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Roger M, Leone P, Blackburn NJ, Horrell S, Chicano TM, Biaso F, Giudici-Orticoni MT, Abriata LA, Hura GL, Hough MA, Sciara G, Ilbert M. Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features. Dalton Trans 2024; 53:1794-1808. [PMID: 38170898 PMCID: PMC10804444 DOI: 10.1039/d3dt03372d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024]
Abstract
Cupredoxins are widely occurring copper-binding proteins with a typical Greek-key beta barrel fold. They are generally described as electron carriers that rely on a T1 copper centre coordinated by four ligands provided by the folded polypeptide. The discovery of novel cupredoxins demonstrates the high diversity of this family, with variations in terms of copper-binding ligands, copper centre geometry, redox potential, as well as biological function. AcoP is a periplasmic cupredoxin belonging to the iron respiratory chain of the acidophilic bacterium Acidithiobacillus ferrooxidans. AcoP presents original features, including high resistance to acidic pH and a constrained green-type copper centre of high redox potential. To understand the unique properties of AcoP, we undertook structural and biophysical characterization of wild-type AcoP and of two Cu-ligand mutants (H166A and M171A). The crystallographic structures, including native reduced AcoP at 1.65 Å resolution, unveil a typical cupredoxin fold. The presence of extended loops, never observed in previously characterized cupredoxins, might account for the interaction of AcoP with physiological partners. The Cu-ligand distances, determined by both X-ray diffraction and EXAFS, show that the AcoP metal centre seems to present both T1 and T1.5 features, in turn suggesting that AcoP might not fit well to the coupled distortion model. The crystal structures of two AcoP mutants confirm that the active centre of AcoP is highly constrained. Comparative analysis with other cupredoxins of known structures, suggests that in AcoP the second coordination sphere might be an important determinant of active centre rigidity due to the presence of an extensive hydrogen bond network. Finally, we show that other cupredoxins do not perfectly follow the coupled distortion model as well, raising the suspicion that further alternative models to describe copper centre geometries need to be developed, while the importance of rack-induced contributions should not be underestimated.
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Affiliation(s)
- Magali Roger
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, BIP UMR 7281, Mediterranean Institute of Microbiology, 13009 Marseille, France.
| | - Philippe Leone
- CNRS, Aix-Marseille University, Laboratoire d'Ingénierie des Systèmes Macromoléculaires, LISM UMR7255, 13009 Marseille, France
| | - Ninian J Blackburn
- Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Sam Horrell
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Tadeo Moreno Chicano
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Frédéric Biaso
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, BIP UMR 7281, Mediterranean Institute of Microbiology, 13009 Marseille, France.
| | - Marie-Thérèse Giudici-Orticoni
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, BIP UMR 7281, Mediterranean Institute of Microbiology, 13009 Marseille, France.
| | - Luciano A Abriata
- Laboratory for Biomolecular Modeling and Protein Purification and Structure Core Facility, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Greg L Hura
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Lab, Berkeley, CA, USA
| | - Michael A Hough
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Giuliano Sciara
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, BIP UMR 7281, Mediterranean Institute of Microbiology, 13009 Marseille, France.
- Aix Marseille Univ, INRAE, BBF UMR1163, Biodiversité et Biotechnologie Fongiques, 13288 Marseille, France
| | - Marianne Ilbert
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, BIP UMR 7281, Mediterranean Institute of Microbiology, 13009 Marseille, France.
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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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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: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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4
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Schulz C, van Gastel M, Pantazis DA, Neese F. Converged Structural and Spectroscopic Properties for Refined QM/MM Models of Azurin. Inorg Chem 2021; 60:7399-7412. [PMID: 33939922 PMCID: PMC8154437 DOI: 10.1021/acs.inorgchem.1c00640] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Indexed: 12/27/2022]
Abstract
Blue copper proteins continue to challenge experiment and theory with their electronic structure and spectroscopic properties that respond sensitively to the coordination environment of the copper ion. In this work, we report state-of-the art electronic structure studies for geometric and spectroscopic properties of the archetypal "Type I" copper protein azurin in its Cu(II) state. A hybrid quantum mechanics/molecular mechanics (QM/MM) approach is used, employing both density functional theory (DFT) and coupled cluster with singles, doubles, and perturbative triples (CCSD(T)) methods for the QM region, the latter method making use of the domain-based local pair natural orbital (DLPNO) approach. Models of increasing QM size are employed to investigate the convergence of critical geometric parameters. It is shown that convergence is slow and that a large QM region is critical for reproducing the short experimental Cu-SCys112 distance. The study of structural convergence is followed by investigation of spectroscopic parameters using both DFT and DLPNO-CC methods and comparing these to the experimental spectrum using simulations. The results allow us to examine for the first time the distribution of spin densities and hyperfine coupling constants at the coupled cluster level, leading us to revisit the experimental assignment of the 33S hyperfine splitting. The wavefunction-based approach to obtain spin-dependent properties of open-shell systems demonstrated here for the case of azurin is transferable and applicable to a large array of bioinorganic systems.
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Affiliation(s)
- Christine
E. Schulz
- Max-Planck-Institut für
Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Maurice van Gastel
- Max-Planck-Institut für
Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für
Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max-Planck-Institut für
Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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5
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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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6
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Mukhopadhyay BP. Putative role of conserved water molecules in the hydration and inter-domain recognition of mono nuclear copper centers in O2-bound human ceruloplasmin: A comparative study between X-ray and MD simulated structures. Bioinformation 2019; 15:402-411. [PMID: 31312077 PMCID: PMC6614124 DOI: 10.6026/97320630015402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/02/2019] [Indexed: 11/23/2022] Open
Abstract
Human Ceruloplasmin (hCP) is an unique multicopper oxidase which involves in different biological functions e.g., iron metabolism, copper transportation, biogenic amine oxidation ,and its malfunction causes Wilson's and Menkes diseases. MD- simulation studies of O2- bound solvated structure have revealed the role of several conserved/ semi-conserved water molecules in the hydration of type-I copper centers and their involvement to recognition dynamics of these metal centers. In O2- bound structure, hydration potentiality of CuRS (Cu1106) type-I copper center is observed to be unique, where two water molecules (W1-W2) are interacting with the metal sites, which was not found in X-ray structures of hCP. Generally, in the interdomain recognition of CuCys-His to CuRS, CuRS to CuPR and CuPR to CuCys-His centers, the copper bound His-residue of one domain interacts with the Glu-residue of other complementary domain through conserved/ semi-conserved (W3 to W5) water- mediated hydrogen bonds (Cu-His...W...Glu), however direct salt-bridge (Cu-His...Glu) interaction were observed in the X- ray structures. The MD- simulated and X- ray structures have indicated some possibilities on the Cu-His...W...Glu ↔ Cu-His...Glu transition during the interdomain recognition of type-I copper centers, which may have some importance in biology and chemistry of ceruloplasmin.
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Affiliation(s)
- Bishnu P. Mukhopadhyay
- Department of Chemistry National Institute of Technology-Durgapur, West Bengal, Durgapur - 713209, India
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7
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Granja-Travez RS, Wilkinson RC, Persinoti GF, Squina FM, Fülöp V, Bugg TDH. Structural and functional characterisation of multi-copper oxidase CueO from lignin-degrading bacterium Ochrobactrum sp. reveal its activity towards lignin model compounds and lignosulfonate. FEBS J 2018; 285:1684-1700. [PMID: 29575798 DOI: 10.1111/febs.14437] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/23/2018] [Accepted: 03/09/2018] [Indexed: 01/09/2023]
Abstract
The identification of enzymes responsible for oxidation of lignin in lignin-degrading bacteria is of interest for biotechnological valorization of lignin to renewable chemical products. The genome sequences of two lignin-degrading bacteria, Ochrobactrum sp., and Paenibacillus sp., contain no B-type DyP peroxidases implicated in lignin degradation in other bacteria, but contain putative multicopper oxidase genes. Multi-copper oxidase CueO from Ochrobactrum sp. was expressed and reconstituted as a recombinant laccase-like enzyme, and kinetically characterized. Ochrobactrum CueO shows activity for oxidation of β-aryl ether and biphenyl lignin dimer model compounds, generating oxidized dimeric products, and shows activity for oxidation of Ca-lignosulfonate, generating vanillic acid as a low molecular weight product. The crystal structure of Ochrobactrum CueO (OcCueO) has been determined at 1.1 Å resolution (PDB: 6EVG), showing a four-coordinate mononuclear type I copper center with ligands His495, His434 and Cys490 with Met500 as an axial ligand, similar to that of Escherichia coli CueO and bacterial azurin proteins, whereas fungal laccase enzymes contain a three-coordinate type I copper metal center. A trinuclear type 2/3 copper cluster was modeled into the active site, showing similar structure to E. coli CueO and fungal laccases, and three solvent channels leading to the active site. Site-directed mutagenesis was carried out on amino acid residues found in the solvent channels, indicating the importance for residues Asp102, Gly103, Arg221, Arg223, and Asp462 for catalytic activity. The work identifies a new bacterial multicopper enzyme with activity for lignin oxidation, and implicates a role for bacterial laccase-like multicopper oxidases in some lignin-degrading bacteria. DATABASE Structural data are available in the PDB under the accession number 6EVG.
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Affiliation(s)
| | | | - Gabriela Felix Persinoti
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, São Paulo, Brasil
| | - Fabio M Squina
- Programa de Processos Tecnológicos e Ambientais, Universidade de Sorocaba, Brazil
| | - Vilmos Fülöp
- School of Life Sciences, University of Warwick, Coventry, UK
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8
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Romero-Muñiz C, Ortega M, Vilhena JG, Díez-Pérez I, Cuevas JC, Pérez R, Zotti LA. Ab initio electronic structure calculations of entire blue copper azurins. Phys Chem Chem Phys 2018; 20:30392-30402. [DOI: 10.1039/c8cp06862c] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We present a theoretical study of the blue-copper azurin extracted from Pseudomonas aeruginosa and several of its single amino acid mutants.
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Affiliation(s)
- Carlos Romero-Muñiz
- Departamento de Física Teórica de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid
- Spain
| | - María Ortega
- Departamento de Física Teórica de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid
- Spain
| | - J. G. Vilhena
- Departamento de Física Teórica de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid
- Spain
- Department of Physics
| | - I. Díez-Pérez
- Department of Materials Science and Physical Chemistry & Institute of Theoretical and Computational Chemistry (IQTCUB)
- University of Barcelona
- Barcelona 08028
- Spain
- Department of Chemistry
| | - Juan Carlos Cuevas
- Departamento de Física Teórica de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid
- Spain
- Condensed Matter Physics Center (IFIMAC)
| | - Rubén Pérez
- Departamento de Física Teórica de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid
- Spain
- Condensed Matter Physics Center (IFIMAC)
| | - Linda A. Zotti
- Departamento de Física Teórica de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid
- Spain
- Condensed Matter Physics Center (IFIMAC)
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9
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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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10
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Wu H, Feng X, Kieviet BD, Zhang K, Zandvliet HJ, Canters GW, Schön PM, Vancso GJ. Electrochemical atomic force microscopy reveals potential stimulated height changes of redox responsive Cu-azurin on gold. Eur Polym J 2016. [DOI: 10.1016/j.eurpolymj.2015.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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11
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Mann SI, Heinisch T, Weitz AC, Hendrich MP, Ward TR, Borovik AS. Modular Artificial Cupredoxins. J Am Chem Soc 2016; 138:9073-6. [PMID: 27385206 DOI: 10.1021/jacs.6b05428] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cupredoxins are electron-transfer proteins that have active sites containing a mononuclear Cu center with an unusual trigonal monopyramidal structure (Type 1 Cu). A single Cu-Scys bond is present within the trigonal plane that is responsible for its unique physical properties. We demonstrate that a cysteine-containing variant of streptavidin (Sav) can serve as a protein host to model the structure and properties of Type 1 Cu sites. A series of artificial Cu proteins are described that rely on Sav and a series of biotinylated synthetic Cu complexes. Optical and EPR measurements highlight the presence of a Cu-Scys bond, and XRD analysis provides structural evidence. We further provide evidence that changes in the linker between the biotin and Cu complex within the synthetic constructs allows for small changes in the placement of Cu centers within Sav that have dramatic effects on the structural and physical properties of the resulting artificial metalloproteins. These findings highlight the utility of the biotin-Sav technology as an approach for simulating active sites of metalloproteins.
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Affiliation(s)
- Samuel I Mann
- Department of Chemistry, University of California-Irvine , 1102 Natural Sciences II, Irvine, California 92697, United States
| | - Tillmann Heinisch
- Department of Chemistry, University of Basel , Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - Andrew C Weitz
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Michael P Hendrich
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Thomas R Ward
- Department of Chemistry, University of Basel , Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - A S Borovik
- Department of Chemistry, University of California-Irvine , 1102 Natural Sciences II, Irvine, California 92697, United States
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12
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Nóbrega CS, Saraiva IH, Carreira C, Devreese B, Matzapetakis M, Pauleta SR. The solution structure of the soluble form of the lipid-modified azurin from Neisseria gonorrhoeae , the electron donor of cytochrome c peroxidase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:169-176. [DOI: 10.1016/j.bbabio.2015.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/25/2015] [Accepted: 11/13/2015] [Indexed: 12/26/2022]
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13
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Harding DJ, Phonsri W, Harding P, Sirirak J, Tangtirungrotechai Y, Webster RD, Adams H. Copper hydrotris(3,5-diphenylpyrazolyl)borate dithiocarbamates: mimicking green copper proteins. NEW J CHEM 2015. [DOI: 10.1039/c4nj01298d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three new copper hydrotris(pyrazolyl)borate dithiocarbamate complexes [TpPh2Cu(dtc)] which mimic green copper proteins are reported.
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Affiliation(s)
- David J. Harding
- Molecular Technology Research Unit Cell
- Walailak University
- Thasala
- Thailand
| | - Wasinee Phonsri
- Molecular Technology Research Unit Cell
- Walailak University
- Thasala
- Thailand
| | - Phimphaka Harding
- Molecular Technology Research Unit Cell
- Walailak University
- Thasala
- Thailand
| | - Jitnapa Sirirak
- Molecular Technology Research Unit Cell
- Walailak University
- Thasala
- Thailand
| | | | - Richard D. Webster
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
| | - Harry Adams
- Department of Chemistry
- University of Sheffield
- Sheffield
- UK
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14
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Ghisaidoobe ABT, Chung SJ. Intrinsic tryptophan fluorescence in the detection and analysis of proteins: a focus on Förster resonance energy transfer techniques. Int J Mol Sci 2014; 15:22518-38. [PMID: 25490136 PMCID: PMC4284722 DOI: 10.3390/ijms151222518] [Citation(s) in RCA: 517] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 11/08/2014] [Accepted: 11/18/2014] [Indexed: 12/18/2022] Open
Abstract
Förster resonance energy transfer (FRET) occurs when the distance between a donor fluorophore and an acceptor is within 10 nm, and its application often necessitates fluorescent labeling of biological targets. However, covalent modification of biomolecules can inadvertently give rise to conformational and/or functional changes. This review describes the application of intrinsic protein fluorescence, predominantly derived from tryptophan (λ EX ≈ 280 nm, λ EM ≈ 350 nm), in protein-related research and mainly focuses on label-free FRET techniques. In terms of wavelength and intensity, tryptophan fluorescence is strongly influenced by its (or the proteinlocal environment, which, in addition to fluorescence quenching, has been applied to study protein conformational changes. Intrinsic Förster resonance energy transfer (iFRET), a recently developed technique, utilizes the intrinsic fluorescence of tryptophan in conjunction with target-specific fluorescent probes as FRET donors and acceptors, respectively, for real time detection of native proteins.
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Affiliation(s)
| | - Sang J Chung
- Department of Chemistry, Dongguk University, Seoul 100-715, Korea.
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15
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Yu F, Cangelosi VM, Zastrow ML, Tegoni M, Plegaria JS, Tebo AG, Mocny CS, Ruckthong L, Qayyum H, Pecoraro VL. Protein design: toward functional metalloenzymes. Chem Rev 2014; 114:3495-578. [PMID: 24661096 PMCID: PMC4300145 DOI: 10.1021/cr400458x] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Fangting Yu
- University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | | | | | | | - Alison G. Tebo
- University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | - Leela Ruckthong
- University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hira Qayyum
- University of Michigan, Ann Arbor, Michigan 48109, United States
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16
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Krishna Y, Sharma S, Ampapathi RS, Koley D. Furan-Based Locked Z-Vinylogous γ-Amino Acid Stabilizing Protein α-Turn in Water-Soluble Cyclic α3γ Tetrapeptides. Org Lett 2014; 16:2084-7. [DOI: 10.1021/ol5002126] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yarkali Krishna
- Medicinal and Process Chemistry
Division and ‡Centre for Nuclear Magnetic Resonance,
SAIF, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh 226031, India
| | - Shrikant Sharma
- Medicinal and Process Chemistry
Division and ‡Centre for Nuclear Magnetic Resonance,
SAIF, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh 226031, India
| | - Ravi S. Ampapathi
- Medicinal and Process Chemistry
Division and ‡Centre for Nuclear Magnetic Resonance,
SAIF, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh 226031, India
| | - Dipankar Koley
- Medicinal and Process Chemistry
Division and ‡Centre for Nuclear Magnetic Resonance,
SAIF, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh 226031, India
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17
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Dow BA, Sukumar N, Matos JO, Choi M, Schulte A, Tatulian SA, Davidson VL. The sole tryptophan of amicyanin enhances its thermal stability but does not influence the electronic properties of the type 1 copper site. Arch Biochem Biophys 2014; 550-551:20-7. [PMID: 24704124 DOI: 10.1016/j.abb.2014.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 03/21/2014] [Accepted: 03/24/2014] [Indexed: 10/25/2022]
Abstract
The cupredoxin amicyanin possesses a single tryptophan residue, Trp45. Its fluorescence is quenched when copper is bound even though it is separated by 10.1Å. Mutation of Trp45 to Ala, Phe, Leu and Lys resulted in undetectable protein expression. A W45Y amicyanin variant was isolated. The W45Y mutation did not alter the spectroscopic properties or intrinsic redox potential of amicyanin, but increased the pKa value for the pH-dependent redox potential by 0.5 units. This is due to a hydrogen-bond involving the His95 copper ligand which is present in reduced W45Y amicyanin but not in native amicyanin. The W45Y mutation significantly decreased the thermal stability of amicyanin, as determined by changes in the visible absorbance of oxidized amicyanin and in the circular dichroism spectra for oxidized, reduced and apo forms of amicyanin. Comparison of the crystal structures suggests that the decreased stability of W45Y amicyanin may be attributed to the loss of a strong interior hydrogen bond between Trp45 and Tyr90 in native amicyanin which links two of the β-sheets that comprise the overall structure of amicyanin. Thus, Trp45 is critical for stabilizing the structure of amicyanin but it does not influence the electronic properties of the copper which quenches its fluorescence.
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Affiliation(s)
- Brian A Dow
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, United States
| | - Narayanasami Sukumar
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Building 436E, Argonne National Laboratory, Argonne, IL 60439, United States.
| | - Jason O Matos
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, United States; Department of Physics, University of Central Florida, Orlando, FL 32816, United States
| | - Moonsung Choi
- Seoul National University of Science and Technology, College of Energy and Biotechnology, Department of Optometry, Seoul 139-743, Republic of Korea
| | - Alfons Schulte
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States
| | - Suren A Tatulian
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, United States.
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Girotto S, Cendron L, Bisaglia M, Tessari I, Mammi S, Zanotti G, Bubacco L. DJ-1 is a copper chaperone acting on SOD1 activation. J Biol Chem 2014; 289:10887-10899. [PMID: 24567322 DOI: 10.1074/jbc.m113.535112] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lack of oxidative stress control is a common and often prime feature observed in many neurodegenerative diseases. Both DJ-1 and SOD1, proteins involved in familial Parkinson disease and amyotrophic lateral sclerosis, respectively, play a protective role against oxidative stress. Impaired activity and modified expression of both proteins have been observed in different neurodegenerative diseases. A potential cooperative action of DJ-1 and SOD1 in the same oxidative stress response pathway may be suggested based on a copper-mediated interaction between the two proteins reported here. To investigate the mechanisms underlying the antioxidative function of DJ-1 in relation to SOD1 activity, we investigated the ability of DJ-1 to bind copper ions. We structurally characterized a novel copper binding site involving Cys-106, and we investigated, using different techniques, the kinetics of DJ-1 binding to copper ions. The copper transfer between the two proteins was also examined using both fluorescence spectroscopy and specific biochemical assays for SOD1 activity. The structural and functional analysis of the novel DJ-1 copper binding site led us to identify a putative role for DJ-1 as a copper chaperone. Alteration of the coordination geometry of the copper ion in DJ-1 may be correlated to the physiological role of the protein, to a potential failure in metal transfer to SOD1, and to successive implications in neurodegenerative etiopathogenesis.
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Affiliation(s)
- Stefania Girotto
- Department of Chemical Sciences, University of Padova, via Marzolo, 1 35131 Padova, Italy; Department of Drug Discovery and Development, Istituto Italiano di Tecnologia, Via Morego, 30 16163 Genoa, Italy
| | - Laura Cendron
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58b 35121 Padova, Italy; Department of Biology, University of Padova, Via Ugo Bassi, 58b 35121 Padova, Italy
| | - Marco Bisaglia
- Department of Biology, University of Padova, Via Ugo Bassi, 58b 35121 Padova, Italy
| | - Isabella Tessari
- Department of Biology, University of Padova, Via Ugo Bassi, 58b 35121 Padova, Italy
| | - Stefano Mammi
- Department of Chemical Sciences, University of Padova, via Marzolo, 1 35131 Padova, Italy
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58b 35121 Padova, Italy
| | - Luigi Bubacco
- Department of Biology, University of Padova, Via Ugo Bassi, 58b 35121 Padova, Italy.
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20
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Husberg C, Ryde U. How are hydrogen bonds modified by metal binding? J Biol Inorg Chem 2013; 18:499-522. [DOI: 10.1007/s00775-013-0996-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 03/11/2013] [Indexed: 10/27/2022]
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21
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Wawrzycka-Gorczyca I, Siwek A. Synthesis, X-ray crystal structure and theoretical study of 4-ethyl-5-(2-thienyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione; structural comparison with its aromatic analogs. ACTA ACUST UNITED AC 2011. [DOI: 10.1524/zkri.2011.1444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The crystal structure of 4-ethyl-5-(2-thienyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (1) was determinäed. The compound crystallizes in the monoclinic space group P21/n (Z = 4) with a = 8.679(2), b = 7.873(2), c = 14.657(3) Å, β = 105.56(3)° and V = 964.8(4) Å3. Its molecular and crystal structure was compared with three aromatic analogs. In three crystal structures of 2,4-dihydro-3H-1,2,4-triazole-3-thione derivatives, Ntriazole—H · · · S(=C) dimer as the main structural motif is formed, while in one Ntriazole—H · · · S hydrogen bonds connect molecules to make helix arrangement. Moreover, in 1, Cethyl—H · · · S(=C), Sthione · · · Sthiophene and πthiophene · · · πtriazole interactions are observed; there are not N—H · · · N hydrogen bonds.
NMR in DMSO and IR experiments confirmed the compound to exist as the thione tautomer.
We carried out extensive conformational searches for 1 at the molecular mechanics level in order to compare structures obtained from different force fields with the experimental results.
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Affiliation(s)
| | - Agata Siwek
- Medical University, Faculty of Pharmacy, Lublin, Polen
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22
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Hulsbergen FB, Reedijk J. Coordination compounds of tripeptides and pentapeptides containing L
-histidyl residues. Studies towards structural models for the active site of copper proteins. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/recl.19931120503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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Najmudin S, Pauleta SR, Moura I, Romão MJ. The 1.4 A resolution structure of Paracoccus pantotrophus pseudoazurin. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:627-35. [PMID: 20516588 PMCID: PMC2882758 DOI: 10.1107/s1744309110013989] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 04/15/2010] [Indexed: 11/10/2022]
Abstract
Pseudoazurins are small type 1 copper proteins that are involved in the flow of electrons between various electron donors and acceptors in the bacterial periplasm, mostly under denitrifying conditions. The previously determined structure of Paracoccus pantotrophus pseudoazurin in the oxidized form was improved to a nominal resolution of 1.4 A, with R and R(free) values of 0.188 and 0.206, respectively. This high-resolution structure makes it possible to analyze the interactions between the monomers and the solvent structure in detail. Analysis of the high-resolution structure revealed the structural regions that are responsible for monomer-monomer recognition during dimer formation and for protein-protein interaction and that are important for partner recognition. The pseudoazurin structure was compared with other structures of various type 1 copper proteins and these were grouped into families according to similarities in their secondary structure; this may be useful in the annotation of copper proteins in newly sequenced genomes and in the identification of novel copper proteins.
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Affiliation(s)
- Shabir Najmudin
- REQUIMTE, Centro de Química Fina e Biotecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Sofia R. Pauleta
- REQUIMTE, Centro de Química Fina e Biotecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Isabel Moura
- REQUIMTE, Centro de Química Fina e Biotecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Maria J. Romão
- REQUIMTE, Centro de Química Fina e Biotecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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Zhekova HR, Seth M, Ziegler T. A Magnetic and Electronic Circular Dichroism Study of Azurin, Plastocyanin, Cucumber Basic Protein, and Nitrite Reductase Based on Time-Dependent Density Functional Theory Calculations. J Phys Chem A 2010; 114:6308-21. [PMID: 20450218 DOI: 10.1021/jp101372s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hristina R. Zhekova
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada, T2N 1N4
| | - Michael Seth
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada, T2N 1N4
| | - Tom Ziegler
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada, T2N 1N4
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25
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Fazelinia H, Cirino PC, Maranas CD. OptGraft: A computational procedure for transferring a binding site onto an existing protein scaffold. Protein Sci 2009; 18:180-95. [PMID: 19177362 DOI: 10.1002/pro.2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
One of the many challenging tasks of protein design is the introduction of a completely new function into an existing protein scaffold. In this study, we introduce a new computational procedure OptGraft for placing a novel binding pocket onto a protein structure so as its geometry is minimally perturbed. This is accomplished by introducing a two-level procedure where we first identify where are the most appropriate locations to graft the new binding pocket into the protein fold by minimizing the departure from a set of geometric restraints using mixed-integer linear optimization. On identifying the suitable locations that can accommodate the new binding pocket, CHARMM energy calculations are employed to identify what mutations in the neighboring residues, if any, are needed to ensure that the minimum energy conformation of the binding pocket conserves the desired geometry. This computational framework is benchmarked against the results available in the literature for engineering a copper binding site into thioredoxin protein. Subsequently, OptGraft is used to guide the transfer of a calcium-binding pocket from thermitase protein (PDB: 1thm) into the first domain of CD2 protein (PDB:1hng). Experimental characterization of three de novo redesigned proteins with grafted calcium-binding centers demonstrated that they all exhibit high affinities for terbium (Kd) approximately 22, 38, and 55 microM) and can selectively bind calcium over magnesium.
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Affiliation(s)
- Hossein Fazelinia
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 , USA
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26
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Rajapandian V, Raman SS, Hakkim V, Parthasarathi R, Subramanian V. Molecular mechanics and molecular dynamics study on azurin using extensible and systematic force field (ESFF). ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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27
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Structural and redox properties in thioether-based (N/S) copper(II/I) complexes: Experimental and theoretical investigations. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.10.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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28
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Abstract
The C-terminal copper-binding loop in the beta-barrel fold of the cupredoxin azurin has been replaced with a range of sequences containing alanine, glycine, and valine residues to assess the importance of amino acid composition and the length of this region. The introduction of 2 and 4 alanines between the coordinating Cys, His, and Met results in loop structures matching those in naturally occurring proteins with the same loop lengths. A loop with 4 alanines between the Cys and His and 3 between the His and Met ligands has a structure identical to that of the WT protein, whose loop is the same length. Loop structure is dictated by length and not sequence allowing the properties of the main surface patch for interactions with partners, to which the loop is a major contributor, to be optimized. Loops with 2 amino acids between the ligands using glycine, alanine, and valine residues have been compared. An empirical relationship is found between copper site protection by the loop and reduction potential. A loop adorned with 4 methyl groups is sufficient to protect the copper ion, enabling most sequences to adequately perform this task. The mutant with 3 alanine residues between the ligands forms a strand-swapped dimer in the crystal structure, an arrangement that has not, to our knowledge, been seen previously for this family of proteins. Cupredoxins function as redox shuttles and are required to be monomeric; therefore, none have evolved with a metal-binding loop of this length.
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29
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Nickel(II)-substituted azurin I from Alcaligenes xylosoxidans as characterized by resonance Raman spectroscopy at cryogenic temperature. J Biol Inorg Chem 2009; 14:611-20. [DOI: 10.1007/s00775-009-0475-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 01/28/2009] [Indexed: 10/21/2022]
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30
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31
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Unique Spectroscopic Features and Electronic Structures of Copper Proteins: Relation to Reactivity. HIGH RESOLUTION EPR 2009. [DOI: 10.1007/978-0-387-84856-3_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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32
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Bizzarri A, Andolfi L, Taranta M, Cannistraro S. Optical and electronic coupling of the redox copper Azurin on ITO-coated quartz substrate. Biosens Bioelectron 2008; 24:204-9. [DOI: 10.1016/j.bios.2008.03.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Revised: 03/19/2008] [Accepted: 03/25/2008] [Indexed: 10/22/2022]
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33
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Sato K, Firbank S, Li C, Banfield M, Dennison C. The Importance of the Long Type 1 Copper‐Binding Loop of Nitrite Reductase for Structure and Function. Chemistry 2008; 14:5820-8. [DOI: 10.1002/chem.200701997] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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34
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Rhee YM, Head-Gordon M. A delicate electronic balance between metal and ligand in [Cu-P-Cu-P] diamondoids: oxidation state dependent plasticity and the formation of a singlet diradicaloid. J Am Chem Soc 2008; 130:3878-87. [PMID: 18314976 DOI: 10.1021/ja0764916] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Transition metal atoms often participate in redox reactions as catalytic sites, where ligand groups play an important role in orchestrating catalytic activity, especially in metalloenzymes. A major issue is to understand connections between oxidation state and geometry at the metal center, because geometric reorganization is directly related to reaction rate. In this article, we analyze an intriguing oxidation-induced geometrical change in [Cu-P-Cu-P] ring structures ( approximately 0.6 A change in metal-metal distance) using quantum chemical approaches. We find that the Cu-P interactions in the ring of the neutral species consist of four localized P --> Cu dative bonds. Successive oxidations extract electrons predominantly from P atoms on the ring rather than Cu sites. It emerges that as a result, the Cu-P interactions change and also exhibit partial Cu(3d) --> P donation, which causes the large distortion in geometry. We also find that the dication possesses a large degree of diradical character, forming a rare example of an observed species that is a singlet diradicaloid. This hypothesis is supported by our computational results as well as previously reported experimental features.
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Affiliation(s)
- Young Min Rhee
- Department of Chemistry, University of California, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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35
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Abstract
Many approaches are being used to engineer metalloproteins, with most of these informed by, and aiming to further elucidate, the basic structural requirements for biological metal centers. Cupredoxins are type 1 (T1) copper-containing electron transfer (ET) proteins with a -barrel fold that is thought to constrain metal site structure. The T1 copper ion is bound by ligands mainly originating from a single active site loop whose length and structure varies. This Highlight article will focus on protein engineering studies which have investigated the role of the metal-binding loop for active site integrity and functionality. Scaffold differences are present within the cupredoxin family and their influence has also been assessed. Given the widespread occurrence of -barrel domains in nature, and the array of metal sites in proteins composed of loop regions, the studies described on this model system have implications for a variety of metalloproteins.
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Affiliation(s)
- Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.
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36
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Kumar S, Singh P, Kaur S. A Cu2+ protein cavity mimicking fluorescent chemosensor for selective Cu2+ recognition: tuning of fluorescence quenching to enhancement through spatial placement of anthracene unit. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.08.101] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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37
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Li C, Banfield MJ, Dennison C. Engineering copper sites in proteins: loops confer native structures and properties to chimeric cupredoxins. J Am Chem Soc 2007; 129:709-18. [PMID: 17227035 DOI: 10.1021/ja0661562] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ligand-containing loops of two copper-binding electron-transfer proteins (cupredoxins) have been swapped. In the azurin (AZ) variant in which the plastocyanin (PC) sequence is introduced (AZPC), the loop adopts a conformation identical to that in PC. The reduction potential of AZPC is raised as compared to AZ and matches that of PC. In the previously published AZAMI variant (AMI = amicyanin), the shorter introduced loop adopts the same conformation as in AMI, and the reduction potential is lowered to equal that of AMI (Yanagisawa, S.; Dennison, C. J. Am. Chem. Soc. 2004, 126, 15711-15719. Li, C.; et al. Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 7258-7263). Thus, the loop structure plays an important role in tuning the reduction potential of a type 1 copper site with contributions from protein dipoles in this region probably the most important feature. The structure of the loop also seems to be a major factor in controlling dissociation and protonation of the C-terminal His ligand, which can act as a switch to regulate electron-transfer reactivity. The PCAZ variant (PC with the AZ loop) possesses an active site, which is different from those of both PC and AZ, and it is assumed that the introduced loop does not adopt a structure as in AZ. This contributes to the observed instability of PCAZ and highlights that loop-scaffold interactions are important for stabilizing the active site of a cupredoxin.
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Affiliation(s)
- Chan Li
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
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38
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Probing electron transfer reactions between two azurins from Alcaligenes xylosoxidans GIFU 1051 with optically active Ru complexes as molecular recognition probes: Importance of the 43rd residue. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2006.08.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Carrell CJ, Ma JK, Antholine WE, Hosler JP, Mathews FS, Davidson VL. Generation of novel copper sites by mutation of the axial ligand of amicyanin. Atomic resolution structures and spectroscopic properties. Biochemistry 2007; 46:1900-12. [PMID: 17295442 DOI: 10.1021/bi0619674] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amicyanin from Paracoccus denitrificans is a type 1 copper protein with three strong equatorial copper ligands provided by nitrogens of His53 and His95 and the sulfur of Cys92, with an additional weak axial ligand provided by the sulfur of Met98. Met98 was replaced with either Gln or Ala. As isolated, the M98A and M98Q mutant proteins contain zinc in the active site. The zinc is then removed and replaced with copper so that the copper-containing proteins may be studied. Each of the mutant amicyanins exhibits a marked decrease in thermal stability relative to that of native amicyanin, consistent with the weaker affinity for copper. Crystal structures were obtained for the oxidized and reduced forms of M98A and M98Q amicyanins at atomic resolution (<or=1.0 A). The crystal structure of oxidized M98A amicyanin exhibits a type 1 ligation geometry but with the axial ligand provided by a water, which fills the void left by the mutation of Met to Ala. The protein undergoes a reversible switch in ligation geometry when going from the aqueous to the frozen state. The visible absorption spectrum in solution is characteristic of type 1 copper, consistent with the crystal structure. On freezing, the blue color is lost, and EPR spectroscopy reveals that the copper is primarily type 2. The crystal structure of reduced M98A amicyanin exhibits an unprecedented ligation geometry in which the His95-Cu coordination is broken, and copper is left with only two ligands from His53 and Cys92 in an almost linear coordination. The replacement of Met98 with Gln yielded a type 1 copper site with increased rhombicity evident from its EPR and visible absorption spectra, and an increase in distance from Cu to the trigonal equatorial plane seen in the crystal structure. Gln98 coordinates more strongly with copper than Met, and the oxidized and reduced forms each exhibit two alternate conformers. EPR and metal analysis of oxidized M98Q amicyanin indicate that a small population of the protein contains weakly bound type 2 copper, which may be removed by washing with EDTA. These results demonstrate that the identity as well as position and rigidity of the axial ligand of the type 1 copper site has a profound influence in the uptake specificity of metal ions, protein stability, and determination of the active site geometry and its spectroscopic properties.
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Affiliation(s)
- Christopher J Carrell
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Copper Proteins as Model Systems for Investigating Intramolecular Electron Transfer Processes. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470141663.ch10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
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Structure and function of a hexameric copper-containing nitrite reductase. Proc Natl Acad Sci U S A 2007; 104:4315-20. [PMID: 17360521 DOI: 10.1073/pnas.0609195104] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dissimilatory nitrite reductase (NIR) is a key enzyme in denitrification, catalyzing the first step that leads to gaseous products (NO, N(2)O, and N(2)). We have determined the crystal structure of a Cu-containing NIR from a methylotrophic denitrifying bacterium, Hyphomicrobium denitrificans, at 2.2-A resolution. The overall structure of this H. denitrificans NIR reveals a trigonal prism-shaped molecule in which a monomer consisting of 447 residues and three Cu atoms is organized into a unique hexamer (i.e., a tightly associated dimer of trimers). Each monomer is composed of an N-terminal region containing a Greek key beta-barrel folding domain, cupredoxin domain I, and a C-terminal region containing cupredoxin domains II and III. Both cupredoxin domains I and II bind one type 1 Cu and are combined with a long loop comprising 31 amino acid residues. The type 2 Cu is ligated at the interface between domain II of one monomer and domain III of an adjacent monomer. Between the two trimeric C-terminal regions are three interfaces formed by an interaction between the domains I, and the type 1 Cu in the domain is required for dimerization of the trimer. The type 1 Cu in domain II functions as an electron acceptor from an electron donor protein and then transfers an electron to the type 2 Cu, binding the substrate to reduce nitrite to NO. The discussion of the intermolecular electron transfer process from cytochrome c(550) to the H. denitrificans NIR is based on x-ray crystallographic and kinetic results.
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Garner DK, Vaughan MD, Hwang HJ, Savelieff MG, Berry SM, Honek JF, Lu Y. Reduction potential tuning of the blue copper center in Pseudomonas aeruginosa azurin by the axial methionine as probed by unnatural amino acids. J Am Chem Soc 2007; 128:15608-17. [PMID: 17147368 DOI: 10.1021/ja062732i] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The conserved axial ligand methionine 121 from Pseudomonas aeruginosa azurin (Az) has been replaced by isostructural unnatural amino acid analogues, oxomethionine (OxM), difluoromethionine (DFM), trifluoromethionine (TFM), selenomethionine (SeM), and norleucine (Nle) using expressed protein ligation. The replacements resulted in < 6 nm shifts in the S(Cys)-Cu charge transfer (CT) band in the electronic absorption spectra and < 8 gauss changes in the copper hyperfine coupling constants (AII) in the X-band electron paramagnetic resonance spectra, suggesting that isostructural replacement of Met resulted in minimal structural perturbation of the copper center. The slight blue shifts of the CT band follow the trend of stronger electronegativity of the ligands. This trend is supported by 19F NMR studies of the fluorinated methionine analogues. However, the order of AII differs, suggesting additional factors influencing AII. In contrast to the small changes in the UV-vis and EPR spectra, a large variation of > 227 mV in reduction potential was observed for the series of variants reported here. Additionally, a linear correlation was established between the reduction potentials and hydrophobicity of the variants. Extension of this analysis to other type 1 copper-containing proteins reveals a linear correlation between change in hydrophobicity and change in reduction potential, independent of the protein scaffold, experimental conditions, measurement techniques, and steric modifications. This analysis has also revealed for the first time high and low potential states for type 1 centers, and the difference may be attributable to destabilization of the protein fold by disruption of hydrophobic or hydrogen bonding interactions that stabilize the type 1 center.
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Affiliation(s)
- Dewain K Garner
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Yang L, Powell DR, Houser RP. Structural variation in copper(I) complexes with pyridylmethylamide ligands: structural analysis with a new four-coordinate geometry index, tau4. Dalton Trans 2007:955-64. [PMID: 17308676 DOI: 10.1039/b617136b] [Citation(s) in RCA: 2249] [Impact Index Per Article: 132.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four Cu(I) complexes were synthesized with a family of pyridylmethylamide ligands, HL(R) [HL(R) = N-(2-pyridylmethyl)acetamide, R = null; 2,2-dimethyl-N-(2-pyridylmethyl)propionamide, R = Me(3); 2,2,2-triphenyl-N-(2-pyridylmethyl)acetamide, R = Ph(3))]. Complexes 1-3 were synthesized from the respective ligand and [Cu(CH(3)CN)(4)]PF(6) in a 2 : 1 molar ratio: [Cu(HL)(2)]PF(6) (1), [Cu(2)(HL(Me3))(4)](PF(6))(2) (2), [Cu(HL(Ph3))(2)]PF(6) (3). Complex 4, [Cu(HL)(CH(3)CN)(PPh(3))]PF(6), was synthesized from the reaction of HL with [Cu(CH(3)CN)(4)]PF(6) and PPh(3) in a 1 : 1 : 1 molar ratio. X-Ray crystal structures reveal that complexes 1, 3 and 4 are mononuclear Cu(I) species, while complex 2 is a Cu(I) dimer. The copper ions are four-coordinate with geometries ranging from distorted tetrahedral to seesaw in 1, 2, and 4. Complexes 1 and 2 are very air sensitive and they display similar electrochemical properties. The coordination geometry of complex 3 is nearly linear, two-coordinate. Complex 3 is exceptionally stable with respect to oxidation in the air, and its cyclic voltammetry shows no oxidation wave in the range of 0-1.5 V. The unusual inertness of complex 3 towards oxidation is attributed to the protection from bulky triphenyl substituent of the HL(Ph3) ligand. A new geometric parameter for four-coordinate compounds, tau(4), is proposed as an improved, simple metric for quantitatively evaluating the geometry of four-coordinate complexes and compounds.
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Affiliation(s)
- Lei Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, USA
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Sukumar N, Chen ZW, Ferrari D, Merli A, Rossi GL, Bellamy HD, Chistoserdov A, Davidson VL, Mathews FS. Crystal structure of an electron transfer complex between aromatic amine dehydrogenase and azurin from Alcaligenes faecalis. Biochemistry 2007; 45:13500-10. [PMID: 17087503 DOI: 10.1021/bi0612972] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The crystal structure of an electron transfer complex of aromatic amine dehydrogenase (AADH) and azurin is presented. Electrons are transferred from the tryptophan tryptophylquinone (TTQ) cofactor of AADH to the type I copper of the cupredoxin azurin. This structure is compared with the complex of the TTQ-containing methylamine dehydrogenase (MADH) and the cupredoxin amicyanin. Despite significant similarities between the two quinoproteins and the two cupredoxins, each is specific for its respective partner and the ionic strength dependence and magnitude of the binding constant for each complex are quite different. The AADH-azurin interface is largely hydrophobic, covering approximately 500 A(2) of surface on each molecule, with one direct hydrogen bond linking them. The closest distance from TTQ to copper is 12.6 A compared with a distance of 9.3 A in the MADH-amicyanin complex. When the MADH-amicyanin complex is aligned with the AADH-azurin complex, the amicyanin lies on top of the azurin but is oriented quite differently. Although the copper atoms differ in position by approximately 4.7 A, the amicyanin bound to MADH appears to be rotated approximately 90 degrees from its aligned position with azurin. Comparison of the structures of the two complexes identifies features of the interface that dictate the specificity of the protein-protein interaction and determine the rate of interprotein electron transfer.
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Affiliation(s)
- Narayanasami Sukumar
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 65211, USA
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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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Li C, Yanagisawa S, Martins BM, Messerschmidt A, Banfield MJ, Dennison C. Basic requirements for a metal-binding site in a protein: the influence of loop shortening on the cupredoxin azurin. Proc Natl Acad Sci U S A 2006; 103:7258-63. [PMID: 16651527 PMCID: PMC1464330 DOI: 10.1073/pnas.0600774103] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Indexed: 11/18/2022] Open
Abstract
The main active-site loop of the copper-binding protein azurin (a cupredoxin) has been shortened from C(112)TFPGH(117)SALM(121) to C(112)TPH(115)PFM(118) (the native loop from the cupredoxin amicyanin) and also to C(112)TPH(115)PM(117). The Cu(II) site structure is almost unaffected by shortening, as is that of the Cu(I) center at alkaline pH in the variant with the C(112)TPH(115)PM(117) loop sequence. Subtle spectroscopic differences due to alterations in the spin density distribution at the Cu(II) site can be attributed mainly to changes in the hydrogen-bonding pattern. Electron transfer is almost unaffected by the introduction of the C(112)TPH(115)PFM(118) loop, but removal of the Phe residue has a sizable effect on reactivity, probably because of diminished homodimer formation. At mildly acidic pH values, the His-115 ligand protonates and dissociates from the cuprous ion, an effect that has a dramatic influence on the reactivity of cupredoxins. These studies demonstrate that the amicyanin loop adopts a conformation identical to that found in the native protein when introduced into azurin, that a shorter than naturally occurring C-terminal active-site loop can support a functional T1 copper site, that CTPHPM is the minimal loop length required for binding this ubiquitous electron transfer center, and that the length and sequence of a metal-binding loop regulates a range of structural and functional features of the active site of a metalloprotein.
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Affiliation(s)
- Chan Li
- Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Sachiko Yanagisawa
- Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Berta M. Martins
- Elitenetzwerk Bayern Macromolecular Science, Mikrobiologie/Proteinkristallographie Laboratories, Universität Bayreuth, D-95440 Bayreuth, Germany; and
| | - Albrecht Messerschmidt
- Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Mark J. Banfield
- Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
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Hansen DF, Led JJ. Determination of the geometric structure of the metal site in a blue copper protein by paramagnetic NMR. Proc Natl Acad Sci U S A 2006; 103:1738-43. [PMID: 16446449 PMCID: PMC1413626 DOI: 10.1073/pnas.0507179103] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The biological function of metalloproteins is closely tied to the geometric and electronic structures of the metal sites. Here, we show that the geometric structure of the metal site of a metalloprotein in solution can be determined from experimentally measured electron-nuclear spin-spin interactions obtained by NMR. Thus, the geometric metal site structure of plastocyanin from Anabaena variabilis was determined by including the paramagnetic relaxation enhancement of protons close to the copper site as restraints in a conventional NMR structure determination, together with the distribution of the unpaired electron onto the ligand atoms. Also, the interproton distances (nuclear Overhauser enhancements) and dihedral angles (scalar nuclear spin-spin couplings) normally used in NMR structure determinations were included as restraints. The structure calculations were carried out with the program X-PLOR and a module that takes into account the specific characteristics of the paramagnetic restraints. A well defined metal site structure was obtained with the structural characteristics of the blue copper site, including a distorted tetrahedral geometry, a short Cu-Cys S gamma bond, and a long Cu-Met S delta bond. Overall, the agreement of the obtained metal site structure of Anabaena variabilis plastocyanin with those of other plastocyanins obtained by x-ray crystallography confirms the reliability of the approach.
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Affiliation(s)
- D. Flemming Hansen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
| | - Jens J. Led
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
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Pompa P, Chiuri R, Manna L, Pellegrino T, del Mercato L, Parak W, Calabi F, Cingolani R, Rinaldi R. Fluorescence resonance energy transfer induced by conjugation of metalloproteins to nanoparticles. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2005.09.133] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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