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Janczak M, Vilhjálmsdóttir J, Ädelroth P. Proton transfer in cytochrome bd-I from E. coli involves Asp-105 in CydB. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149489. [PMID: 39009175 DOI: 10.1016/j.bbabio.2024.149489] [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: 04/30/2024] [Accepted: 06/27/2024] [Indexed: 07/17/2024]
Abstract
Cytochrome bds are bacterial terminal oxidases expressed under low oxygen conditions, and they are important for the survival of many pathogens and hence potential drug targets. The largest subunit CydA contains the three redox-active cofactors heme b558, heme b595 and the active site heme d. One suggested proton transfer pathway is found at the interface between the CydA and the other major subunit CydB. Here we have studied the O2 reduction mechanism in E. coli cyt. bd-I using the flow-flash technique and focused on the mechanism, kinetics and pathway for proton transfer. Our results show that the peroxy (P) to ferryl (F) transition, coupled to the oxidation of the low-spin heme b558 is pH dependent, with a maximum rate constant (~104 s-1) that is slowed down at higher pH. We assign this behavior to rate-limitation by internal proton transfer from a titratable residue with pKa ~ 9.7. Proton uptake from solution occurs with the same P➔F rate constant. Site-directed mutagenesis shows significant effects on catalytic turnover in the CydB variants Asp58B➔Asn and Asp105B➔Asn variants consistent with them playing a role in proton transfer. Furthermore, in the Asp105B➔Asn variant, the reactions up to P formation occur essentially as in the wildtype bd-I, but the P➔F transition is specifically inhibited, supporting a direct and specific role for Asp105B in the functional proton transfer pathway in bd-I. We further discuss the possible identity of the high pKa proton donor, and the conservation pattern of the Asp-105B in the cyt. bd superfamily.
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Affiliation(s)
- M Janczak
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - J Vilhjálmsdóttir
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - P Ädelroth
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
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2
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Borisov VB, Arutyunyan AM. The fully reduced terminal oxidase bd-I isolated from Escherichia coli binds cyanide. J Inorg Biochem 2024; 259:112653. [PMID: 38943845 DOI: 10.1016/j.jinorgbio.2024.112653] [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: 04/09/2024] [Revised: 06/03/2024] [Accepted: 06/25/2024] [Indexed: 07/01/2024]
Abstract
Cytochrome bd-I from Escherichia coli belongs to the superfamily of prokaryotic bd-type oxygen reductases. It contains three hemes, b558, b595 and d, and couples oxidation of quinol by dioxygen with the generation of a proton-motive force. The enzyme exhibits resistance to various stressors and is considered as a target protein for next-generation antimicrobials. By using electronic absorption and MCD spectroscopy, this work shows that cyanide binds to heme d2+ in the isolated fully reduced cytochrome bd-I. Cyanide-induced difference absorption spectra display changes near the heme d2+ α-band, a minimum at 633 nm and a maximum around 600 nm, and a W-shaped response in the Soret region. Apparent dissociation constant (Kd) of the cyanide complex of heme d2+ is ∼0.052 M. Kinetics of cyanide binding is monophasic, indicating the presence of a single ligand binding site in the enzyme. Consistently, MCD data show that cyanide binds to heme d2+ but not to b5582+ or b5952+. This agrees with the published structural data that the enzyme's active site is not a di-heme site. The observed rate of binding (kobs) increases as the concentration of cyanide is increased, giving a second-order rate constant (kon) of ∼0.1 M-1 s-1.
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Affiliation(s)
- Vitaliy B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia.
| | - Alexander M Arutyunyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
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3
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Duport C, Armengaud J, Schmitt C, Morin D, Lacapère JJ. Elucidating the pivotal role of TSPO in porphyrin-related cellular processes, in Bacillus cereus. Biochimie 2024; 224:51-61. [PMID: 38423451 DOI: 10.1016/j.biochi.2024.02.008] [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: 01/11/2024] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 03/02/2024]
Abstract
A structural homolog of the mammalian TSPO has been identified in the human pathogen Bacillus cereus. BcTSPO, in its recombinant form, has previously been shown to bind and degrade porphyrins. In this study, we generated a ΔtspO mutant strain in B. cereus ATCC 14579 and assessed the impact of the absence of BcTSPO on cellular proteomics and physiological characteristics. The proteomic analysis revealed correlations between the lack of BcTSPO and the observed growth defects, increased oxygen consumption, ATP deficiency, heightened tryptophan catabolism, reduced motility, and impaired biofilm formation in the ΔtspO mutant strain. Our results also suggested that BcTSPO plays a crucial role in regulating intracellular levels of metabolites from the coproporphyrin-dependent branch of the heme biosynthetic pathway. This regulation potentially underlies alterations in the metabolic landscape, emphasizing the pivotal role of BcTSPO in B. cereus aerobic metabolism. Notably, our study unveils, for the first time, the involvement of TSPO in tryptophan metabolism. These findings underscore the multifaceted role of TSPO, not only in metabolic pathways but also potentially in the microorganism's virulence mechanisms.
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Affiliation(s)
| | - Jean Armengaud
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, 30200, Bagnols-sur-Cèze, France
| | - Caroline Schmitt
- Assistance Publique Hôpitaux de Paris (AP-HP), Centre Français des Porphyries, Hôpital Louis Mourier, 92700, Colombes, France; INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018, Paris, France
| | - Didier Morin
- INSERM, U955, équipe 3, Faculté de Médecine, Université Paris Est, 94010, Creteil, France
| | - Jean-Jacques Lacapère
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS UMR 7203, Laboratoire des BioMolécules (LBM), 4 place Jussieu, F-75005, Paris, France
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4
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Seitz C, Ahn SH, Wei H, Kyte M, Cook GM, Krause KL, McCammon JA. Targeting Tuberculosis: Novel Scaffolds for Inhibiting Cytochrome bd Oxidase. J Chem Inf Model 2024; 64:5232-5241. [PMID: 38874541 DOI: 10.1021/acs.jcim.4c00344] [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: 06/15/2024]
Abstract
Discovered in the 1920s, cytochrome bd is a terminal oxidase that has received renewed attention as a drug target since its atomic structure was first determined in 2016. Only found in prokaryotes, we study it here as a drug target for Mycobacterium tuberculosis (Mtb). Most previous drug discovery efforts toward cytochrome bd have involved analogues of the canonical substrate quinone, known as Aurachin D. Here, we report six new cytochrome bd inhibitor scaffolds determined from a computational screen and confirmed on target activity through in vitro testing. These scaffolds provide new avenues for lead optimization toward Mtb therapeutics.
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Affiliation(s)
- Christian Seitz
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Surl-Hee Ahn
- Department of Chemical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Haixin Wei
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Matson Kyte
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
| | - Kurt L Krause
- Department of Biochemistry, University of Otago, Dunedin 9016, New Zealand
| | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, United States
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5
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McKay LS, Spandrio AR, Johnson RM, Sobran MA, Marlatt SA, Mote KB, Dedloff MR, Nash ZM, Julio SM, Cotter PA. Cytochrome oxidase requirements in Bordetella reveal insights into evolution towards life in the mammalian respiratory tract. PLoS Pathog 2024; 20:e1012084. [PMID: 38976749 PMCID: PMC11257404 DOI: 10.1371/journal.ppat.1012084] [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: 02/29/2024] [Revised: 07/18/2024] [Accepted: 06/17/2024] [Indexed: 07/10/2024] Open
Abstract
Little is known about oxygen utilization during infection by bacterial respiratory pathogens. The classical Bordetella species, including B. pertussis, the causal agent of human whooping cough, and B. bronchiseptica, which infects nearly all mammals, are obligate aerobes that use only oxygen as the terminal electron acceptor for electron transport-coupled oxidative phosphorylation. B. bronchiseptica, which occupies many niches, has eight distinct cytochrome oxidase-encoding loci, while B. pertussis, which evolved from a B. bronchiseptica-like ancestor but now survives exclusively in and between human respiratory tracts, has only three functional cytochrome oxidase-encoding loci: cydAB1, ctaCDFGE1, and cyoABCD1. To test the hypothesis that the three cytochrome oxidases encoded within the B. pertussis genome represent the minimum number and class of cytochrome oxidase required for respiratory infection, we compared B. bronchiseptica strains lacking one or more of the eight possible cytochrome oxidases in vitro and in vivo. No individual cytochrome oxidase was required for growth in ambient air, and all three of the cytochrome oxidases conserved in B. pertussis were sufficient for growth in ambient air and low oxygen. Using a high-dose, large-volume persistence model and a low-dose, small-volume establishment of infection model, we found that B. bronchiseptica producing only the three B. pertussis-conserved cytochrome oxidases was indistinguishable from the wild-type strain for infection. We also determined that CyoABCD1 is sufficient to cause the same level of bacterial burden in mice as the wild-type strain and is thus the primary cytochrome oxidase required for murine infection, and that CydAB1 and CtaCDFGE1 fulfill auxiliary roles or are important for aspects of infection we have not assessed, such as transmission. Our results shed light on the environment at the surface of the ciliated epithelium, respiration requirements for bacteria that colonize the respiratory tract, and the evolution of virulence in bacterial pathogens.
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Affiliation(s)
- Liliana S. McKay
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Alexa R. Spandrio
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Richard M. Johnson
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - M. Ashley Sobran
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Sara A. Marlatt
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Katlyn B. Mote
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Margaret R. Dedloff
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Zachary M. Nash
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Steven M. Julio
- Department of Biology, Westmont College, Santa Barbara, California, United States of America
| | - Peggy A. Cotter
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina, United States of America
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6
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Nastasi MR, Caruso L, Giordano F, Mellini M, Rampioni G, Giuffrè A, Forte E. Cyanide Insensitive Oxidase Confers Hydrogen Sulfide and Nitric Oxide Tolerance to Pseudomonas aeruginosa Aerobic Respiration. Antioxidants (Basel) 2024; 13:383. [PMID: 38539916 PMCID: PMC10968556 DOI: 10.3390/antiox13030383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 07/31/2024] Open
Abstract
Hydrogen sulfide (H2S) and nitric oxide (NO) are long-known inhibitors of terminal oxidases in the respiratory chain. Yet, they exert pivotal signaling roles in physiological processes, and in several bacterial pathogens have been reported to confer resistance against oxidative stress, host immune responses, and antibiotics. Pseudomonas aeruginosa, an opportunistic pathogen causing life-threatening infections that are difficult to eradicate, has a highly branched respiratory chain including four terminal oxidases of the haem-copper type (aa3, cbb3-1, cbb3-2, and bo3) and one oxidase of the bd-type (cyanide-insensitive oxidase, CIO). As Escherichia coli bd-type oxidases have been shown to be H2S-insensitive and to readily recover their activity from NO inhibition, here we tested the effect of H2S and NO on CIO by performing oxygraphic measurements on membrane preparations from P. aeruginosa PAO1 and isogenic mutants depleted of CIO only or all other terminal oxidases except CIO. We show that O2 consumption by CIO is unaltered even in the presence of high levels of H2S, and that CIO expression is enhanced and supports bacterial growth under such stressful conditions. In addition, we report that CIO is reversibly inhibited by NO, while activity recovery after NO exhaustion is full and fast, suggesting a protective role of CIO under NO stress conditions. As P. aeruginosa is exposed to H2S and NO during infection, the tolerance of CIO towards these stressors agrees with the proposed role of CIO in P. aeruginosa virulence.
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Affiliation(s)
- Martina R. Nastasi
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, 00185 Rome, Italy; (M.R.N.); (F.G.)
| | - Lorenzo Caruso
- Department of Science, Roma Tre University, 00146 Rome, Italy (M.M.); (G.R.)
| | - Francesca Giordano
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, 00185 Rome, Italy; (M.R.N.); (F.G.)
| | - Marta Mellini
- Department of Science, Roma Tre University, 00146 Rome, Italy (M.M.); (G.R.)
| | - Giordano Rampioni
- Department of Science, Roma Tre University, 00146 Rome, Italy (M.M.); (G.R.)
- IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| | - Alessandro Giuffrè
- Institute of Molecular Biology and Pathology, National Research Council, 00185 Rome, Italy
| | - Elena Forte
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, 00185 Rome, Italy; (M.R.N.); (F.G.)
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7
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Saha P, Das S, Indurthi HK, Kumar R, Roy A, Kalia NP, Sharma DK. Cytochrome bd oxidase: an emerging anti-tubercular drug target. RSC Med Chem 2024; 15:769-787. [PMID: 38516593 PMCID: PMC10953478 DOI: 10.1039/d3md00587a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/25/2024] [Indexed: 03/23/2024] Open
Abstract
Cytochrome bd (cyt-bd) oxidase, one of the two terminal oxidases in the Mycobacterium tuberculosis (Mtb) oxidative phosphorylation pathway, plays an indispensable role in maintaining the functionality of the metabolic pathway under stressful conditions. However, the absence of this oxidase in eukaryotic cells allows researchers to select it as a potential drug target for the synthesis of anti-tubercular (anti-TB) molecules. Cyt-bd inhibitors have often been combined with cytochrome bcc/aa3 super-complex inhibitors in anti-TB drug regimens to achieve a desired bactericidal response. The functional redundancy between both the terminal oxidases is responsible for this. The cryo-EM structure of cyt-bd oxidase from Mtb (PDB ID: 7NKZ) further accelerated the research to identify its inhibitor. Herein, we have summarized the reported anti-TB cyt-bd inhibitors, insight into the rationale behind targeting cyt-bd oxidase, and an outline of the architecture of Mtb cyt-bd oxidase.
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Affiliation(s)
- Pallavi Saha
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Samarpita Das
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Harish K Indurthi
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Rohit Kumar
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
| | - Arnab Roy
- Department of Pharmacology and Toxicology, NIPER-Hyderabad Hyderabad 500037 India
| | - Nitin Pal Kalia
- Department of Pharmacology and Toxicology, NIPER-Hyderabad Hyderabad 500037 India
| | - Deepak K Sharma
- Department of Pharmaceutical Engg. and Tech, IIT-Banaras Hindu University Varanasi UP 221005 India
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8
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Sharma V, Hellwig P, Pereira M. Editorial: Computational and experimental insights in proton and ion translocating bioenergetic systems. Front Chem 2024; 12:1384385. [PMID: 38505678 PMCID: PMC10948602 DOI: 10.3389/fchem.2024.1384385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 02/28/2024] [Indexed: 03/21/2024] Open
Affiliation(s)
- Vivek Sharma
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Petra Hellwig
- Laboratoire de Bioelectrochimie et Spectroscopie, UMR, CMC, CNRS University of Strasbourg, Strasbourg, France
| | - Manuela Pereira
- Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisbon and BioISI - Biosystems and Integrative Sciences Institute, Lisbon, Portugal
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9
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Khalfaoui-Hassani B, Blaby-Haas CE, Verissimo A, Daldal F. The Escherichia coli MFS-type transporter genes yhjE, ydiM, and yfcJ are required to produce an active bo3 quinol oxidase. PLoS One 2023; 18:e0293015. [PMID: 37862358 PMCID: PMC10588857 DOI: 10.1371/journal.pone.0293015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 10/04/2023] [Indexed: 10/22/2023] Open
Abstract
Heme-copper oxygen reductases are membrane-bound oligomeric complexes that are integral to prokaryotic and eukaryotic aerobic respiratory chains. Biogenesis of these enzymes is complex and requires coordinated assembly of the subunits and their cofactors. Some of the components are involved in the acquisition and integration of different heme and copper (Cu) cofactors into these terminal oxygen reductases. As such, MFS-type transporters of the CalT family (e.g., CcoA) are required for Cu import and heme-CuB center biogenesis of the cbb3-type cytochrome c oxidases (cbb3-Cox). However, functionally homologous Cu transporters for similar heme-Cu containing bo3-type quinol oxidases (bo3-Qox) are unknown. Despite the occurrence of multiple MFS-type transporters, orthologs of CcoA are absent in bacteria like Escherichia coli that contain bo3-Qox. In this work, we identified a subset of uncharacterized MFS transporters, based on the presence of putative metal-binding residues, as likely candidates for the missing Cu transporter. Using a genetic approach, we tested whether these transporters are involved in the biogenesis of E. coli bo3-Qox. When respiratory growth is dependent on bo3-Qox, because of deletion of the bd-type Qox enzymes, three candidate genes, yhjE, ydiM, and yfcJ, were found to be critical for E. coli growth. Radioactive metal uptake assays showed that ΔydiM has a slower 64Cu uptake, whereas ΔyhjE accumulates reduced 55Fe in the cell, while no similar uptake defect is associated with ΔycfJ. Phylogenomic analyses suggest plausible roles for the YhjE, YdiM, and YfcJ transporters, and overall findings illustrate the diverse roles that the MFS-type transporters play in cellular metal homeostasis and production of active heme-Cu oxygen reductases.
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Affiliation(s)
- Bahia Khalfaoui-Hassani
- Université de Pau et des Pays de l’Adour, E2S UPPA, IPREM, UMR CNRS, Pau, France
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Crysten E. Blaby-Haas
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Lawrence Berkeley National Laboratory, The Molecular Foundry, Berkeley, CA, United States of America
| | - Andreia Verissimo
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
- bioMT-Institute for Biomolecular Targeting, Geisel School of Medicine at Dartmouth, Hanover, NH, United States of America
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
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10
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Nastasi MR, Borisov VB, Forte E. The terminal oxidase cytochrome bd-I confers carbon monoxide resistance to Escherichia coli cells. J Inorg Biochem 2023; 247:112341. [PMID: 37515940 DOI: 10.1016/j.jinorgbio.2023.112341] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/12/2023] [Accepted: 07/22/2023] [Indexed: 07/31/2023]
Abstract
Carbon monoxide (CO) plays a multifaceted role in the physiology of organisms, from poison to signaling molecule. Heme proteins, including terminal oxidases, are plausible CO targets. Three quinol oxidases terminate the branched aerobic respiratory chain of Escherichia coli. These are the heme‑copper cytochrome bo3 and two copper-lacking bd-type cytochromes, bd-I and bd-II. All three enzymes generate a proton motive force during the four-electron oxygen reduction reaction that is used for ATP production. The bd-type oxidases also contribute to mechanisms of bacterial defense against various types of stresses. Here we report that in E. coli cells, at the enzyme concentrations tested, cytochrome bd-I is much more resistant to inhibition by CO than cytochrome bd-II and cytochrome bo3. The apparent half-maximal inhibitory concentration values, IC50, for inhibition of O2 consumption of the membrane-bound bd-II and bo3 oxidases by CO at ~150 μM O2 were estimated to be 187.1 ± 11.1 and 183.3 ± 13.5 μM CO, respectively. Under the same conditions, the maximum inhibition observed with the membrane-bound cytochrome bd-I was 20 ± 10% at ~200 μM CO.
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Affiliation(s)
- Martina R Nastasi
- Department of Biochemical Sciences, Sapienza University of Rome, I-00185 Rome, Italy
| | - Vitaliy B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Elena Forte
- Department of Biochemical Sciences, Sapienza University of Rome, I-00185 Rome, Italy.
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11
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Borisov VB. Generation of Membrane Potential by Cytochrome bd. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1504-1512. [PMID: 38105020 DOI: 10.1134/s0006297923100073] [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: 06/10/2023] [Revised: 07/08/2023] [Accepted: 07/11/2023] [Indexed: 12/19/2023]
Abstract
An overview of current notions on the mechanism of generation of a transmembrane electric potential difference (Δψ) during the catalytic cycle of a bd-type triheme terminal quinol oxidase is presented in this work. It is suggested that the main contribution to Δψ formation is made by the movement of H+ across the membrane along the intra-protein hydrophilic proton-conducting pathway from the cytoplasm to the active site for oxygen reduction of this bacterial enzyme.
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Affiliation(s)
- Vitaliy B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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12
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Kägi J, Sloan W, Schimpf J, Nasiri HR, Lashley D, Friedrich T. Exploring ND-011992, a quinazoline-type inhibitor targeting quinone reductases and quinol oxidases. Sci Rep 2023; 13:12226. [PMID: 37507428 PMCID: PMC10382516 DOI: 10.1038/s41598-023-39430-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023] Open
Abstract
Bacterial energy metabolism has become a promising target for next-generation tuberculosis chemotherapy. One strategy to hamper ATP production is to inhibit the respiratory oxidases. The respiratory chain of Mycobacterium tuberculosis comprises a cytochrome bcc:aa3 and a cytochrome bd ubiquinol oxidase that require a combined approach to block their activity. A quinazoline-type compound called ND-011992 has previously been reported to ineffectively inhibit bd oxidases, but to act bactericidal in combination with inhibitors of cytochrome bcc:aa3 oxidase. Due to the structural similarity of ND-011992 to quinazoline-type inhibitors of respiratory complex I, we suspected that this compound is also capable of blocking other respiratory chain complexes. Here, we synthesized ND-011992 and a bromine derivative to study their effect on the respiratory chain complexes of Escherichia coli. And indeed, ND-011992 was found to inhibit respiratory complex I and bo3 oxidase in addition to bd-I and bd-II oxidases. The IC50 values are all in the low micromolar range, with inhibition of complex I providing the lowest value with an IC50 of 0.12 µM. Thus, ND-011992 acts on both, quinone reductases and quinol oxidases and could be very well suited to regulate the activity of the entire respiratory chain.
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Affiliation(s)
- Jan Kägi
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Willough Sloan
- Department of Chemistry, William & Mary, Williamsburg, VA, USA
| | - Johannes Schimpf
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Hamid R Nasiri
- Department of Cellular Microbiology, University Hohenheim, Stuttgart, Germany
| | - Dana Lashley
- Department of Chemistry, William & Mary, Williamsburg, VA, USA.
| | - Thorsten Friedrich
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
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13
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Capela R, Félix R, Clariano M, Nunes D, Perry MDJ, Lopes F. Target Identification in Anti-Tuberculosis Drug Discovery. Int J Mol Sci 2023; 24:10482. [PMID: 37445660 DOI: 10.3390/ijms241310482] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/17/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the etiological agent of tuberculosis (TB), a disease that, although preventable and curable, remains a global epidemic due to the emergence of resistance and a latent form responsible for a long period of treatment. Drug discovery in TB is a challenging task due to the heterogeneity of the disease, the emergence of resistance, and uncomplete knowledge of the pathophysiology of the disease. The limited permeability of the cell wall and the presence of multiple efflux pumps remain a major barrier to achieve effective intracellular drug accumulation. While the complete genome sequence of Mtb has been determined and several potential protein targets have been validated, the lack of adequate models for in vitro and in vivo studies is a limiting factor in TB drug discovery programs. In current therapeutic regimens, less than 0.5% of bacterial proteins are targeted during the biosynthesis of the cell wall and the energetic metabolism of two of the most important processes exploited for TB chemotherapeutics. This review provides an overview on the current challenges in TB drug discovery and emerging Mtb druggable proteins, and explains how chemical probes for protein profiling enabled the identification of new targets and biomarkers, paving the way to disruptive therapeutic regimens and diagnostic tools.
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Affiliation(s)
- Rita Capela
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Rita Félix
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Marta Clariano
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Diogo Nunes
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Maria de Jesus Perry
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Francisca Lopes
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
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14
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Kruth S, Nett M. Aurachins, Bacterial Antibiotics Interfering with Electron Transport Processes. Antibiotics (Basel) 2023; 12:1067. [PMID: 37370386 DOI: 10.3390/antibiotics12061067] [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: 05/31/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Aurachins are farnesylated quinolone alkaloids of bacterial origin and excellent inhibitors of the respiratory chain in pro- and eukaryotes. Therefore, they have become important tool compounds for the investigation of electron transport processes and they also serve as lead structures for the development of antibacterial and antiprotozoal drugs. Especially aurachin D proved to be a valuable starting point for structure-activity relationship studies. Aurachin D is a selective inhibitor of the cytochrome bd oxidase, which has received increasing attention as a target for the treatment of infectious diseases caused by mycobacteria. Moreover, aurachin D possesses remarkable activities against Leishmania donovani, the causative agent of leishmaniasis. Aurachins are naturally produced by myxobacteria of the genus Stigmatella as well as by some Streptomyces and Rhodococcus strains. The recombinant production of these antibiotics turned out to be challenging due to their complex biosynthesis and their inherent toxicity. Recently, the biotechnological production of aurachin D was established in E. coli with a titer which is higher than previously reported from natural producer organisms.
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Affiliation(s)
- Sebastian Kruth
- Laboratory of Technical Biology, Department of Biochemical and Chemical Engineering, TU Dortmund University, 44227 Dortmund, Germany
| | - Markus Nett
- Laboratory of Technical Biology, Department of Biochemical and Chemical Engineering, TU Dortmund University, 44227 Dortmund, Germany
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15
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Makarchuk I, Kägi J, Gerasimova T, Wohlwend D, Friedrich T, Melin F, Hellwig P. pH-dependent kinetics of NO release from E. coli bd-I and bd-II oxidase reveals involvement of Asp/Glu58 B. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148952. [PMID: 36535430 DOI: 10.1016/j.bbabio.2022.148952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 12/06/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022]
Abstract
Escherichia coli contains two cytochrome bd oxidases, bd-I and bd-II. The structure of both enzymes is highly similar, but they exhibit subtle differences such as the accessibility of the active site through a putative proton channel. Here, we demonstrate that the duroquinol:dioxygen oxidoreductase activity of bd-I increased with alkaline pH, whereas bd-II showed a broad activity maximum around pH 7. Likewise, the pH dependence of NO release from the reduced active site, an essential property of bd oxidases, differed between the two oxidases as detected by UV/vis spectroscopy. Both findings may be attributed to differences in the proton channel leading to the active site heme d. The channel comprises a titratable residue (Asp58B in bd-I and Glu58B in bd-II). Conservative mutations at this position drastically altered NO release demonstrating its contribution to the process.
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Affiliation(s)
- Iryna Makarchuk
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France
| | - Jan Kägi
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Tatjana Gerasimova
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Daniel Wohlwend
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Thorsten Friedrich
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany
| | - Frédéric Melin
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France
| | - Petra Hellwig
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France.
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16
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Azarkina NV, Borisov VB, Oleynikov IP, Sudakov RV, Vygodina TV. Interaction of Terminal Oxidases with Amphipathic Molecules. Int J Mol Sci 2023; 24:ijms24076428. [PMID: 37047401 PMCID: PMC10095113 DOI: 10.3390/ijms24076428] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 04/14/2023] Open
Abstract
The review focuses on recent advances regarding the effects of natural and artificial amphipathic compounds on terminal oxidases. Terminal oxidases are fascinating biomolecular devices which couple the oxidation of respiratory substrates with generation of a proton motive force used by the cell for ATP production and other needs. The role of endogenous lipids in the enzyme structure and function is highlighted. The main regularities of the interaction between the most popular detergents and terminal oxidases of various types are described. A hypothesis about the physiological regulation of mitochondrial-type enzymes by lipid-soluble ligands is considered.
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Affiliation(s)
- Natalia V Azarkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Vitaliy B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Ilya P Oleynikov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Roman V Sudakov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Tatiana V Vygodina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
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17
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F1·Fo ATP Synthase/ATPase: Contemporary View on Unidirectional Catalysis. Int J Mol Sci 2023; 24:ijms24065417. [PMID: 36982498 PMCID: PMC10049701 DOI: 10.3390/ijms24065417] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/05/2023] [Accepted: 03/10/2023] [Indexed: 03/14/2023] Open
Abstract
F1·Fo-ATP synthases/ATPases (F1·Fo) are molecular machines that couple either ATP synthesis from ADP and phosphate or ATP hydrolysis to the consumption or production of a transmembrane electrochemical gradient of protons. Currently, in view of the spread of drug-resistant disease-causing strains, there is an increasing interest in F1·Fo as new targets for antimicrobial drugs, in particular, anti-tuberculosis drugs, and inhibitors of these membrane proteins are being considered in this capacity. However, the specific drug search is hampered by the complex mechanism of regulation of F1·Fo in bacteria, in particular, in mycobacteria: the enzyme efficiently synthesizes ATP, but is not capable of ATP hydrolysis. In this review, we consider the current state of the problem of “unidirectional” F1·Fo catalysis found in a wide range of bacterial F1·Fo and enzymes from other organisms, the understanding of which will be useful for developing a strategy for the search for new drugs that selectively disrupt the energy production of bacterial cells.
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18
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Grund TN, Kabashima Y, Kusumoto T, Wu D, Welsch S, Sakamoto J, Michel H, Safarian S. The cryoEM structure of cytochrome bd from C. glutamicum provides novel insights into structural properties of actinobacterial terminal oxidases. Front Chem 2023; 10:1085463. [PMID: 36688035 PMCID: PMC9846854 DOI: 10.3389/fchem.2022.1085463] [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: 11/01/2022] [Accepted: 12/12/2022] [Indexed: 01/05/2023] Open
Abstract
Cytochromes bd are essential for microaerobic respiration of many prokaryotes including a number of human pathogens. These enzymes catalyze the reduction of molecular oxygen to water using quinols as electron donors. Their importance for prokaryotic survival and the absence of eukaryotic homologs make these enzyme ideal targets for antimicrobial drugs. Here, we determined the cryoEM structure of the menaquinol-oxidizing cytochrome bd-type oxygen reductase of the facultative anaerobic Actinobacterium Corynebacterium glutamicum at a resolution of 2.7 Å. The obtained structure adopts the signature pseudosymmetrical heterodimeric architecture of canonical cytochrome bd oxidases formed by the core subunits CydA and CydB. No accessory subunits were identified for this cytochrome bd homolog. The two b-type hemes and the oxygen binding heme d are organized in a triangular geometry with a protein environment around these redox cofactors similar to that of the closely related cytochrome bd from M. tuberculosis. We identified oxygen and a proton conducting channels emerging from the membrane space and the cytoplasm, respectively. Compared to the prototypical enzyme homolog from the E. coli, the most apparent difference is found in the location and size of the proton channel entry site. In canonical cytochrome bd oxidases quinol oxidation occurs at the highly flexible periplasmic Q-loop located in the loop region between TMHs six and seven. An alternative quinol-binding site near heme b 595 was previously identified for cytochrome bd from M. tuberculosis. We discuss the relevance of the two quinol oxidation sites in actinobacterial bd-type oxidases and highlight important differences that may explain functional and electrochemical differences between C. glutamicum and M. tuberculosis. This study expands our current understanding of the structural diversity of actinobacterial and proteobacterial cytochrome bd oxygen reductases and provides deeper insights into the unique structural and functional properties of various cytochrome bd variants from different phylae.
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Affiliation(s)
- Tamara N. Grund
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Yoshiki Kabashima
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Fukuoka, Japan
| | - Tomoichirou Kusumoto
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Fukuoka, Japan
| | - Di Wu
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Junshi Sakamoto
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Fukuoka, Japan
| | - Hartmut Michel
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Schara Safarian
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt, Germany,Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand,Fraunhofer Institute for Translational Medicine and Pharmacology ITMP Frankfurt, Frankfurt, Germany,*Correspondence: Schara Safarian,
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19
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Joshi K, Chan CH, Levar CE, Bond DR. Single Amino Acid Residues Control Potential‐Dependent Inactivation of an Inner Membrane
bc‐
Cytochrome**. ChemElectroChem 2022. [DOI: 10.1002/celc.202200907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Komal Joshi
- Department of Biochemistry Molecular Biology and Biophysics University of Minnesota Twin Cities St. Paul MN 55108 USA
- The BioTechnology Institute University of Minnesota Twin Cities St. Paul MN 55108 USA
| | - Chi H. Chan
- The BioTechnology Institute University of Minnesota Twin Cities St. Paul MN 55108 USA
| | - Caleb E. Levar
- The BioTechnology Institute University of Minnesota Twin Cities St. Paul MN 55108 USA
| | - Daniel R. Bond
- The BioTechnology Institute University of Minnesota Twin Cities St. Paul MN 55108 USA
- Department of Plant and Microbial Biology University of Minnesota Twin Cities St. Paul MN 55108 USA
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20
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Identification of Small Molecule Inhibitors against Mycobacteria in Activated Macrophages. Molecules 2022; 27:molecules27185824. [PMID: 36144572 PMCID: PMC9504936 DOI: 10.3390/molecules27185824] [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: 08/15/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/17/2022] Open
Abstract
Mycobacterial pathogens are intrinsically resistant to many available antibiotics, making treatment extremely challenging, especially in immunocompromised individuals and patients with underlying and chronic lung conditions. Even with lengthy therapy and the use of a combination of antibiotics, clinical success for non-tuberculous mycobacteria (NTM) is achieved in fewer than half of the cases. The need for novel antibiotics that are effective against NTM is urgent. To identify such new compounds, a whole cell high-throughput screen (HTS) was performed in this study. Compounds from the Chembridge DIVERSet library were tested for their ability to inhibit intracellular survival of M. avium subsp. hominissuis (MAH) expressing dtTomato protein, using fluorescence as a readout. Fifty-eight compounds were identified to significantly inhibit fluorescent readings of MAH. In subsequent assays, it was found that treatment of MAH-infected THP-1 macrophages with 27 of 58 hit compounds led to a significant reduction in intracellular viable bacteria, while 19 compounds decreased M. abscessus subsp. abscessus (Mab) survival rates within phagocytic cells. In addition, the hit compounds were tested in M. tuberculosis H37Ra (Mtb) and 14 compounds were found to exhibit activity in activated THP-1 cells. While the majority of compounds displayed inhibitory activity against both replicating (extracellular) and non-replicating (intracellular) forms of bacteria, a set of compounds appeared to be effective exclusively against intracellular bacteria. The efficacy of these compounds was examined in combination with current antibiotics and survival of both NTM and Mtb were evaluated within phagocytic cells. In time-kill dynamic studies, it was found that co-treatment promoted increased bacterial clearance when compared with the antibiotic or compound group alone. This study describes promising anti-NTM and anti-Mtb compounds with potential novel mechanisms of action that target intracellular bacteria in activated macrophages.
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21
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Response of Mycobacterium smegmatis to the Cytochrome bcc Inhibitor Q203. Int J Mol Sci 2022; 23:ijms231810331. [PMID: 36142240 PMCID: PMC9498996 DOI: 10.3390/ijms231810331] [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] [Received: 08/16/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
For the design of next-generation tuberculosis chemotherapy, insight into bacterial defence against drugs is required. Currently, targeting respiration has attracted strong attention for combatting drug-resistant mycobacteria. Q203 (telacebec), an inhibitor of the cytochrome bcc complex in the mycobacterial respiratory chain, is currently evaluated in phase-2 clinical trials. Q203 has bacteriostatic activity against M. tuberculosis, which can be converted to bactericidal activity by concurrently inhibiting an alternative branch of the mycobacterial respiratory chain, cytochrome bd. In contrast, non-tuberculous mycobacteria, such as Mycobacterium smegmatis, show only very little sensitivity to Q203. In this report, we investigated factors that M. smegmatis employs to adapt to Q203 in the presence or absence of a functional cytochrome bd, especially regarding its terminal oxidases. In the presence of a functional cytochrome bd, M. smegmatis responds to Q203 by increasing the expression of cytochrome bcc as well as of cytochrome bd, whereas a M. smegmatisbd-KO strain adapted to Q203 by increasing the expression of cytochrome bcc. Interestingly, single-cell studies revealed cell-to-cell variability in drug adaptation. We also investigated the role of a putative second cytochrome bd isoform postulated for M. smegmatis. Although this putative isoform showed differential expression in response to Q203 in the M. smegmatisbd-KO strain, it did not display functional features similar to the characterised cytochrome bd variant.
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22
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Forte E, Nastasi MR, Borisov VB. Preparations of Terminal Oxidase Cytochrome bd-II Isolated from Escherichia coli Reveal Significant Hydrogen Peroxide Scavenging Activity. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:720-730. [PMID: 36171653 DOI: 10.1134/s0006297922080041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 06/16/2023]
Abstract
Cytochrome bd-II is one of the three terminal quinol oxidases of the aerobic respiratory chain of Escherichia coli. Preparations of the detergent-solubilized untagged bd-II oxidase isolated from the bacterium were shown to scavenge hydrogen peroxide (H2O2) with high rate producing molecular oxygen (O2). Addition of H2O2 to the same buffer that does not contain enzyme or contains thermally denatured cytochrome bd-II does not lead to any O2 production. The latter observation rules out involvement of adventitious transition metals bound to the protein. The H2O2-induced O2 production is not susceptible to inhibition by N-ethylmaleimide (the sulfhydryl binding compound), antimycin A (the compound that binds specifically to a quinol binding site), and CO (diatomic gas that binds specifically to the reduced heme d). However, O2 formation is inhibited by cyanide (IC50 = 4.5 ± 0.5 µM) and azide. Addition of H2O2 in the presence of dithiothreitol and ubiquinone-1 does not inactivate cytochrome bd-II and apparently does not affect the O2 reductase activity of the enzyme. The ability of cytochrome bd-II to detoxify H2O2 could play a role in bacterial physiology by conferring resistance to the peroxide-mediated stress.
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Affiliation(s)
- Elena Forte
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, I-00185, Italy
| | - Martina R Nastasi
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, I-00185, Italy
| | - Vitaliy B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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23
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Borisov VB, Forte E. Bioenergetics and Reactive Nitrogen Species in Bacteria. Int J Mol Sci 2022; 23:7321. [PMID: 35806323 PMCID: PMC9266656 DOI: 10.3390/ijms23137321] [Citation(s) in RCA: 6] [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: 06/08/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 11/24/2022] Open
Abstract
The production of reactive nitrogen species (RNS) by the innate immune system is part of the host's defense against invading pathogenic bacteria. In this review, we summarize recent studies on the molecular basis of the effects of nitric oxide and peroxynitrite on microbial respiration and energy conservation. We discuss possible molecular mechanisms underlying RNS resistance in bacteria mediated by unique respiratory oxygen reductases, the mycobacterial bcc-aa3 supercomplex, and bd-type cytochromes. A complete picture of the impact of RNS on microbial bioenergetics is not yet available. However, this research area is developing very rapidly, and the knowledge gained should help us develop new methods of treating infectious diseases.
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Affiliation(s)
- Vitaliy B. Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - Elena Forte
- Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy;
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