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Yang M, Dong PT, Cen L, Shi W, He X, Li J. Targeting Fusobacterium nucleatum through chemical modifications of host-derived transfer RNA fragments. THE ISME JOURNAL 2023; 17:880-890. [PMID: 37005460 PMCID: PMC10202947 DOI: 10.1038/s41396-023-01398-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/13/2023] [Accepted: 03/17/2023] [Indexed: 04/04/2023]
Abstract
Host mucosal barriers possess an arsenal of defense molecules to maintain host-microbe homeostasis such as antimicrobial peptides and immunoglobulins. In addition to these well-established defense molecules, we recently reported small RNAs (sRNAs)-mediated interactions between human oral keratinocytes and Fusobacterium nucleatum (Fn), an oral pathobiont with increasing implications in extra-oral diseases. Specifically, upon Fn infection, oral keratinocytes released Fn-targeting tRNA-derived sRNAs (tsRNAs), an emerging class of noncoding sRNAs with gene regulatory functions. To explore potential antimicrobial activities of tsRNAs, we chemically modify the nucleotides of the Fn-targeting tsRNAs and demonstrate that the resultant tsRNA derivatives, termed MOD-tsRNAs, exhibit growth inhibitory effect against various Fn type strains and clinical tumor isolates without any delivery vehicle in the nanomolar concentration range. In contrast, the same MOD-tsRNAs do not inhibit other representative oral bacteria. Further mechanistic studies uncover the ribosome-targeting functions of MOD-tsRNAs in inhibiting Fn. Taken together, our work provides an engineering approach to targeting pathobionts through co-opting host-derived extracellular tsRNAs.
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Affiliation(s)
- Mengdi Yang
- Department of Bioengineering, Northeastern University, Boston, MA, 02115, USA
| | - Pu-Ting Dong
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, 02142, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, 02115, USA
| | - Lujia Cen
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, 02142, USA
| | - Wenyuan Shi
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, 02142, USA
| | - Xuesong He
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, 02142, USA.
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, 02115, USA.
| | - Jiahe Li
- Department of Bioengineering, Northeastern University, Boston, MA, 02115, USA.
- Department of Biomedical Engineering, College of Engineering and School of Medicine, University of Michigan, Ann Arbor, MI, 48109-5622, USA.
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2
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Rotor subunits adaptations in ATP synthases from photosynthetic organisms. Biochem Soc Trans 2021; 49:541-550. [PMID: 33890627 PMCID: PMC8106487 DOI: 10.1042/bst20190936] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/17/2021] [Accepted: 03/22/2021] [Indexed: 11/17/2022]
Abstract
Driven by transmembrane electrochemical ion gradients, F-type ATP synthases are the primary source of the universal energy currency, adenosine triphosphate (ATP), throughout all domains of life. The ATP synthase found in the thylakoid membranes of photosynthetic organisms has some unique features not present in other bacterial or mitochondrial systems. Among these is a larger-than-average transmembrane rotor ring and a redox-regulated switch capable of inhibiting ATP hydrolysis activity in the dark by uniquely adapted rotor subunit modifications. Here, we review recent insights into the structure and mechanism of ATP synthases specifically involved in photosynthesis and explore the cellular physiological consequences of these adaptations at short and long time scales.
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Lin WY, Liaw SJ. Deacidification by FhlA-dependent hydrogenase is involved in urease activity and urinary stone formation in uropathogenic Proteus mirabilis. Sci Rep 2020; 10:19546. [PMID: 33177598 PMCID: PMC7658346 DOI: 10.1038/s41598-020-76561-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/26/2020] [Indexed: 11/09/2022] Open
Abstract
Proteus mirabilis is an important uropathogen, featured with urinary stone formation. Formate hydrogenlyase (FHL), consisting of formate dehydrogenase H and hydrogenase for converting proton to hydrogen, has been implicated in virulence. In this study, we investigated the role of P. mirabilis FHL hydrogenase and the FHL activator, FhlA. fhlA and hyfG (encoding hydrogenase large subunit) displayed a defect in acid resistance. fhlA and hyfG mutants displayed a delay in medium deacidification compared to wild-type and ureC mutant failed to deacidify the medium. In addition, loss of fhlA or hyfG decreased urease activity in the pH range of 5-8. The reduction of urease activities in fhlA and hyfG mutants subsided gradually over the pH range and disappeared at pH 9. Furthermore, mutation of fhlA or hyfG resulted in a decrease in urinary stone formation in synthetic urine. These indicate fhlA- and hyf-mediated deacidification affected urease activity and stone formation. Finally, fhlA and hyfG mutants exhibited attenuated colonization in mice. Altogether, we found expression of fhlA and hyf confers medium deacidification via facilitating urease activity, thereby urinary stone formation and mouse colonization. The link of acid resistance to urease activity provides a potential strategy for counteracting urinary tract infections by P. mirabilis.
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Affiliation(s)
- Wen-Yuan Lin
- Department and Graduate Institute of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, No. 1, Chang-Te Street, Taipei, 10016, Taiwan, ROC
| | - Shwu-Jen Liaw
- Department and Graduate Institute of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, No. 1, Chang-Te Street, Taipei, 10016, Taiwan, ROC. .,Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University, Taipei, Taiwan, Republic of China.
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Mikoyan G, Karapetyan L, Vassilian A, Trchounian A, Trchounian K. External succinate and potassium ions influence Dcu dependent FOF1-ATPase activity and H+ flux of Escherichia coli at different pHs. J Bioenerg Biomembr 2020; 52:377-382. [DOI: 10.1007/s10863-020-09847-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/19/2020] [Indexed: 01/12/2023]
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Karapetyan L, Valle A, Bolivar J, Trchounian A, Trchounian K. Evidence for Escherichia coli DcuD carrier dependent F OF 1-ATPase activity during fermentation of glycerol. Sci Rep 2019; 9:4279. [PMID: 30862913 PMCID: PMC6414658 DOI: 10.1038/s41598-019-41044-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/27/2019] [Indexed: 01/11/2023] Open
Abstract
During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work reveals the total and N,N'-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5 in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40% and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD is absent. No significant differences were determined in wild type and mutants specific growth rate except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact on H+ fluxes, FOF1-ATPase activity and depends on potassium ions.
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Affiliation(s)
- L Karapetyan
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
| | - A Valle
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Institute of Biomolecules (INBIO), University of Cádiz, Avda. República Saharui s/n, 11510, Puerto Real, Cádiz, Spain
| | - J Bolivar
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Institute of Biomolecules (INBIO), University of Cádiz, Avda. República Saharui s/n, 11510, Puerto Real, Cádiz, Spain
| | - A Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
- Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia
| | - K Trchounian
- Department of Biochemistry, Microbiology and Biotechnology, Faculty of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
- Scientific-Research Institute of Biology, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
- Microbial Biotechnologies and Biofuel Innovation Center, Yerevan State University, 1 A. Manoogian str., 0025, Yerevan, Armenia.
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Gevorgyan H, Trchounian A, Trchounian K. Understanding the Role ofEscherichia coliHydrogenases and Formate Dehydrogenases in the FOF1-ATPase Activity during the Mixed Acid Fermentation of Mixture of Carbon Sources. IUBMB Life 2018; 70:1040-1047. [DOI: 10.1002/iub.1915] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/16/2018] [Accepted: 06/25/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Heghine Gevorgyan
- Department of Biochemistry, Microbiology and Biotechnology; Faculty of Biology, Yerevan State University; Yerevan Armenia
| | - Armen Trchounian
- Department of Biochemistry, Microbiology and Biotechnology; Faculty of Biology, Yerevan State University; Yerevan Armenia
- Scientific-Research Institute of Biology, Faculty of Biology; Yerevan State University; Yerevan Armenia
| | - Karen Trchounian
- Scientific-Research Institute of Biology, Faculty of Biology; Yerevan State University; Yerevan Armenia
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Blbulyan S, Trchounian A. Impact of membrane-associated hydrogenases on the FOF1-ATPase in Escherichia coli during glycerol and mixed carbon fermentation: ATPase activity and its inhibition by N,N′-dicyclohexylcarbodiimide in the mutants lacking hydrogenases. Arch Biochem Biophys 2015; 579:67-72. [DOI: 10.1016/j.abb.2015.05.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/28/2015] [Accepted: 05/29/2015] [Indexed: 10/23/2022]
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8
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Trchounian A, Gary Sawers R. Novel insights into the bioenergetics of mixed-acid fermentation: Can hydrogen and proton cycles combine to help maintain a proton motive force? IUBMB Life 2013; 66:1-7. [DOI: 10.1002/iub.1236] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/04/2013] [Accepted: 12/08/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Armen Trchounian
- Department of Microbiology; Plants and Microbes Biotechnology, Faculty of Biology, Yerevan State University; Yerevan Armenia
| | - R. Gary Sawers
- Institute of Biology/Microbiology; Martin Luther University of Halle-Wittenberg; Halle (Saale) Germany
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Trchounian A. Mechanisms for hydrogen production by different bacteria during mixed-acid and photo-fermentation and perspectives of hydrogen production biotechnology. Crit Rev Biotechnol 2013; 35:103-13. [DOI: 10.3109/07388551.2013.809047] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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10
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Trchounian K, Poladyan A, Vassilian A, Trchounian A. Multiple and reversible hydrogenases for hydrogen production byEscherichia coli: dependence on fermentation substrate, pH and the F0F1-ATPase. Crit Rev Biochem Mol Biol 2012; 47:236-49. [DOI: 10.3109/10409238.2012.655375] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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11
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Extremely High Frequency Electromagnetic Radiation Enforces Bacterial Effects of Inhibitors and Antibiotics. Cell Biochem Biophys 2008; 51:97-103. [DOI: 10.1007/s12013-008-9020-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2008] [Indexed: 11/25/2022]
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12
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Copper (II) ions affect Escherichia coli membrane vesicles' SH-groups and a disulfide-dithiol interchange between membrane proteins. Cell Biochem Biophys 2008; 51:45-50. [PMID: 18458828 DOI: 10.1007/s12013-008-9014-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Accepted: 04/21/2008] [Indexed: 11/27/2022]
Abstract
The SH-groups in Escherichia coli membrane vesicles, prepared from cells grown in fermentation conditions on glucose at slightly alkaline pH, have a role in the F0F1-ATPase operation. The changes in the number of these groups by ATP are observed under certain conditions. In this study, copper ions (Cu2+) in concentration of 0.1 mM were shown to increase the number of SH-groups in 1.5- to 1.6-fold independent from K+ ions, and the suppression of the increased level of SH-groups by ATP was determined for Cu2+ in the presence of K+. Moreover, the increase in the number of SH-groups by Cu2+ was absent as well as the inhibition in ATP-dependent increasing SH-groups number by Cu2+ lacked when vesicles were treated with N-ethylmaleimide (NEM), specific thiol-reagent. Such an effect was not observed with zinc (Zn2+), cobalt (Co2+), or Cu+ ions. The increased level of SH-groups was observed in the hycE or hyfR mutants with defects in hydrogenases 3 or 4, whereas the ATP-dependent increase in the number of these groups was determined in hycE not in hyfR mutants. Both changes in SH-groups number disappeared in the atp or hyc mutants deleted for the F0F1-ATPase or hydrogenase 3 (no activity of hydrogenase 4 was detected in the hyc mutant used). A direct effect of Cu2+ but not Cu+ on the F0F1-ATPase is suggested to lead to conformational changes or damaging consequences, increasing accessible SH-groups number and disturbing disulfide-dithiol interchange within a protein-protein complex, where this ATPase works with K+ uptake system or hydrogenase 4 (Hyd-4); breaks in disulfides are not ruled out.
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13
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Hakobyan M, Poladyan A, Bagramyan K. Energy transformation coupled to formate oxidation during anaerobic fermentation. Biophysics (Nagoya-shi) 2006. [DOI: 10.1134/s0006350906030122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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14
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Poladyan A, Trchounian A. The increase in the number of accessible SH-groups in the enterococcal membrane vesicles by ATP and nicotinamide adenine dinucleotides. Curr Microbiol 2006; 52:300-4. [PMID: 16550463 DOI: 10.1007/s00284-005-0293-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Accepted: 11/03/2005] [Indexed: 11/27/2022]
Abstract
The number of accessible SH groups was determined in membrane vesicles prepared from Enterococcus hirae grown under anaerobic conditions at alkaline pH (pH 8.0). Addition of ATP or nicotinamide adenine dinucleotides (NAD(+) +NADH) to the vesicles caused a approximately 4-fold or approximately 1.9-fold increase in the number of SH-groups, respectively. This was inhibited by treatment with N-ethylmaleimide. The increase was significant when ATP and NAD(+) +NADH both were added. The change was lacking in the presence of the F0F1-ATPase inhibitors N,N'-diclohexylcarbodiimide or sodium azide. This was also absent in atp mutant with defect in the F0F1-ATPase and, in addition, it was less in potassium ion-free medium. These results are correlated with data about K+-dependent F0F1-ATPase activity, suggesting a relationship between the F0F1-ATPase and K+ uptake Trk-like system. The latter may be regulated by NAD or NADH mediating conformational changes.
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Affiliation(s)
- Anna Poladyan
- Department of Biophysics of the Biological Faculty, Yerevan State University, 1 Alex Manoukian Str., 375025, Yerevan, Armenia
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15
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Coppi MV. The hydrogenases of Geobacter sulfurreducens: a comparative genomic perspective. MICROBIOLOGY-SGM 2005; 151:1239-1254. [PMID: 15817791 DOI: 10.1099/mic.0.27535-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The hydrogenase content of the genome of Geobacter sulfurreducens, a member of the family Geobacteraceae within the delta-subdivision of the Proteobacteria, was examined and found to be distinct from that of Desulfovibrio species, another family of delta-Proteobacteria on which extensive research concerning hydrogen metabolism has been conducted. Four [NiFe]-hydrogenases are encoded in the G. sulfurreducens genome: two periplasmically oriented, membrane-bound hydrogenases, Hya and Hyb, and two cytoplasmic hydrogenases, Mvh and Hox. None of these [NiFe]-hydrogenases has a counterpart in Desulfovibrio species. Furthermore, the large and small subunits of Mvh and Hox appear to be related to archaeal and cyanobacterial hydrogenases, respectively. Clusters encoding [Fe]-hydrogenases and periplasmic [NiFeSe]-hydrogenases, which are commonly found in the genomes of Desulfovibrio species, are not present in the genome of G. sulfurreducens. Hydrogen-evolving Ech hydrogenases, which are present in the genomes of at least two Desulfovibrio species, were also absent from the G. sulfurreducens genome, despite the fact that G. sulfurreducens is capable of hydrogen production. Instead, the G. sulfurreducens genome contained a cluster encoding a multimeric Ech hydrogenase related (Ehr) complex that was similar in content to operons encoding Ech hydrogenases, but did not appear to encode a hydrogenase. Phylogenetic analysis revealed that the G. sulfurreducens ehr cluster is part of a family of related clusters found in both the Archaea and Bacteria.
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Affiliation(s)
- Maddalena V Coppi
- Department of Microbiology, 203N Morrill Science Center IVN, University of Massachusetts-Amherst, Amherst, MA 01003, USA
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Hakobyan M, Sargsyan H, Bagramyan K. Proton translocation coupled to formate oxidation in anaerobically grown fermenting Escherichia coli. Biophys Chem 2005; 115:55-61. [PMID: 15848284 DOI: 10.1016/j.bpc.2005.01.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Accepted: 01/04/2005] [Indexed: 11/24/2022]
Abstract
Proton translocation, coupled to formate oxidation and hydrogen evolution, was studied in anaerobically grown fermenting Escherichia coli JW136 carrying hydrogenase 1 (hya) and hydrogenase 2 (hyb) double deletions. Rapid acidification of the medium by EDTA-treated anaerobic suspension of the whole cells or its alkalization by inverted membranes was observed in response to application of formate. The formate-dependent proton translocation and 2H(+)-K(+) exchange coupled to H(2) evolution were sensitive to the uncoupler, carbonylcyanide-m-chlorophenylhydrazone, and to copper ions, inhibitors of hydrogenases. No pH changes were observed in a suspension of formate-pulsed aerobically grown ("respiring") cells. The apparent H(+)/formate ratio of 1.3 was obtained in cells oxidizing formate. The 2H(+)-K(+) exchange of the ATP synthase inhibitor N,N'-dicyclohexylcarbodiimide-sensitive ion fluxes does take place in JW136 cell suspension. Hydrogen formation from formate by cell suspensions of E. coli JW136 resulted in the formation of a membrane potential (Deltapsi) across the cytoplasmic membrane of -130 mV (inside negative). This was abolished in the presence of copper ions, although they had little effect on the value of Deltapsi generated by E. coli under respiration. We conclude that the hydrogen production by hydrogenase 3 is coupled to formate-dependent proton pumping that regulates 2H(+)-K(+) exchange in fermenting bacteria.
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Affiliation(s)
- Marta Hakobyan
- Department of Biophysics, Yerevan State University, Armenia
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Trchounian A. Escherichia coli proton-translocating F0F1-ATP synthase and its association with solute secondary transporters and/or enzymes of anaerobic oxidation–reduction under fermentation. Biochem Biophys Res Commun 2004; 315:1051-7. [PMID: 14985119 DOI: 10.1016/j.bbrc.2004.02.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2004] [Indexed: 11/26/2022]
Abstract
The Escherichia coli proton-translocating F0F1-ATP synthase has a priority in H+ circulation through the membrane in maintaining proton-motive force in the context of ATP synthesis and hydrolysis. Recent advances in the study of this complex under fermentative growth have led to hypothesis that, in the absence of oxidative phosphorylation, F0F1 is implicated as an essential part of H+ movement and ATP hydrolysis, associated with solute secondary transporters and/or enzymes of anaerobic oxidation-reduction. These associations can result from a protein-protein interaction by dithiol-disulfide interchange. In such associations F0F1 has novel functions in bacterial cell physiology.
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Affiliation(s)
- Armen Trchounian
- Department of Biophysics of the Biological Faculty, Yerevan State University, 1 A. Manoukian Street, 375049 Yerevan, Armenia.
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Mnatsakanyan N, Poladian A, Bagramyan K, Trchounian A. The number of accessible SH-groups in Escherichia coli membrane vesicles is increased by ATP or by formate. Biochem Biophys Res Commun 2003; 308:655-9. [PMID: 12914800 DOI: 10.1016/s0006-291x(03)01460-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The number of accessible SH-groups was determined in membrane vesicles prepared from Escherichia coli growing in fermentation conditions at slightly alkaline pH on glucose with or without added formate. Addition of ATP or formate to the vesicles caused a approximately 1.4-fold increase in the number of accessible SH-groups. The increase was inhibited by treatment with N-ethylmaleimide or the presence of the F(0)F(1)-ATPase inhibitors N,N(')-dicyclohexylcarbodiimide or sodium azide. The increase in accessible SH-groups was also absent in strains with the ATP synthase operon deleted or with the single F(0) domain cysteine Cysb21 changed to Ala. Using hyc and hyf mutants, it was shown that the increase was also largely dependent on hydrogenase 4 or hydrogenase 3, main components of formate hydrogen lyase, when bacteria were grown in the absence or presence of added formate. These results suggest a relationship between the F(0)F(1)-ATP synthase and hydrogenase 4 or hydrogenase 3 under fermentation conditions.
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Affiliation(s)
- Nelli Mnatsakanyan
- Department of Biophysics of the Biological Faculty, Yerevan State University, Armenia
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