable definitions of what does and does not qualify as a dynamical effect. We demonstrate that no dynamical effect (according to these definitions) has ever been experimentally shown to contribute to catalysis. Furthermore, the existence of non-negligible dynamical contributions to catalysis is not supported by consistent theoretical studies. Our review is aimed, in part, at readers with a background in chemical physics and biophysics, and illustrates that despite a substantial body of experimental effort, there has not yet been any study that consistently established a connection between an enzyme's conformational dynamics and a significant increase in the catalytic contribution of the chemical step. We also make the point that the dynamical proposal is not a semantic issue but a well-defined scientific hypothesis with well-defined conclusions.
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Affiliation(s)
- Arieh Warshel
- Department of Chemistry, University of Southern California, SGM 418, 3620 McClintock Avenue, Los Angeles, California 90089, USA
| | - Ram Prasad Bora
- Department of Chemistry, University of Southern California, SGM 418, 3620 McClintock Avenue, Los Angeles, California 90089, USA
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36
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Dopson M, Holmes DS, Lazcano M, McCredden TJ, Bryan CG, Mulroney KT, Steuart R, Jackaman C, Watkin ELJ. Multiple Osmotic Stress Responses in Acidihalobacter prosperus Result in Tolerance to Chloride Ions. Front Microbiol 2017; 7:2132. [PMID: 28111571 PMCID: PMC5216662 DOI: 10.3389/fmicb.2016.02132] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/19/2016] [Indexed: 11/16/2022] Open
Abstract
Extremely acidophilic microorganisms (pH optima for growth of ≤3) are utilized for the extraction of metals from sulfide minerals in the industrial biotechnology of “biomining.” A long term goal for biomining has been development of microbial consortia able to withstand increased chloride concentrations for use in regions where freshwater is scarce. However, when challenged by elevated salt, acidophiles experience both osmotic stress and an acidification of the cytoplasm due to a collapse of the inside positive membrane potential, leading to an influx of protons. In this study, we tested the ability of the halotolerant acidophile Acidihalobacter prosperus to grow and catalyze sulfide mineral dissolution in elevated concentrations of salt and identified chloride tolerance mechanisms in Ac. prosperus as well as the chloride susceptible species, Acidithiobacillus ferrooxidans. Ac. prosperus had optimum iron oxidation at 20 g L−1 NaCl while At. ferrooxidans iron oxidation was inhibited in the presence of 6 g L−1 NaCl. The tolerance to chloride in Ac. prosperus was consistent with electron microscopy, determination of cell viability, and bioleaching capability. The Ac. prosperus proteomic response to elevated chloride concentrations included the production of osmotic stress regulators that potentially induced production of the compatible solute, ectoine uptake protein, and increased iron oxidation resulting in heightened electron flow to drive proton export by the F0F1 ATPase. In contrast, At. ferrooxidans responded to low levels of Cl− with a generalized stress response, decreased iron oxidation, and an increase in central carbon metabolism. One potential adaptation to high chloride in the Ac. prosperus Rus protein involved in ferrous iron oxidation was an increase in the negativity of the surface potential of Rus Form I (and Form II) that could help explain how it can be active under elevated chloride concentrations. These data have been used to create a model of chloride tolerance in the salt tolerant and susceptible species Ac. prosperus and At. ferrooxidans, respectively.
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Affiliation(s)
- Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University Kalmar, Sweden
| | - David S Holmes
- Facultad de Ciencias Biologicas, Universidad Andres BelloSantiago, Chile; Center for Bioinformatics and Genome Biology, Fundacion Ciencia y VidaSantiago, Chile
| | - Marcelo Lazcano
- Facultad de Ciencias Biologicas, Universidad Andres BelloSantiago, Chile; Center for Bioinformatics and Genome Biology, Fundacion Ciencia y VidaSantiago, Chile
| | - Timothy J McCredden
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Perth, WA, Australia
| | - Christopher G Bryan
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Perth, WA, Australia
| | - Kieran T Mulroney
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Perth, WA, Australia
| | - Robert Steuart
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Perth, WA, Australia
| | - Connie Jackaman
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Perth, WA, Australia
| | - Elizabeth L J Watkin
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University Perth, WA, Australia
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37
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Simonson T, Roux B. Concepts and protocols for electrostatic free energies. MOLECULAR SIMULATION 2016. [DOI: 10.1080/08927022.2015.1121544] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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38
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Zanetti-Polzi L, Corni S, Daidone I, Amadei A. Extending the essential dynamics analysis to investigate molecular properties: application to the redox potential of proteins. Phys Chem Chem Phys 2016; 18:18450-9. [PMID: 27339768 DOI: 10.1039/c6cp03394f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Here, a methodology is proposed to investigate the collective fluctuation modes of an arbitrary set of observables, maximally contributing to the fluctuation of another functionally relevant observable. The methodology, based on the analysis of fully classical molecular dynamics (MD) simulations, exploits the essential dynamics (ED) method, originally developed to analyse the collective motions in proteins. We apply this methodology to identify the residues that are more relevant for determining the reduction potential (E(0)) of a redox-active protein. To this aim, the fluctuation modes of the single-residue electrostatic potentials mostly contributing to the fluctuations of the total electrostatic potential (the main determinant of E(0)) are investigated for wild-type azurin and two of its mutants with a higher E(0). By comparing the results here obtained with a previous study on the same systems [Zanetti-Polzi et al., Org. Biomol. Chem., 2015, 13, 11003] we show that the proposed methodology is able to identify the key sites that determine E(0). This information can be used for a general deeper understanding of the molecular mechanisms on the basis of the redox properties of the proteins under investigation, as well as for the rational design of mutants with a higher or lower E(0). From the results of the present analysis we propose a new azurin mutant that, according to our calculations, shows a further increase of E(0).
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Affiliation(s)
- Laura Zanetti-Polzi
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), 67010, L'Aquila, Italy.
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39
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Dinpajooh M, Martin DR, Matyushov DV. Polarizability of the active site of cytochrome c reduces the activation barrier for electron transfer. Sci Rep 2016; 6:28152. [PMID: 27306204 PMCID: PMC4910110 DOI: 10.1038/srep28152] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/27/2016] [Indexed: 11/12/2022] Open
Abstract
Enzymes in biology’s energy chains operate with low energy input distributed through multiple electron transfer steps between protein active sites. The general challenge of biological design is how to lower the activation barrier without sacrificing a large negative reaction free energy. We show that this goal is achieved through a large polarizability of the active site. It is polarized by allowing a large number of excited states, which are populated quantum mechanically by electrostatic fluctuations of the protein and hydration water shells. This perspective is achieved by extensive mixed quantum mechanical/molecular dynamics simulations of the half reaction of reduction of cytochrome c. The barrier for electron transfer is consistently lowered by increasing the number of excited states included in the Hamiltonian of the active site diagonalized along the classical trajectory. We suggest that molecular polarizability, in addition to much studied electrostatics of permanent charges, is a key parameter to consider in order to understand how enzymes work.
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Affiliation(s)
- Mohammadhasan Dinpajooh
- Department of Physics and School of Molecular Sciences, Arizona State University, PO Box 871504, Tempe, AZ 85287-1504, USA
| | - Daniel R Martin
- Department of Physics and School of Molecular Sciences, Arizona State University, PO Box 871504, Tempe, AZ 85287-1504, USA
| | - Dmitry V Matyushov
- Department of Physics and School of Molecular Sciences, Arizona State University, PO Box 871504, Tempe, AZ 85287-1504, USA
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40
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Hosseinzadeh P, Lu Y. Design and fine-tuning redox potentials of metalloproteins involved in electron transfer in bioenergetics. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:557-581. [PMID: 26301482 PMCID: PMC4761536 DOI: 10.1016/j.bbabio.2015.08.006] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/20/2015] [Indexed: 12/25/2022]
Abstract
Redox potentials are a major contributor in controlling the electron transfer (ET) rates and thus regulating the ET processes in the bioenergetics. To maximize the efficiency of the ET process, one needs to master the art of tuning the redox potential, especially in metalloproteins, as they represent major classes of ET proteins. In this review, we first describe the importance of tuning the redox potential of ET centers and its role in regulating the ET in bioenergetic processes including photosynthesis and respiration. The main focus of this review is to summarize recent work in designing the ET centers, namely cupredoxins, cytochromes, and iron-sulfur proteins, and examples in design of protein networks involved these ET centers. We then discuss the factors that affect redox potentials of these ET centers including metal ion, the ligands to metal center and interactions beyond the primary ligand, especially non-covalent secondary coordination sphere interactions. We provide examples of strategies to fine-tune the redox potential using both natural and unnatural amino acids and native and nonnative cofactors. Several case studies are used to illustrate recent successes in this area. Outlooks for future endeavors are also provided. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.
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Affiliation(s)
- Parisa Hosseinzadeh
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews St., Urbana, IL, 61801, USA
| | - Yi Lu
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews St., Urbana, IL, 61801, USA.
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41
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42
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Shen L, Yang W. Quantum Mechanics/Molecular Mechanics Method Combined with Hybrid All-Atom and Coarse-Grained Model: Theory and Application on Redox Potential Calculations. J Chem Theory Comput 2016; 12:2017-27. [PMID: 26930454 DOI: 10.1021/acs.jctc.5b01107] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We developed a new multiresolution method that spans three levels of resolution with quantum mechanical, atomistic molecular mechanical, and coarse-grained models. The resolution-adapted all-atom and coarse-grained water model, in which an all-atom structural description of the entire system is maintained during the simulations, is combined with the ab initio quantum mechanics and molecular mechanics method. We apply this model to calculate the redox potentials of the aqueous ruthenium and iron complexes by using the fractional number of electrons approach and thermodynamic integration simulations. The redox potentials are recovered in excellent accordance with the experimental data. The speed-up of the hybrid all-atom and coarse-grained water model renders it computationally more attractive. The accuracy depends on the hybrid all-atom and coarse-grained water model used in the combined quantum mechanical and molecular mechanical method. We have used another multiresolution model, in which an atomic-level layer of water molecules around redox center is solvated in supramolecular coarse-grained waters for the redox potential calculations. Compared with the experimental data, this alternative multilayer model leads to less accurate results when used with the coarse-grained polarizable MARTINI water or big multipole water model for the coarse-grained layer.
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Affiliation(s)
- Lin Shen
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Weitao Yang
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
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43
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Bím D, Rulíšek L, Srnec M. Accurate Prediction of One-Electron Reduction Potentials in Aqueous Solution by Variable-Temperature H-Atom Addition/Abstraction Methodology. J Phys Chem Lett 2016; 7:7-13. [PMID: 26647144 DOI: 10.1021/acs.jpclett.5b02452] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A robust and efficient theoretical approach for calculation of the reduction potentials of charged species in aqueous solution is presented. Within this approach, the reduction potential of a charged complex (with a charge |n| ≥ 2) is probed by means of the reduction potential of its neutralized (protonated/deprotonated) cognate, employing one or several H-atom addition/abstraction thermodynamic cycles. This includes a separation of one-electron reduction from protonation/deprotonation through the temperature dependence. The accuracy of the method has been assessed for the set of 15 transition-metal complexes that are considered as highly challenging systems for computational electrochemistry. Unlike the standard computational protocol(s), the presented approach yields results that are in excellent agreement with experimental electrochemical data. Last but not least, the applicability and limitations of the approach are thoroughly discussed.
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Affiliation(s)
- Daniel Bím
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo náměstí 2, 166 10 Praha 6, Czech Republic
| | - Lubomír Rulíšek
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo náměstí 2, 166 10 Praha 6, Czech Republic
| | - Martin Srnec
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 3, 182 20 Praha 8, Czech Republic
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44
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Jin H, Goyal P, Das AK, Gaus M, Meuwly M, Cui Q. Copper Oxidation/Reduction in Water and Protein: Studies with DFTB3/MM and VALBOND Molecular Dynamics Simulations. J Phys Chem B 2015; 120:1894-910. [PMID: 26624804 DOI: 10.1021/acs.jpcb.5b09656] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We apply two recently developed computational methods, DFTB3 and VALBOND, to study copper oxidation/reduction processes in solution and protein. The properties of interest include the coordination structure of copper in different oxidation states in water or in a protein (plastocyanin) active site, the reduction potential of the copper ion in different environments, and the environmental response to copper oxidation. The DFTB3/MM and VALBOND simulation results are compared to DFT/MM simulations and experimental results whenever possible. For a copper ion in aqueous solution, DFTB3/MM results are generally close to B3LYP/MM with a medium basis, including both solvation structure and reduction potential for Cu(II); for Cu(I), however, DFTB3/MM finds a two-water coordination, similar to previous Born-Oppenheimer molecular dynamics simulations using BLYP and HSE, whereas B3LYP/MM leads to a tetrahedron coordination. For a tetraammonia copper complex in aqueous solution, VALBOND and DFTB3/MM are consistent in terms of both structural and dynamical properties of solvent near copper for both oxidation states. For copper reduction in plastocyanin, DFTB3/MM simulations capture the key properties of the active site, and the computed reduction potential and reorganization energy are in fair agreement with experiment, especially when the periodic boundary condition is used. Overall, the study supports the value of VALBOND and DFTB3(/MM) for the analysis of fundamental copper redox chemistry in water and protein, and the results also help highlight areas where further improvements in these methods are desirable.
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Affiliation(s)
- Haiyun Jin
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Puja Goyal
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Akshaya Kumar Das
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Michael Gaus
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Markus Meuwly
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Qiang Cui
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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45
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Blumberger J. Recent Advances in the Theory and Molecular Simulation of Biological Electron Transfer Reactions. Chem Rev 2015; 115:11191-238. [DOI: 10.1021/acs.chemrev.5b00298] [Citation(s) in RCA: 238] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jochen Blumberger
- Department of Physics and
Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
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46
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Casalini S, Berto M, Kovtun A, Operamolla A, Di Rocco G, Facci P, Liscio A, Farinola GM, Borsari M, Bortolotti CA. Surface Immobilized His-tagged Azurin as a Model Interface for the Investigation of Vectorial Electron Transfer in Biological Systems. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.07.156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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47
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Zanetti-Polzi L, Bortolotti CA, Daidone I, Aschi M, Amadei A, Corni S. A few key residues determine the high redox potential shift in azurin mutants. Org Biomol Chem 2015; 13:11003-13. [PMID: 26381463 DOI: 10.1039/c5ob01819f] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The wide range of variability of the reduction potential (E(0)) of blue-copper proteins has been the subject of a large number of studies in the past several years. In particular, a series of azurin mutants have been recently rationally designed tuning E(0) over a very broad range (700 mV) without significantly altering the redox-active site [Marshall et al., Nature, 2009, 462, 113]. This clearly suggests that interactions outside the primary coordination sphere are relevant to determine E(0) in cupredoxins. However, the molecular determinants of the redox potential variability are still undisclosed. Here, by means of atomistic molecular dynamics simulations and hybrid quantum/classical calculations, the mechanisms that determine the E(0) shift of two azurin mutants with high potential shifts are unravelled. The reduction potentials of native azurin and of the mutants are calculated obtaining results in good agreement with the experiments. The analysis of the simulations reveals that only a small number of residues (including non-mutated ones) are relevant in determining the experimentally observed E(0) variation via site-specific, but diverse, mechanisms. These findings open the path to the rational design of new azurin mutants with different E(0).
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Affiliation(s)
- Laura Zanetti-Polzi
- Center S3, CNR-Institute of Nanoscience, Via Campi 213/A, 41125, Modena, Italy.
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48
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de la Lande A, Gillet N, Chen S, Salahub DR. Progress and challenges in simulating and understanding electron transfer in proteins. Arch Biochem Biophys 2015; 582:28-41. [PMID: 26116376 DOI: 10.1016/j.abb.2015.06.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 06/15/2015] [Accepted: 06/22/2015] [Indexed: 11/19/2022]
Abstract
This Review presents an overview of the most common numerical simulation approaches for the investigation of electron transfer (ET) in proteins. We try to highlight the merits of the different approaches but also the current limitations and challenges. The article is organized into three sections. Section 2 deals with direct simulation algorithms of charge migration in proteins. Section 3 summarizes the methods for testing the applicability of the Marcus theory for ET in proteins and for evaluating key thermodynamic quantities entering the reaction rates (reorganization energies and driving force). Recent studies interrogating the validity of the theory due to the presence of non-ergodic effects or of non-linear responses are also described. Section 4 focuses on the tunneling aspects of electron transfer. How can the electronic coupling between charge transfer states be evaluated by quantum chemistry approaches and rationalized? What interesting physics regarding the impact of protein dynamics on tunneling can be addressed? We will illustrate the different sections with examples taken from the literature to show what types of system are currently manageable with current methodologies. We also take care to recall what has been learned on the biophysics of ET within proteins thanks to the advent of atomistic simulations.
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Affiliation(s)
- Aurélien de la Lande
- Laboratoire de Chimie Physique, UMR 8000, CNRS, Université Paris Sud. 15, av. Jean Perrin, 91405 Orsay, France.
| | - Natacha Gillet
- Laboratoire de Chimie Physique, UMR 8000, CNRS, Université Paris Sud. 15, av. Jean Perrin, 91405 Orsay, France
| | - Shufeng Chen
- Laboratoire de Chimie Physique, UMR 8000, CNRS, Université Paris Sud. 15, av. Jean Perrin, 91405 Orsay, France
| | - Dennis R Salahub
- Department of Chemistry, CMS - Centre for Molecular Simulation and IQST - Institute for Quantum Science and Technology, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada.
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Li J, Farrokhnia M, Rulíšek L, Ryde U. Catalytic Cycle of Multicopper Oxidases Studied by Combined Quantum- and Molecular-Mechanical Free-Energy Perturbation Methods. J Phys Chem B 2015; 119:8268-84. [DOI: 10.1021/acs.jpcb.5b02864] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jilai Li
- Department
of Theoretical Chemistry, Lund University, Chemical Centre, P.O. Box 124, SE-221 00 Lund, Sweden
- Institute
of Theoretical Chemistry, Jilin University, Changchun 130023, People’s Republic of China
| | - Maryam Farrokhnia
- Department
of Theoretical Chemistry, Lund University, Chemical Centre, P.O. Box 124, SE-221 00 Lund, Sweden
- The
Persian Gulf Marine Biotechnology Research Center, The Persian Gulf
Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Lubomír Rulíšek
- Institute
of Organic Chemistry and Biochemistry, Gilead Sciences and IOCB Research
Center, Academy of Sciences of the Czech Republic, Flemingovo
náměstí 2, 166
10 Prague 6, Czech Republic
| | - Ulf Ryde
- Department
of Theoretical Chemistry, Lund University, Chemical Centre, P.O. Box 124, SE-221 00 Lund, Sweden
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50
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Laurent AD, Adamo C, Jacquemin D. Dye chemistry with time-dependent density functional theory. Phys Chem Chem Phys 2015; 16:14334-56. [PMID: 24548975 DOI: 10.1039/c3cp55336a] [Citation(s) in RCA: 233] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this perspective, we present an overview of the determination of excited-state properties of "real-life" dyes, and notably of their optical absorption and emission spectra, performed during the last decade with time-dependent density functional theory (TD-DFT). We discuss the results obtained with both vertical and adiabatic (vibronic) approximations, choosing relevant examples for several series of dyes. These examples include reproducing absorption wavelengths of numerous families of coloured molecules, understanding the specific band shape of amino-anthraquinones, optimising the properties of dyes used in solar cells, mimicking the fluorescence wavelengths of fluorescent brighteners and BODIPY dyes, studying optically active biomolecules and photo-induced proton transfer, as well as improving the properties of photochromes.
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Affiliation(s)
- Adèle D Laurent
- Chimie Et Interdisciplinarité, Synthèse, Analyse, Modélisation (CEISAM), UMR CNRS no. 6230, BP 92208, Université de Nantes, 2, Rue de la Houssinière, 44322 Nantes, Cedex 3, France.
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