1
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Bhattacharya A, Samanta S, Nath AK, Ghatak A, Dey SG, Dey A. Intermediates involved in the reduction of SO 2: insight into the mechanism of sulfite reductases. Chem Commun (Camb) 2024; 60:7709-7712. [PMID: 38963718 DOI: 10.1039/d4cc02124j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Sulfite reductases (SiRs) catalyze the reduction of SO32- to H2S in biosynthetic sulfur assimilation and dissimilation of sulfate. The mechanism of the 6e-/6H+ reduction of SO32- at the siroheme cofactor is debated, and proposed intermediates involved in this 6e- reduction are yet to be spectroscopically characterized. The reaction of SO2 with a ferrous iron porphyrin is investigated, and two intermediates are trapped and characterized: an initial Fe(III)-SO22- species, which undergoes proton-assisted S-O bond cleavage to form an Fe(III)-SO species. These species are characterized using a combination of resonance Raman (with 34S-labelled SO2), EPR and DFT calculations. Results obtained help reconcile the different proposed mechanisms for the SiRs.
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Affiliation(s)
- Aishik Bhattacharya
- School of Chemical Sciences Indian Association for the Cultivation of Science, 2A & 2B, Raja SC Mullick Road, Kolkata, West Bengal PIN-700032, India.
| | - Soumya Samanta
- School of Chemical Sciences Indian Association for the Cultivation of Science, 2A & 2B, Raja SC Mullick Road, Kolkata, West Bengal PIN-700032, India.
| | - Arnab Kumar Nath
- School of Chemical Sciences Indian Association for the Cultivation of Science, 2A & 2B, Raja SC Mullick Road, Kolkata, West Bengal PIN-700032, India.
| | - Arnab Ghatak
- School of Chemical Sciences Indian Association for the Cultivation of Science, 2A & 2B, Raja SC Mullick Road, Kolkata, West Bengal PIN-700032, India.
| | - Somdatta Ghosh Dey
- School of Chemical Sciences Indian Association for the Cultivation of Science, 2A & 2B, Raja SC Mullick Road, Kolkata, West Bengal PIN-700032, India.
| | - Abhishek Dey
- School of Chemical Sciences Indian Association for the Cultivation of Science, 2A & 2B, Raja SC Mullick Road, Kolkata, West Bengal PIN-700032, India.
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2
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Esfahani BG, Walia N, Neselu K, Aragon M, Askenasy I, Wei A, Mendez JH, Stroupe ME. Dimerization of assimilatory NADPH-dependent sulfite reductase reveals elements for diflavin reductase binding at a minimal interface. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.14.599029. [PMID: 38915618 PMCID: PMC11195156 DOI: 10.1101/2024.06.14.599029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Escherichia coli NADPH-dependent assimilatory sulfite reductase is responsible for fixing sulfur for incorporation into sulfur-containing biomolecules. The oxidoreductase is composed of two subunits, an NADPH, FMN, and FAD-binding diflavin reductase and an iron siroheme and Fe4S4-containing oxidase. How they interact has been an unknown for over 50 years because the complex is highly flexible, thus has been intransigent for traditional X-ray or cryo-EM structural analysis. Using a combination of the chameleon plunging system with a fluorinated lipid we overcame the challenge of preserving the minimal dimer between the subunits for high-resolution cryo-EM analysis. Here, we report the first structure of the complex between the reductase and oxidase, revealing how they interact in a minimal interface. Further, we determined the structural elements that discriminate between the pairing of a siroheme-containing oxidase with a diflavin reductase or a ferredoxin partner to channel the six electrons that reduce sulfite to sulfide.
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Affiliation(s)
- Behrouz Ghazi Esfahani
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32303, USA
| | - Nidhi Walia
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32303, USA
- Current Location: Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Kasahun Neselu
- New York Structural Biology Center, New York, NY, 10027, USA
| | - Mahira Aragon
- New York Structural Biology Center, New York, NY, 10027, USA
| | - Isabel Askenasy
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32303, USA
- Current Location: Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Alex Wei
- New York Structural Biology Center, New York, NY, 10027, USA
| | | | - M. Elizabeth Stroupe
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32303, USA
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3
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Walia N, Murray DT, Garg Y, He H, Weiss KL, Nagy G, Elizabeth Stroupe M. Domain crossover in the reductase subunit of NADPH-dependent assimilatory sulfite reductase. J Struct Biol 2023; 215:108028. [PMID: 37704014 DOI: 10.1016/j.jsb.2023.108028] [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: 06/25/2023] [Revised: 09/08/2023] [Accepted: 09/10/2023] [Indexed: 09/15/2023]
Abstract
NADPH-dependent assimilatory sulfite reductase (SiR) from Escherichia coli performs a six-electron reduction of sulfite to the bioavailable sulfide. SiR is composed of a flavoprotein (SiRFP) reductase subunit and a hemoprotein (SiRHP) oxidase subunit. There is no known high-resolution structure of SiR or SiRFP, thus we do not yet fully understand how the subunits interact to perform their chemistry. Here, we used small-angle neutron scattering to understand the impact of conformationally restricting the highly mobile SiRFP octamer into an electron accepting (closed) or electron donating (open) conformation, showing that SiR remains active, flexible, and asymmetric even with these conformational restrictions. From these scattering data, we model the first solution structure of SiRFP. Further, computational modeling of the N-terminal 52 amino acids that are responsible for SiRFP oligomerization suggests an eight-helical bundle tethers together the SiRFP subunits to form the SiR core. Finally, mass spectrometry analysis of the closed SiRFP variant show that SiRFP is capable of inter-molecular domain crossover, in which the electron donating domain from one polypeptide is able to interact directly with the electron accepting domain of another polypeptide. This structural characterization suggests that SiR performs its high-volume electron transfer through both inter- and intramolecular pathways between SiRFP domains and, thus, cis or trans transfer from reductase to oxidase subunits. Such highly redundant potential for electron transfer makes this system a potential target for designing synthetic enzymes.
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Affiliation(s)
- Nidhi Walia
- Department of Biological Science, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA
| | - Daniel T Murray
- Department of Biological Science, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA(1)
| | - Yashika Garg
- Department of Biological Science, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA
| | - Huan He
- Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA; Translational Science Laboratory, College of Medicine, 1115 West Call Street, Tallahassee, FL 32306, USA
| | - Kevin L Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Gergely Nagy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - M Elizabeth Stroupe
- Department of Biological Science, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA.
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4
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Bhattacharya A, Kumar Nath A, Ghatak A, Nayek A, Dinda S, Saha R, Ghosh Dey S, Dey A. Reduction of Sulfur Dioxide to Sulfur Monoxide by Ferrous Porphyrin. Angew Chem Int Ed Engl 2023; 62:e202215235. [PMID: 36588338 DOI: 10.1002/anie.202215235] [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: 10/19/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/03/2023]
Abstract
The reduction of SO2 to fixed forms of sulfur can address the growing concerns regarding its detrimental effect on health and the environment as well as enable its valorization into valuable chemicals. The naturally occurring heme enzyme sulfite reductase (SiR) is known to reduce SO2 to H2 S and is an integral part of the global sulfur cycle. However, its action has not yet been mimicked in artificial systems outside of the protein matrix even after several decades of structural elucidation of the enzyme. While the coordination of SO2 to transition metals is documented, its reduction using molecular catalysts has remained elusive. Herein reduction of SO2 by iron(II) tetraphenylporphyrin is demonstrated. A combination of spectroscopic data backed up by theoretical calculations indicate that FeII TPP reduces SO2 by 2e- /2H+ to form an intermediate [FeIII -SO]+ species, also proposed for SiR, which releases SO. The SO obtained from the chemical reduction of SO2 could be evidenced in the form of a cheletropic adduct of butadiene resulting in an organic sulfoxide.
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Affiliation(s)
- Aishik Bhattacharya
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Arnab Kumar Nath
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Arnab Ghatak
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Abhijit Nayek
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Souvik Dinda
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Rajat Saha
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Somdatta Ghosh Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
| | - Abhishek Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, Kolkata, WB 700032, India
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5
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Wu T, Rajabimoghadam K, Puri A, Hebert DD, Qiu YL, Eichelberger S, Siegler MA, Swart M, Hendrich MP, Garcia-Bosch I. A 4H +/4e - Electron-Coupled-Proton Buffer Based on a Mononuclear Cu Complex. J Am Chem Soc 2022; 144:16905-16915. [PMID: 36083845 PMCID: PMC10123533 DOI: 10.1021/jacs.2c05454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this research article, we describe a 4H+/4e- electron-coupled-proton buffer (ECPB) based on Cu and a redox-active ligand. The protonated/reduced ECPB (complex 1: [Cu(8H+/14e-)]1+), consisting of CuI with 2 equiv of the ligand (catLH4: 1,1'-(4,5-dimethoxy-1,2-phenylene)bis(3-(tert-butyl)urea)), reacted with H+/e- acceptors such as O2 to generate the deprotonated/oxidized ECPB. The resulting compound, (complex 5: [Cu(4H+/10e-)]1+), was characterized by X-ray diffraction analysis, nuclear magnetic resonance (1H-NMR), and density functional theory, and it is electronically described as a cuprous bis(benzoquinonediimine) species. The stoichiometric 4H+/4e- reduction of 5 was carried out with H+/e- donors to generate 1 (CuI and 2 equiv of catLH4) and the corresponding oxidation products. The 1/5 ECPB system catalyzed the 4H+/4e- reduction of O2 to H2O and the dehydrogenation of organic substrates in a decoupled (oxidations and reductions are separated in time and space) and a coupled fashion (oxidations and reductions coincide in time and space). Mechanistic analysis revealed that upon reductive protonation of 5 and oxidative deprotonation of 1, fast disproportionation reactions regenerate complexes 5 and 1 in a stoichiometric fashion to maintain the ECPB equilibrium.
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Affiliation(s)
- Tong Wu
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | | | - Ankita Puri
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - David D Hebert
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Yi Lin Qiu
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Sidney Eichelberger
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Maxime A Siegler
- Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Marcel Swart
- University of Girona, IQCC, Campus Montilivi (Cie#x300;ncies), 17003 Girona, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Michael P Hendrich
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Isaac Garcia-Bosch
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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6
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Khan SN, Griffith A, De Proft F, Miliordos E, Havenith RWA, Bykov D, Cunha AV. [Fe 4S 4] cubane in sulfite reductases: new insights into bonding properties and reactivity. Phys Chem Chem Phys 2022; 24:18543-18551. [PMID: 35904932 DOI: 10.1039/d2cp02124b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dissimilatory sulfite reductase enzyme has very characteristic active site where the substrate binds to an iron site, ligated by a siroheme macrocycle and a thiol directly connected to a [Fe4S4] cluster. This arrangement gives the enzyme remarkable efficiency in reducing sulfite and nitrite all the way to hydrogen sulfide and ammonia. For the first time we present a theoretical study where substrate binding modalities and activation are elucidated using active site models containing proton supply side chains and the [Fe4S4] cluster. Density functional theory (DFT) was deployed in conjunction with the energy decomposition scheme (as implemented in AMS), the quantum theory of atoms in molecules (QTAIM), and conceptual DFT (cDFT) descriptors. We quantified the role of the electrostatic interactions inside the active site created by the side chains as well as the influence of the [Fe4S4] cluster on the substrate binding. Furthermore, using conceptual DFT results we shed light of the activation process, thus, laying foundation for further mechanistic studies. We found that the bonding of the ligands to the iron complex is dominated by electrostatic interactions, but the presence of the [Fe4S4] cubane leads to substantial changes in electronic interaction. The spin state of the cubane, however, affects the binding energy only marginally. The conceptual DFT results show that the presence of the [Fe4S4] cubane affects the reactivity of the active site as it is involved in electron transfer. This is corroborated by an increase in the electrophilicity index, thus making the active site more prone to react with the ligands. The interaction energies between the ligand and the siroheme group are also increased upon the presence of the cubane group, thus, suggesting that the siroheme group is not an innocent spectator but plays an active role in the reactivity of the dSIR active site.
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Affiliation(s)
- Shahriar N Khan
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA
| | - Alexa Griffith
- Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6373, USA.
| | - Frank De Proft
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA
| | - Remco W A Havenith
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Ghent Quantum Chemistry Group, Department of Chemistry, Ghent University, Krijgslaan 281 (S3), B-9000 Gent, Belgium
| | - Dmytro Bykov
- Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6373, USA.
| | - Ana V Cunha
- Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6373, USA. .,Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.,Department of Chemistry of the University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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7
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Murray DT, Walia N, Weiss KL, Stanley CB, Nagy G, Stroupe ME. Neutron scattering maps the higher-order assembly of NADPH-dependent assimilatory sulfite reductase. Biophys J 2022; 121:1799-1812. [PMID: 35443926 DOI: 10.1016/j.bpj.2022.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/09/2022] [Accepted: 04/15/2022] [Indexed: 11/30/2022] Open
Abstract
Precursor molecules for biomass incorporation must be imported into cells and made available to the molecular machines that build the cell. Sulfur-containing macromolecules require that sulfur be in its S2- oxidation state before assimilation into amino acids, cofactors, and vitamins that are essential to organisms throughout the biosphere. In α-proteobacteria, NADPH-dependent assimilatory sulfite reductase (SiR) performs the final six-electron reduction of sulfur. SiR is a dodecameric oxidoreductase composed of an octameric flavoprotein reductase (SiRFP) and four hemoprotein metalloenzyme oxidases (SiRHP). SiR performs the electron transfer reduction reaction to produce sulfide from sulfite through coordinated domain movements and subunit interactions without release of partially reduced intermediates. Efforts to understand the electron transfer mechanism responsible for SiR's efficiency are confounded by structural heterogeneity arising from intrinsically disordered regions throughout its complex, including the flexible linker joining SiRFP's flavin-binding domains. As a result, high-resolution structures of SiR dodecamer and its subcomplexes are unknown, leaving a gap in the fundamental understanding of how SiR performs this uniquely large-volume electron transfer reaction. Here, we use deuterium labeling, in vitro reconstitution, analytical ultracentrifugation (AUC), small-angle neutron scattering (SANS), and neutron contrast variation (NCV) to observe the relative subunit positions within SiR's higher-order assembly. AUC and SANS reveal SiR to be a flexible dodecamer and confirm the mismatched SiRFP and SiRHP subunit stoichiometry. NCV shows that the complex is asymmetric, with SiRHP on the periphery of the complex and the centers of mass between SiRFP and SiRHP components over 100 Å apart. SiRFP undergoes compaction upon assembly into SiR's dodecamer and SiRHP adopts multiple positions in the complex. The resulting map of SiR's higher-order structure supports a cis/trans mechanism for electron transfer between domains of reductase subunits as well as between tightly-bound or transiently-interacting reductase and oxidase subunits.
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Affiliation(s)
- Daniel T Murray
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Nidhi Walia
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Kevin L Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Christopher B Stanley
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA; Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Gergely Nagy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - M Elizabeth Stroupe
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA.
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8
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Bhunia S, Ghatak A, Dey A. Second Sphere Effects on Oxygen Reduction and Peroxide Activation by Mononuclear Iron Porphyrins and Related Systems. Chem Rev 2022; 122:12370-12426. [PMID: 35404575 DOI: 10.1021/acs.chemrev.1c01021] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation and reduction of O2 and H2O2 by synthetic and biosynthetic iron porphyrin models have proved to be a versatile platform for evaluating second-sphere effects deemed important in naturally occurring heme active sites. Advances in synthetic techniques have made it possible to install different functional groups around the porphyrin ligand, recreating artificial analogues of the proximal and distal sites encountered in the heme proteins. Using judicious choices of these substituents, several of the elegant second-sphere effects that are proposed to be important in the reactivity of key heme proteins have been evaluated under controlled environments, adding fundamental insight into the roles played by these weak interactions in nature. This review presents a detailed description of these efforts and how these have not only demystified these second-sphere effects but also how the knowledge obtained resulted in functional mimics of these heme enzymes.
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Affiliation(s)
- Sarmistha Bhunia
- School of Chemical Science, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata 700032, India
| | - Arnab Ghatak
- School of Chemical Science, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata 700032, India
| | - Abhishek Dey
- School of Chemical Science, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata 700032, India
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9
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Patel SS, Kumar D, Tripathi CB. Brønsted acid catalyzed radical addition to quinone methides. Chem Commun (Camb) 2021; 57:5151-5154. [PMID: 33900314 DOI: 10.1039/d1cc01335a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A fundamental quest for alkyl radical generation under mild conditions through photoinduced Brønsted acid catalysis is addressed. The optimized protocol does not require any organic dyes or transition metal photocatalyst. Under blue light irradiation with diphenyl phosphate as a catalyst and dihydropyridine derivatives as a radical source, functionalized arylmethane derivatives are obtained in high yield.
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Affiliation(s)
- Shiv Shankar Patel
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow-226031, India.
| | - Dileep Kumar
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow-226031, India.
| | - Chandra Bhushan Tripathi
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow-226031, India. and Chemical Sciences Division, Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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10
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Reed CJ, Lam QN, Mirts EN, Lu Y. Molecular understanding of heteronuclear active sites in heme-copper oxidases, nitric oxide reductases, and sulfite reductases through biomimetic modelling. Chem Soc Rev 2021; 50:2486-2539. [PMID: 33475096 PMCID: PMC7920998 DOI: 10.1039/d0cs01297a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Heme-copper oxidases (HCO), nitric oxide reductases (NOR), and sulfite reductases (SiR) catalyze the multi-electron and multi-proton reductions of O2, NO, and SO32-, respectively. Each of these reactions is important to drive cellular energy production through respiratory metabolism and HCO, NOR, and SiR evolved to contain heteronuclear active sites containing heme/copper, heme/nonheme iron, and heme-[4Fe-4S] centers, respectively. The complexity of the structures and reactions of these native enzymes, along with their large sizes and/or membrane associations, make it challenging to fully understand the crucial structural features responsible for the catalytic properties of these active sites. In this review, we summarize progress that has been made to better understand these heteronuclear metalloenzymes at the molecular level though study of the native enzymes along with insights gained from biomimetic models comprising either small molecules or proteins. Further understanding the reaction selectivity of these enzymes is discussed through comparisons of their similar heteronuclear active sites, and we offer outlook for further investigations.
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Affiliation(s)
- Christopher J Reed
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA.
| | - Quan N Lam
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA
| | - Evan N Mirts
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA. and Department of Biochemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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11
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Novák Vanclová AMG, Zoltner M, Kelly S, Soukal P, Záhonová K, Füssy Z, Ebenezer TE, Lacová Dobáková E, Eliáš M, Lukeš J, Field MC, Hampl V. Metabolic quirks and the colourful history of the Euglena gracilis secondary plastid. THE NEW PHYTOLOGIST 2020; 225:1578-1592. [PMID: 31580486 DOI: 10.1111/nph.16237] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/25/2019] [Indexed: 05/20/2023]
Abstract
Euglena spp. are phototrophic flagellates with considerable ecological presence and impact. Euglena gracilis harbours secondary green plastids, but an incompletely characterised proteome precludes accurate understanding of both plastid function and evolutionary history. Using subcellular fractionation, an improved sequence database and MS we determined the composition, evolutionary relationships and hence predicted functions of the E. gracilis plastid proteome. We confidently identified 1345 distinct plastid protein groups and found that at least 100 proteins represent horizontal acquisitions from organisms other than green algae or prokaryotes. Metabolic reconstruction confirmed previously studied/predicted enzymes/pathways and provided evidence for multiple unusual features, including uncoupling of carotenoid and phytol metabolism, a limited role in amino acid metabolism, and dual sets of the SUF pathway for FeS cluster assembly, one of which was acquired by lateral gene transfer from Chlamydiae. Plastid paralogues of trafficking-associated proteins potentially mediating fusion of transport vesicles with the outermost plastid membrane were identified, together with derlin-related proteins, potential translocases across the middle membrane, and an extremely simplified TIC complex. The Euglena plastid, as the product of many genomes, combines novel and conserved features of metabolism and transport.
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Affiliation(s)
| | - Martin Zoltner
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Steven Kelly
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - Petr Soukal
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
| | - Kristína Záhonová
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
- Faculty of Science, University of Ostrava, Ostrava, 710 00, Czechia
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - Zoltán Füssy
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - ThankGod E Ebenezer
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Eva Lacová Dobáková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - Marek Eliáš
- Faculty of Science, University of Ostrava, Ostrava, 710 00, Czechia
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
- Faculty of Science, University of South Bohemia, České Budějovice, 370 05, Czechia
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - Vladimír Hampl
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
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12
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Surana P, Jainarayanan AK, Anand NM, Sharma M. Analysing non-synonymous mutations in XDR and MDR tuberculosis drugs. J Clin Tuberc Other Mycobact Dis 2019; 17:100124. [PMID: 31788566 PMCID: PMC6880092 DOI: 10.1016/j.jctube.2019.100124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tuberculosis is a bacterial disease caused by Mycobacterium tuberculosis. It is known to be the second-largest cause of death and models a severe risk to public health throughout the world. Though it affects people of almost every age, individuals with weakened immune systems, (e.g., HIV infection) are more likely to get infected. The present study deals with analyzing non-synonymous mutations in anti-tuberculosis drugs, which may have a significant role in causing XDR and MDR tuberculosis drug resistance. Continued use of tuberculosis drugs, discontinuation of medicines and various other factors can promote drug resistance in the host's body. To understand the actual cause of resistance, we have identified some patterns of mutations which might be responsible for a change in the structure of the protein, ultimately causing drug resistance. Here, we aim to present some of the unique mutation patterns in the genes associated with the marketed drugs that might have a deleterious effect. In this study, we have used molecular docking approach for understanding the ligand binding affinity of the mutated drugs. The results are further validated by molecular dynamics studies.
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Affiliation(s)
| | - Ashwin Kumar Jainarayanan
- Indian Institute of Science Education and Research, Mohali, India
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Mukta Sharma
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
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13
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Wei R, Chen X, Gong Y. Side-On OMoF2(η2-SO) and OWF2(η2-SO) Complexes Featuring Peroxo-Like Sulfur Monoxide Ligand. Inorg Chem 2019; 58:15652-15658. [DOI: 10.1021/acs.inorgchem.9b02766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rui Wei
- Department of Radiochemistry, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiuting Chen
- Department of Radiochemistry, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Yu Gong
- Department of Radiochemistry, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
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14
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Tavolieri AM, Murray DT, Askenasy I, Pennington JM, McGarry L, Stanley CB, Stroupe ME. NADPH-dependent sulfite reductase flavoprotein adopts an extended conformation unique to this diflavin reductase. J Struct Biol 2019; 205:170-179. [DOI: 10.1016/j.jsb.2019.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/30/2018] [Accepted: 01/03/2019] [Indexed: 11/17/2022]
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15
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Mirts EN, Petrik ID, Hosseinzadeh P, Nilges MJ, Lu Y. A designed heme-[4Fe-4S] metalloenzyme catalyzes sulfite reduction like the native enzyme. Science 2018; 361:1098-1101. [PMID: 30213908 DOI: 10.1126/science.aat8474] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/25/2018] [Indexed: 01/17/2023]
Abstract
Multielectron redox reactions often require multicofactor metalloenzymes to facilitate coupled electron and proton movement, but it is challenging to design artificial enzymes to catalyze these important reactions, owing to their structural and functional complexity. We report a designed heteronuclear heme-[4Fe-4S] cofactor in cytochrome c peroxidase as a structural and functional model of the enzyme sulfite reductase. The initial model exhibits spectroscopic and ligand-binding properties of the native enzyme, and sulfite reduction activity was improved-through rational tuning of the secondary sphere interactions around the [4Fe-4S] and the substrate-binding sites-to be close to that of the native enzyme. By offering insight into the requirements for a demanding six-electron, seven-proton reaction that has so far eluded synthetic catalysts, this study provides strategies for designing highly functional multicofactor artificial enzymes.
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Affiliation(s)
- Evan N Mirts
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Igor D Petrik
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Parisa Hosseinzadeh
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Mark J Nilges
- School of Chemical Sciences Electron Paramagnetic Resonance Lab, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yi Lu
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. .,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Pacific Northwest National Laboratory, Richland, WA 99352, USA
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16
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Cepeda MR, McGarry L, Pennington JM, Krzystek J, Stroupe ME. The role of extended Fe 4S 4 cluster ligands in mediating sulfite reductase hemoprotein activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:933-940. [PMID: 29852252 DOI: 10.1016/j.bbapap.2018.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/08/2018] [Accepted: 05/24/2018] [Indexed: 10/14/2022]
Abstract
The siroheme-containing subunit from the multimeric hemoflavoprotein NADPH-dependent sulfite reductase (SiR/SiRHP) catalyzes the six electron-reduction of SO32- to S2-. Siroheme is an iron-containing isobacteriochlorin that is found in sulfite and homologous siroheme-containing nitrite reductases. Siroheme does not work alone but is covalently coupled to a Fe4S4 cluster through one of the cluster's ligands. One long-standing hypothesis predicted from this observation is that the environment of one iron-containing cofactor influences the properties of the other. We tested this hypothesis by identifying three amino acids (F437, M444, and T477) that interact with the Fe4S4 cluster and probing the effect of altering them to alanine on the function and structure of the resulting enzymes by use of activity assays, X-ray crystallographic analysis, and EPR spectroscopy. We showed that F437 and M444 gate access for electron transfer to the siroheme-cluster assembly and the direct hydrogen bond between T477 and one of the cluster sulfides is important for determining the geometry of the siroheme active site.
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Affiliation(s)
- Marisa R Cepeda
- Department of Biological Science, Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; Department of Biological Sciences, Georgia Institute of Technology, 310 Ferst Dr. NW, Atlanta, CA 30332, USA
| | - Lauren McGarry
- Department of Biological Science, Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Joseph M Pennington
- Department of Biological Science, Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - M Elizabeth Stroupe
- Department of Biological Science, Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
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17
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Zanello P. The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part V. {[Fe4S4](SCysγ)4} proteins. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2016.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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18
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Nguyen LQ, Knowles RR. Catalytic C–N Bond-Forming Reactions Enabled by Proton-Coupled Electron Transfer Activation of Amide N–H Bonds. ACS Catal 2016. [DOI: 10.1021/acscatal.6b00486] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Lucas Q. Nguyen
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Robert R. Knowles
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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19
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Askenasy I, Pennington JM, Tao Y, Marshall AG, Young NL, Shang W, Stroupe ME. The N-terminal Domain of Escherichia coli Assimilatory NADPH-Sulfite Reductase Hemoprotein Is an Oligomerization Domain That Mediates Holoenzyme Assembly. J Biol Chem 2015; 290:19319-33. [PMID: 26088143 PMCID: PMC4521050 DOI: 10.1074/jbc.m115.662379] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 06/05/2015] [Indexed: 11/06/2022] Open
Abstract
Assimilatory NADPH-sulfite reductase (SiR) from Escherichia coli is a structurally complex oxidoreductase that catalyzes the six-electron reduction of sulfite to sulfide. Two subunits, one a flavin-binding flavoprotein (SiRFP, the α subunit) and the other an iron-containing hemoprotein (SiRHP, the β subunit), assemble to make a holoenzyme of about 800 kDa. How the two subunits assemble is not known. The iron-rich cofactors in SiRHP are unique because they are a covalent arrangement of a Fe4S4 cluster attached through a cysteine ligand to an iron-containing porphyrinoid called siroheme. The link between cofactor biogenesis and SiR stability is also ill-defined. By use of hydrogen/deuterium exchange and biochemical analysis, we show that the α8β4 SiR holoenzyme assembles through the N terminus of SiRHP and the NADPH binding domain of SiRFP. By use of small angle x-ray scattering, we explore the structure of the SiRHP N-terminal oligomerization domain. We also report a novel form of the hemoprotein that occurs in the absence of its cofactors. Apo-SiRHP forms a homotetramer, also dependent on its N terminus, that is unable to assemble with SiRFP. From these results, we propose that homotetramerization of apo-SiRHP serves as a quality control mechanism to prevent formation of inactive holoenzyme in the case of limiting cellular siroheme.
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Affiliation(s)
- Isabel Askenasy
- From the Department of Biological Science and Institute of Molecular Biophysics and
| | - Joseph M Pennington
- From the Department of Biological Science and Institute of Molecular Biophysics and
| | - Yeqing Tao
- the Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306
| | - Alan G Marshall
- the Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, the National High Magnetic Field Laboratory, Tallahassee, Florida 32310, and
| | - Nicolas L Young
- the National High Magnetic Field Laboratory, Tallahassee, Florida 32310, and
| | - Weifeng Shang
- the Center for Synchrotron Radiation Research and Instrumentation and Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
| | - M Elizabeth Stroupe
- From the Department of Biological Science and Institute of Molecular Biophysics and
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20
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Pereira CT, Moutran A, Fessel M, Balan A. The sulfur/sulfonates transport systems in Xanthomonas citri pv. citri. BMC Genomics 2015; 16:524. [PMID: 26169280 PMCID: PMC4501297 DOI: 10.1186/s12864-015-1736-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 06/29/2015] [Indexed: 11/16/2022] Open
Abstract
Background The Xanthomonas citri pv. citri (X. citri) is a phytopathogenic bacterium that infects different species of citrus plants where it causes canker disease. The adaptation to different habitats is related to the ability of the cells to metabolize and to assimilate diverse compounds, including sulfur, an essential element for all organisms. In Escherichia coli, the necessary sulfur can be obtained by a set of proteins whose genes belong to the cys regulon. Although the cys regulon proteins and their importance have been described in many other bacteria, there are no data related to these proteins in X. citri or in the Xanthomonas genus. The study of the relevance of these systems in these phytopathogenic bacteria that have distinct mechanisms of infection is one essential step toward understanding their physiology. In this work, we used bioinformatics, molecular modeling and transcription analysis (RT-PCR) to identify and characterize the putative cys regulon genes in X. citri. Results We showed that the ATP Binding Cassette Transporter (ABC transporter) SbpCysUWA for sulfate uptake is conserved in X. citri and translated in presence of sulfate. On the other hand, differently from what is predicted in databases, according molecular modeling and phylogenetic analysis, X. citri does not show a proper taurine transporter, but two different ABC systems related to the alkanesulfonate/sulfonate transport that were recently acquired during evolution. RT-PCR analysis evidenced that these genes and their putative transcriptional regulator CysB are rather transcripted in XAM1, a medium with defined concentration of sulfate, than LB. Conclusions The presence of at least three distinct systems for sulfate and sulfonates assimilation in X. citri evidenced the importance of these compounds for the bacterium. The transcription of genes involved with alkanesulfonate/sulfur compounds in XAM1 along to CysB suggests that despite the differences in the transporters, the regulation of these systems might be similar to the described for E. coli. Altogether, these results will serve as a foundation for further studies aimed to understanding the relevance of sulfur in growth, virulence and pathogenesis of X. citri and related bacteria. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1736-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cristiane Tambascia Pereira
- Laboratório de Biologia Estrutural Aplicada, Departamento de Microbiologia, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, CEP 05508-000, Brazil. .,Laboratório Nacional de Biociências (LNBio), Centro de Pesquisas em Energia e Materiais (CNPEM), Campinas, SP, CEP 13083-970, Brazil.
| | - Alexandre Moutran
- Laboratório Nacional de Biociências (LNBio), Centro de Pesquisas em Energia e Materiais (CNPEM), Campinas, SP, CEP 13083-970, Brazil.
| | - Melissa Fessel
- Laboratório Nacional de Biociências (LNBio), Centro de Pesquisas em Energia e Materiais (CNPEM), Campinas, SP, CEP 13083-970, Brazil.
| | - Andrea Balan
- Laboratório de Biologia Estrutural Aplicada, Departamento de Microbiologia, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, CEP 05508-000, Brazil.
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21
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Surducan M, Makarov SV, Silaghi-Dumitrescu R. O-S Bond Activation in Structures Isoelectronic with Ferric Peroxide Species Known in O-O-Activating Enzymes: Relevance for Sulfide Activation and Sulfite Reductases. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402657] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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22
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Dereven'kov IA, Salnikov DS, Makarov SV, Boss GR, Koifman OI. Kinetics and mechanism of oxidation of super-reduced cobalamin and cobinamide species by thiosulfate, sulfite and dithionite. Dalton Trans 2014; 42:15307-16. [PMID: 23999614 DOI: 10.1039/c3dt51714d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We studied the kinetics of reactions of cob(I)alamin and cob(I)inamide with thiosulfate, sulfite, and dithionite by UV-Visible (UV-Vis) and stopped-flow spectroscopy. We found that the two Co(I) species were oxidized by these sulfur-containing compounds to Co(II) forms: oxidation by excess thiosulfate leads to penta-coordinate complexes and oxidation by excess sulfite or dithionite leads to hexa-coordinate Co(II)-SO2(-) complexes. The net scheme involves transfer of three electrons in the case of oxidation by thiosulfate and one electron for oxidation by sulfite and dithionite. On the basis of kinetic data, the nature of the reactive oxidants was suggested, i.e., HS2O3(-) (for oxidation by thiosulfate), S2O5(2-), HSO3(-), and aquated SO2 (for oxidation by sulfite), and S2O4(2-) and SO2(-) (for oxidation by dithionite). No difference was observed in kinetics with cob(i)alamin or cob(i)inamide as reductants.
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Affiliation(s)
- Ilia A Dereven'kov
- State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000 Ivanovo, Russia.
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23
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Migliore A, Polizzi NF, Therien M, Beratan DN. Biochemistry and theory of proton-coupled electron transfer. Chem Rev 2014; 114:3381-465. [PMID: 24684625 PMCID: PMC4317057 DOI: 10.1021/cr4006654] [Citation(s) in RCA: 345] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Indexed: 02/01/2023]
Affiliation(s)
- Agostino Migliore
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Nicholas F. Polizzi
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Michael
J. Therien
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - David N. Beratan
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
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24
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Gerlach DL, Coucouvanis D, Lehnert N. Connecting [4Fe-4S] Clusters and Hemes - Towards Modeling the Active Site of Sulfite Reductase. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300308] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Paritala H, Carroll KS. New targets and inhibitors of mycobacterial sulfur metabolism. Infect Disord Drug Targets 2013; 13:85-115. [PMID: 23808874 PMCID: PMC4332622 DOI: 10.2174/18715265113139990022] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 05/08/2013] [Indexed: 11/22/2022]
Abstract
The identification of new antibacterial targets is urgently needed to address multidrug resistant and latent tuberculosis infection. Sulfur metabolic pathways are essential for survival and the expression of virulence in many pathogenic bacteria, including Mycobacterium tuberculosis. In addition, microbial sulfur metabolic pathways are largely absent in humans and therefore, represent unique targets for therapeutic intervention. In this review, we summarize our current understanding of the enzymes associated with the production of sulfated and reduced sulfur-containing metabolites in Mycobacteria. Small molecule inhibitors of these catalysts represent valuable chemical tools that can be used to investigate the role of sulfur metabolism throughout the Mycobacterial lifecycle and may also represent new leads for drug development. In this light, we also summarize recent progress made in the development of inhibitors of sulfur metabolism enzymes.
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Affiliation(s)
| | - Kate S. Carroll
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, 33458, USA
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26
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Goodman C. Reduction deduction. Nat Chem Biol 2013. [DOI: 10.1038/nchembio.1170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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