Conformational H-bonding Modulations of the Iron Active SiteCysteine Ligand of Superoxide Reductase: Absorption andResonance Raman Studies
| Autor: | Stéphane Torelli, Yohann Moreau, Vincent Nivière, Julien Valton, Alain Desbois |
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| Přispěvatelé: | Département Plateforme (PF I2BC), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Chimie computationnelle, modélisation et rayons X (COMX), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Catalyse Bioinorganique et Environnement (BioCE ), Biocatalyse (BIOCAT), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Coordination sphere
Stereochemistry Protein Conformation [SDV]Life Sciences [q-bio] Iron General Physics and Astronomy 010402 general chemistry Ligands Spectrum Analysis Raman 01 natural sciences Catalysis Bacterial Proteins Catalytic Domain 0103 physical sciences Amino Acid Sequence Cysteine Physical and Theoretical Chemistry Histidine 010304 chemical physics biology Bond strength Ligand Chemistry Hydrogen bond Active site Hydrogen Bonding Resonance (chemistry) 0104 chemical sciences Superoxide reductase biology.protein Mutagenesis Site-Directed Spectrophotometry Ultraviolet [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] Oxidoreductases Sulfur |
| Zdroj: | Physical Chemistry Chemical Physics Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2021, 23 (8), pp.4636-4645. ⟨10.1039/d0cp03898a⟩ Physical Chemistry Chemical Physics, 2021, 23 (8), pp.4636-4645. ⟨10.1039/d0cp03898a⟩ Physical Chemistry Chemical Physics, 2021, ⟨10.1039/D0CP03898A⟩ |
| ISSN: | 1463-9076 1463-9084 |
| Popis: | Publisher: The Royal Society of Chemistry; Superoxide reductases (SORs) are mononuclear non-heme iron enzymes involved in superoxide radical detoxification in some microorganisms. Their atypical active site is made of an iron atom pentacoordinated by four equatorial nitrogen atoms from histidine residues and one axial sulfur atom from a cysteinate residue, which plays a central role in catalysis. In most SORs, the residue immediately following the cysteinate ligand is an asparagine, which belongs to the second coordination sphere and is expected to have a critical influence on the properties of the active site. In this work, in order to investigate the role of this asparagine residue in the Desulfoarculus baarsii enzyme (Asn117), we carried out, in comparison with the wild-type enzyme, absorption and resonance Raman (RR) studies on a SOR mutant in which Asn117 was changed into an alanine. RR analysis was developed in order to assign the different bands using excitation in the (Cys116)–S−→ Fe3+ charge transfer band. By investigating the correlation between the (Cys116)–S− → Fe3+ charge transfer band maximum with the frequency of each RR band in different SOR forms, we assessed the contribution of the ν(Fe–S) vibration among the different RR bands. The data showed that Asn117, by making hydrogen bond interactions with Lys74 and Tyr76, allows a rigidification of the backbone of the Cys116 ligand, as well as that of the neighboring residues Ile118 and His119. Such a structural role of Asn117 has a deep impact on the S–Fe bond. It results in a tight control of the H-bond distance between the Ile118 and His119 NH peptidic moiety with the cysteine sulfur ligand, which in turn enables fine-tuning of the S–Fe bond strength, an essential property for the SOR active site. This study illustrates the intricate roles of second coordination sphere residues to adjust the ligand to metal bond properties in the active site of metalloenzymes. |
| Databáze: | OpenAIRE |
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