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Modenez IA, Macedo LJA, Melo AFAA, Pereira AR, Oliveira ON, Crespilho FN. Nanosized non-proteinaceous complexes III and IV mimicking electron transfer of mitochondrial respiratory chain. J Colloid Interface Sci 2021; 599:198-206. [PMID: 33945968 DOI: 10.1016/j.jcis.2021.04.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/24/2021] [Accepted: 04/13/2021] [Indexed: 11/25/2022]
Abstract
Synthetic biology pursues the understanding of biological processes and their possible mimicry with artificial bioinspired materials. A number of materials have already been used to mimic the active site of simple redox proteins, including nanosized iron oxides due to their redox properties. However, the mimicry of membrane redox protein complexes is still a challenge. Herein, magnetic iron oxide nanoparticles (NPs), incorporated as non-proteinaceous complexes III and IV in a mitochondrial model membrane, catalyze electron transfer (ET) similarly to the natural complexes towards cytochrome c. The associated molecular mechanism is experimentally proven in solution and in a Langmuir-Blodgett film. A direct and entropy-driven ET, with rate constant of 2.63 ± 0.05Lmol-1 at 25 °C, occurs between the iron sites of the NPs and the cytochrome c heme group, not affecting the protein secondary and tertiary structures. This process requires an activation energy of 40.2 ± 1.5 kJ mol-1 resulting in an overall Gibbs free energy of -55.3 kJ mol-1. Furthermore, the protein-NP system is governed by electrostatic and non-polar forces that contribute to an associative mechanism in the transition state. Finally, the incorporated NPs in a model membrane were able to catalyze ET, such as the natural complexes in respiratory chain. This work presents an experimental approach demonstrating that inorganic nanostructured systems may behave as embedded proteins in the eukaryotic cells membrane, opening the way for more sophisticated and robust mimicry of membrane protein complexes.
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Affiliation(s)
- Iago A Modenez
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos 13560-970, Brazil
| | - Lucyano J A Macedo
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos 13560-970, Brazil
| | - Antonio F A A Melo
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos 13560-970, Brazil; Materials Engineering Graduate Program, Federal Institute of Education, Science and Technology of Piauí, Central Campus, Teresina 64000-040, PI, Brazil
| | - Andressa R Pereira
- São Carlos Institute of Physics, University of São Paulo, São Carlos 13560-590, Brazil
| | - Osvaldo N Oliveira
- São Carlos Institute of Physics, University of São Paulo, São Carlos 13560-590, Brazil
| | - Frank N Crespilho
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos 13560-970, Brazil.
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Loginova NV, Harbatsevich HI, Osipovich NP, Ksendzova GA, Koval’chuk TV, Polozov GI. Metal Complexes as Promising Agents for Biomedical Applications. Curr Med Chem 2020; 27:5213-5249. [DOI: 10.2174/0929867326666190417143533] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/02/2019] [Accepted: 03/29/2019] [Indexed: 12/24/2022]
Abstract
Background::
In this review article, a brief overview of novel metallotherapeutic agents
(with an emphasis on the complexes of essential biometals) promising for medical application is
presented. We have also focused on the recent work carried out by our research team, specifically
the development of redox-active antimicrobial complexes of sterically hindered diphenols with some
essential biometals (copper, zinc, nickel).
Results::
The complexes of essential metals (manganese, iron, cobalt, nickel, copper, zinc) described
in the review show diverse in vitro biological activities, ranging from antimicrobial and antiinflammatory
to antiproliferative and enzyme inhibitory. It is necessary to emphasize that the type of
organic ligands in these metal complexes seems to be responsible for their pharmacological
activities. In the last decades, there has been a significant interest in synthesis and biological
evaluation of metal complexes with redox-active ligands. A substantial step in the development of
these redox-active agents is the study of their physicochemical and biological properties, including
investigations in vitro of model enzyme systems, which can provide evidence on a plausible
mechanism underlying the pharmacological activity. When considering the peculiarities of the
pharmacological activity of the sterically hindered diphenol derivatives and their nickel(II),
copper(II) and zinc(II) complexes synthesized, we took into account the following: (i) all these
compounds are potential antioxidants and (ii) their antimicrobial activity possibly results from their
ability to affect the electron-transport chain.
Conclusion::
We obtained novel data demonstrating that the level of antibacterial and antifungal
activity in the series of the above-mentioned metal-based antimicrobials depends not only on the
nature of the phenolic ligands and complexing metal ions, but also on the lipophilicity and reducing
ability of the ligands and metal complexes, specifically regarding the potential biotargets of their
antimicrobial action – ferricytochrome c and the superoxide anion radical. The combination of
antibacterial, antifungal and antioxidant activity allows one to consider these compounds as
promising substances for developing therapeutic agents with a broad spectrum of activities.
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Affiliation(s)
| | | | - Nikolai P. Osipovich
- Research Institute for Physico-Chemical Problems of the Belarusian State University, Minsk, Belarus
| | - Galina A. Ksendzova
- Research Institute for Physico-Chemical Problems of the Belarusian State University, Minsk, Belarus
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Nelp MT, Zheng V, Davis KM, Stiefel KJE, Groves JT. Potent Activation of Indoleamine 2,3-Dioxygenase by Polysulfides. J Am Chem Soc 2019; 141:15288-15300. [PMID: 31436417 DOI: 10.1021/jacs.9b07338] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Indoleamine 2,3-dioxygenase (IDO1) is a heme enzyme that catalyzes the oxygenation of the indole ring of tryptophan to afford N-formylkynurenine. This activity significantly suppresses the immune response, mediating inflammation and autoimmune reactions. These consequential effects are regulated through redox changes in the heme cofactor of IDO1, which autoxidizes to the inactive ferric state during turnover. This change in redox status increases the lability of the heme cofactor leading to further suppression of activity. The cell can thus regulate IDO1 activity through the supply of heme and reducing agents. We show here that polysulfides bind to inactive ferric IDO1 and reduce it to the oxygen-binding ferrous state, thus activating IDO1 to maximal turnover even at low, physiologically significant concentrations. The on-rate for hydrogen disulfide binding to ferric IDO1 was found to be >106 M-1 s-1 at pH 7 using stopped-flow spectrometry. Fe K-edge XANES and EPR spectroscopy indicated initial formation of a low-spin ferric sulfur-bound species followed by reduction to the ferrous state. The μM affinity of polysulfides for IDO1 implicates these polysulfides as important signaling factors in immune regulation through the kynurenine pathway. Tryptophan significantly enhanced the relatively lower-affinity binding of hydrogen sulfide to IDO1, inspiring the use of the small molecule 3-mercaptoindole (3MI), which selectively binds to and activates ferric IDO1. 3MI sustains turnover by catalytically transferring reducing equivalents from glutathione to IDO1, representing a novel strategy of upregulating innate immunosuppression for treatment of autoimmune disorders. Reactive sulfur species are thus likely unrecognized immune-mediators with potential as therapeutic agents through these interactions with IDO1.
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Affiliation(s)
- Micah T Nelp
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Vincent Zheng
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Katherine M Davis
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Katherine J E Stiefel
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - John T Groves
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
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de Aguiar I, Rocha dos Santos E, Mafud AC, Annies V, Navarro-Silva MA, Rodrigues dos Santos Malta V, do Prado Gambardella MT, de Assis Marques F, Carlos RM. Synthesis and characterization of Mn(I) complexes and their larvicidal activity against Aedes aegypti, vector of dengue fever. INORG CHEM COMMUN 2017. [DOI: 10.1016/j.inoche.2017.07.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Grzyb J, Kalwarczyk E, Worch R. Photoreduction of natural redox proteins by CdTe quantum dots is size-tunable and conjugation-independent. RSC Adv 2015. [DOI: 10.1039/c5ra02900g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Colloidal CdTe quantum dots may photoreduce both heme and iron–sulfur cluster containing proteins. Reduction level may be tuned by choosing different size of nanocrystals.
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Powell HV, Schnippering M, Cheung M, Macpherson JV, Mackenzie SR, Stavros VG, Unwin PR. Probing Redox Reactions of Immobilized Cytochrome c Using Evanescent Wave Cavity Ring-Down Spectroscopy in a Thin-Layer Electrochemical Cell. Chemphyschem 2010; 11:2985-91. [DOI: 10.1002/cphc.201000213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Redox-active metal(II) complexes of sterically hindered phenolic ligands: Antibacterial activity and reduction of cytochrome c. Polyhedron 2010. [DOI: 10.1016/j.poly.2010.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Takahashi I, Inomata T, Funahashi Y, Ozawa T, Masuda H. Electron-Transfer Reactions through the Associated Interaction between Cytochromec and Self-Assembled Monolayers of Optically Active Cobalt(III) Complexes: Molecular Recognition Ability Induced by the Chirality of the Cobalt(III) Units. Chemistry 2007; 13:8007-17. [PMID: 17616958 DOI: 10.1002/chem.200700155] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Self-assembled monolayers (SAMs) of optically active Co(III) complexes ((S)-2/(R)-2) that contain (S)- or (R)-phenylalanine derivatives as a molecular recognition site were constructed on Au electrodes ((S)-2-Au/(R)-2-Au). Molecular recognition characteristics induced by the S and R configurations were investigated by measurements of electron-transfer reactions with horse heart cytochrome c (cyt c). The electrochemical studies indicate that the maximum current of cyt c reduction is obtained when the Au electrode is modified by 2 with a moderate coverage of approximately 4.0 x 10(-11) mol cm(-2). Since the Au electrode is not densely packed with the Co(III) units at this concentration, we conclude that the penetrative association process between cyt c and the Co(III) unit plays an important role in this electron-transfer system. The differences in the electron-transfer rates of (S)-2-Au and (R)-2-Au increase with increasing scan rates, a result indicating that the chiral ligand has an influence on the rate of association of the complexes with cyt c. 3-Au has a mixed monolayer composed of 2 and hexanethiol and exhibits electron-transfer behavior comparable to 2-Au. The difference in the association rates of (S)-3-Au and (R)-3-Au is larger than that between (S)-2-Au and (R)-2-Au, which indicates that the molecular recognition ability of 3-Au has been enhanced by filling the gap between molecules of 2 with hexanethiols. The differences in the oxidation rates of cyt c(II) between (S)-2-Au and (R)-2-Au and between (S)-3-Au and (R)-3-Au were larger than the differences in the rates of the reduction of cyt c(III); this suggests that the size of the heme crevice varies according to the oxidation state of cyt c.
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Affiliation(s)
- Isao Takahashi
- Department of Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
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Bernhardt PV, Chen KI, Sharpe PC. Transition metal complexes as mediator-titrants in protein redox potentiometry. J Biol Inorg Chem 2006; 11:930-6. [PMID: 16868742 DOI: 10.1007/s00775-006-0148-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 07/05/2006] [Indexed: 10/24/2022]
Abstract
A selection of nine macrocyclic Fe(III/II) and Co(III/II) transition metal complexes has been chosen to serve as a universal set of mediator-titrants in redox potentiometry of protein samples. The potential range spanned by these mediators is approximately from +300 to -700 mV vs the normal hydrogen electrode, which covers the range of most protein redox potentials accessible in aqueous solution. The complexes employed exhibit stability in both their oxidized and their reduced forms as well as pH-independent redox potentials within the range 6 < pH < 9. The mediators were also chosen on the basis of their very weak visible absorption maxima in both oxidation states, which will enable (for the first time) optical redox potentiometric titrations of proteins with relatively low extinction coefficients. This has previously been impractical with organic mediators, such as indoles, viologens and quinones, whose optical spectra interfere strongly with those of the protein.
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Affiliation(s)
- Paul V Bernhardt
- Centre for Metals in Biology, Department of Chemistry, University of Queensland, Brisbane, 4072, QLD, Australia.
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