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Makarchuk I, Gerasimova T, Kägi J, Wohlwend D, Melin F, Friedrich T, Hellwig P. Mutating the environment of heme b 595 of E. coli cytochrome bd-I oxidase shifts its redox potential by 200 mV without inactivating the enzyme. Bioelectrochemistry 2023; 151:108379. [PMID: 36736178 DOI: 10.1016/j.bioelechem.2023.108379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 01/11/2023] [Accepted: 01/22/2023] [Indexed: 01/31/2023]
Abstract
Cytochrome bd-I catalyzes the reduction of oxygen to water with the aid of hemes b558, b595 and d. Here, effects of a mutation of E445, a ligand of heme b595 and of R448, hydrogen bonded to E445 are studied electrochemically in the E. coli enzyme. The equilibrium potential of the three hemes are shifted by up to 200 mV in these mutants. Strikingly the E445D and the R448N mutants show a turnover of 41 ± 2 % and 20 ± 4 %, respectively. Electrocatalytic studies confirm that the mutants react with oxygen and bind and release NO. These results point towards the ability of cytochrome bd to react even if the electron transfer is less favorable.
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Affiliation(s)
- Iryna Makarchuk
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Tatjana Gerasimova
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Jan Kägi
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Daniel Wohlwend
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Frédéric Melin
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Thorsten Friedrich
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Petra Hellwig
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany.
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De Simone G, Fattibene P, Sebastiani F, Smulevich G, Coletta M, Ascenzi P. Dissociation of the proximal His-Fe bond upon NO binding to ferrous zebrafish nitrobindin. J Inorg Biochem 2022; 236:111962. [PMID: 36075159 DOI: 10.1016/j.jinorgbio.2022.111962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/22/2022] [Accepted: 08/09/2022] [Indexed: 12/15/2022]
Abstract
Nitrobindins (Nbs) are all-β-barrel heme-proteins present in prokaryotes and eukaryotes. Although the physiological role(s) of Nbs are still unclear, it has been postulated that they are involved in the NO/O2 metabolism, which is particularly relevant in fishes for the oxygen supply. Here, the reactivity of ferrous Danio rerio Nb (Dr-Nb(II)) towards NO has been investigated from the spectroscopic and kinetic viewpoints and compared with those of Mycobacterium tuberculosis Nb, Arabidopsis thaliana Nb, Homo sapiens Nb, and Equus ferus caballus myoglobin. Between pH 5.5 and 9.1 at 22.0 °C, Dr-Nb(II) nitrosylation is a monophasic process; values of the second-order rate constant for Dr-Nb(II) nitrosylation and of the first-order rate constant for Dr-Nb(II)-NO denitrosylation are pH-independent ranging between 1.6 × 106 M-1 s-1 and 2.3 × 106 M-1 s-1 and between 5.3 × 10-2 s-1 and 8.2 × 10-2 s-1, respectively. Interestingly, both UV-Vis and EPR spectroscopies indicate that the heme-Fe(II) atom of Dr-Nb(II)-NO is five-coordinated. Kinetics of Dr-Nb(II) nitrosylation may reflect the ligand accessibility to the metal center, which is likely impaired by the crowded network of water molecules which shields the heme pocket from the bulk solvent. On the other hand, kinetics of Dr-Nb(II)-NO denitrosylation may reflect an easy pathway for the ligand escape into the outer solvent.
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Affiliation(s)
| | - Paola Fattibene
- Servizio Grandi Strumentazioni e Core Facilities, Istituto Superiore di Sanità, Roma, Italy
| | | | | | | | - Paolo Ascenzi
- Laboratorio Interdipartimentale di Microscopia Elettronica, Università Roma Tre, 00146 Roma, Italy.
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Chatterjee D, Chrzanowska M, Katafias A, van Eldik R. Reaction mechanisms relevant to the formation and utilization of [Ru(edta)(NO)] complexes in aqueous media. J Inorg Biochem 2021; 225:111595. [PMID: 34555599 DOI: 10.1016/j.jinorgbio.2021.111595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/13/2021] [Accepted: 08/27/2021] [Indexed: 12/11/2022]
Abstract
The advancement of Ru(edta) complexes (edta4- = ethylenediamineteraacetate) mediated reactions, including NO generation and its utilization, has not been systematically reviewed to date. This review aims to report the research progress that has been made in exploring the application of Ru(edta) complexes in trapping and generation of NO. Furthermore, utilization of the potential of Ru(edta) complexes to mimic NO synthase and nitrite reductase activity, including thermodynamics and kinetics of NO binding to Ru(edta) complexes, their NO scavenging (in vitro), and antitumor activity will be discussed. Also, the role of [Ru(edta)(NO)] in mediating electrochemical reduction of nitrite, S-nitrosylation of biological thiols, and cross-talk between NO and H2S, will be covered. Reports on the NO-related chemistry of Fe(edta) complexes showing similar behavior are contextualized in this review for comparison purposes. The research contributions compiled herein will provide in-depth mechanistic knowledge for understanding the diverse routes pertaining to the formation of the [Ru(edta)(NO)] species, and its role in effecting the aforementioned reactions of biochemical significance.
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