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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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2
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El Harrar T, Gohlke H. Cumulative Millisecond-Long Sampling for a Comprehensive Energetic Evaluation of Aqueous Ionic Liquid Effects on Amino Acid Interactions. J Chem Inf Model 2023; 63:281-298. [PMID: 36520535 DOI: 10.1021/acs.jcim.2c01123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The interactions of amino acid side-chains confer diverse energetic contributions and physical properties to a protein's stability and function. Various computational tools estimate the effect of changing a given amino acid on the protein's stability based on parametrized (free) energy functions. When parametrized for the prediction of protein stability in water, such energy functions can lead to suboptimal results for other solvents, such as ionic liquids (IL), aqueous ionic liquids (aIL), or salt solutions. However, to our knowledge, no comprehensive data are available describing the energetic effects of aIL on intramolecular protein interactions. Here, we present the most comprehensive set of potential of mean force (PMF) profiles of pairwise protein-residue interactions to date, covering 50 relevant interactions in water, the two biotechnologically relevant aIL [BMIM/Cl] and [BMIM/TfO], and [Na/Cl]. These results are based on a cumulated simulation time of >1 ms. aIL and salt ions can weaken, but also strengthen, specific residue interactions by more than 3 kcal mol-1, depending on the residue pair, residue-residue configuration, participating ions, and concentration, necessitating considering such interactions specifically. These changes originate from a complex interplay of competitive or cooperative noncovalent ion-residue interactions, changes in solvent structural dynamics, or unspecific charge screening effects and occur at the contact distance but also at larger, solvent-separated distances. This data provide explanations at the atomistic and energetic levels for complex IL effects on protein stability and should help improve the prediction accuracies of computational tools that estimate protein stability based on (free) energy functions.
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Affiliation(s)
- Till El Harrar
- Institute of Biotechnology, RWTH Aachen University, 52074 Aachen, Germany.,John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Biochemistry), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
| | - Holger Gohlke
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Biochemistry), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany.,Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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3
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Determining the structure and binding mechanism of oxytocin-Cu 2+ complex using paramagnetic relaxation enhancement NMR analysis. J Biol Inorg Chem 2021; 26:809-815. [PMID: 34459989 DOI: 10.1007/s00775-021-01897-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/23/2021] [Indexed: 12/30/2022]
Abstract
Oxytocin is a neuropeptide that binds copper ions in nature. The structure of oxytocin in interaction with Cu2+ was determined here by NMR, showing which atoms of the peptide are involved in binding. Paramagnetic relaxation enhancement NMR analyses indicated a binding mechanism where the amino terminus was required for binding and subsequently Tyr2, Ile3 and Gln4 bound in that order. The aromatic ring of Tyr2 formed a π-cation interaction with Cu2+. Oxytocin copper complex structure revealed by paramagnetic relaxation enhancement NMR analyses.
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4
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Yamaguchi T, Akatsu M, Taborosi A, Kohzuma T. Unusual Protein Stability of the Met16Leu Pseudoazurin Variant. CHEM LETT 2020. [DOI: 10.1246/cl.200578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Miyu Akatsu
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Attila Taborosi
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, 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, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
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5
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Yamaguchi A, Edanami Y, Yamaguchi T, Shibuya Y, Fukaya N, Kohzuma T. Effect of Cavity Size of Mesoporous Silica on Type 1 Copper Site Geometry in Pseudoazurin. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20190355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Akira Yamaguchi
- Institute of Quantum Beam Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
| | - Yurie Edanami
- Institute of Quantum Beam Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
| | - Takahide Yamaguchi
- Institute of Quantum Beam Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
- Frontier Research Center for Applied Atomic Sciences, Ibaraki University, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Yuuta Shibuya
- New Industry Creation Hatchery Center, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Norihisa Fukaya
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Takamitsu Kohzuma
- Institute of Quantum Beam Science, Ibaraki University, 2-1-1 Bunkyo, 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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6
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Cahyono RN, Yamanaka M, Nagao S, Shibata N, Higuchi Y, Hirota S. 3D domain swapping of azurin from Alcaligenes xylosoxidans. Metallomics 2020; 12:337-345. [PMID: 31956880 DOI: 10.1039/c9mt00255c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Protein oligomers have gained interest, owing to their increased knowledge in cells and promising utilization for future materials. Various proteins have been shown to 3D domain swap, but there has been no domain swapping report on a blue copper protein. Here, we found that azurin from Alcaligenes xylosoxidans oligomerizes by the procedure of 2,2,2-trifluoroethanol addition to Cu(i)-azurin at pH 5.0, lyophilization, and dissolution at pH 7.0, whereas it slightly oligomerizes when using Cu(ii)-azurin. The amount of high order oligomers increased with the addition of Cu(ii) ions to the dissolution process of a similar procedure for apoazurin, indicating that Cu(ii) ions enhance azurin oligomerization. The ratio of the absorbance at 460 nm to that at ∼620 nm of the azurin dimer (Abs460/Abs618 = 0.113) was higher than that of the monomer (Abs460/Abs622 = 0.067) and the EPR A‖ value of the dimer (5.85 mT) was slightly smaller than that of the monomer (5.95 mT), indicating a slightly more rhombic copper coordination for the dimer. The redox potential of the azurin dimer was 342 ± 5 mV vs. NHE, which was 50 mV higher than that of the monomer. According to X-ray crystal analysis, the azurin dimer exhibited a domain-swapped structure, where the N-terminal region containing three β-strands was exchanged between protomers. The copper coordination structure was tetrahedrally distorted in the azurin dimer, similar to that in the monomer; however, the Cu-O(Gly45) bond length was longer for the dimer (monomer, 2.46-2.59 Å; dimer, 2.98-3.25 Å). These results open the door for designing oligomers of blue copper proteins by domain swapping.
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Affiliation(s)
- Robby Noor Cahyono
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan. and Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta, 55281, Indonesia
| | - Masaru Yamanaka
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
| | - Satoshi Nagao
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
| | - Naoki Shibata
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Yoshiki Higuchi
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Shun Hirota
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
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7
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Slope LN, Hill MG, Smith CF, Teare P, de Cogan FJ, Britton MM, Peacock AFA. Tuning coordination chemistry through the second sphere in designed metallocoiled coils. Chem Commun (Camb) 2020; 56:3729-3732. [PMID: 32129331 DOI: 10.1039/c9cc08189e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The metal hydration state within a designed coiled coil can be progressively tuned across the full integer range (3 → 0 aqua ligands), by careful choice of a second sphere terminal residue, including the lesser used Trp. Potential implications include a four-fold change in MRI relaxivity when applied to lanthanide coiled coils.
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Affiliation(s)
- Louise N Slope
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Michael G Hill
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Catherine F Smith
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Paul Teare
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Felicity J de Cogan
- Institute of Microbiology and Infection, University of Birmingham, B15 2TT, UK
| | - Melanie M Britton
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Anna F A Peacock
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
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8
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Taborosi A, Yamaguchi T, Odani A, Yamauchi O, Kohzuma T. The Role for the Weak Interaction on the Stabilization of Copper-Containing Complex: DFT Investigation of Noncovalent Interactions in Ternary-Cu(II) (DA)(AA) Complexes (DA = Diamine and AA = Amino Acids) as a Model of Metalloprotein. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20190197] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Attila Taborosi
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
| | - Takahide Yamaguchi
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
- Frontier Research Center for Applied Atomic Science, 162-1 Shirakata, Tokai, Naka, Ibaraki 319-1106, Japan
| | - Akira Odani
- Graduate School of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Osamu Yamauchi
- Graduate School of Science, Nagoya University, Furou-cho, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Takamitsu Kohzuma
- Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
- Frontier Research Center for Applied Atomic Science, 162-1 Shirakata, Tokai, Naka, Ibaraki 319-1106, Japan
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9
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10
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Yamaguchi T, Nihei Y, Sutherland DEK, Stillman MJ, Kohzuma T. Stabilization of protein structure through π-π interaction in the second coordination sphere of pseudoazurin. Protein Sci 2017; 26:1921-1931. [PMID: 28691165 DOI: 10.1002/pro.3226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/01/2017] [Accepted: 07/04/2017] [Indexed: 11/11/2022]
Abstract
Noncovalent, weak interactions in the second coordination sphere of the copper active site of Pseudoazurin (PAz) from Achromobacter cycloclastes were examined using a series of Met16X variants. In this study, the differences in protein stability due to the changes in the nature of the 16th amino acid (Met, Phe, Val, Ile) were investigated by electrospray ionization mass spectrometry (ESI-MS) and far-UV circular dichroism (CD) as a result of acid denaturation. The percentage of native states (folded holo forms) of Met16Phe variants was estimated to be 75% at pH 2.9 although the wild-type (WT), Met16Val and Met16Ile PAz, became completely unfolded. The high stability under acidic conditions is correlated with the result of the active site being stabilized by the aromatic substitution of the Met16 residue. The π-π interaction in the second coordination sphere makes a significant contribution to the stability of active site and the protein matrix.
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Affiliation(s)
- Takahide Yamaguchi
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| | - Yuko Nihei
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| | - Duncan E K Sutherland
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
| | - Martin J Stillman
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
| | - Takamitsu Kohzuma
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
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11
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Fukuda Y, Mizohata E, Inoue T. New molecular packing in a crystal of pseudoazurin from Alcaligenes faecalis: a double-helical arrangement of blue copper. Acta Crystallogr F Struct Biol Commun 2017; 73:159-166. [PMID: 28291752 PMCID: PMC5349310 DOI: 10.1107/s2053230x17002631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 02/15/2017] [Indexed: 11/10/2022] Open
Abstract
Pseudoazurin from the denitrifying bacterium Alcaligenes faecalis (AfPAz) is a blue copper protein and functions as an electron donor to copper-containing nitrite reductase (CuNIR). Conventionally, AfPAz has been crystallized using highly concentrated ammonium sulfate as a precipitant. Here, a needle-like crystal of AfPAz grown in a solution containing a macromolecular precipitant, polyethylene glycol 8000 (PEG 8000), is reported. The crystal belonged to space group P61, with unit-cell parameters a = b = 68.7, c = 94.2 Å. The structure has been determined and refined at 2.6 Å resolution. The asymmetric unit contained two AfPAz molecules contacting each other on negatively charged surfaces. The molecular packing of the crystal showed a right-handed double-helical arrangement of AfPAz molecules and hence of blue copper sites. This structure provides insight into the excluded-volume effect of PEG and the manner of assembly of AfPAz.
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Affiliation(s)
- Yohta Fukuda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Eiichi Mizohata
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tsuyoshi Inoue
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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12
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Rakshit R, Mukherjee C. Secondary Interactions versus Intramolecular π–π Interactions in CuII–Diradical Complexes. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Richa Rakshit
- Department of Chemistry Indian Institute of Technology Guwahati 781029 Guwahati Assam India
| | - Chandan Mukherjee
- Department of Chemistry Indian Institute of Technology Guwahati 781029 Guwahati Assam India
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14
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Caballero AB, Terol-Ordaz L, Espargaró A, Vázquez G, Nicolás E, Sabaté R, Gamez P. Histidine-Rich Oligopeptides To Lessen Copper-Mediated Amyloid-β Toxicity. Chemistry 2016; 22:7268-80. [DOI: 10.1002/chem.201600286] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Ana B. Caballero
- Department of Inorganic and Organic Chemistry; University of Barcelona; Martí i Franquès 1-11 08028 Barcelona Spain
| | - Laia Terol-Ordaz
- Department of Inorganic and Organic Chemistry; University of Barcelona; Martí i Franquès 1-11 08028 Barcelona Spain
| | - Alba Espargaró
- Department of Physical Chemistry; Faculty of Pharmacy and; Institute of Nanoscience and Nanotechnology (IN2UB); University of Barcelona; Avda. Joan XXIII 27-31 08028 Barcelona Spain
| | - Guillem Vázquez
- Department of Inorganic and Organic Chemistry; University of Barcelona; Martí i Franquès 1-11 08028 Barcelona Spain
| | - Ernesto Nicolás
- Department of Inorganic and Organic Chemistry; University of Barcelona; Martí i Franquès 1-11 08028 Barcelona Spain
| | - Raimon Sabaté
- Department of Physical Chemistry; Faculty of Pharmacy and; Institute of Nanoscience and Nanotechnology (IN2UB); University of Barcelona; Avda. Joan XXIII 27-31 08028 Barcelona Spain
| | - Patrick Gamez
- Department of Inorganic and Organic Chemistry; University of Barcelona; Martí i Franquès 1-11 08028 Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA); Passeig Lluís Companys 23 08010 Barcelona Spain
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15
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Hayat NM, Shamaan NA, Sabullah MK, Shukor MY, Syed MA, Khalid A, Dahalan FA, Ahmad SA. The use of Lates calcarifer as a biomarker for heavy metals detection. RENDICONTI LINCEI-SCIENZE FISICHE E NATURALI 2016. [DOI: 10.1007/s12210-015-0501-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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16
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Yamaguchi T, Akao K, Takashina A, Asamura S, Unno M, Szilagyi RK, Kohzuma T. X-ray crystallographic evidence for the simultaneous presence of axial and rhombic sites in cupredoxins: atomic resolution X-ray crystal structure analysis of pseudoazurin and DFT modelling. RSC Adv 2016. [DOI: 10.1039/c6ra19282c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The simultaneous presence of axial (blue) and rhombic (green) Cu sites in pseudoazurin is described from experiments and computational modelling.
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Affiliation(s)
- T. Yamaguchi
- Institute of Quantum Beam Science
- Ibaraki University
- Mito
- Japan
| | - K. Akao
- Institute of Quantum Beam Science
- Ibaraki University
- Mito
- Japan
| | - A. Takashina
- Institute of Quantum Beam Science
- Ibaraki University
- Mito
- Japan
| | - S. Asamura
- Institute of Quantum Beam Science
- Ibaraki University
- Mito
- Japan
| | - M. Unno
- Institute of Quantum Beam Science
- Ibaraki University
- Mito
- Japan
- Frontier Research Center for Applied Atomic Sciences
| | - R. K. Szilagyi
- Department of Chemistry and Biochemistry
- Montana State University
- Bozeman
- USA
- MTA-ELTE “Momentum” Chemical Structure/Function Laboratory
| | - T. Kohzuma
- Institute of Quantum Beam Science
- Ibaraki University
- Mito
- Japan
- Frontier Research Center for Applied Atomic Sciences
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17
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YAMAGUCHI T, KOHZUMA T. Molecular Science in Biology(3)– Quantum Beam, Synchrotron Radiation andX-ray Absorption Spectroscopy –. JOURNAL OF COMPUTER CHEMISTRY-JAPAN 2016. [DOI: 10.2477/jccj.2016-0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Takahide YAMAGUCHI
- Institute of Quantum Beam Science, Graduate School of Science and Engineering,Ibaraki University 2-1-1 Bunkyo, Mito, Ibaraki 210-8512
| | - Takamitsu KOHZUMA
- Institute of Quantum Beam Science, Graduate School of Science and Engineering,Ibaraki University 2-1-1 Bunkyo, Mito, Ibaraki 210-8512
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18
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Yamaguchi T, Yano J, Yachandra VK, Nihei Y, Togashi H, Szilagyi RK, Kohzuma T. The Allosteric Regulation of Axial/Rhombic Population in a “Type 1” Copper Site: Multi-Edge X-ray Absorption Spectroscopic and Density Functional Studies of Pseudoazurin. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2015. [DOI: 10.1246/bcsj.20150225] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Junko Yano
- Physical Biosciences Division, Lawrence Berkeley National Laboratory
| | | | - Yuko Nihei
- Institute of Applied Beam Science, Ibaraki University
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19
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Sun W, Ren H, Tao Y, Xiao D, Qin X, Deng L, Shao M, Gao J, Chen X. Two Aromatic Rings Coupled a Sulfur-Containing Group to Favor Protein Electron Transfer by Instantaneous Formations of π∴S:π↔π:S∴π or π∴π:S↔π:π∴S Five-Electron Bindings. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2015; 119:9149-9158. [PMID: 26120374 PMCID: PMC4479289 DOI: 10.1021/acs.jpcc.5b01740] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The cooperative interactions among two aromatic rings with a S-containing group are described, which may participate in electron hole transport in proteins. Ab initio calculations reveal the possibility for the formations of the π∴S:π↔π:S∴π and π∴π:S↔π:π∴S five-electron bindings in the corresponding microsurrounding structures in proteins, both facilitating electron hole transport as efficient relay stations. The relay functionality of these two special structures comes from their low local ionization energies and proper binding energies, which varies with the different aromatic amino acids, S-containing residues, and the arrangements of the same aromatic rings according to the local microsurroundings in proteins.
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Affiliation(s)
- Weichao Sun
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Haisheng Ren
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ye Tao
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Dong Xiao
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Xin Qin
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Li Deng
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Mengyao Shao
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Jiali Gao
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Xiaohua Chen
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People's Republic of China
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
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The assessment of cholinesterase from the liver of Puntius javanicus as detection of metal ions. ScientificWorldJournal 2014; 2014:571094. [PMID: 25401148 PMCID: PMC4225846 DOI: 10.1155/2014/571094] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 06/27/2014] [Accepted: 07/30/2014] [Indexed: 11/18/2022] Open
Abstract
Crude extract of ChE from the liver of Puntius javanicus was purified using procainamide-sepharyl 6B. S-Butyrylthiocholine iodide (BTC) was selected as the specific synthetic substrate for this assay with the highest maximal velocity and lowest biomolecular constant at 53.49 µmole/min/mg and 0.23 mM, respectively, with catalytic efficiency ratio of 0.23. The optimum parameter was obtained at pH 7.5 and optimal temperature in the range of 25 to 30°C. The effect of different storage condition was assessed where ChE activity was significantly decreased after 9 days of storage at room temperature. However, ChE activity showed no significant difference when stored at 4.0, 0, and −25°C for 15 days. Screening of heavy metals shows that chromium, copper, and mercury strongly inhibited P. javanicus ChE by lowering the activity below 50%, while several pairwise combination of metal ions exhibited synergistic inhibiting effects on the enzyme which is greater than single exposure especially chromium, copper, and mercury. The results showed that P. javanicus ChE has the potential to be used as a biosensor for the detection of metal ions.
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Gast P, Broeren FG, Sottini S, Aoki R, Takashina A, Yamaguchi T, Kohzuma T, Groenen EJ. The type 1 copper site of pseudoazurin: Axial and rhombic. J Inorg Biochem 2014; 137:57-63. [DOI: 10.1016/j.jinorgbio.2014.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 03/25/2014] [Accepted: 03/28/2014] [Indexed: 11/29/2022]
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Domínguez-Martín A, Choquesillo-Lazarte D, Dobado JA, Martínez-García H, Lezama L, González-Pérez JM, Castiñeiras A, Niclós-Gutiérrez J. Structural consequences of the N7 and C8 translocation on the metal binding behavior of adenine. Inorg Chem 2013; 52:1916-25. [PMID: 23356582 DOI: 10.1021/ic302147u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
7-Deaza-8-aza-adenine, namely 4-aminopyrazolo[3,4-d]pyrimidine (H4app), is a bioisoster of adenine (Hade) resulting from the translocation of N7 and C8 atoms on the purine moiety. With the aim of studying the influence of this translocation on the metal binding abilities of H4app, we have prepared and structurally characterized two ternary copper(II) complexes having H4app and one N-benzyl-iminodiacetate chelator (MEBIDA or FBIDA, with a methyl or fluoro group in para- of the benzyl aromatic ring): [Cu(2)(MEBIDA)(2)(μ(2)-N1,N8-H4app)(H(2)O)(2)]·4H(2)O (1) and [Cu(4)(FBIDA)(4)(μ(2)-N8,N9-H4app)(2)(H(2)O)]·3.5H(2)O (2). Furthermore, thermal, spectral, and magnetic properties have been also investigated. In 1, H(N9)4app is disordered over two equally pondered positions and the μ(2)-N1,N8 coordination mode is assisted by N6-H···O and N9-H···O intramolecular interactions, respectively. The acyclic nonlinear molecular topology of 2 is strongly influenced by two intramolecular H-bonding interactions (O-H···O-carboxylate) involving the apical aqua ligand of a terminal Cu(II) atom. Thus, both compounds have in common the Cu-N8 bond. In order to better understand our limited structural information, DFT calculations for the individual tautomers of H4app as well as mononuclear Cu(II) model systems have been carried out. According to previous results, we conclude that H(N9)4app is the most stable tautomer followed by H(N8)4app. When N9 and N8 are metalated, then the tautomer H(N1)4app can come into play as observed in compound 2. Likewise, the findings concerning compound 1 suggest that the formation of a Cu-N1 bond in H4app results was favored compared to neutral adenine, for which only one case has been reported with such coordination despite the large variety of related Cu(II)-Hade described in the literature.
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Affiliation(s)
- Alicia Domínguez-Martín
- Department of Inorganic Chemistry, Faculty of Pharmacy, University of Granada, E-18071 Granada, Spain.
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23
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Direct electron transfer from pseudoazurin to nitrous oxide reductase in catalytic N2O reduction. J Inorg Biochem 2012; 115:163-73. [DOI: 10.1016/j.jinorgbio.2012.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 11/22/2022]
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24
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Reetz MT. Artificial Metalloenzymes as Catalysts in Stereoselective Diels-Alder Reactions. CHEM REC 2012; 12:391-406. [DOI: 10.1002/tcr.201100043] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Indexed: 11/05/2022]
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25
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Cambria MT, Gullotto D, Garavaglia S, Cambria A. In silico study of structural determinants modulating the redox potential ofRigidoporus lignosusand other fungal laccases. J Biomol Struct Dyn 2012; 30:89-101. [DOI: 10.1080/07391102.2012.674275] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Molina P, Tárraga A, Otón F. Imidazole derivatives: a comprehensive survey of their recognition properties. Org Biomol Chem 2012; 10:1711-24. [PMID: 22281703 DOI: 10.1039/c2ob06808g] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Due to its amphoteric nature the imidazole ring can function as selective and effective anion and/or cation and even neutral organic molecules receptor system. As a result, the design of new multichannel imidazole-based receptors capable of recognizing different types of analytes is strongly demanded. This review summarizes the most recent and relevant advances in this area.
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Affiliation(s)
- Pedro Molina
- Departamento de Química Orgánica, Universidad de Murcia, Campus de Espinardo, 30100 Murcia, Spain.
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27
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New SY, Marshall NM, Hor TSA, Xue F, Lu Y. Redox tuning of two biological copper centers through non-covalent interactions: same trend but different magnitude. Chem Commun (Camb) 2012; 48:4217-9. [DOI: 10.1039/c2cc30901g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Podtetenieff J, Taglieber A, Bill E, Reijerse EJ, Reetz MT. An Artificial Metalloenzyme: Creation of a Designed Copper Binding Site in a Thermostable Protein. Angew Chem Int Ed Engl 2010; 49:5151-5. [PMID: 20572232 DOI: 10.1002/anie.201002106] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- John Podtetenieff
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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Podtetenieff J, Taglieber A, Bill E, Reijerse E, Reetz M. An Artificial Metalloenzyme: Creation of a Designed Copper Binding Site in a Thermostable Protein. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002106] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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Rationally tuning the reduction potential of a single cupredoxin beyond the natural range. Nature 2009; 462:113-6. [PMID: 19890331 DOI: 10.1038/nature08551] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Accepted: 09/30/2009] [Indexed: 11/08/2022]
Abstract
Redox processes are at the heart of numerous functions in chemistry and biology, from long-range electron transfer in photosynthesis and respiration to catalysis in industrial and fuel cell research. These functions are accomplished in nature by only a limited number of redox-active agents. A long-standing issue in these fields is how redox potentials are fine-tuned over a broad range with little change to the redox-active site or electron-transfer properties. Resolving this issue will not only advance our fundamental understanding of the roles of long-range, non-covalent interactions in redox processes, but also allow for design of redox-active proteins having tailor-made redox potentials for applications such as artificial photosynthetic centres or fuel cell catalysts for energy conversion. Here we show that two important secondary coordination sphere interactions, hydrophobicity and hydrogen-bonding, are capable of tuning the reduction potential of the cupredoxin azurin over a 700 mV range, surpassing the highest and lowest reduction potentials reported for any mononuclear cupredoxin, without perturbing the metal binding site beyond what is typical for the cupredoxin family of proteins. We also demonstrate that the effects of individual structural features are additive and that redox potential tuning of azurin is now predictable across the full range of cupredoxin potentials.
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31
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Shimazaki Y, Yajima T, Takani M, Yamauchi O. Metal complexes involving indole rings: Structures and effects of metal–indole interactions. Coord Chem Rev 2009. [DOI: 10.1016/j.ccr.2008.04.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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32
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Nakabayashi Y, Tashiro M, Yajima T, Takani M, Tani A, Motoyama T, Odani A, Yamauchi O. Adduct formation between ternary Pt(II)–amino acid–aromatic diimine complexes and flavin mononucleotide and its effect on redox properties. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.03.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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33
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Shimazaki Y, Takani M, Yamauchi O. Metal complexes of amino acids and amino acid side chain groups. Structures and properties. Dalton Trans 2009:7854-69. [PMID: 19771344 DOI: 10.1039/b905871k] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Yanagisawa S, Crowley PB, Firbank SJ, Lawler AT, Hunter DM, McFarlane W, Li C, Kohzuma T, Banfield MJ, Dennison C. π-Interaction Tuning of the Active Site Properties of Metalloproteins. J Am Chem Soc 2008; 130:15420-8. [DOI: 10.1021/ja8038135] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sachiko Yanagisawa
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Peter B. Crowley
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Susan J. Firbank
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Anne T. Lawler
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - David M. Hunter
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - William McFarlane
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Chan Li
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Takamitsu Kohzuma
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Mark J. Banfield
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K., UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland, School of Natural Sciences (Chemistry), Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K., and Institute of Applied Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
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Yamauchi O, Yajima T, Fujii R, Shimazaki Y, Yabusaki M, Takani M, Tashiro M, Motoyama T, Kakuto M, Nakabayashi Y. CH⋯Metal(II) axial interaction in planar complexes (metal=Cu, Pd) and implications for possible environmental effects of alkyl groups at biological copper sites. J Inorg Biochem 2008; 102:1218-26. [DOI: 10.1016/j.jinorgbio.2007.11.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Revised: 10/15/2007] [Accepted: 11/30/2007] [Indexed: 11/29/2022]
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36
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Abdelhamid RF, Obara Y, Kohzuma T. Alkaline transition of pseudoazurin Met16X mutant proteins: protein stability influenced by the substitution of Met16 in the second sphere coordination. J Inorg Biochem 2008; 102:1373-9. [PMID: 18343503 DOI: 10.1016/j.jinorgbio.2008.01.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 01/08/2008] [Accepted: 01/16/2008] [Indexed: 10/22/2022]
Abstract
Several blue copper proteins are known to change the active site structure at alkaline pH (alkaline transition). Spectroscopic studies of Met16Phe, Met16Tyr, Met16Trp, and Met16Val pseudoazurin variants were performed to investigate the second sphere role through alkaline transition. The visible electronic absorption and resonance Raman spectra of Met16Phe, Met16Tyr, and Met16Trp variants showed the increasing of axial component at pH approximately 11 like wild-type PAz. The visible electronic absorption and far-UV CD spectra of Met16Val demonstrated that the destabilization of the protein structure was triggered at pH>11. Resonance Raman (RR) spectra of PAz showed that the intensity-weighted averaged Cu-S(Cys) stretching frequency was shifted to higher frequency region at pH approximately 11. The higher frequency shift of Cu-S(Cys) bond is implied the stronger Cu-S(Cys) bond at alkaline transition pH approximately 11. The visible electronic absorption and far-UV CD spectra of Met16X PAz revealed that the Met16Val variant is denatured at pH>11, but Met16Phe, Met16Tyr, and Met16Trp mutant proteins are not denatured even at pH>11. These observations suggest that Met16 is important to maintain the protein structure through the possible weak interaction between methionine -SCH3 part and coordinated histidine imidazole moiety. The introduction of pi-pi interaction in the second coordination sphere may be contributed to the enhancement of protein structure stability.
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Affiliation(s)
- Rehab F Abdelhamid
- Institute of Applied Beam Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
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