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Mammoser CC, LeMasters BE, Edwards SG, McRae EM, Mullins MH, Wang Y, Garcia NM, Edmonds KA, Giedroc DP, Thielges MC. The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion. Commun Chem 2023; 6:175. [PMID: 37612467 PMCID: PMC10447441 DOI: 10.1038/s42004-023-00977-4] [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: 02/23/2023] [Accepted: 08/07/2023] [Indexed: 08/25/2023] Open
Abstract
Blue copper proteins are models for illustrating how proteins tune metal properties. Nevertheless, the mechanisms by which the protein controls the metal site remain to be fully elucidated. A hindrance is that the closed shell Cu(I) site is inaccessible to most spectroscopic analyses. Carbon deuterium (C-D) bonds used as vibrational probes afford nonperturbative, selective characterization of the key cysteine and methionine copper ligands in both redox states. The structural integrity of Nostoc plastocyanin was perturbed by disrupting potential hydrogen bonds between loops of the cupredoxin fold via mutagenesis (S9A, N33A, N34A), variably raising the midpoint potential. The C-D vibrations show little change to suggest substantial alteration to the Cu(II) coordination in the oxidized state or in the Cu(I) interaction with the cysteine ligand. They rather indicate, along with visible and NMR spectroscopy, that the methionine ligand distinctly interacts more strongly with the Cu(I) ion, in line with the increases in midpoint potential. Here we show that the protein structure determines the redox properties by restricting the interaction between the methionine ligand and Cu(I) in the reduced state.
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Affiliation(s)
- Claire C Mammoser
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Brynn E LeMasters
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
- Department of Chemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Sydney G Edwards
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Emma M McRae
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - M Hunter Mullins
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
- Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yiqi Wang
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Nicholas M Garcia
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
- University of Wisconsin School of Medicine and Public Health, Madison, WI, 53726, USA
| | - Katherine A Edmonds
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - David P Giedroc
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Megan C Thielges
- Indiana University Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
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2
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Yamaguchi T, Taborosi A, Sakai C, Akao K, Mori S, Kohzuma T. Systematic elucidation of the second coordination sphere effect on the structure and properties of a blue copper protein, pseudoazurin. J Inorg Biochem 2023; 246:112292. [PMID: 37354604 DOI: 10.1016/j.jinorgbio.2023.112292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/26/2023]
Abstract
The rational structural and computational studies of a blue copper protein, pseudoazurin (PAz), and its Met16X (X = Phe, Leu, Val, Ile) variants gave clear functional meanings of the noncovalent interaction (NCI) through the second coordination sphere. The high-resolution X-ray crystal structures of Met16X PAz demonstrated that the active site geometry is significantly affected by the substitution of Met16, which is located within the NCI distance from the His81 imidazole ring at the copper active site. The computational chemistry calculations based on the crystal structure analyses confirmed that the NCI of S-π/CH-π (wild-type), π-π (Met16Phe), double CH-π (Met16Leu), and single CH-π (Met16Val and Met16Ile). The estimated interaction energies for the NCI demonstrated that the fine-tuning of the protein stability and Cu site properties form the second coordination sphere of PAz.
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Affiliation(s)
- Takahide Yamaguchi
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan; Frontier Research Center for Applied Atomic Sciences, Ibaraki University, 162-1, Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Attila Taborosi
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan; Research Initiative for Supra-Materials, Faculty of Engineering, Shinshu University, 4-17-1, Wakasato, Nagano, Nagano 380-8553, Japan
| | - Chihiro Sakai
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Kohei Akao
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Seiji Mori
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan; Frontier Research Center for Applied Atomic Sciences, Ibaraki University, 162-1, Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Takamitsu Kohzuma
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan; Frontier Research Center for Applied Atomic Sciences, Ibaraki University, 162-1, Shirakata, Tokai, Ibaraki 319-1106, Japan.
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3
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Fedoretz-Maxwell BP, Shin CH, MacNeil GA, Worrall LJ, Park R, Strynadka NCJ, Walsby CJ, Warren JJ. The Impact of Second Coordination Sphere Methionine-Aromatic Interactions in Copper Proteins. Inorg Chem 2022; 61:5563-5571. [DOI: 10.1021/acs.inorgchem.2c00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brooklyn P. Fedoretz-Maxwell
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Catherine H. Shin
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Gregory A. MacNeil
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Liam J. Worrall
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Rachel Park
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Natalie C. J. Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Charles J. Walsby
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Jeffrey J. Warren
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
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4
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Espinoza-Cara A, Zitare U, Alvarez-Paggi D, Klinke S, Otero LH, Murgida DH, Vila AJ. Engineering a bifunctional copper site in the cupredoxin fold by loop-directed mutagenesis. Chem Sci 2018; 9:6692-6702. [PMID: 30310603 PMCID: PMC6115626 DOI: 10.1039/c8sc01444b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/27/2018] [Indexed: 12/30/2022] Open
Abstract
Copper sites in proteins are designed to perform either electron transfer or redox catalysis. Type 1 and CuA sites are electron transfer hubs bound to a rigid protein fold that prevents binding of exogenous ligands and side reactions. Here we report the engineering of two Type 1 sites by loop-directed mutagenesis within a CuA scaffold with unique electronic structures and functional features. A copper-thioether axial bond shorter than the copper-thiolate bond is responsible for the electronic structure features, in contrast to all other natural or chimeric sites where the copper thiolate bond is short. These sites display highly unusual features, such as: (1) a high reduction potential despite a strong interaction with the axial ligand, which we attribute to changes in the hydrogen bond network and (2) the ability to bind exogenous ligands such as imidazole and azide. This strategy widens the possibility of using natural protein scaffolds with functional features not present in nature.
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Affiliation(s)
- Andrés Espinoza-Cara
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Rosario , Argentina .
- Área Biofísica , Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
| | - Ulises Zitare
- Departamento de Química Inorgánica , Analítica y Química Física-INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires-CONICET , Buenos Aires , Argentina
| | - Damián Alvarez-Paggi
- Departamento de Química Inorgánica , Analítica y Química Física-INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires-CONICET , Buenos Aires , Argentina
- Fundación Instituto Leloir , IIBBA-CONICET , Buenos Aires , Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir , IIBBA-CONICET , Buenos Aires , Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM. , Buenos Aires , Argentina
| | - Lisandro H Otero
- Fundación Instituto Leloir , IIBBA-CONICET , Buenos Aires , Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM. , Buenos Aires , Argentina
| | - Daniel H Murgida
- Departamento de Química Inorgánica , Analítica y Química Física-INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires-CONICET , Buenos Aires , Argentina
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Rosario , Argentina .
- Área Biofísica , Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM. , Buenos Aires , Argentina
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5
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Savelieff MG, Lu Y. CuA centers and their biosynthetic models in azurin. J Biol Inorg Chem 2010; 15:461-83. [DOI: 10.1007/s00775-010-0625-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2009] [Accepted: 01/20/2010] [Indexed: 11/28/2022]
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6
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Sinnecker S, Neese F. QM/MM calculations with DFT for taking into account protein effects on the EPR and optical spectra of metalloproteins. Plastocyanin as a case study. J Comput Chem 2007; 27:1463-75. [PMID: 16807973 DOI: 10.1002/jcc.20426] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A detailed study of the influence of the surrounding protein on magnetic and optical spectra of metalloproteins is presented using the quantum-mechanical/molecular mechanical (QM/MM) approach. The well-studied type I copper site in plastocyanin in the cupric oxidation state is taken as a test case because its spectroscopic properties have been extensively studied and are well understood. The calculations have been performed using nonrelativistic and scalar relativistic (at the level of the zeroth order regular approximation, ZORA) calculations (B3LYP functional). Linear response theory has been used to calculate first- and second-order properties, namely the EPR g-tensor, the central metal hyperfine couplings (HFCs), the HFCs of the directly coordinating ligands, as well as superhyperfine couplings (1H, 14N) from remote nuclei, transition energies, and oscillator strengths. Two different model systems have been defined that do not and do include important amino acids from the second coordination sphere, respectively. For comparison, calculations have been carried out in the gas phase and in a dielectric continuum (conductor like screening model, COSMO) with a dielectric constant of four. The best results were obtained at the scalar relativistic ZORA level for the largest model in conjunction with explicit modeling of the protein environment through the QM/MM procedure, which is also considered to be the highest level of theory used in this work. The protein effects beyond the second coordination sphere were found to be quite substantial (up to 30% changes on some properties), and were found to require an explicit treatment of the protein beyond the second coordination sphere. In addition, the embedding water cage was found to have a nonnegligible influence on the calculated spectroscopic data, which is of the same order as the influence of the protein backbone charges. However, while qualitatively satisfactory, the errors in the calculated spectroscopic parameters are still substantial, and can all be traced back to the fact that the linear-response of the presently available functionals is "too stiff" with respect to the external perturbations at least for the model systems studied here. Ligand field-based approaches are used to correct for systematic errors in the DFT procedures. As a consequence, we propose a new breakdown of the copper hyperfine interaction into Fermi-contact, spin-dipolar and spin-orbit contributions.
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Affiliation(s)
- Sebastian Sinnecker
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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7
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Yanagisawa S, Banfield MJ, Dennison C. The role of hydrogen bonding at the active site of a cupredoxin: the Phe114Pro azurin variant. Biochemistry 2006; 45:8812-22. [PMID: 16846224 DOI: 10.1021/bi0606851] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Phe114Pro mutation to the cupredoxin azurin (AZ) leads to a number of structural changes at the active site attributed to deletion of one of the hydrogen bonds to the Cys112 ligand, removal of the bulky phenyl group from the hydrophobic patch of the protein, and steric interactions made by the introduced Pro. The remaining hydrogen bond between the coordinating thiolate and the backbone amide of Asn47 is strengthened. At the type-1 copper site, the Cu(II)-O(Gly45) axial interaction decreases, while the metal moves out of the plane formed by the equatorial His46, Cys112, and His117 ligands, shortening the bond to the axially coordinating Met121. The resulting distorted tetrahedral geometry is distinct from the trigonal bipyramidal arrangement in the wild-type (WT) protein. The unique position of the main S(Cys) --> Cu(II) ligand-to-metal charge-transfer transition in AZ (628 nm) has shifted in the Phe114Pro variant to a value that is more typical for cupredoxins (599 nm). This probably occurs because of the removal of the Phe114-Cys112 hydrogen bond. The Phe114Pro mutation results in a 90 mV decrease in the reduction potential of AZ, and removal of the second hydrogen bond to the Cys ligand seems to be the major cause of this change. The C-terminal His117 ligand does not protonate in the reduced Phe114Pro AZ variant, which suggests that none of the structural features altered by the mutation are responsible for the absence of this effect in the WT protein. Upon reduction, the copper displaces further from the equatorial ligand plane and the Cu-S(Met121) bond length decreases. These changes are larger than those seen in the WT protein and contribute to the order of magnitude decrease in the intrinsic electron-transfer capabilities of the Phe114Pro variant.
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Affiliation(s)
- Sachiko Yanagisawa
- Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
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Affiliation(s)
- Francesco Musiani
- Department of Agro-Environmental Science and Technology, University of Bologna, Viale Giuseppe Fanin 40, I-40127 Bologna, Italy, and International School for Advanced Studies (SISSA/ISAS) and INFM DEMOCRITOS Simulation Center, Via Beirut 2-4, I-34014 Trieste, Italy
| | - Paolo Carloni
- Department of Agro-Environmental Science and Technology, University of Bologna, Viale Giuseppe Fanin 40, I-40127 Bologna, Italy, and International School for Advanced Studies (SISSA/ISAS) and INFM DEMOCRITOS Simulation Center, Via Beirut 2-4, I-34014 Trieste, Italy
| | - Stefano Ciurli
- Department of Agro-Environmental Science and Technology, University of Bologna, Viale Giuseppe Fanin 40, I-40127 Bologna, Italy, and International School for Advanced Studies (SISSA/ISAS) and INFM DEMOCRITOS Simulation Center, Via Beirut 2-4, I-34014 Trieste, Italy
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