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Di Rocco G, Battistuzzi G, Ranieri A, Bortolotti CA, Borsari M, Sola M. Thermodynamics and Kinetics of Electron Transfer of Electrode-Immobilized Small Laccase from Streptomyces coelicolor. Molecules 2022; 27:molecules27228079. [PMID: 36432180 PMCID: PMC9692349 DOI: 10.3390/molecules27228079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/14/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
The thermodynamic and kinetic properties for heterogeneous electron transfer (ET) were measured for the electrode-immobilized small laccase (SLAC) from Streptomyces coelicolor subjected to different electrostatic and covalent protein-electrode linkages, using cyclic voltammetry. Once immobilized electrostatically onto a gold electrode using mixed carboxyl- and hydroxy-terminated alkane-thiolate SAMs or covalently exploiting the same SAM subjected to N-hydroxysuccinimide+1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (NHS-EDC) chemistry, the SLAC-electrode electron flow occurs through the T1 center. The E°' values (from +0.2 to +0.1 V vs. SHE at pH 7.0) are lower by more than 0.2 V compared to the protein either in solution or immobilized with different anchoring strategies using uncharged SAMs. For the present electrostatic and covalent binding, this effect can, respectively, be ascribed to the negative charge of the SAM surfaces and to deletion of the positive charge of Lys/Arg residues due to amide bond formation which both selectively stabilize the more positively charged oxidized SLAC. Observation of enthalpy/entropy compensation within the series indicates that the immobilized proteins experience different reduction-induced solvent reorganization effects. The E°' values for the covalently attached SLAC are sensitive to three acid base equilibria, with apparent pKa values of pKa1ox = 5.1, pKa1red = 7.5, pKa2ox = 8.4, pKa2red = 10.9, pKa2ox = 8.9, pKa2red = 11.3 possibly involving one residue close to the T1 center and two residues (Lys and/or Arg) along with moderate protein unfolding, respectively. Therefore, the E°' value of immobilized SLAC turns out to be particularly sensitive to the anchoring mode and medium conditions.
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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
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological 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
- Correspondence: (A.R.); (M.B.)
| | - Carlo Augusto Bortolotti
- 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
- Correspondence: (A.R.); (M.B.)
| | - Marco Sola
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
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Electrochemical Characterization of an Engineered Red Copper Protein Featuring an Unprecedented Entropic Control of the Reduction Potential. Bioelectrochemistry 2022; 146:108095. [DOI: 10.1016/j.bioelechem.2022.108095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 12/12/2022]
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3
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Vilbert AC, Liu Y, Dai H, Lu Y. Recent advances in tuning redox properties of electron transfer centers in metalloenzymes catalyzing oxygen reduction reaction and H 2 oxidation important for fuel cells design. CURRENT OPINION IN ELECTROCHEMISTRY 2021; 30:100780. [PMID: 34435160 PMCID: PMC8382256 DOI: 10.1016/j.coelec.2021.100780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Current fuel-cell catalysts for oxygen reduction reaction (ORR) and H2 oxidation use precious metals and, for ORR, require high overpotentials. In contrast, metalloenzymes perform their respective reaction at low overpotentials using earth-abundant metals, making metalloenzymes ideal candidates for inspiring electrocatalytic design. Critical to the success of these enzymes are redox-active metal centers surrounding the enzyme active sites that ensure fast electron transfer (ET) to or away from the active site, by tuning the catalytic potential of the reaction as observed in multicopper oxidases but also in dictating the catalytic bias of the reaction as realized in hydrogenases. This review summarizes recent advances in studying these ET centers in multicopper oxidases and heme-copper oxidases that perform ORR and hydrogenases in carrying out H2 oxidation. Insights gained from understanding how the reduction potential of the ET centers effects reactivity at the active site in both the enzymes and their models are provided.
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Affiliation(s)
| | - Yiwei Liu
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huiguang Dai
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yi Lu
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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4
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Di Rocco G, Battistuzzi G, Borsari M, Bortolotti CA, Ranieri A, Sola M. The enthalpic and entropic terms of the reduction potential of metalloproteins: Determinants and interplay. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.214071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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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: 0.6] [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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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: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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7
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Morgada MN, Emiliani F, Chacón KN, Álvarez-Paggi D, Murgida DH, Blackburn NJ, Abriata LA, Vila AJ. pH-Induced Binding of the Axial Ligand in an Engineered Cu A Site Favors the π u State. Inorg Chem 2019; 58:15687-15691. [DOI: 10.1021/acs.inorgchem.9b01868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marcos N. Morgada
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda,
Predio CONICET Rosario, 2000 Rosario, Argentina
| | - Florencia Emiliani
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda,
Predio CONICET Rosario, 2000 Rosario, Argentina
| | - Kelly N. Chacón
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, Oregon 97239, United States
| | - Damián Álvarez-Paggi
- INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria C1428EHA, Buenos Aires, Argentina
| | - Daniel H. Murgida
- INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria C1428EHA, Buenos Aires, Argentina
| | - Ninian J. Blackburn
- Department of Chemical Physiology and Biochemistry, Oregon Health and Sciences University, Portland, Oregon 97239, United States
| | - Luciano A. Abriata
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda,
Predio CONICET Rosario, 2000 Rosario, Argentina
| | - Alejandro J. Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda,
Predio CONICET Rosario, 2000 Rosario, Argentina
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Zitare UA, Szuster J, Santalla MC, Llases ME, Morgada MN, Vila AJ, Murgida DH. Fine Tuning of Functional Features of the Cu A Site by Loop-Directed Mutagenesis. Inorg Chem 2019; 58:2149-2157. [PMID: 30644741 DOI: 10.1021/acs.inorgchem.8b03244] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here we report the spectroscopic and electrochemical characterization of three novel chimeric CuA proteins in which either one or the three loops surrounding the metal ions in the Thermus thermophilus protein have been replaced by homologous human and plant sequences while preserving the set of coordinating amino acids. These conservative modifications mimic basic differences between CuA sites from different organisms and allow for fine tuning the energy gap between alternative electronic ground states of CuA.. This results in a systematic modulation of thermodynamic and kinetic electron transfer (ET) parameters and in the selection of one of two possible redox-active molecular orbitals, which differ in the ET reorganization energy by a factor of 2. Moreover, the ET mechanism is found to be frictionally controlled, and the modifications introduced into the different chimeras do not affect the frictional activation parameter.
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Affiliation(s)
- Ulises A Zitare
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| | - Jonathan Szuster
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| | - María C Santalla
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| | - María E Llases
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Instituto de Biología Molecular y Celular de Rosario (IBR) , Universidad Nacional de Rosario and CONICET, 2000 Rosario , Argentina
| | - Marcos N Morgada
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Instituto de Biología Molecular y Celular de Rosario (IBR) , Universidad Nacional de Rosario and CONICET, 2000 Rosario , Argentina
| | - Alejandro J Vila
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Instituto de Biología Molecular y Celular de Rosario (IBR) , Universidad Nacional de Rosario and CONICET, 2000 Rosario , Argentina
| | - Daniel H Murgida
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
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Leguto AJ, Smith MA, Morgada MN, Zitare UA, Murgida DH, Lancaster KM, Vila AJ. Dramatic Electronic Perturbations of Cu A Centers via Subtle Geometric Changes. J Am Chem Soc 2019; 141:1373-1381. [PMID: 30582893 DOI: 10.1021/jacs.8b12335] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CuA is a binuclear copper site acting as electron entry port in terminal heme-copper oxidases. In the oxidized form, CuA is a mixed valence pair whose electronic structure can be described using a potential energy surface with two minima, σu* and πu, that are variably populated at room temperature. We report that mutations in the first and second coordination spheres of the binuclear metallocofactor can be combined in an additive manner to tune the energy gap and, thus, the relative populations of the two lowest-lying states. A series of designed mutants span σu*/πu energy gaps ranging from 900 to 13 cm-1. The smallest gap corresponds to a variant with an effectively degenerate ground state. All engineered sites preserve the mixed-valence character of this metal center and the electron transfer functionality. An increase of the Cu-Cu distance less than 0.06 Å modifies the σu*/πu energy gap by almost 2 orders of magnitude, with longer distances eliciting a larger population of the πu state. This scenario offers a stark contrast to synthetic systems, as model compounds require a lengthening of 0.5 Å in the Cu-Cu distance to stabilize the πu state. These findings show that the tight control of the protein environment allows drastic perturbations in the electronic structure of CuA sites with minor geometric changes.
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Affiliation(s)
- Alcides J Leguto
- Instituto de Biología Molecular y Celular de Rosario (IBR), Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario and CONICET , 2000 Rosario , Argentina
| | - Meghan A Smith
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Marcos N Morgada
- Instituto de Biología Molecular y Celular de Rosario (IBR), Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario and CONICET , 2000 Rosario , Argentina
| | - Ulises A Zitare
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires and CONICET , 1428 Buenos Aires , Argentina
| | - Daniel H Murgida
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires and CONICET , 1428 Buenos Aires , Argentina
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR), Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario and CONICET , 2000 Rosario , Argentina
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The role of molecular crowding in long-range metalloprotein electron transfer: Dissection into site- and scaffold-specific contributions. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.10.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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11
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Kroneck PMH. Walking the seven lines: binuclear copper A in cytochrome c oxidase and nitrous oxide reductase. J Biol Inorg Chem 2017; 23:27-39. [PMID: 29218634 DOI: 10.1007/s00775-017-1510-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/20/2017] [Indexed: 01/19/2023]
Abstract
The enzymes nitrous oxide reductase (N2OR) and cytochrome c oxidase (COX) are constituents of important biological processes. N2OR is the terminal reductase in a respiratory chain converting N2O to N2 in denitrifying bacteria; COX is the terminal oxidase of the aerobic respiratory chain of certain bacteria and eukaryotic organisms transforming O2 to H2O accompanied by proton pumping. Different spectroscopies including magnetic resonance techniques, were applied to show that N2OR has a mixed-valent Cys-bridged [Cu1.5+(CyS)2Cu1.5+] copper site, and that such a binuclear center, called CuA, does also exist in COX. A sequence motif shared between the CuA center of N2OR and the subunit II of COX raises the issue of a putative evolutionary relationship of the two enzymes. The suggestion of a binuclear CuA in COX, with one unpaired electron delocalized between two equivalent Cu nuclei, was difficult to accept originally, even though regarded as a clever solution to many experimental observations. This minireview in honor of Helmut Sigel traces several of the critical steps forward in understanding the nature of CuA in N2OR and COX, and discusses its unique electronic features to some extent including the contributions made by the development of methodology and the discovery of a novel multi-copper enzyme. Left: X-band (9.130 GHz) and C-band (4.530 GHz, 1st harmonic display of experimental spectrum) EPR spectra of bovine heart cytochrome c oxidase, recorded at 20K. Right: Ribbon presentation of the CuA domain in cytochrome c oxidase and nitrous oxide reductase.
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Affiliation(s)
- Peter M H Kroneck
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
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