1
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Miller C, Huntoon D, Kaley N, Ogutu I, Fiedler AT, Bennett B, Liu D, Holz R. Role of second-sphere arginine residues in metal binding and metallocentre assembly in nitrile hydratases. J Inorg Biochem 2024; 256:112565. [PMID: 38677005 DOI: 10.1016/j.jinorgbio.2024.112565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/07/2024] [Accepted: 04/13/2024] [Indexed: 04/29/2024]
Abstract
Two conserved second-sphere βArg (R) residues in nitrile hydratases (NHase), that form hydrogen bonds with the catalytically essential sulfenic and sulfinic acid ligands, were mutated to Lys and Ala residues in the Co-type NHase from Pseudonocardia thermophila JCM 3095 (PtNHase) and the Fe-type NHase from Rhodococcus equi TG328-2 (ReNHase). Only five of the eight mutants (PtNHase βR52A, βR52K, βR157A, βR157K and ReNHase βR61A) were successfully expressed and purified. Apart from the PtNHase βR52A mutant that exhibited no detectable activity, the kcat values obtained for the PtNHase and ReNHase βR mutant enzymes were between 1.8 and 12.4 s-1 amounting to <1% of the kcat values observed for WT enzymes. The metal content of each mutant was also significantly decreased with occupancies ranging from ∼10 to ∼40%. UV-Vis spectra coupled with EPR data obtained on the ReNHase mutant enzyme, suggest a decrease in the Lewis acidity of the active site metal ion. X-ray crystal structures of the four PtNHase βR mutant enzymes confirmed the mutation and the low active site metal content, while also providing insight into the active site hydrogen bonding network. Finally, DFT calculations suggest that the equatorial sulfenic acid ligand, which has been shown to be the catalytic nucleophile, is protonated in the mutant enzyme. Taken together, these data confirm the necessity of the conserved second-sphere βR residues in the proposed subunit swapping process and post-translational modification of the α-subunit in the α activator complex, along with stabilizing the catalytic sulfenic acid in its anionic form.
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Affiliation(s)
- Callie Miller
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Delanie Huntoon
- Department of Chemistry, Marquette University, Milwaukee, WI 53233, USA
| | - Nicholas Kaley
- Department of Chemistry and Biochemistry, Loyola University, Chicago, IL 60660, USA
| | - Irene Ogutu
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Adam T Fiedler
- Department of Chemistry, Marquette University, Milwaukee, WI 53233, USA
| | - Brian Bennett
- Department of Physics, Marquette University, Milwaukee, WI 53233, USA
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University, Chicago, IL 60660, USA
| | - Richard Holz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA.
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2
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Dolińska MM, Kirwan AJ, Megarity CF. Retuning the potential of the electrochemical leaf. Faraday Discuss 2024. [PMID: 38848142 DOI: 10.1039/d4fd00020j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
The electrochemical leaf enables the electrification and control of multi-enzyme cascades by exploiting two discoveries: (i) the ability to electrify the photosynthetic enzyme ferredoxin NADP+ reductase (FNR), driving it to catalyse the interconversion of NADP+/NADPH whilst it is entrapped in a highly porous, metal oxide electrode, and (ii) the evidence that additional enzymes can be co-entrapped in the electrode pores where, through one NADP(H)-dependent enzyme, extended cascades can be driven by electrical connection to FNR, via NADP(H) recycling. By changing a critical active-site tyrosine to serine, FNR's exclusivity for NADP(H) is swapped for unphosphorylated NAD(H). Here we present an electrochemical study of this variant FNR, and show that in addition to the intended inversion of cofactor preference, this change to the active site has altered FNR's tuning of the flavin reduction potential, making it less reductive. Exploiting the ability to monitor the variant's activity with NADP(H) as a function of potential has revealed a trapped intermediate state, relieved only by applying a negative overpotential, which allows catalysis to proceed. Inhibition by NADP+ (very tightly bound) with respect to NAD(H) turnover was also revealed and interestingly, this inhibition changes depending on the applied potential. These findings are of critical importance for future exploitation of the electrochemical leaf.
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Affiliation(s)
- Marta M Dolińska
- School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
| | - Adam J Kirwan
- School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
| | - Clare F Megarity
- School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
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3
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Valetti F, Morra S, Barbieri L, Dezzani S, Ratto A, Catucci G, Sadeghi SJ, Gilardi G. Oxygen-resistant [FeFe]hydrogenases: new biocatalysis tools for clean energy and cascade reactions. Faraday Discuss 2024. [PMID: 38836410 DOI: 10.1039/d4fd00010b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The use of enzymes to generate hydrogen, instead of using rare metal catalysts, is an exciting area of study in modern biochemistry and biotechnology, as well as biocatalysis driven by sustainable hydrogen. Thus far, the oxygen sensitivity of the fastest hydrogen-producing/exploiting enzymes, [FeFe]hydrogenases, has hindered their practical application, thereby restricting innovations mainly to their [NiFe]-based, albeit slower, counterparts. Recent exploration of the biodiversity of clostridial hydrogen-producing enzymes has yielded the isolation of representatives from a relatively understudied group. These enzymes possess an inherent defense mechanism against oxygen-induced damage. This discovery unveils fresh opportunities for applications such as electrode interfacing, biofuel cells, immobilization, and entrapment for enhanced stability in practical uses. Furthermore, it suggests potential combinations with cascade reactions for CO2 conversion or cofactor regeneration, like NADPH, facilitating product separation in biotechnological processes. This work provides an overview of this new class of biocatalysts, incorporating unpublished protein engineering strategies to further investigate the dynamic mechanism of oxygen protection and to address crucial details remaining elusive such as still unidentified switching hot-spots and their effects. Variants with improved kcat as well as chimeric versions with promising features to attain gain-of-function variants and applications in various biotechnological processes are also presented.
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Affiliation(s)
- Francesca Valetti
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
| | - Simone Morra
- Faculty of Engineering, University of Nottingham, Nottingham, UK
| | - Lisa Barbieri
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
- University School for Advanced Studies IUSS Pavia, Italy
| | - Sabrina Dezzani
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
- University School for Advanced Studies IUSS Pavia, Italy
| | - Alessandro Ratto
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
| | - Gianluca Catucci
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
| | - Sheila J Sadeghi
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
| | - Gianfranco Gilardi
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
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4
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Shomar H, Bokinsky G. Harnessing iron‑sulfur enzymes for synthetic biology. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119718. [PMID: 38574823 DOI: 10.1016/j.bbamcr.2024.119718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/13/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024]
Abstract
Reactions catalysed by iron-sulfur (Fe-S) enzymes appear in a variety of biosynthetic pathways that produce valuable natural products. Harnessing these biosynthetic pathways by expression in microbial cell factories grown on an industrial scale would yield enormous economic and environmental benefits. However, Fe-S enzymes often become bottlenecks that limits the productivity of engineered pathways. As a consequence, achieving the production metrics required for industrial application remains a distant goal for Fe-S enzyme-dependent pathways. Here, we identify and review three core challenges in harnessing Fe-S enzyme activity, which all stem from the properties of Fe-S clusters: 1) limited Fe-S cluster supply within the host cell, 2) Fe-S cluster instability, and 3) lack of specialized reducing cofactor proteins often required for Fe-S enzyme activity, such as enzyme-specific flavodoxins and ferredoxins. We highlight successful methods developed for a variety of Fe-S enzymes and electron carriers for overcoming these difficulties. We use heterologous nitrogenase expression as a grand case study demonstrating how each of these challenges can be addressed. We predict that recent breakthroughs in protein structure prediction and design will prove well-suited to addressing each of these challenges. A reliable toolkit for harnessing Fe-S enzymes in engineered metabolic pathways will accelerate the development of industry-ready Fe-S enzyme-dependent biosynthesis pathways.
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Affiliation(s)
- Helena Shomar
- Institut Pasteur, université Paris Cité, Inserm U1284, Diversité moléculaire des microbes (Molecular Diversity of Microbes lab), 75015 Paris, France
| | - Gregory Bokinsky
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.
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5
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Giri NC, Mintmier B, Radhakrishnan M, Mielke JW, Wilcoxen J, Basu P. The critical role of a conserved lysine residue in periplasmic nitrate reductase catalyzed reactions. J Biol Inorg Chem 2024:10.1007/s00775-024-02057-x. [PMID: 38782786 DOI: 10.1007/s00775-024-02057-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 04/10/2024] [Indexed: 05/25/2024]
Abstract
Periplasmic nitrate reductase NapA from Campylobacter jejuni (C. jejuni) contains a molybdenum cofactor (Moco) and a 4Fe-4S cluster and catalyzes the reduction of nitrate to nitrite. The reducing equivalent required for the catalysis is transferred from NapC → NapB → NapA. The electron transfer from NapB to NapA occurs through the 4Fe-4S cluster in NapA. C. jejuni NapA has a conserved lysine (K79) between the Mo-cofactor and the 4Fe-4S cluster. K79 forms H-bonding interactions with the 4Fe-4S cluster and connects the latter with the Moco via an H-bonding network. Thus, it is conceivable that K79 could play an important role in the intramolecular electron transfer and the catalytic activity of NapA. In the present study, we show that the mutation of K79 to Ala leads to an almost complete loss of activity, suggesting its role in catalytic activity. The inhibition of C. jejuni NapA by cyanide, thiocyanate, and azide has also been investigated. The inhibition studies indicate that cyanide inhibits NapA in a non-competitive manner, while thiocyanate and azide inhibit NapA in an uncompetitive manner. Neither inhibition mechanism involves direct binding of the inhibitor to the Mo-center. These results have been discussed in the context of the loss of catalytic activity of NapA K79A variant and a possible anion binding site in NapA has been proposed.
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Affiliation(s)
- Nitai C Giri
- Department of Chemistry and Chemical Biology, Indiana University Indianapolis, Indianapolis, IN, USA
| | - Breeanna Mintmier
- Department of Chemistry and Chemical Biology, Indiana University Indianapolis, Indianapolis, IN, USA
| | - Manohar Radhakrishnan
- Department of Chemistry and Chemical Biology, Indiana University Indianapolis, Indianapolis, IN, USA
| | - Jonathan W Mielke
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Jarett Wilcoxen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
| | - Partha Basu
- Department of Chemistry and Chemical Biology, Indiana University Indianapolis, Indianapolis, IN, USA.
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6
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Decembrino D, Cannella D. The thin line between monooxygenases and peroxygenases. P450s, UPOs, MMOs, and LPMOs: A brick to bridge fields of expertise. Biotechnol Adv 2024; 72:108321. [PMID: 38336187 DOI: 10.1016/j.biotechadv.2024.108321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/04/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Many scientific fields, although driven by similar purposes and dealing with similar technologies, often appear so isolated and far from each other that even the vocabularies to describe the very same phenomenon might differ. Concerning the vast field of biocatalysis, a special role is played by those redox enzymes that employ oxygen-based chemistry to unlock transformations otherwise possible only with metal-based catalysts. As such, greener chemical synthesis methods and environmentally-driven biotechnological approaches were enabled over the last decades by the use of several enzymes and ultimately resulted in the first industrial applications. Among what can be called today the environmental biorefinery sector, biomass transformation, greenhouse gas reduction, bio-gas/fuels production, bioremediation, as well as bulk or fine chemicals and even pharmaceuticals manufacturing are all examples of fields in which successful prototypes have been demonstrated employing redox enzymes. In this review we decided to focus on the most prominent enzymes (MMOs, LPMO, P450 and UPO) capable of overcoming the ∼100 kcal mol-1 barrier of inactivated CH bonds for the oxyfunctionalization of organic compounds. Harnessing the enormous potential that lies within these enzymes is of extreme value to develop sustainable industrial schemes and it is still deeply coveted by many within the aforementioned fields of application. Hence, the ambitious scope of this account is to bridge the current cutting-edge knowledge gathered upon each enzyme. By creating a broad comparison, scientists belonging to the different fields may find inspiration and might overcome obstacles already solved by the others. This work is organised in three major parts: a first section will be serving as an introduction to each one of the enzymes regarding their structural and activity diversity, whereas a second one will be encompassing the mechanistic aspects of their catalysis. In this regard, the machineries that lead to analogous catalytic outcomes are depicted, highlighting the major differences and similarities. Finally, a third section will be focusing on the elements that allow the oxyfunctionalization chemistry to occur by delivering redox equivalents to the enzyme by the action of diverse redox partners. Redox partners are often overlooked in comparison to the catalytic counterparts, yet they represent fundamental elements to better understand and further develop practical applications based on mono- and peroxygenases.
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Affiliation(s)
- Davide Decembrino
- Photobiocatalysis Unit - Crop Production and Biostimulation Lab (CPBL), and Biomass Transformation Lab (BTL), École Interfacultaire de Bioingénieurs, Université Libre de Bruxelles, Belgium.
| | - David Cannella
- Photobiocatalysis Unit - Crop Production and Biostimulation Lab (CPBL), and Biomass Transformation Lab (BTL), École Interfacultaire de Bioingénieurs, Université Libre de Bruxelles, Belgium.
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7
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Chinopoulos C. Complex I activity in hypoxia: implications for oncometabolism. Biochem Soc Trans 2024; 52:529-538. [PMID: 38526218 PMCID: PMC11088919 DOI: 10.1042/bst20230189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/06/2024] [Accepted: 03/14/2024] [Indexed: 03/26/2024]
Abstract
Certain cancer cells within solid tumors experience hypoxia, rendering them incapable of oxidative phosphorylation (OXPHOS). Despite this oxygen deficiency, these cells exhibit biochemical pathway activity that relies on NAD+. This mini-review scrutinizes the persistent, residual Complex I activity that oxidizes NADH in the absence of oxygen as the electron acceptor. The resulting NAD+ assumes a pivotal role in fueling the α-ketoglutarate dehydrogenase complex, a critical component in the oxidative decarboxylation branch of glutaminolysis - a hallmark oncometabolic pathway. The proposition is that through glutamine catabolism, high-energy phosphate intermediates are produced via substrate-level phosphorylation in the mitochondrial matrix substantiated by succinyl-CoA ligase, partially compensating for an OXPHOS deficiency. These insights provide a rationale for exploring Complex I inhibitors in cancer treatment, even when OXPHOS functionality is already compromised.
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8
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Kamboj N, Dey A, Birara S, Majumder M, Sengupta S, Metre RK. Designing one-compartment H 2O 2 fuel cell using electroactive phenalenyl-based [Fe 2(hnmh-PLY) 3] complex as the cathode material. Dalton Trans 2024; 53:7152-7162. [PMID: 38572846 DOI: 10.1039/d4dt00134f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
The sustainable chemical energy of H2O2 as a fuel and an oxidant in an advantageous single-compartment fuel cell design can be converted into electric energy, which requires molecular engineering to design suitable cathodes for lowering the high overpotential associated with H2O2 reduction. The present work covers the synthesis and structural characterization of a novel cathode material, [FeIII2(hnmh-PLY)3] complex, 1, designed from a PLY-derived Schiff base ligand (E)-9-(2-((2-hydroxynaphthalen-1-yl)methylene)hydrazineyl)-1H-phenalen-1-one, hnmh-PLYH2. Complex 1, when coated on the surface of a glassy carbon electrode (GC-1) significantly catalyzed the reduction of H2O2 in an acidic medium. Therefore, a complex 1 modified glassy carbon electrode was employed in a one-compartment H2O2 fuel cell operated in 0.1 M HCl with Ni foam as the corresponding anode to produce a high open circuit potential (OCP) of 0.65 V and a peak power density (PPD) of 2.84 mW cm-2. CV studies of complex 1 revealed the crucial participation of two Fe(III) centers for initiating H2O2 reduction, and the role of coordinated redox-active PLY units is also highlighted. In the solid state, the π-conjugated network of coordinating (hnmh-PLY) ligands in complex 1 has manifested interesting face-to-face π-π stacking interactions, which have helped the reduction of the complex and facilitated the overall catalytic performance.
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Affiliation(s)
- Nisha Kamboj
- Department of Chemistry, Indian Institute of Technology Jodhpur, Rajasthan-342030, India.
| | - Ayan Dey
- Department of Metallurgical and Materials Engineering, Indian Institute of Technology Jodhpur, Rajasthan-342030, India.
| | - Sunita Birara
- Department of Chemistry, Indian Institute of Technology Jodhpur, Rajasthan-342030, India.
| | - Moumita Majumder
- Department of Chemistry, School of Science and Environmental Studies, Dr Vishwanath Karad MIT World Peace University, Pune, Maharashtra-411038, India.
| | - Srijan Sengupta
- Department of Metallurgical and Materials Engineering, Indian Institute of Technology Jodhpur, Rajasthan-342030, India.
| | - Ramesh K Metre
- Department of Chemistry, Indian Institute of Technology Jodhpur, Rajasthan-342030, India.
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9
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Kisgeropoulos EC, Artz JH, Blahut M, Peters JW, King PW, Mulder DW. Properties of the iron-sulfur cluster electron transfer relay in an [FeFe]-hydrogenase that is tuned for H 2 oxidation catalysis. J Biol Chem 2024; 300:107292. [PMID: 38636659 PMCID: PMC11126806 DOI: 10.1016/j.jbc.2024.107292] [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: 02/12/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/20/2024] Open
Abstract
[FeFe]-hydrogenases catalyze the reversible oxidation of H2 from electrons and protons at an organometallic active site cofactor named the H-cluster. In addition to the H-cluster, most [FeFe]-hydrogenases possess accessory FeS cluster (F-cluster) relays that function in mediating electron transfer with catalysis. There is significant variation in the structural properties of F-cluster relays among the [FeFe]-hydrogenases; however, it is unknown how this variation relates to the electronic and thermodynamic properties, and thus the electron transfer properties, of enzymes. Clostridium pasteurianum [FeFe]-hydrogenase II (CpII) exhibits a large catalytic bias for H2 oxidation (compared to H2 production), making it a notable system for examining if F-cluster properties contribute to the overall function and efficiency of the enzyme. By applying a combination of multifrequency and potentiometric electron paramagnetic resonance, we resolved two electron paramagnetic resonance signals with distinct power- and temperature-dependent properties at g = 2.058 1.931 1.891 (F2.058) and g = 2.061 1.920 1.887 (F2.061), with assigned midpoint potentials of -140 ± 18 mV and -406 ± 12 mV versus normal hydrogen electrode, respectively. Spectral analysis revealed features consistent with spin-spin coupling between the two [4Fe-4S] F-clusters, and possible functional models are discussed that account for the contribution of coupling to the electron transfer landscape. The results signify the interplay of electronic coupling and free energy properties and parameters of the FeS clusters to the electron transfer mechanism through the relay and provide new insight as to how relays functionally complement the catalytic directionality of active sites to achieve highly efficient catalysis.
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Affiliation(s)
| | - Jacob H Artz
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Matthew Blahut
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - John W Peters
- Department of Chemistry and Biochemistry, The University of Oklahoma, Norman, Oklahoma, USA
| | - Paul W King
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA; Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado Boulder, Boulder, Colorado, USA
| | - David W Mulder
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA.
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10
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Lam Q, Van Stappen C, Lu Y, Dikanov SA. HYSCORE and QM/MM Studies of Second Sphere Variants of the Type 1 Copper Site in Azurin: Influence of Mutations on the Hyperfine Couplings of Remote Nitrogens. J Phys Chem B 2024; 128:3350-3359. [PMID: 38564809 DOI: 10.1021/acs.jpcb.3c08194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Secondary coordination sphere (SCS) interactions have been shown to play important roles in tuning reduction potentials and electron transfer (ET) properties of the Type 1 copper proteins, but the precise roles of these interactions are not fully understood. In this work, we examined the influence of F114P, F114N, and N47S mutations in the SCS on the electronic structure of the T1 copper center in azurin (Az) by studying the hyperfine couplings of (i) histidine remote Nε nitrogens and (ii) the amide Np using the two-dimensional (2D) pulsed electron paramagnetic resonance (EPR) technique HYSCORE (hyperfine sublevel correlation) combined with quantum mechanics/molecular mechanics (QM/MM) and DLPNO-CCSD calculations. Our data show that some components of hyperfine tensor and isotropic coupling in N47SAz and F114PAz (but not F114NAz) deviate by up to ∼±20% from WTAz, indicating that these mutations significantly influence the spin density distribution between the CuII site and coordinating ligands. Furthermore, our calculations support the assignment of Np to the backbone amide of residue 47 (both in Asn and Ser variants). Since the spin density distributions play an important role in tuning the covalency of the Cu-Scys bond of Type 1 copper center that has been shown to be crucial in controlling the reduction potentials, this study provides additional insights into the electron spin factor in tuning the reduction potentials and ET properties.
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Affiliation(s)
- Quan Lam
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Sergei A Dikanov
- Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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11
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Zhong F, Reik ME, Ragusa MJ, Pletneva EV. The structure of the diheme cytochrome c 4 from Neisseria gonorrhoeae reveals multiple contributors to tuning reduction potentials. J Inorg Biochem 2024; 253:112496. [PMID: 38330683 PMCID: PMC11034767 DOI: 10.1016/j.jinorgbio.2024.112496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/10/2024]
Abstract
Cytochrome c4 (c4) is a diheme protein implicated as an electron donor to cbb3 oxidases in multiple pathogenic bacteria. Despite its prevalence, understanding of how specific structural features of c4 optimize its function is lacking. The human pathogen Neisseria gonorrhoeae (Ng) thrives in low oxygen environments owing to the activity of its cbb3 oxidase. Herein, we report characterization of Ng c4. Spectroelectrochemistry experiments of the wild-type (WT) protein have shown that the two Met/His-ligated hemes differ in potentials by ∼100 mV, and studies of the two His/His-ligated variants provided unambiguous assignment of heme A from the N-terminal domain of the protein as the high-potential heme. The crystal structure of the WT protein at 2.45 Å resolution has revealed that the two hemes differ in their solvent accessibility. In particular, interactions made by residues His57 and Ser59 in Loop1 near the axial ligand Met63 contribute to the tight enclosure of heme A, working together with the surface charge, to raise the reduction potential of the heme iron in this domain. The structure reveals a prominent positively-charged patch, which encompasses surfaces of both domains. In contrast to prior findings with c4 from Pseudomonas stutzeri, the interdomain interface of Ng c4 contributes minimally to the values of the heme iron potentials in the two domains. Analyses of the heme solvent accessibility, interface properties, and surface charges offer insights into the interplay of these structural elements in tuning redox properties of c4 and other multiheme proteins.
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Affiliation(s)
- Fangfang Zhong
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, United States
| | - Morgan E Reik
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, United States
| | - Michael J Ragusa
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, United States
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12
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Polanco EA, Opdam LV, Passerini L, Huber M, Bonnet S, Pandit A. An artificial metalloenzyme that can oxidize water photocatalytically: design, synthesis, and characterization. Chem Sci 2024; 15:3596-3609. [PMID: 38455019 PMCID: PMC10915814 DOI: 10.1039/d3sc05870k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/29/2024] [Indexed: 03/09/2024] Open
Abstract
In nature, light-driven water oxidation (WO) catalysis is performed by photosystem II via the delicate interplay of different cofactors positioned in its protein scaffold. Artificial systems for homogeneous photocatalytic WO are based on small molecules that often have limited solubility in aqueous solutions. In this work, we alleviated this issue and present a cobalt-based WO-catalyst containing artificial metalloenzyme (ArM) that is active in light-driven, homogeneous WO catalysis in neutral-pH aqueous solutions. A haem-containing electron transfer protein, cytochrome B5 (CB5), served to host a first-row transition-metal-based WO catalyst, CoSalen (CoIISalen, where H2Salen = N,N'-bis(salicylidene)ethylenediamine), thus producing an ArM capable of driving photocatalytic WO. The CoSalen ArM formed a water-soluble pre-catalyst in the presence of [Ru(bpy)3](ClO4)2 as photosensitizer and Na2S2O8 as the sacrificial electron acceptor, with photocatalytic activity similar to that of free CoSalen. During photocatalysis, the CoSalen-protein interactions were destabilized, and the protein partially unfolded. Rather than forming tens of nanometer sized CoOx nanoparticles as free CoSalen does under photocatalytic WO conditions, the CB5 : CoSalen ArM showed limited protein cross-linking and remained soluble. We conclude that a weak, dynamic interaction between a soluble cobalt species and apoCB5 was formed, which generated a catalytically active adduct during photocatalysis. A detailed analysis was performed on protein stability and decomposition processes during the harsh oxidizing reaction conditions of WO, which will serve for the future design of WO ArMs with improved activity and stability.
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Affiliation(s)
- Ehider A Polanco
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Laura V Opdam
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Leonardo Passerini
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University Niels Bohrweg 2 2333 CA Leiden The Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University Niels Bohrweg 2 2333 CA Leiden The Netherlands
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Anjali Pandit
- Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
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13
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Oliveira AS, Rubio J, Noble CEM, Anderson JLR, Anders J, Mulholland AJ. Fluctuation Relations to Calculate Protein Redox Potentials from Molecular Dynamics Simulations. J Chem Theory Comput 2024; 20:385-395. [PMID: 38150288 PMCID: PMC10782445 DOI: 10.1021/acs.jctc.3c00785] [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: 07/19/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/28/2023]
Abstract
The tunable design of protein redox potentials promises to open a range of applications in biotechnology and catalysis. Here, we introduce a method to calculate redox potential changes by combining fluctuation relations with molecular dynamics simulations. It involves the simulation of reduced and oxidized states, followed by the instantaneous conversion between them. Energy differences introduced by the perturbations are obtained using the Kubo-Onsager approach. Using a detailed fluctuation relation coupled with Bayesian inference, these are postprocessed into estimates for the redox potentials in an efficient manner. This new method, denoted MD + CB, is tested on a de novo four-helix bundle heme protein (the m4D2 "maquette") and five designed mutants, including some mutants characterized experimentally in this work. The MD + CB approach is found to perform reliably, giving redox potential shifts with reasonably good correlation (0.85) to the experimental values for the mutants. The MD + CB approach also compares well with redox potential shift predictions using a continuum electrostatic method. The estimation method employed within the MD + CB approach is straightforwardly transferable to standard equilibrium MD simulations and holds promise for redox protein engineering and design applications.
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Affiliation(s)
- A. S.
F. Oliveira
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
- School
of Biochemistry, University of Bristol, Bristol BS8 1DT, U.K.
- BrisSynBio
Synthetic Biology Research Centre, University
of Bristol, Bristol BS8 1TQ, U.K.
| | - J. Rubio
- School
of Mathematics and Physics, University of
Surrey, Guildford GU2 7XH, U.K.
- Department
of Physics and Astronomy, University of
Exeter, Stocker Road, Exeter EX4
4QL, U.K.
| | - C. E. M. Noble
- School
of Biochemistry, University of Bristol, Bristol BS8 1DT, U.K.
- BrisSynBio
Synthetic Biology Research Centre, University
of Bristol, Bristol BS8 1TQ, U.K.
| | - J. L. R. Anderson
- School
of Biochemistry, University of Bristol, Bristol BS8 1DT, U.K.
- BrisSynBio
Synthetic Biology Research Centre, University
of Bristol, Bristol BS8 1TQ, U.K.
| | - J. Anders
- Department
of Physics and Astronomy, University of
Exeter, Stocker Road, Exeter EX4
4QL, U.K.
- Institute
of Physics and Astronomy, University of
Potsdam, Potsdam 14476, Germany
| | - A. J. Mulholland
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
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14
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Marciesky M, Aga DS, Bradley IM, Aich N, Ng C. Mechanisms and Opportunities for Rational In Silico Design of Enzymes to Degrade Per- and Polyfluoroalkyl Substances (PFAS). J Chem Inf Model 2023; 63:7299-7319. [PMID: 37981739 PMCID: PMC10716909 DOI: 10.1021/acs.jcim.3c01303] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/21/2023]
Abstract
Per and polyfluoroalkyl substances (PFAS) present a unique challenge to remediation techniques because their strong carbon-fluorine bonds make them difficult to degrade. This review explores the use of in silico enzymatic design as a potential PFAS degradation technique. The scope of the enzymes included is based on currently known PFAS degradation techniques, including chemical redox systems that have been studied for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) defluorination, such as those that incorporate hydrated electrons, sulfate, peroxide, and metal catalysts. Bioremediation techniques are also discussed, namely the laccase and horseradish peroxidase systems. The redox potential of known reactants and enzymatic radicals/metal-complexes are then considered and compared to potential enzymes for degrading PFAS. The molecular structure and reaction cycle of prospective enzymes are explored. Current knowledge and techniques of enzyme design, particularly radical-generating enzymes, and application are also discussed. Finally, potential routes for bioengineering enzymes to enable or enhance PFAS remediation are considered as well as the future outlook for computational exploration of enzymatic in situ bioremediation routes for these highly persistent and globally distributed contaminants.
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Affiliation(s)
- Melissa Marciesky
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Diana S Aga
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Ian M Bradley
- Department of Civil, Structural, and Environmental Engineering, State University of New York at Buffalo, Buffalo, New York 14228, United States
- Research and Education in Energy, Environmental and Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Nirupam Aich
- Department of Civil and Environmental Engineering, University of Nebraska─Lincoln, Lincoln, Nebraska 68588-0531, United States
| | - Carla Ng
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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15
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de Lira-Sánchez JA, Esparza-Perusquía M, Martínez F, Pardo JP, Flores-Herrera O. Heavy metals do not induce ROS production by mitochondrial respirasome. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148999. [PMID: 37516232 DOI: 10.1016/j.bbabio.2023.148999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/21/2023] [Accepted: 07/24/2023] [Indexed: 07/31/2023]
Affiliation(s)
- Jaime A de Lira-Sánchez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | - Mercedes Esparza-Perusquía
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | - Federico Martínez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | - Juan P Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | - Oscar Flores-Herrera
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico.
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16
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Fernandes TM, Silva MA, Morgado L, Salgueiro CA. Hemes on a string: insights on the functional mechanisms of PgcA from Geobacter sulfurreducens. J Biol Chem 2023; 299:105167. [PMID: 37595873 PMCID: PMC10570954 DOI: 10.1016/j.jbc.2023.105167] [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: 05/24/2023] [Revised: 08/05/2023] [Accepted: 08/10/2023] [Indexed: 08/20/2023] Open
Abstract
Microbial extracellular reduction of insoluble compounds requires soluble electron shuttles that diffuse in the environment, freely diffusing cytochromes, or direct contact with cellular conductive appendages that release or harvest electrons to assure a continuous balance between cellular requirements and environmental conditions. In this work, we produced and characterized the three cytochrome domains of PgcA, an extracellular triheme cytochrome that contributes to Fe(III) and Mn(IV) oxides reduction in Geobacter sulfurreducens. The three monoheme domains are structurally homologous, but their heme groups show variable axial coordination and reduction potential values. Electron transfer experiments monitored by NMR and visible spectroscopy show the variable extent to which the domains promiscuously exchange electrons while reducing different electron acceptors. The results suggest that PgcA is part of a new class of cytochromes - microbial heme-tethered redox strings - that use low-complexity protein stretches to bind metals and promote intra- and intermolecular electron transfer events through its cytochrome domains.
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Affiliation(s)
- Tomás M Fernandes
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Marta A Silva
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Leonor Morgado
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
| | - Carlos A Salgueiro
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
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17
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Van Stappen C, Dai H, Jose A, Tian S, Solomon EI, Lu Y. Primary and Secondary Coordination Sphere Effects on the Structure and Function of S-Nitrosylating Azurin. J Am Chem Soc 2023; 145:20610-20623. [PMID: 37696009 PMCID: PMC10539042 DOI: 10.1021/jacs.3c07399] [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] [Indexed: 09/13/2023]
Abstract
Much progress has been made in understanding the roles of the secondary coordination sphere (SCS) in tuning redox potentials of metalloproteins. In contrast, the impact of SCS on reactivity is much less understood. A primary example is how copper proteins can promote S-nitrosylation (SNO), which is one of the most important dynamic post-translational modifications, and is crucial in regulating nitric oxide storage and transportation. Specifically, the factors that instill CuII with S-nitrosylating capabilities and modulate activity are not well understood. To address this issue, we investigated the influence of the primary and secondary coordination sphere on CuII-catalyzed S-nitrosylation by developing a series of azurin variants with varying catalytic capabilities. We have employed a multidimensional approach involving electronic absorption, S and Cu K-edge XAS, EPR, and resonance Raman spectroscopies together with QM/MM computational analysis to examine the relationships between structure and molecular mechanism in this reaction. Our findings have revealed that kinetic competency is correlated with three balancing factors, namely Cu-S bond strength, Cu spin localization, and relative S(ps) vs S(pp) contributions to the ground state. Together, these results support a reaction pathway that proceeds through the attack of the Cu-S bond rather than electrophilic addition to CuII or radical attack of SCys. The insights gained from this work provide not only a deeper understanding of SNO in biology but also a basis for designing artificial and tunable SNO enzymes to regulate NO and prevent diseases due to SNO dysregulation.
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Affiliation(s)
- Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, 105 E 24th St., Austin, Texas 78712, United States
| | - Huiguang Dai
- Department of Chemistry, University of Texas at Austin, 105 E 24th St., Austin, Texas 78712, United States
- Department of Chemistry, University of Urbana-Champaign, Champaign, Illinois 61801, United States
| | - Anex Jose
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Shiliang Tian
- Department of Chemistry, University of Urbana-Champaign, Champaign, Illinois 61801, United States
| | - Edward I Solomon
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, 105 E 24th St., Austin, Texas 78712, United States
- Department of Chemistry, University of Urbana-Champaign, Champaign, Illinois 61801, United States
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18
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Gurhan H, Barnes F. Impact of weak radiofrequency and static magnetic fields on key signaling molecules, intracellular pH, membrane potential, and cell growth in HT-1080 fibrosarcoma cells. Sci Rep 2023; 13:14223. [PMID: 37648766 PMCID: PMC10469173 DOI: 10.1038/s41598-023-41167-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/23/2023] [Indexed: 09/01/2023] Open
Abstract
There are substantial concerns that extended exposures to weak radiofrequency (RF) fields can lead to adverse health effects. In this study, HT-1080 fibrosarcoma cells were simultaneously exposed to a static magnetic flux density between 10 [Formula: see text] and 300 [Formula: see text] and RF magnetic fields with amplitudes ranging from 1 nT to 1.5 μT in the frequency range from 1.8 to 7.2 MHz for four days. Cell growth rates, intracellular pH, hydrogen peroxide, peroxynitrite, membrane potential and mitochondrial calcium were measured. Results were dependent on carrier frequency and the magnitude of the RF magnetic field, modulation frequencies and the background static magnetic field (SMF). Iron sulphur (Fe-S) clusters are essential for the generation of reactive oxygen species and reactive nitrogen species (ROS and RNS). We believe the observed changes are associated with hyperfine couplings between the chemically active electrons and nuclear spins. Controlling external magnetic fields may have important clinical implications on aging, cancer, arthritis, and Alzheimer's.
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Affiliation(s)
- Hakki Gurhan
- Department of Electrical, Computer and Energy Engineering, University of Colorado at Boulder, 425 UCB #1B55, Boulder, CO, 80309, USA.
| | - Frank Barnes
- Department of Electrical, Computer and Energy Engineering, University of Colorado at Boulder, 425 UCB #1B55, Boulder, CO, 80309, USA
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19
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Guberman-Pfeffer MJ. Structural Determinants of Redox Conduction Favor Robustness over Tunability in Microbial Cytochrome Nanowires. J Phys Chem B 2023; 127:7148-7161. [PMID: 37552847 DOI: 10.1021/acs.jpcb.3c02912] [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] [Indexed: 08/10/2023]
Abstract
Structural determinants of a 103-fold variation in electrical conductivity for helical homopolymers of tetra-, hexa-, and octa-heme cytochromes (named Omc- E, S, and Z, respectively) from Geobacter sulfurreducens are investigated with the Pathways model for electron tunneling, classical molecular dynamics, and hybrid quantum/classical molecular mechanics. Thermally averaged electronic couplings for through-space heme-to-heme electron transfer in the "nanowires" computed with density functional theory are ≤0.015 eV. Pathways analyses also indicate that couplings match within a factor of 5 for all "nanowires", but some alternative tunneling routes are found involving covalent protein backbone bonds (Omc- S and Z) or propionic acid-ligating His H-bonds on adjacent hemes (OmcZ). Reorganization energies computed from electrostatic vertical energy gaps or a version of the Marcus continuum expression parameterized on the total (donor + acceptor) solvent-accessible surface area typically agree within 20% and fall within the range 0.48-0.98 eV. Reaction free energies in all three "nanowires" are ≤|0.28| eV, even though Coulombic interactions primarily tune the site redox energies by 0.7-1.2 eV. Given the conserved energetic parameters, redox conductivity differs by < 103-fold among the cytochrome "nanowires". Redox currents do not exceed 3.0 × 10-3 pA at a physiologically relevant 0.1 V bias, with the slowest electron transfers being on a (μs) timescale much faster than typical (ms) enzymatic turnovers. Thus, the "nanowires" are proposed to be functionally robust to variations in structure that provide a habitat-customized protein interface. The 30 pA to 30 nA variation in conductivity previously reported from atomic force microscopy experiments is not intrinsic to the structures and/or does not result from the physiologically relevant redox conduction mechanism.
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Affiliation(s)
- Matthew J Guberman-Pfeffer
- Department of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar Street, New Haven, Connecticut 06510, United States
- Microbial Sciences Institute, Yale University, 840 West Campus Drive, West Haven, Connecticut 06516, United States
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20
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Sousa RAL, Yehia A, Abulseoud OA. Attenuation of ferroptosis as a potential therapeutic target for neuropsychiatric manifestations of post-COVID syndrome. Front Neurosci 2023; 17:1237153. [PMID: 37554293 PMCID: PMC10405289 DOI: 10.3389/fnins.2023.1237153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/10/2023] [Indexed: 08/10/2023] Open
Abstract
Coronavirus disease-19 (COVID-19), caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), is associated with the persistence of pre-existing or the emergence of new neurological and psychiatric manifestations as a part of a multi-system affection known collectively as "post-COVID syndrome." Cognitive decline is the most prominent feature among these manifestations. The underlying neurobiological mechanisms remain under intense investigation. Ferroptosis is a form of cell death that results from the excessive accumulation of intracellular reactive iron, which mediates lipid peroxidation. The accumulation of lipid-based reactive oxygen species (ROS) and the impairment of glutathione peroxidase 4 (GPX4) activity trigger ferroptosis. The COVID-19-associated cytokine storm enhances the levels of circulating pro-inflammatory cytokines and causes immune-cell hyper-activation that is tightly linked to iron dysregulation. Severe COVID-19 presents with iron overload as one of the main features of its pathogenesis. Iron overload promotes a state of inflammation and immune dysfunction. This is well demonstrated by the strong association between COVID-19 severity and high levels of ferritin, which is a well-known inflammatory and iron overload biomarker. The dysregulation of iron, the high levels of lipid peroxidation biomarkers, and the inactivation of GPX4 in COVID-19 patients make a strong case for ferroptosis as a potential mechanism behind post-COVID neuropsychiatric deficits. Therefore, here we review the characteristics of iron and the attenuation of ferroptosis as a potential therapeutic target for neuropsychiatric post-COVID syndrome.
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Affiliation(s)
- Ricardo A. L. Sousa
- Department of Psychiatry and Psychology, Mayo Clinic Arizona, Phoenix, AZ, United States
| | - Asmaa Yehia
- Department of Psychiatry and Psychology, Mayo Clinic Arizona, Phoenix, AZ, United States
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Osama A. Abulseoud
- Department of Psychiatry and Psychology, Mayo Clinic Arizona, Phoenix, AZ, United States
- Department of Neuroscience, Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Phoenix, AZ, United States
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21
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Gaynor RB, McIntyre BN, Lindsey SL, Clavo KA, Shy WE, Mees DE, Mu G, Donnadieu B, Creutz SE. Steric Effects on the Chelation of Mn 2+ and Zn 2+ by Hexadentate Polyimidazole Ligands: Modeling Metal Binding by Calprotectin Site 2. Chemistry 2023; 29:e202300447. [PMID: 37067464 PMCID: PMC10640917 DOI: 10.1002/chem.202300447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 04/18/2023]
Abstract
Recently, there has been increasing interest in the design of ligands that bind Mn2+ with high affinity and selectivity, but this remains a difficult challenge. It has been proposed that the cavity size of the binding pocket is a critical factor in most synthetic and biological examples of selective Mn2+ binding. Here, we use a bioinspired approach adapted from the hexahistidine binding site of the manganese-sequestering protein calprotectin to systematically study the effect of cavity size on Mn2+ and Zn2+ binding. We have designed a hexadentate, trisimidazole ligand whose cavity size can be tuned through peripheral modification of the steric bulk of the imidazole substituents. Conformational dynamics and redox potentials of the complexes are dependent on ligand steric bulk. Stability constants are consistent with the hypothesis that larger ligand cavities are relatively favorable for Mn2+ over Zn2+ , but this effect alone may not be sufficient to achieve Mn2+ selectivity.
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Affiliation(s)
- Ryan B Gaynor
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Baylee N McIntyre
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Shelby L Lindsey
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Kaylee A Clavo
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - William E Shy
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - David E Mees
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Ge Mu
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Bruno Donnadieu
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Sidney E Creutz
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
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22
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Chino M, Di Costanzo LF, Leone L, La Gatta S, Famulari A, Chiesa M, Lombardi A, Pavone V. Designed Rubredoxin miniature in a fully artificial electron chain triggered by visible light. Nat Commun 2023; 14:2368. [PMID: 37185349 PMCID: PMC10130062 DOI: 10.1038/s41467-023-37941-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Designing metal sites into de novo proteins has significantly improved, recently. However, identifying the minimal coordination spheres, able to encompass the necessary information for metal binding and activity, still represents a great challenge, today. Here, we test our understanding with a benchmark, nevertheless difficult, case. We assemble into a miniature 28-residue protein, the quintessential elements required to fold properly around a FeCys4 redox center, and to function efficiently in electron-transfer. This study addresses a challenge in de novo protein design, as it reports the crystal structure of a designed tetra-thiolate metal-binding protein in sub-Å agreement with the intended design. This allows us to well correlate structure to spectroscopic and electrochemical properties. Given its high reduction potential compared to natural and designed FeCys4-containing proteins, we exploit it as terminal electron acceptor of a fully artificial chain triggered by visible light.
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Affiliation(s)
- Marco Chino
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Luigi Franklin Di Costanzo
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055, Portici, Italy
| | - Linda Leone
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Salvatore La Gatta
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Antonino Famulari
- Department of Chemistry, University of Torino, Via Giuria 9, 10125, Torino, Italy
- Department of Condensed Matter Physics, University of Zaragoza, Calle Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Mario Chiesa
- Department of Chemistry, University of Torino, Via Giuria 9, 10125, Torino, Italy
| | - Angela Lombardi
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy.
| | - Vincenzo Pavone
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy.
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23
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Barrera J, H Haeri H, Heinrich J, Stein M, Hinderberger D, Kulak N. Impact of N-heteroaromatic N-termini in Cu(II) ATCUN metallopeptides on their biorelevant redox activity. Dalton Trans 2023; 52:3279-3286. [PMID: 36633467 DOI: 10.1039/d2dt02044k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cu(II) complexes with ATCUN peptide ligands have been investigated for their ROS (reactive oxygen species) generation and oxidative DNA degradation abilities. The biological activity of most ATCUN complexes such as Cu-GGH (Gly-Gly-His) is, however, low. Tuning the redox chemistry by incorporation of N-heteroaromatics reinstates ROS production which leads to efficient DNA cleavage.
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Affiliation(s)
- Jannis Barrera
- Institute of Chemistry, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany. .,Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Haleh H Haeri
- Institute of Chemistry, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle, Germany
| | - Julian Heinrich
- Institute of Chemistry, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
| | - Matthias Stein
- Max Planck Institute for Dynamics of Complex Technical Systems, Molecular Simulations and Design Group, Sandtorstrasse 1, 39106 Magdeburg, Germany
| | - Dariush Hinderberger
- Institute of Chemistry, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle, Germany
| | - Nora Kulak
- Institute of Chemistry, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
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24
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Abstract
Significance: The significance of ferroptosis in cancer therapeutics has now been unveiled. Specific ferroptosis inducers are expected as a promising strategy for cancer treatment, especially in cancers with epithelial mesenchymal transition and possibly in cancers with activated Hippo signaling pathways, both of which cause resistance to traditional chemotherapy but tend to show ferroptosis susceptibility. Recent Advances: Ferroptosis is a new form of regulated non-apoptotic cell death, which is characterized by iron-dependent lipid peroxidation, leading eventually to plasma membrane rupture. Its core mechanisms have been elucidated, consisting of a driving force as catalytic Fe(II)-dependent Fenton reaction and an incorporation of polyunsaturated fatty acids to membrane phospholipids via peroxisome-dependent and -independent pathways, and suppressing factors as prevention of lipid peroxidation with glutathione peroxidase 4 and direct membrane repair via coenzyme Q10 and ESCRT-III pathways. Critical Issues: Developments of ferroptosis inducers are in progress by nanotechnology-based drugs or by innovative engineering devices. Especially, low-temperature (non-thermal) plasma is a novel technology at the preclinical stage. The exposure can induce ferroptosis selectively in cancer cells rich in catalytic Fe(II). Future Directions: We also summarize and discuss the recently uncovered responsible molecular mechanisms in association with iron metabolism, ferroptosis and cancer therapeutics. Targeting ferroptosis in addition to the current therapeutic modalities would be important to cure advanced-stage cancer.
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Affiliation(s)
- Yashiro Motooka
- Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinya Toyokuni
- Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Biosystem Science Division, Center for Low-Temperature Plasma Sciences, Nagoya University, Nagoya, Japan
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25
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Čapek J, Večerek B. Why is manganese so valuable to bacterial pathogens? Front Cell Infect Microbiol 2023; 13:943390. [PMID: 36816586 PMCID: PMC9936198 DOI: 10.3389/fcimb.2023.943390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 01/04/2023] [Indexed: 02/05/2023] Open
Abstract
Apart from oxygenic photosynthesis, the extent of manganese utilization in bacteria varies from species to species and also appears to depend on external conditions. This observation is in striking contrast to iron, which is similar to manganese but essential for the vast majority of bacteria. To adequately explain the role of manganese in pathogens, we first present in this review that the accumulation of molecular oxygen in the Earth's atmosphere was a key event that linked manganese utilization to iron utilization and put pressure on the use of manganese in general. We devote a large part of our contribution to explanation of how molecular oxygen interferes with iron so that it enhances oxidative stress in cells, and how bacteria have learned to control the concentration of free iron in the cytosol. The functioning of iron in the presence of molecular oxygen serves as a springboard for a fundamental understanding of why manganese is so valued by bacterial pathogens. The bulk of this review addresses how manganese can replace iron in enzymes. Redox-active enzymes must cope with the higher redox potential of manganese compared to iron. Therefore, specific manganese-dependent isoenzymes have evolved that either lower the redox potential of the bound metal or use a stronger oxidant. In contrast, redox-inactive enzymes can exchange the metal directly within the individual active site, so no isoenzymes are required. It appears that in the physiological context, only redox-inactive mononuclear or dinuclear enzymes are capable of replacing iron with manganese within the same active site. In both cases, cytosolic conditions play an important role in the selection of the metal used. In conclusion, we summarize both well-characterized and less-studied mechanisms of the tug-of-war for manganese between host and pathogen.
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Affiliation(s)
- Jan Čapek
- *Correspondence: Jan Čapek, ; Branislav Večerek,
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26
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Guberman-Pfeffer MJ. Structural Determinants of Redox Conduction Favor Robustness over Tunability in Microbial Cytochrome Nanowires. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.21.525004. [PMID: 36712098 PMCID: PMC9882360 DOI: 10.1101/2023.01.21.525004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Helical homopolymers of multiheme cytochromes catalyze biogeochemically significant electron transfers with a reported 10 3 -fold variation in conductivity. Herein, classical molecular dynamics and hybrid quantum/classical molecular mechanics are used to elucidate the structural determinants of the redox potentials and conductivities of the tetra-, hexa-, and octaheme outer-membrane cytochromes E, S, and Z, respectively, from Geobacter sulfurreducens . Second-sphere electrostatic interactions acting on minimally polarized heme centers are found to regulate redox potentials over a computed 0.5-V range. However, the energetics of redox conduction are largely robust to the structural diversity: Single-step electronic couplings (⟨H mn ⟩), reaction free energies , and reorganization energies (λ mn ) are always respectively <|0.026|, <|0.26|, and between 0.5 - 1.0 eV. With these conserved parameter ranges, redox conductivity differed by less than a factor of 10 among the 'nanowires' and is sufficient to meet the demands of cellular respiration if 10 2 - 10 3 'nanowires' are expressed. The 'nanowires' are proposed to be differentiated by the protein packaging to interface with a great variety of environments, and not by conductivity, because the rate-limiting electron transfers are elsewhere in the respiratory process. Conducting-probe atomic force microscopy measurements that find conductivities 10 3 -10 6 -fold more than cellular demands are suggested to report on functionality that is either not used or not accessible under physiological conditions. The experimentally measured difference in conductivity between Omc- S and Z is suggested to not be an intrinsic feature of the CryoEM-resolved structures.
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Affiliation(s)
- Matthew J. Guberman-Pfeffer
- Department of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar St., New Haven, CT, 06510
- Microbial Sciences Institute, Yale University, 840 West Campus Drive, West Haven, CT, 06516
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27
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Gilep A, Varaksa T, Bukhdruker S, Kavaleuski A, Ryzhykau Y, Smolskaya S, Sushko T, Tsumoto K, Grabovec I, Kapranov I, Okhrimenko I, Marin E, Shevtsov M, Mishin A, Kovalev K, Kuklin A, Gordeliy V, Kaluzhskiy L, Gnedenko O, Yablokov E, Ivanov A, Borshchevskiy V, Strushkevich N. Structural insights into 3Fe-4S ferredoxins diversity in M. tuberculosis highlighted by a first redox complex with P450. Front Mol Biosci 2023; 9:1100032. [PMID: 36699703 PMCID: PMC9868604 DOI: 10.3389/fmolb.2022.1100032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 12/21/2022] [Indexed: 01/11/2023] Open
Abstract
Ferredoxins are small iron-sulfur proteins and key players in essential metabolic pathways. Among all types, 3Fe-4S ferredoxins are less studied mostly due to anaerobic requirements. Their complexes with cytochrome P450 redox partners have not been structurally characterized. In the present work, we solved the structures of both 3Fe-4S ferredoxins from M. tuberculosis-Fdx alone and the fusion FdxE-CYP143. Our SPR analysis demonstrated a high-affinity binding of FdxE to CYP143. According to SAXS data, the same complex is present in solution. The structure reveals extended multipoint interactions and the shape/charge complementarity of redox partners. Furthermore, FdxE binding induced conformational changes in CYP143 as evident from the solved CYP143 structure alone. The comparison of FdxE-CYP143 and modeled Fdx-CYP51 complexes further revealed the specificity of ferredoxins. Our results illuminate the diversity of electron transfer complexes for the production of different secondary metabolites.
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Affiliation(s)
- Andrei Gilep
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus,Laboratory of Intermolecular Interactions, Institute of Biomedical Chemistry, Moscow, Russia
| | - Tatsiana Varaksa
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Sergey Bukhdruker
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Anton Kavaleuski
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Yury Ryzhykau
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia,Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Sviatlana Smolskaya
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Tatsiana Sushko
- Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Kouhei Tsumoto
- Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo, Japan,Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Irina Grabovec
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Ivan Kapranov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Ivan Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Egor Marin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Mikhail Shevtsov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Alexey Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Kirill Kovalev
- European Molecular Biology Laboratory, Hamburg Unit C/O DESY, Hamburg, Germany
| | - Alexander Kuklin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia,Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Valentin Gordeliy
- Institute of Crystallography, University of Aachen (RWTH), Aachen, Germany
| | - Leonid Kaluzhskiy
- Laboratory of Intermolecular Interactions, Institute of Biomedical Chemistry, Moscow, Russia
| | - Oksana Gnedenko
- Laboratory of Intermolecular Interactions, Institute of Biomedical Chemistry, Moscow, Russia
| | - Evgeniy Yablokov
- Laboratory of Intermolecular Interactions, Institute of Biomedical Chemistry, Moscow, Russia
| | - Alexis Ivanov
- Laboratory of Intermolecular Interactions, Institute of Biomedical Chemistry, Moscow, Russia
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia,Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia,*Correspondence: Valentin Borshchevskiy, ; Natallia Strushkevich,
| | - Natallia Strushkevich
- Skolkovo Institute of Science and Technology, Moscow, Russia,*Correspondence: Valentin Borshchevskiy, ; Natallia Strushkevich,
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28
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Solomon LA, Witten J, Kodali G, Moser CC, Dutton PL. Tailorable Tetrahelical Bundles as a Toolkit for Redox Studies. J Phys Chem B 2022; 126:8177-8187. [PMID: 36219580 PMCID: PMC9589594 DOI: 10.1021/acs.jpcb.2c05119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Oxidoreductases have evolved over millions of years to perform a variety of metabolic tasks crucial for life. Understanding how these tasks are engineered relies on delivering external electron donors or acceptors to initiate electron transfer reactions. This is a challenge. Small-molecule redox reagents can act indiscriminately, poisoning the cell. Natural redox proteins are more selective, but finding the right partner can be difficult due to the limited number of redox potentials and difficulty tuning them. De novo proteins offer an alternative path. They are robust and can withstand mutations that allow for tailorable changes. They are also devoid of evolutionary artifacts and readily bind redox cofactors. However, no reliable set of engineering principles have been developed that allow for these proteins to be fine-tuned so their redox midpoint potential (Em) can form donor/acceptor pairs with any natural oxidoreductase. This work dissects protein-cofactor interactions that can be tuned to modulate redox potentials of acceptors and donors using a mutable de novo designed tetrahelical protein platform with iron tetrapyrrole cofactors as a test case. We show a series of engineered heme b-binding de novo proteins and quantify their resulting effect on Em. By focusing on the surface charge and buried charges, as well as cofactor placement, chemical modification, and ligation of cofactors, we are able to achieve a broad range of Em values spanning a range of 330 mV. We anticipate this work will guide the design of proteinaceous tools that can interface with natural oxidoreductases inside and outside the cell while shedding light on how natural proteins modulate Em values of bound cofactors.
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Affiliation(s)
- Lee A. Solomon
- Department
of Chemistry and Biochemistry, George Mason
University, Fairfax, Virginia22030, United States,
| | - Joshua Witten
- Department
of Biology, George Mason University, Fairfax, Virginia22030, United States
| | - Goutham Kodali
- Department
of Biochemistry and Biophysics, University
of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Christopher C. Moser
- Department
of Biochemistry and Biophysics, University
of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - P. Leslie Dutton
- Department
of Biochemistry and Biophysics, University
of Pennsylvania, Philadelphia, Pennsylvania19104, United States
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29
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Barber-Zucker S, Mateljak I, Goldsmith M, Kupervaser M, Alcalde M, Fleishman SJ. Designed High-Redox Potential Laccases Exhibit High Functional Diversity. ACS Catal 2022; 12:13164-13173. [PMID: 36366766 PMCID: PMC9638991 DOI: 10.1021/acscatal.2c03006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/29/2022] [Indexed: 11/29/2022]
Abstract
![]()
White-rot fungi secrete an impressive repertoire of high-redox
potential laccases (HRPLs) and peroxidases for efficient oxidation
and utilization of lignin. Laccases are attractive enzymes for the
chemical industry due to their broad substrate range and low environmental
impact. Since expression of functional recombinant HRPLs is challenging,
however, iterative-directed evolution protocols have been applied
to improve their expression, activity, and stability. We implement
a rational, stabilize-and-diversify strategy to two HRPLs that we
could not functionally express. First, we use the PROSS stability-design
algorithm to allow functional expression in yeast. Second, we use
the stabilized enzymes as starting points for FuncLib active-site
design to improve their activity and substrate diversity. Four of
the FuncLib-designed HRPLs and their PROSS progenitor exhibit substantial
diversity in reactivity profiles against high-redox potential substrates,
including lignin monomers. Combinations of 3–4 subtle mutations
that change the polarity, solvation, and sterics of the substrate-oxidation
site result in orders of magnitude changes in reactivity profiles.
These stable and versatile HRPLs are a step toward generating an effective
lignin-degrading consortium of enzymes that can be secreted from yeast.
The stabilize-and-diversify strategy can be applied to other challenging
enzyme families to study and expand the utility of natural enzymes.
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Affiliation(s)
- Shiran Barber-Zucker
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Ivan Mateljak
- Department of Biocatalysis, Institute of Catalysis, CSIC, Cantoblanco, Madrid 28049, Spain
- EvoEnzyme S.L., Parque Científico de Madrid, C/Faraday, 7, Campus de Cantoblanco, Madrid 28049, Spain
| | - Moshe Goldsmith
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Meital Kupervaser
- Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Miguel Alcalde
- Department of Biocatalysis, Institute of Catalysis, CSIC, Cantoblanco, Madrid 28049, Spain
| | - Sarel J. Fleishman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
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30
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Piper SEH, Casadevall C, Reisner E, Clarke TA, Jeuken LJC, Gates AJ, Butt JN. Photocatalytic Removal of the Greenhouse Gas Nitrous Oxide by Liposomal Microreactors. Angew Chem Int Ed Engl 2022; 61:e202210572. [PMID: 35951464 PMCID: PMC9825952 DOI: 10.1002/anie.202210572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Indexed: 01/11/2023]
Abstract
Nitrous oxide (N2 O) is a potent greenhouse and ozone-reactive gas for which emissions are growing rapidly due to increasingly intensive agriculture. Synthetic catalysts for N2 O decomposition typically contain precious metals and/or operate at elevated temperatures driving a desire for more sustainable alternatives. Here we demonstrate self-assembly of liposomal microreactors enabling catalytic reduction of N2 O to the climate neutral product N2 . Photoexcitation of graphitic N-doped carbon dots delivers electrons to encapsulated N2 O Reductase enzymes via a lipid-soluble biomolecular wire provided by the MtrCAB protein complex. Within the microreactor, electron transfer from MtrCAB to N2 O Reductase is facilitated by the general redox mediator methyl viologen. The liposomal microreactors use only earth-abundant elements to catalyze N2 O removal in ambient, aqueous conditions.
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Affiliation(s)
- Samuel E. H. Piper
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Carla Casadevall
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Erwin Reisner
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Thomas A. Clarke
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Lars J. C. Jeuken
- Leiden Institute of ChemistryLeiden UniversityPO Box 95022300 RALeidenThe Netherlands
| | - Andrew J. Gates
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Julea N. Butt
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK,School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
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31
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Piper SEH, Casadevall C, Reisner E, Clarke TA, Jeuken LJC, Gates AJ, Butt JN. Photocatalytic Removal of the Greenhouse Gas Nitrous Oxide by Liposomal Microreactors. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202210572. [PMID: 38529325 PMCID: PMC10962689 DOI: 10.1002/ange.202210572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Indexed: 11/11/2022]
Abstract
Nitrous oxide (N2O) is a potent greenhouse and ozone-reactive gas for which emissions are growing rapidly due to increasingly intensive agriculture. Synthetic catalysts for N2O decomposition typically contain precious metals and/or operate at elevated temperatures driving a desire for more sustainable alternatives. Here we demonstrate self-assembly of liposomal microreactors enabling catalytic reduction of N2O to the climate neutral product N2. Photoexcitation of graphitic N-doped carbon dots delivers electrons to encapsulated N2O Reductase enzymes via a lipid-soluble biomolecular wire provided by the MtrCAB protein complex. Within the microreactor, electron transfer from MtrCAB to N2O Reductase is facilitated by the general redox mediator methyl viologen. The liposomal microreactors use only earth-abundant elements to catalyze N2O removal in ambient, aqueous conditions.
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Affiliation(s)
- Samuel E. H. Piper
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Carla Casadevall
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Erwin Reisner
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Thomas A. Clarke
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Lars J. C. Jeuken
- Leiden Institute of ChemistryLeiden UniversityPO Box 95022300 RALeidenThe Netherlands
| | - Andrew J. Gates
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
| | - Julea N. Butt
- School of ChemistryUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUK
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32
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Kisgeropoulos EC, Bharadwaj VS, Mulder DW, King PW. The Contribution of Proton-Donor pKa on Reactivity Profiles of [FeFe]-hydrogenases. Front Microbiol 2022; 13:903951. [PMID: 36246213 PMCID: PMC9563086 DOI: 10.3389/fmicb.2022.903951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/17/2022] [Indexed: 11/24/2022] Open
Abstract
The [FeFe]-hydrogenases are enzymes that catalyze the reversible activation of H2 coupled to the reduction–oxidation of electron carriers. Members of the different taxonomic groups of [FeFe]-hydrogenases display a wide range of preference, or bias, for H2 oxidation or H2 production reactions, despite sharing a common catalytic cofactor, or H-cluster. Identifying the properties that control reactivity remains an active area of investigation, and models have emerged that include diversity in the catalytic site coordination environments and compositions of electron transfer chains. The kinetics of proton-coupled electron transfer at the H-cluster might be expected to be a point of control of reactivity. To test this hypothesis, systematic changes were made to the conserved cysteine residue that functions in proton exchange with the H-cluster in the three model enzymes: CaI, CpII, and CrHydA1. CaI and CpII both employ electron transfer accessory clusters but differ in bias, whereas CrHydA1 lacks accessory clusters having only the H-cluster. Changing from cysteine to either serine (more basic) or aspartate (more acidic) modifies the sidechain pKa and thus the barrier for the proton exchange step. The reaction rates for H2 oxidation or H2 evolution were surveyed and measured for model [FeFe]-hydrogenases, and the results show that the initial proton-transfer step in [FeFe]-hydrogenase is tightly coupled to the control of reactivity; a change from cysteine to more basic serine favored H2 oxidation in all enzymes, whereas a change to more acidic aspartate caused a shift in preference toward H2 evolution. Overall, the changes in reactivity profiles were profound, spanning 105 in ratio of the H2 oxidation-to-H2 evolution rates. The fact that the change in reactivity follows a common trend implies that the effect of changing the proton-transfer residue pKa may also be framed as an effect on the scaling relationship between the H-cluster di(thiolmethyl)amine (DTMA) ligand pKa and Em values of the H-cluster. Experimental observations that support this relationship, and how it relates to catalytic function in [FeFe]-hydrogenases, are discussed.
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33
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Synthesis, characterization and anticancer activities of cationic η6-p-cymene ruthenium(II) complexes containing phosphine and nitrogenous ligands. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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34
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Guo J, Fisher OS. Orchestrating copper binding: structure and variations on the cupredoxin fold. J Biol Inorg Chem 2022; 27:529-540. [PMID: 35994119 DOI: 10.1007/s00775-022-01955-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/07/2022] [Indexed: 11/26/2022]
Abstract
A large number of copper binding proteins coordinate metal ions using a shared three-dimensional fold called the cupredoxin domain. This domain was originally identified in Type 1 "blue copper" centers but has since proven to be a common domain architecture within an increasingly large and diverse group of copper binding domains. The cupredoxin fold has a number of qualities that make it ideal for coordinating Cu ions for purposes including electron transfer, enzyme catalysis, assembly of other copper sites, and copper sequestration. The structural core does not undergo major conformational changes upon metal binding, but variations within the coordination environment of the metal site confer a range of Cu-binding affinities, reduction potentials, and spectroscopic properties. Here, we discuss these proteins from a structural perspective, examining how variations within the overall cupredoxin fold and metal binding sites are linked to distinct spectroscopic properties and biological functions. Expanding far beyond the blue copper proteins, cupredoxin domains are used by a growing number of proteins and enzymes as a means of binding copper ions, with many more likely remaining to be identified.
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Affiliation(s)
- Jing Guo
- Department of Chemistry, Lehigh University, Bethlehem, PA, USA
| | - Oriana S Fisher
- Department of Chemistry, Lehigh University, Bethlehem, PA, USA.
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35
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Van Stappen C, Deng Y, Liu Y, Heidari H, Wang JX, Zhou Y, Ledray AP, Lu Y. Designing Artificial Metalloenzymes by Tuning of the Environment beyond the Primary Coordination Sphere. Chem Rev 2022; 122:11974-12045. [PMID: 35816578 DOI: 10.1021/acs.chemrev.2c00106] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metalloenzymes catalyze a variety of reactions using a limited number of natural amino acids and metallocofactors. Therefore, the environment beyond the primary coordination sphere must play an important role in both conferring and tuning their phenomenal catalytic properties, enabling active sites with otherwise similar primary coordination environments to perform a diverse array of biological functions. However, since the interactions beyond the primary coordination sphere are numerous and weak, it has been difficult to pinpoint structural features responsible for the tuning of activities of native enzymes. Designing artificial metalloenzymes (ArMs) offers an excellent basis to elucidate the roles of these interactions and to further develop practical biological catalysts. In this review, we highlight how the secondary coordination spheres of ArMs influence metal binding and catalysis, with particular focus on the use of native protein scaffolds as templates for the design of ArMs by either rational design aided by computational modeling, directed evolution, or a combination of both approaches. In describing successes in designing heme, nonheme Fe, and Cu metalloenzymes, heteronuclear metalloenzymes containing heme, and those ArMs containing other metal centers (including those with non-native metal ions and metallocofactors), we have summarized insights gained on how careful controls of the interactions in the secondary coordination sphere, including hydrophobic and hydrogen bonding interactions, allow the generation and tuning of these respective systems to approach, rival, and, in a few cases, exceed those of native enzymes. We have also provided an outlook on the remaining challenges in the field and future directions that will allow for a deeper understanding of the secondary coordination sphere a deeper understanding of the secondary coordintion sphere to be gained, and in turn to guide the design of a broader and more efficient variety of ArMs.
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Affiliation(s)
- Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yunling Deng
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yiwei Liu
- Department of Chemistry, University of Illinois, Urbana-Champaign, 505 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Hirbod Heidari
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Jing-Xiang Wang
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yu Zhou
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Aaron P Ledray
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States.,Department of Chemistry, University of Illinois, Urbana-Champaign, 505 South Mathews Avenue, Urbana, Illinois 61801, United States
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36
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Cryo-EM structure of an extracellular Geobacter OmcE cytochrome filament reveals tetrahaem packing. Nat Microbiol 2022; 7:1291-1300. [PMID: 35798889 PMCID: PMC9357133 DOI: 10.1038/s41564-022-01159-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 05/23/2022] [Indexed: 12/11/2022]
Abstract
Electrically conductive appendages from the anaerobic bacterium Geobacter sulfurreducens were first observed two decades ago, with genetic and biochemical data suggesting that conductive fibres were type IV pili. Recently, an extracellular conductive filament of G. sulfurreducens was found to contain polymerized c-type cytochrome OmcS subunits, not pilin subunits. Here we report that G. sulfurreducens also produces a second, thinner appendage comprised of cytochrome OmcE subunits and solve its structure using cryo-electron microscopy at ~4.3 Å resolution. Although OmcE and OmcS subunits have no overall sequence or structural similarities, upon polymerization both form filaments that share a conserved haem packing arrangement in which haems are coordinated by histidines in adjacent subunits. Unlike OmcS filaments, OmcE filaments are highly glycosylated. In extracellular fractions from G. sulfurreducens, we detected type IV pili comprising PilA-N and -C chains, along with abundant B-DNA. OmcE is the second cytochrome filament to be characterized using structural and biophysical methods. We propose that there is a broad class of conductive bacterial appendages with conserved haem packing (rather than sequence homology) that enable long-distance electron transport to chemicals or other microbial cells.
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37
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Mihajlović-Lalić LE, Stanković D, Novaković I, Grgurić-Šipka S. (Electro)chemical and antimicrobial characterization of novel Ru(II) bipyridine complexes with acetylpyridine analogs. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2090247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Dalibor Stanković
- University of Belgrade- Faculty of Chemistry, Belgrade, Serbia
- "VINČA" Institute of Nuclear Sciences-National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Irena Novaković
- Center for Chemistry, University of Belgrade-ICTM, Belgrade, Serbia
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Mandal S, Samajdar RN, Parida S, Mishra S, Bhattacharyya AJ. Transition Metal Phthalocyanines as Redox Mediators in Li-O 2 Batteries: A Combined Experimental and Theoretical Study of the Influence of 3d Electrons in Redox Mediation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:26714-26723. [PMID: 35658407 DOI: 10.1021/acsami.2c04332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Redox mediation is an innovative strategy for ensuring efficient energy harvesting from metal-oxygen systems. This work presents a systematic exploratory analysis of first-row transition-metal phthalocyanines as solution-state redox mediators for lithium-oxygen batteries. Our findings, based on experiment and theory, convincingly demonstrate that d5 (Mn), d7 (Co), and d8 (Ni) configurations function better compared to d6 (Fe) and d9 (Cu) in redox mediation of the discharge step. The d10 configuration (Zn) and non-d analogues (Mg) do not show any redox mediation because of the inability of binding with oxygen. The solution-state discharge product, transition-metal bound Li2O2, undergoes dissociation and oxidation in the charging step of the battery, thus confirming a bifunctional redox mediation. Apart from the reaction pathways predicted based on thermodynamic considerations, density functional theory calculations also reveal interesting effects of electrochemical perturbation on the redox mediation mechanisms and the role of the transition-metal center.
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Affiliation(s)
- Subhankar Mandal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, Karnataka, India
| | - Rudra N Samajdar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, Karnataka, India
| | - Sanjukta Parida
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Sabyashachi Mishra
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
- Centre for Computational and Data Sciences, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Aninda J Bhattacharyya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, Karnataka, India
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Electrochemical Characterization of an Engineered Red Copper Protein Featuring an Unprecedented Entropic Control of the Reduction Potential. Bioelectrochemistry 2022; 146:108095. [DOI: 10.1016/j.bioelechem.2022.108095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 12/12/2022]
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40
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From iron to bacterial electroconductive filaments: Exploring cytochrome diversity using Geobacter bacteria. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214284] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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41
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Tobolska A, Wezynfeld NE, Wawrzyniak UE, Bal W, Wróblewski W. Tuning Receptor Properties of Metal-Amyloid Beta Complexes. Studies on the Interaction between Ni(II)-Aβ 5-9 and Phosphates/Nucleotides. Inorg Chem 2021; 60:19448-19456. [PMID: 34878265 PMCID: PMC8693174 DOI: 10.1021/acs.inorgchem.1c03285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Amyloid-beta (Aβ) peptides, potentially relevant in the pathology of Alzheimer's disease, possess distinctive coordination properties, enabling an effective binding of transition-metal ions, with a preference for Cu(II). In this work, we found that a N-truncated Aβ analogue bearing a His-2 motif, Aβ5-9, forms a stable Ni(II) high-spin octahedral complex at a physiological pH of 7.4 with labile coordination sites and facilitates ternary interactions with phosphates and nucleotides. As the pH increased above 9, a spin transition from a high-spin to a low-spin square-planar Ni(II) complex was observed. Employing electrochemical techniques, we showed that interactions between the binary Ni(II)-Aβ5-9 complex and phosphate species result in significant changes in the Ni(II) oxidation signal. Thus, the Ni(II)-Aβ5-9 complex could potentially serve as a receptor in electrochemical biosensors for phosphate species. The obtained results could also be important for nickel toxicology.
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Affiliation(s)
- Aleksandra Tobolska
- Chair of Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, Warsaw 00-664, Poland.,Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw 02-093, Poland
| | - Nina E Wezynfeld
- Chair of Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, Warsaw 00-664, Poland
| | - Urszula E Wawrzyniak
- Chair of Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, Warsaw 00-664, Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, Warsaw 02-106, Poland
| | - Wojciech Wróblewski
- Chair of Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, Warsaw 00-664, Poland
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42
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Heghmanns M, Günzel A, Brandis D, Kutin Y, Engelbrecht V, Winkler M, Happe T, Kasanmascheff M. Fine-tuning of FeS proteins monitored via pulsed EPR redox potentiometry at Q-band. BIOPHYSICAL REPORTS 2021; 1:100016. [PMID: 36425453 PMCID: PMC9680799 DOI: 10.1016/j.bpr.2021.100016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/30/2021] [Indexed: 06/16/2023]
Abstract
As essential electron translocating proteins in photosynthetic organisms, multiple plant-type ferredoxin (Fdx) isoforms are involved in a high number of reductive metabolic processes in the chloroplast. To allow quick cellular responses under changing environmental conditions, different plant-type Fdxs in Chlamydomonas reinhardtii were suggested to have adapted their midpoint potentials to a wide range of interaction partners. We performed pulsed electron paramagnetic resonance (EPR) monitored redox potentiometry at Q-band on three Fdx isoforms for a straightforward determination of their midpoint potentials. Additionally, site-directed mutagenesis was used to tune the midpoint potential of CrFdx1 in a range of approximately -338 to -511 mV, confirming the importance of single positions in the protein environment surrounding the [2Fe2S] cluster. Our results present a new target for future studies aiming to modify the catalytic activity of CrFdx1 that plays an essential role either as electron acceptor of photosystem I or as electron donor to hydrogenases under certain conditions. Additionally, the precisely determined redox potentials in this work using pulsed EPR demonstrate an alternative method that provides additional advantages compared with the well-established continuous wave EPR technique.
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Affiliation(s)
- Melanie Heghmanns
- TU Dortmund University, Department of Chemistry and Chemical Biology, Dortmund, Germany
| | - Alexander Günzel
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Bochum, Germany
| | - Dörte Brandis
- TU Dortmund University, Department of Chemistry and Chemical Biology, Dortmund, Germany
| | - Yury Kutin
- TU Dortmund University, Department of Chemistry and Chemical Biology, Dortmund, Germany
| | - Vera Engelbrecht
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Bochum, Germany
| | - Martin Winkler
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Bochum, Germany
| | - Thomas Happe
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Photobiotechnology, Bochum, Germany
| | - Müge Kasanmascheff
- TU Dortmund University, Department of Chemistry and Chemical Biology, Dortmund, Germany
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Kroneck PMH. Nature's nitrite-to-ammonia expressway, with no stop at dinitrogen. J Biol Inorg Chem 2021; 27:1-21. [PMID: 34865208 PMCID: PMC8840924 DOI: 10.1007/s00775-021-01921-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/22/2021] [Indexed: 12/26/2022]
Abstract
Since the characterization of cytochrome c552 as a multiheme nitrite reductase, research on this enzyme has gained major interest. Today, it is known as pentaheme cytochrome c nitrite reductase (NrfA). Part of the NH4+ produced from NO2- is released as NH3 leading to nitrogen loss, similar to denitrification which generates NO, N2O, and N2. NH4+ can also be used for assimilatory purposes, thus NrfA contributes to nitrogen retention. It catalyses the six-electron reduction of NO2- to NH4+, hosting four His/His ligated c-type hemes for electron transfer and one structurally differentiated active site heme. Catalysis occurs at the distal side of a Fe(III) heme c proximally coordinated by lysine of a unique CXXCK motif (Sulfurospirillum deleyianum, Wolinella succinogenes) or, presumably, by the canonical histidine in Campylobacter jejeuni. Replacement of Lys by His in NrfA of W. succinogenes led to a significant loss of enzyme activity. NrfA forms homodimers as shown by high resolution X-ray crystallography, and there exist at least two distinct electron transfer systems to the enzyme. In γ-proteobacteria (Escherichia coli) NrfA is linked to the menaquinol pool in the cytoplasmic membrane through a pentaheme electron carrier (NrfB), in δ- and ε-proteobacteria (S. deleyianum, W. succinogenes), the NrfA dimer interacts with a tetraheme cytochrome c (NrfH). Both form a membrane-associated respiratory complex on the extracellular side of the cytoplasmic membrane to optimize electron transfer efficiency. This minireview traces important steps in understanding the nature of pentaheme cytochrome c nitrite reductases, and discusses their structural and functional features.
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Affiliation(s)
- Peter M H Kroneck
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
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45
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A bound iron porphyrin is redox active in hybrid bacterial reaction centers modified to possess a four-helix bundle domain. Photochem Photobiol Sci 2021; 21:91-99. [PMID: 34850374 DOI: 10.1007/s43630-021-00142-7] [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: 09/29/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
In this paper we report the design of hybrid reaction centers with a novel redox-active cofactor. Reaction centers perform the primary photochemistry of photosynthesis, namely the light-induced transfer of an electron from the bacteriochlorophyll dimer to a series of electron acceptors. Hybrid complexes were created by the fusion of an artificial four-helix bundle to the M-subunit of the reaction center. Despite the large modification, optical spectra show that the purified hybrid reaction centers assemble as active complexes that retain the characteristic cofactor absorption peaks and are capable of light-induced charge separation. The four-helix bundle could bind iron-protoporphyrin in either a reduced and oxidized state. After binding iron-protoporphyrin to the hybrid reaction centers, light excitation results in a new derivative signal with a maximum at 402 nm and minimum at 429 nm. This signal increases in amplitude with longer light durations and persists in the dark. No signal is observed when iron-protoporphyrin is added to reaction centers without the four-helix bundle domain or when a redox-inactive zinc-protoporphyrin is bound. The results are consistent with the signal arising from a new redox reaction, electron transfer from the iron-protoporphyrin to the oxidized bacteriochlorophyll dimer. These outcomes demonstrate the feasibility of binding porphyrins to the hybrid reaction centers to gain new light-driven functions.
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Wielend D, Salinas Y, Mayr F, Bechmann M, Yumusak C, Neugebauer H, Brüggemann O, Sariciftci NS. Immobilized Poly(anthraquinones) for Electrochemical Energy Storage Applications: Structure‐Property Relations. ChemElectroChem 2021. [DOI: 10.1002/celc.202101315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Dominik Wielend
- Linz Institute for Organic Solar Cells (LIOS) Institute of Physical Chemistry Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
| | - Yolanda Salinas
- Institute of Polymer Chemistry (ICP) Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
| | - Felix Mayr
- Linz Institute for Organic Solar Cells (LIOS) Institute of Physical Chemistry Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
- Institute of Applied Physics Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
| | - Matthias Bechmann
- Institute of Organic Chemistry Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
| | - Cigdem Yumusak
- Linz Institute for Organic Solar Cells (LIOS) Institute of Physical Chemistry Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
- Materials Research Centre Faculty of Chemistry Brno University of Technology Purkyňova 118 612 00 Brno Czech Republic
| | - Helmut Neugebauer
- Linz Institute for Organic Solar Cells (LIOS) Institute of Physical Chemistry Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
| | - Oliver Brüggemann
- Institute of Polymer Chemistry (ICP) Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
| | - Niyazi Serdar Sariciftci
- Linz Institute for Organic Solar Cells (LIOS) Institute of Physical Chemistry Johannes Kepler University Linz Altenberger Straße 69 4040 Linz Austria
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Buades AB, Viñas C, Fontrodona X, Teixidor F. 1.3 V Inorganic Sequential Redox Chain with an All-Anionic Couple 1-/2- in a Single Framework. Inorg Chem 2021; 60:16168-16177. [PMID: 34693711 PMCID: PMC9180739 DOI: 10.1021/acs.inorgchem.1c01822] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The relatively low symmetry of [3,3′-Co(1,2-C2B9H11)2]− ([1]−), along with the high number
of available
substitution sites, 18 on the boron atoms and 4 on the carbon atoms,
allows a fairly regioselective and stepwise chlorination of the platform
and therefore a very controlled tuning of the electrochemical potential
tuning. This is not so easily found in other systems, e.g., ferrocene.
In this work, we show how a single platform with boron and carbon
in the ligand, and only cobalt can produce a tuning of potentials
in a stepwise manner in the 1.3 V range. The platform used is made
of two icosahedra sharing one vertex. The E1/2 tuning has been achieved from [1]− by sequential chlorination, which has given potentials whose values
increase sequentially and linearly with the number of chloro groups
in the platform. [Cl8-1]−, [Cl10-1]−, and [Cl12-1]− have been obtained, which
are added to the existing [Cl-1]−,
[Cl2-1]−, [Cl4-1]−, and [Cl6-1]− described earlier to give the 1.3 V range. It is envisaged
to extend this range also sequentially by changing the metal from
cobalt to iron. The last successful synthesis of the highest chlorinated
derivatives of cobaltabis(dicarbollide) dates back to 1982, and since
then, no more advances have occurred toward more substituted metallacarborane
chlorinated compounds. [Cl8-1]−, [Cl10-1]−, and [Cl12-1]− are made
with an easy and fast method. The key point of the reaction is the
use of the protonated form of [Co(C2B9H11)2]−, as a starting material,
and the use of sulfuryl chloride, a less hazardous and easier to use
chlorinating agent. In addition, we present a complete, spectroscopic,
crystallographic, and electrochemical characterization, together with
a study of the influence of the chlorination position in the electrochemical
properties. By sequential halogenation of [Co(C2B9H11)2]− ([1]−) with chlorine, the [Cl8-1]−, [Cl10-1]−, and [Cl12-1]− derivatives
of [1]− have been prepared and isolated.
The E1/2 values increase sequentially
and linearly with the number of chloro groups in the platform. If
these potentials are added to the existing E1/2 values due to [Cl-1]−, [Cl2-1]−, [Cl4-1]−, and [Cl6-1]− described earlier, a 1.3 V range is obtained. This
allows tuning of the desired potentials for the purposes of nature.
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Affiliation(s)
- Ana B Buades
- Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas, Campus Universitat Autonòma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Clara Viñas
- Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas, Campus Universitat Autonòma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Xavier Fontrodona
- Departamento de Química and Serveis Tècnics de Recerca, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
| | - Francesc Teixidor
- Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas, Campus Universitat Autonòma de Barcelona (UAB), 08193 Bellaterra, Spain
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Kumar B, Das T, Das S, Maniukiewicz W, Nesterov DS, Kirillov AM, Das S. Coupling 6-chloro-3-methyluracil with copper: structural features, theoretical analysis, and biofunctional properties. Dalton Trans 2021; 50:13533-13542. [PMID: 34505590 DOI: 10.1039/d1dt02018h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As nucleobases in RNA and DNA, uracil and 5-methyluracil represent a recognized class of bioactive molecules and versatile ligands for coordination compounds with various biofunctional properties. In this study, 6-chloro-3-methyluracil (Hcmu) was used as an unexplored building block for the self-assembly generation of a new bioactive copper(II) complex, [Cu(cmu)2(H2O)2]·4H2O (1). This compound was isolated as a stable crystalline solid and fully characterized in solution and solid state by a variety of spectroscopic methods (UV-vis, EPR, fluorescence spectroscopy), cyclic voltammetry, X-ray diffraction, and DFT calculations. The structural, topological, H-bonding, and Hirshfeld surface features of 1 were also analyzed in detail. The compound 1 shows a distorted octahedral {CuN2O4} coordination environment with two trans cmu- ligands adopting a bidentate N,O-coordination mode. The monocopper(II) molecular units participate in strong H-bonding interactions with water molecules of crystallization, leading to structural 0D → 3D extension into a 3D H-bonded network with a tfz-d topology. Molecular docking and ADME analysis as well as antibacterial and antioxidant activity studies were performed to assess the bioactivity of 1. In particular, this compound exhibits a prominent antibacterial effect against Gram negative (E. coli, P. aeruginosa) and positive (S. aureus, B. cereus) bacteria. The obtained copper(II) complex also represents the first structurally characterized coordination compound derived from 6-chloro-3-methyluracil, thus introducing this bioactive building block into a family of uracil metal complexes with notable biofunctional properties.
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Affiliation(s)
- Brajesh Kumar
- Department of Chemistry, National Institute of Technology Patna, Ashok Rajpath, Patna 800005, India.
| | - Tushar Das
- Department of Chemistry, National Institute of Technology Patna, Ashok Rajpath, Patna 800005, India.
| | - Subhadeep Das
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mallick Rd, Kolkata 700032, India
| | - Waldemar Maniukiewicz
- Institute of General and Ecological Chemistry, Lodz University of Technology, Żeromskiego 116, Łódź, Poland
| | - Dmytro S Nesterov
- Centro de Química Estrutural and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
| | - Alexander M Kirillov
- Centro de Química Estrutural and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal. .,Research Institute of Chemistry, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya st., Moscow, 117198, Russian Federation
| | - Subrata Das
- Department of Chemistry, National Institute of Technology Patna, Ashok Rajpath, Patna 800005, India.
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Schröder GC, Meilleur F. Metalloprotein catalysis: structural and mechanistic insights into oxidoreductases from neutron protein crystallography. Acta Crystallogr D Struct Biol 2021; 77:1251-1269. [PMID: 34605429 PMCID: PMC8489226 DOI: 10.1107/s2059798321009025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
Metalloproteins catalyze a range of reactions, with enhanced chemical functionality due to their metal cofactor. The reaction mechanisms of metalloproteins have been experimentally characterized by spectroscopy, macromolecular crystallography and cryo-electron microscopy. An important caveat in structural studies of metalloproteins remains the artefacts that can be introduced by radiation damage. Photoreduction, radiolysis and ionization deriving from the electromagnetic beam used to probe the structure complicate structural and mechanistic interpretation. Neutron protein diffraction remains the only structural probe that leaves protein samples devoid of radiation damage, even when data are collected at room temperature. Additionally, neutron protein crystallography provides information on the positions of light atoms such as hydrogen and deuterium, allowing the characterization of protonation states and hydrogen-bonding networks. Neutron protein crystallography has further been used in conjunction with experimental and computational techniques to gain insight into the structures and reaction mechanisms of several transition-state metal oxidoreductases with iron, copper and manganese cofactors. Here, the contribution of neutron protein crystallography towards elucidating the reaction mechanism of metalloproteins is reviewed.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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50
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Diversification of Ferredoxins across Living Organisms. Curr Issues Mol Biol 2021; 43:1374-1390. [PMID: 34698119 PMCID: PMC8928951 DOI: 10.3390/cimb43030098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 12/17/2022] Open
Abstract
Ferredoxins, iron-sulfur (Fe-S) cluster proteins, play a key role in oxidoreduction reactions. To date, evolutionary analysis of these proteins across the domains of life have been confined to observing the abundance of Fe-S cluster types (2Fe-2S, 3Fe-4S, 4Fe-4S, 7Fe-8S (3Fe-4s and 4Fe-4S) and 2[4Fe-4S]) and the diversity of ferredoxins within these cluster types was not studied. To address this research gap, here we propose a subtype classification and nomenclature for ferredoxins based on the characteristic spacing between the cysteine amino acids of the Fe-S binding motif as a subtype signature to assess the diversity of ferredoxins across the living organisms. To test this hypothesis, comparative analysis of ferredoxins between bacterial groups, Alphaproteobacteria and Firmicutes and ferredoxins collected from species of different domains of life that are reported in the literature has been carried out. Ferredoxins were found to be highly diverse within their types. Large numbers of alphaproteobacterial species ferredoxin subtypes were found in Firmicutes species and the same ferredoxin subtypes across the species of Bacteria, Archaea, and Eukarya, suggesting shared common ancestral origin of ferredoxins between Archaea and Bacteria and lateral gene transfer of ferredoxins from prokaryotes (Archaea/Bacteria) to eukaryotes. This study opened new vistas for further analysis of diversity of ferredoxins in living organisms.
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