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Ishikawa M, Masuya T, Kuroda S, Uno S, Butler NL, Foreman S, Murai M, Barquera B, Miyoshi H. The side chain of ubiquinone plays a critical role in Na + translocation by the NADH-ubiquinone oxidoreductase (Na +-NQR) from Vibrio cholerae. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148547. [PMID: 35337841 DOI: 10.1016/j.bbabio.2022.148547] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/18/2022] [Accepted: 03/17/2022] [Indexed: 11/19/2022]
Abstract
The Na+-pumping NADH-ubiquinone (UQ) oxidoreductase (Na+-NQR) is an essential bacterial respiratory enzyme that generates a Na+ gradient across the cell membrane. However, the mechanism that couples the redox reactions to Na+ translocation remains unknown. To address this, we examined the relation between reduction of UQ and Na+ translocation using a series of synthetic UQs with Vibrio cholerae Na+-NQR reconstituted into liposomes. UQ0 that has no side chain and UQCH3 and UQC2H5, which have methyl and ethyl side chains, respectively, were catalytically reduced by Na+-NQR, but their reduction generated no membrane potential, indicating that the overall electron transfer and Na+ translocation are not coupled. While these UQs were partly reduced by electron leak from the cofactor(s) located upstream of riboflavin, this complete loss of Na+ translocation cannot be explained by the electron leak. Lengthening the UQ side chain to n-propyl (C3H7) or longer significantly restored Na+ translocation. It has been considered that Na+ translocation is completed when riboflavin, a terminal redox cofactor residing within the membrane, is reduced. In this view, the role of UQ is simply to accept electrons from the reduced riboflavin to regenerate the stable neutral riboflavin radical and reset the catalytic cycle. However, the present study revealed that the final UQ reduction via reduced riboflavin makes an important contribution to Na+ translocation through a critical role of its side chain. Based on the results, we discuss the critical role of the UQ side chain in Na+ translocation.
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Affiliation(s)
- Moe Ishikawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Takahiro Masuya
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Seina Kuroda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Shinpei Uno
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Nicole L Butler
- Department of Biological Science, Rensselaer Polytechnic Institute, Troy, NY 12180, United States
| | - Sara Foreman
- Department of Biological Science, Rensselaer Polytechnic Institute, Troy, NY 12180, United States
| | - Masatoshi Murai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Blanca Barquera
- Department of Biological Science, Rensselaer Polytechnic Institute, Troy, NY 12180, United States; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, United States
| | - Hideto Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
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2
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New insights into the structure, assembly and biological roles of 10–12 nm connective tissue microfibrils from fibrillin-1 studies. Biochem J 2016; 473:827-38. [DOI: 10.1042/bj20151108] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/26/2016] [Indexed: 12/21/2022]
Abstract
The 10–12 nm diameter microfibrils of the extracellular matrix (ECM) impart both structural and regulatory properties to load-bearing connective tissues. The main protein component is the calcium-dependent glycoprotein fibrillin, which assembles into microfibrils at the cell surface in a highly regulated process involving specific proteolysis, multimerization and glycosaminoglycan interactions. In higher metazoans, microfibrils act as a framework for elastin deposition and modification, resulting in the formation of elastic fibres, but they can also occur in elastin-free tissues where they perform structural roles. Fibrillin microfibrils are further engaged in a number of cell matrix interactions such as with integrins, bone morphogenetic proteins (BMPs) and the large latent complex of transforming growth factor-β (TGFβ). Fibrillin-1 (FBN1) mutations are associated with a range of heritable connective disorders, including Marfan syndrome (MFS) and the acromelic dysplasias, suggesting that the roles of 10–12 nm diameter microfibrils are pleiotropic. In recent years the use of molecular, cellular and whole-organism studies has revealed that the microfibril is not just a structural component of the ECM, but through its network of cell and matrix interactions it can exert profound regulatory effects on cell function. In this review we assess what is known about the molecular properties of fibrillin that enable it to assemble into the 10–12 nm diameter microfibril and perform such diverse roles.
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Fibrillin-containing microfibrils are key signal relay stations for cell function. J Cell Commun Signal 2015; 9:309-25. [PMID: 26449569 DOI: 10.1007/s12079-015-0307-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 09/29/2015] [Indexed: 12/26/2022] Open
Abstract
Fibrillins constitute the backbone of microfibrils in the extracellular matrix of elastic and non-elastic tissues. Mutations in fibrillins are associated with a wide range of connective tissue disorders, the most common is Marfan syndrome. Microfibrils are on one hand important for structural stability in some tissues. On the other hand, microfibrils are increasingly recognized as critical mediators and drivers of cellular signaling. This review focuses on the signaling mechanisms initiated by fibrillins and microfibrils, which are often dysregulated in fibrillin-associated disorders. Fibrillins regulate the storage and bioavailability of growth factors of the TGF-β superfamily. Cells sense microfibrils through integrins and other receptors. Fibrillins potently regulate pathways of the immune response, inflammation and tissue homeostasis. Emerging evidence show the involvement of microRNAs in disorders caused by fibrillin deficiency. A thorough understanding of fibrillin-mediated cell signaling pathways will provide important new leads for therapeutic approaches of the underlying disorders.
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Miura H, Mogi T, Ano Y, Migita CT, Matsutani M, Yakushi T, Kita K, Matsushita K. Cyanide-insensitive quinol oxidase (CIO) from Gluconobacter oxydans is a unique terminal oxidase subfamily of cytochrome bd. ACTA ACUST UNITED AC 2013; 153:535-45. [DOI: 10.1093/jb/mvt019] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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5
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Sunassee SN, Davies-Coleman MT. Cytotoxic and antioxidant marine prenylated quinones and hydroquinones. Nat Prod Rep 2012; 29:513-35. [DOI: 10.1039/c2np00086e] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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6
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Olivieri J, Smaldone S, Ramirez F. Fibrillin assemblies: extracellular determinants of tissue formation and fibrosis. FIBROGENESIS & TISSUE REPAIR 2010; 3:24. [PMID: 21126338 PMCID: PMC3012016 DOI: 10.1186/1755-1536-3-24] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 12/02/2010] [Indexed: 11/13/2022]
Abstract
The extracellular matrix (ECM) plays a key role in tissue formation, homeostasis and repair, mutations in ECM components have catastrophic consequences for organ function and therefore, for the fitness and survival of the organism. Collagen, fibrillin and elastin polymers represent the architectural scaffolds that impart specific mechanic properties to tissues and organs. Fibrillin assemblies (microfibrils) have the additional function of distributing, concentrating and modulating local transforming growth factor (TGF)-β and bone morphogenetic protein (BMP) signals that regulate a plethora of cellular activities, including ECM formation and remodeling. Fibrillins also contain binding sites for integrin receptors, which induce adaptive responses to changes in the extracellular microenvironment by reorganizing the cytoskeleton, controlling gene expression, and releasing and activating matrix-bound latent TGF-β complexes. Genetic evidence has indicated that fibrillin-1 and fibrillin-2 contribute differently to the organization and structural properties of non-collagenous architectural scaffolds, which in turn translate into discrete regulatory outcomes of locally released TGF-β and BMP signals. Additionally, the study of congenital dysfunctions of fibrillin-1 has yielded insights into the pathogenesis of acquired connective tissue disorders of the connective tissue, such as scleroderma. On the one hand, mutations that affect the structure or expression of fibrillin-1 perturb microfibril biogenesis, stimulate improper latent TGF-β activation, and give rise to the pleiotropic manifestations in Marfan syndrome (MFS). On the other hand, mutations located around the integrin-binding site of fibrillin-1 perturb cell matrix interactions, architectural matrix assembly and extracellular distribution of latent TGF-β complexes, and lead to the highly restricted fibrotic phenotype of Stiff Skin syndrome. Understanding the molecular similarities and differences between congenital and acquired forms of skin fibrosis may therefore provide new therapeutic tools to mitigate or even prevent disease progression in scleroderma and perhaps other fibrotic conditions.
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Affiliation(s)
- Jacopo Olivieri
- Scienze Mediche e Chirurgiche, Sezione Clinica Medica, Universita' Politecnica delle Marche, Ancona, Italy
| | - Silvia Smaldone
- Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, USA
| | - Francesco Ramirez
- Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, USA
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7
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Wei J, Kitada S, Stebbins JL, Placzek W, Zhai D, Wu B, Rega MF, Zhang Z, Cellitti J, Yang L, Dahl R, Reed JC, Pellecchia M. Synthesis and biological evaluation of Apogossypolone derivatives as pan-active inhibitors of antiapoptotic B-cell lymphoma/leukemia-2 (Bcl-2) family proteins. J Med Chem 2010; 53:8000-11. [PMID: 21033669 DOI: 10.1021/jm100746q] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Overexpression of antiapoptotic Bcl-2 family proteins is commonly related with tumor maintenance, progression, and chemoresistance. Inhibition of these antiapoptotic proteins is an attractive approach for cancer therapy. Guided by nuclear magnetic resonance (NMR) binding assays, a series of 5,5' substituted compound 6a (Apogossypolone) derivatives was synthesized and identified pan-active antagonists of antiapoptotic Bcl-2 family proteins, with binding potency in the low micromolar to nanomolar range. Compound 6f inhibits the binding of BH3 peptides to Bcl-X(L), Bcl-2, and Mcl-1 with IC(50) values of 3.10, 3.12, and 2.05 μM, respectively. In a cellular assay, 6f potently inhibits cell growth in several human cancer cell lines in a dose-dependent manner. Compound 6f further displays in vivo efficacy in transgenic mice and demonstrated superior single-agent antitumor efficacy in a PPC-1 mouse xenograft model. Together with its negligible toxicity, compound 6f represents a promising drug lead for the development of novel apoptosis-based therapies for cancer.
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Affiliation(s)
- Jun Wei
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA
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8
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Borisov VB, Davletshin AI, Konstantinov AA. Peroxidase activity of cytochrome bd from Escherichia coli. BIOCHEMISTRY (MOSCOW) 2010; 75:428-36. [PMID: 20618131 DOI: 10.1134/s000629791004005x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cytochrome bd from Escherichia coli is able to oxidize such substrates as guaiacol, ferrocene, benzohydroquinone, and potassium ferrocyanide through the peroxidase mechanism, while none of these donors is oxidized in the oxidase reaction (i.e. in the reaction that involves molecular oxygen as the electron acceptor). Peroxidation of guaiacol has been studied in detail. The dependence of the rate of the reaction on the concentration of the enzyme and substrates as well as the effect of various inhibitors of the oxidase reaction on the peroxidase activity have been tested. The dependence of the guaiacol-peroxidase activity on the H2O2 concentration is linear up to the concentration of 8 mM. At higher concentrations of H2O2, inactivation of the enzyme is observed. Guaiacol markedly protects the enzyme from inactivation induced by peroxide. The peroxidase activity of cytochrome bd increases with increasing guaiacol concentration, reaching saturation in the range from 0.5 to 2.5 mM, but then starts falling. Such inhibitors of the ubiquinol-oxidase activity of cytochrome bd as cyanide, pentachlorophenol, and 2-n-heptyl 4-hydroxyquinoline-N-oxide also suppress its guaiacol-peroxidase activity; in contrast, zinc ions have no influence on the enzyme-catalyzed peroxidation of guaiacol. These data suggest that guaiacol interacts with the enzyme in the center of ubiquinol binding and donates electrons into the di-heme center of oxygen reduction via heme b(558), and H2O2 is reduced by heme d. Although the peroxidase activity of cytochrome bd from E. coli is low compared to peroxidases, it might be of physiological significance for the bacterium itself and plays a pathophysiological role for humans and animals.
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Affiliation(s)
- V B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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9
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Yap LL, Lin MT, Ouyang H, Samoilova RI, Dikanov SA, Gennis RB. The quinone-binding sites of the cytochrome bo3 ubiquinol oxidase from Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1924-32. [PMID: 20416270 DOI: 10.1016/j.bbabio.2010.04.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 03/04/2010] [Accepted: 04/13/2010] [Indexed: 11/18/2022]
Abstract
Cytochrome bo(3) is the major respiratory oxidase located in the cytoplasmic membrane of Escherichia coli when grown under high oxygen tension. The enzyme catalyzes the 2-electron oxidation of ubiquinol-8 and the 4-electron reduction of dioxygen to water. When solubilized and isolated using dodecylmaltoside, the enzyme contains one equivalent of ubiquinone-8, bound at a high affinity site (Q(H)). The quinone bound at the Q(H) site can form a stable semiquinone, and the amino acid residues which hydrogen bond to the semiquinone have been identified. In the current work, it is shown that the tightly bound ubiquinone-8 at the Q(H) site is not displaced by ubiquinol-1 even during enzyme turnover. Furthermore, the presence of high affinity inhibitors, HQNO and aurachin C1-10, does not displace ubiquinone-8 from the Q(H) site. The data clearly support the existence of a second binding site for ubiquinone, the Q(L) site, which can rapidly exchange with the substrate pool. HQNO is shown to bind to a single site on the enzyme and to prevent formation of the stable ubisemiquinone, though without displacing the bound quinone. Inhibition of the steady state kinetics of the enzyme indicates that aurachin C1-10 may compete for binding with quinol at the Q(L) site while, at the same time, preventing formation of the ubisemiquinone at the Q(H) site. It is suggested that the two quinone binding sites may be adjacent to each other or partially overlap.
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Affiliation(s)
- Lai Lai Yap
- Department of Biochemistry, University of Illinois, 600 S. Goodwin Avenue, Urbana, IL 61801, USA
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10
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Kido Y, Sakamoto K, Nakamura K, Harada M, Suzuki T, Yabu Y, Saimoto H, Yamakura F, Ohmori D, Moore A, Harada S, Kita K. Purification and kinetic characterization of recombinant alternative oxidase from Trypanosoma brucei brucei. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:443-50. [DOI: 10.1016/j.bbabio.2009.12.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 12/23/2009] [Accepted: 12/25/2009] [Indexed: 10/20/2022]
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11
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Complementation of coenzyme Q-deficient yeast by coenzyme Q analogues requires the isoprenoid side chain. FEBS J 2010; 277:2067-82. [PMID: 20345901 DOI: 10.1111/j.1742-4658.2010.07622.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The ubiquinone coenzyme Q (CoQ) is synthesized in mitochondria with a large, hydrophobic isoprenoid side chain. It functions in mitochondrial respiration as well as protecting membranes from oxidative damage. Yeast that cannot synthesize CoQ (DeltaCoQ) are viable, but cannot grow on nonfermentable carbon sources, unless supplied with ubiquinone. Previously we demonstrated that the isoprenoid side chain of the exogenous ubiquinone was important for growth of a DeltaCoQ strain on the nonfermentable substrate glycerol [James AM et al. (2005) J Biol Chem280, 21295-21312]. In the present study we investigated the structural requirements of exogenously supplied CoQ(2) for growth on glycerol and found that the first double bond of the initial isoprenoid unit is essential for utilization of respiratory substrates. As CoQ(2) analogues that did not complement growth on glycerol supported respiration in isolated mitochondria, discrimination does not occur via the respiratory chain complexes. The endogenous form of CoQ in yeast (CoQ(6)) is extremely hydrophobic and transported to mitochondria via the endocytic pathway when supplied exogenously. We found that CoQ(2) does not require this pathway when supplied exogenously and the pathway is unlikely to be responsible for the structural discrimination observed. Interestingly, decylQ, an analogue unable to support growth on glycerol, is not toxic, but antagonizes growth of DeltaCoQ yeast in the presence of exogenous CoQ(2). Using a DeltaCoQ double-knockout library we identified a number of genes that decrease the ability of yeast to grow on exogenous CoQ. Here we suggest that CoQ or its redox state may be a signal for growth during the shift to respiration.
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12
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Abstract
Quinone oxidoreductases are a class of membrane enzymes that catalyse the oxidation or reduction of membrane-bound quinols/quinones. The conversion of quinone/quinol by these enzymes is difficult to study because of the hydrophobic nature of the enzymes and their substrates. We describe some biochemical properties of quinones and quinone oxidoreductases and then look in more detail at two model membranes that can be used to study quinone oxidoreductases in a native-like membrane environment with their native lipophilic quinone substrates. The results obtained with these model membranes are compared with classical enzyme assays that use water-soluble quinone analogues.
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Affiliation(s)
- Sophie A. Weiss
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
| | - Lars J. C. Jeuken
- Centre for Self Organising Molecular Systems, University of Leeds, Leeds, LS2 9JT, UK
- Institute of Membrane and Systems Biology, University of Leeds, Leeds, LS2 9JT, UK
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13
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Mogi T, Ano Y, Nakatsuka T, Toyama H, Muroi A, Miyoshi H, Migita CT, Ui H, Shiomi K, Omura S, Kita K, Matsushita K. Biochemical and spectroscopic properties of cyanide-insensitive quinol oxidase from Gluconobacter oxydans. J Biochem 2009; 146:263-71. [PMID: 19416958 DOI: 10.1093/jb/mvp067] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cyanide-insensitive quinol oxidase (CioAB), a relative of cytochrome bd, has no spectroscopic features of hemes b(595) and d in the wild-type bacteria and is difficult to purify for detailed characterization. Here we studied enzymatic and spectroscopic properties of CioAB from the acetic acid bacterium Gluconobacter oxydans. Gluconobacter oxydans CioAB showed the K(m) value for ubiquinol-1 comparable to that of Escherichia coli cytochrome bd but it was more resistant to KCN and quinone-analogue inhibitors except piericidin A and LL-Z1272gamma. We obtained the spectroscopic evidence for the presence of hemes b(595) and d. Heme b(595) showed the alpha peak at 587 nm in the reduced state and a rhombic high-spin signal at g = 6.3 and 5.5 in the air-oxidized state. Heme d showed the alpha peak at 626 and 644 nm in the reduced and air-oxidized state, respectively, and an axial high-spin signal at g = 6.0 and low-spin signals at g = 2.63, 2.37 and 2.32. We found also a broad low-spin signal at g = 3.2, attributable to heme b(558). Further, we identified the presence of heme D by mass spectrometry. In conclusion, CioAB binds all three ham species present in cytochrome bd quinol oxidase.
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Affiliation(s)
- Tatsushi Mogi
- Department of Biomedical Chemistry, the University of Tokyo, Bunkyo-ku, Japan.
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14
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Nasiri HR, Panisch R, Madej MG, Bats JW, Lancaster CRD, Schwalbe H. The correlation of cathodic peak potentials of vitamin K(3) derivatives and their calculated electron affinities. The role of hydrogen bonding and conformational changes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:601-8. [PMID: 19265668 DOI: 10.1016/j.bbabio.2009.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/16/2009] [Accepted: 02/17/2009] [Indexed: 11/25/2022]
Abstract
2-methyl-1,4-naphtoquinone 1 (vitamin K(3), menadione) derivatives with different substituents at the 3-position were synthesized to tune their electrochemical properties. The thermodynamic midpoint potential (E(1/2)) of the naphthoquinone derivatives yielding a semi radical naphthoquinone anion were measured by cyclic voltammetry in the aprotic solvent dimethoxyethane (DME). Using quantum chemical methods, a clear correlation was found between the thermodynamic midpoint potentials and the calculated electron affinities (E(A)). Comparison of calculated and experimental values allowed delineation of additional factors such as the conformational dependence of quinone substituents and hydrogen bonding which can influence the electron affinities (E(A)) of the quinone. This information can be used as a model to gain insight into enzyme-cofactor interactions, particularly for enzyme quinone binding modes and the electrochemical adjustment of the quinone motif.
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Affiliation(s)
- Hamid Reza Nasiri
- Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
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15
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Mogi T. Probing the haem d-binding site in cytochrome bd quinol oxidase by site-directed mutagenesis. J Biochem 2009; 145:763-70. [DOI: 10.1093/jb/mvp033] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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16
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Mogi T. Effects of replacement of low-spin haem b by haem O on Escherichia coli cytochromes bo and bd quinol oxidases. J Biochem 2009; 145:599-607. [PMID: 19174546 DOI: 10.1093/jb/mvp015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cytochromes bo and bd are terminal ubiquinol oxidases in the aerobic respiratory chain of Escherichia coli and generate proton motive force across the membrane. To probe roles of haem species in the oxidation of quinols, intramolecular electron transfer and the dioxygen reduction, we replaced b-haems with haem O by using the haem O synthase-overproducing system, which can accumulate haem O in cytoplasmic membranes. Characterizations of spectroscopic properties of cytochromes bo and bd isolated from BL21 (DE3)/pLysS and BL21 (DE3)/pLysS/pTTQ18-cyoE after 4 h of the aerobic induction of haem O synthase (CyoE) showed the specific incorporation of haem O into the low-spin haem-binding site in both oxidases. We found that the resultant haem oo- and obd-type oxidase severely reduced the ubiquinol-1 oxidase activity due to the perturbations of the quinol oxidation site. Our observations suggest that haem B is required at the low-spin haem site for the oxidation of quinols by cytochromes bo and bd.
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Affiliation(s)
- Tatsushi Mogi
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
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17
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Characterization of cytochrome bo3 activity in a native-like surface-tethered membrane. Biochem J 2009; 417:555-60. [PMID: 18821852 DOI: 10.1042/bj20081345] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have developed a simple native-like surface-tethered membrane system to investigate the activity of cbo(3) (cytochrome bo(3)), a terminal oxidase in Escherichia coli. The tethered membranes consist of E. coli inner-membrane extracts mixed with additional E. coli lipids containing various amounts of the cbo(3) substrate UQ-10 (ubiquinol-10). Tethered membranes are formed by self-assembly from vesicles on to gold electrodes functionalized with cholesterol derivatives. cbo(3) activity was monitored using CV (cyclic voltammetry) with electron transfer to cbo(3) mediated by UQ-10. The apparent K(m) for oxygen with this system is 1.1+/-0.4 microM, in good agreement with values reported in the literature for whole-cell experiments and for purified cbo(3). Increasing the concentration of lipophilic UQ-10 in the membrane leads to an increase in cbo(3) activity. The activity of cbo(3) with long-chain ubiquinones appears to be different from previous reports using short-chain substrate analogues such as UQ-1 in that typical Michaelis-Menten kinetics are not observed using UQ-10. This native-like membrane model thus provides new insights into the interaction of transmembrane enzymes with hydrophobic substrates which contrasts with studies using hydrophilic UQ analogues.
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18
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Ramirez F, Carta L, Lee-Arteaga S, Liu C, Nistala H, Smaldone S. Fibrillin-rich microfibrils - structural and instructive determinants of mammalian development and physiology. Connect Tissue Res 2008; 49:1-6. [PMID: 18293172 DOI: 10.1080/03008200701820708] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Fibrillin-rich microfibrils have emerged recently as an informative model system in which to study fundamental questions related to extracellular matrix biology and connective tissue pathophysiology. As a result, these studies have yielded novel clinical concepts and promising therapeutic strategies. These achievements have been based on the realization from studies of genetically engineered mice that mutations in fibrillin-rich microfibrils impair both the structural integrity of connective tissues and signaling events by TGF-beta/BMP superfamily members. In this view, fibrillin-rich microfibrils represent architectural assemblies that specify the concentration and timely release of local effectors of morphogenesis and tissue remodeling, in addition to conferring structural integrity to individual organ systems. This review summarizes the evidence supporting our current understanding of the structural and instructive roles that fibrillin-rich microfibrils play during embryonic development and in human diseases.
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Affiliation(s)
- Francesco Ramirez
- Child Health Institute of New Jersey, Robert W. Johnson Medical School, New Brunswick, New Jersey, USA.
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Kobayashi R, Suzuki T, Yoshida M. Escherichia coli phage-shock protein A (PspA) binds to membrane phospholipids and repairs proton leakage of the damaged membranes. Mol Microbiol 2007; 66:100-9. [PMID: 17725563 DOI: 10.1111/j.1365-2958.2007.05893.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Escherichia coli phage-shock protein A (PspA), a 25.3 kDa peripheral membrane protein, is induced under the membrane stress conditions and is assumed to help maintain membrane potential. Here, we report that purified PspA, existing as a large oligomer, is really able to suppress proton leakage of the membranes. This was demonstrated for membrane vesicles prepared from the PspA-lacking E. coli mutants, and for membrane vesicles damaged by ethanol and Triton X-100 prepared from the mutant and the wild-type cells. PspA also suppressed proton leakage of damaged liposomes made from E. coli total lipids. Furthermore, we found that PspA bound preferentially to liposomes containing phosphatidylserine and phosphatidylglycerol. All these effects were not observed for monomer PspA that was prepared by refolding of urea-denatured PspA. These results indicate that oligomers of PspA bind to membrane phospholipids and suppress proton leakage.
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Affiliation(s)
- Ryuji Kobayashi
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama 226-8503, Japan
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20
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Fedorov SN, Radchenko OS, Shubina LK, Balaneva NN, Bode AM, Stonik VA, Dong Z. Evaluation of cancer-preventive activity and structure-activity relationships of 3-demethylubiquinone Q2, isolated from the ascidian Aplidium glabrum, and its synthetic analogs. Pharm Res 2006; 23:70-81. [PMID: 16320003 PMCID: PMC2227315 DOI: 10.1007/s11095-005-8813-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Accepted: 09/28/2005] [Indexed: 01/03/2023]
Abstract
PURPOSE 3-Demethylubiquinone Q2 was isolated from the ascidian Aplidium glabrum. The cancer-preventive properties and the structure-activity relationship for 3-demethylubiquinone Q2 and 12 of its synthetic analogs are reported. METHODS Compounds, having one or several di- or triprenyl substitutions and quinone moieties with methoxyls in different positions, were synthesized. The cancer-preventive properties of compounds and were tested in JB6 Cl41 mouse skin cells, using a variety of assessments, including the methanethiosulfonate (MTS) assay, flow cytometry, and soft agar assay. Statistical nonparametric methods were used to confirm statistical significance. RESULTS All quinones tested were shown to inhibit JB6 Cl41 cell transformation, to induce apoptosis, AP-1, and NF-kappaB activity, and to inhibit p53 activity. The most promising effects were indicated for compounds containing two isoprene units in a side chain and a methoxyl group at the para-position to a polyprenyl substitution. CONCLUSIONS Quinones and demonstrated cancer-preventive activity in JB6 Cl41 cells, which may be attributed to the induction of p53-independent apoptosis. These activities depended on the length of side chains and on the positions of the methoxyl groups in the quinone part of the molecule.
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Affiliation(s)
- Sergey N. Fedorov
- Hormel Institute, University of Minnesota, 801 16 Avenue NE, Austin, Minnesota 55912, USA
- Pacific Institute of Bioorganic Chemistry, 159 Prospect 100-let Vladivostoku, Vladivostok, 690022, Russia
| | - Oleg S. Radchenko
- Hormel Institute, University of Minnesota, 801 16 Avenue NE, Austin, Minnesota 55912, USA
| | - Larisa K. Shubina
- Hormel Institute, University of Minnesota, 801 16 Avenue NE, Austin, Minnesota 55912, USA
| | - Nadezhda N. Balaneva
- Hormel Institute, University of Minnesota, 801 16 Avenue NE, Austin, Minnesota 55912, USA
| | - Ann M. Bode
- Pacific Institute of Bioorganic Chemistry, 159 Prospect 100-let Vladivostoku, Vladivostok, 690022, Russia
| | - Valentin A. Stonik
- Hormel Institute, University of Minnesota, 801 16 Avenue NE, Austin, Minnesota 55912, USA
- To whom correspondence should be addressed. (e-mail: )
| | - Zigang Dong
- Pacific Institute of Bioorganic Chemistry, 159 Prospect 100-let Vladivostoku, Vladivostok, 690022, Russia
- To whom correspondence should be addressed. (e-mail: )
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Matsumoto Y, Muneyuki E, Fujita D, Sakamoto K, Miyoshi H, Yoshida M, Mogi T. Kinetic mechanism of quinol oxidation by cytochrome bd studied with ubiquinone-2 analogs. J Biochem 2006; 139:779-88. [PMID: 16672279 DOI: 10.1093/jb/mvj087] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cytochrome bd is a heterodimeric terminal ubiquinol oxidase of Escherichia coli under microaerophilic growth conditions. The oxidase activity shows sigmoidal concentration-dependence with low concentrations of ubiquinols, and a marked substrate inhibition with high concentrations of ubiquinol-2 analogs [Sakamoto, K., Miyoshi, H., Takegami, K., Mogi, T., Anraku, Y., and Iwamura H. (1996) J. Biol. Chem. 271, 29897-29902]. Kinetic analysis of the oxidation of the ubiquinol-2 analogs, where the 2- or 3-methoxy group has been substituted with an azido or ethoxy group, suggested that its peculiar enzyme kinetics can be explained by a modified ping-pong bi-bi mechanism with the formation of inactive binary complex FS in the one-electron reduced oxygenated state and inactive ternary complex (E2S)S(n) on the oxidation of the second quinol molecule. Structure-function studies on the ubiquinol-2 analogs suggested that the 6-diprenyl group and the 3-methoxy group on the quinone ring are involved in the substrate inhibition. We also found that oxidized forms of ubiquinone-2 analogs served as weak noncompetitive inhibitors. These results indicate that the mechanism for the substrate oxidation by cytochrome bd is different from that of the heme-copper terminal quinol oxidase and is tightly coupled to dioxygen reduction chemistry.
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Affiliation(s)
- Yushi Matsumoto
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8503
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22
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Mogi T, Mizuochi-Asai E, Endou S, Akimoto S, Nakamura H. Role of a putative third subunit YhcB on the assembly and function of cytochrome bd-type ubiquinol oxidase from Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:860-4. [PMID: 16863643 DOI: 10.1016/j.bbabio.2006.05.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 05/20/2006] [Accepted: 05/25/2006] [Indexed: 11/29/2022]
Abstract
Recent proteome studies on the Escherichia coli membrane proteins suggested that YhcB is a putative third subunit of cytochrome bd-type ubiquinol oxidase (CydAB) (F. Stenberg, P. Chovanec, S.L. Maslen, C.V. Robinson, L.L. Ilag, G. von Heijne, D.O. Daley, Protein complexes of the Escherichia coli cell envelope. J. Biol. Chem. 280 (2005) 34409-34419). We isolated and characterized cytochrome bd from the DeltayhcB strain, and found that the formation of the CydAB heterodimer, the spectroscopic properties of bound hemes, and kinetic parameters for the ubiquinol-1 oxidation were identical to those of cytochrome bd from the wild-type strain. Anion-exchange chromatography and SDS-polyacrylamide gel electrophoresis showed that YhcB was not associated with the cytochrome bd complex. We concluded that YhcB is dispensable for the assembly and function of cytochrome bd. YhcB, which is distributed only in gamma-proteobacteria, may be a part of another membrane protein complex or may form a homo multimeric complex.
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Affiliation(s)
- Tatsushi Mogi
- ATP System Project, ERATO, JST, Midori-ku, Yokohama, Japan.
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23
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Matsumoto Y, Murai M, Fujita D, Sakamoto K, Miyoshi H, Yoshida M, Mogi T. Mass spectrometric analysis of the ubiquinol-binding site in cytochrome bd from Escherichia coli. J Biol Chem 2005; 281:1905-12. [PMID: 16299377 DOI: 10.1074/jbc.m508206200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytochrome bd is a heterodimeric terminal ubiquinol oxidase in the aerobic respiratory chain of Escherichia coli. For understanding the unique catalytic mechanism of the quinol oxidation, mass spectrometry was used to identify amino acid residue(s) that can be labeled with a reduced form of 2-azido-3-methoxy-5-methyl-6-geranyl-1,4-benzoquinone or 2-methoxy-3-azido-5-methyl-6-geranyl-1,4-benzoquinone. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry demonstrated that the photo inactivation of ubiquinol-1 oxidase activity was accompanied by the labeling of subunit I with both azidoquinols. The cross-linked domain was identified by reverse-phase high performance liquid chromatography of subunit I peptides produced by in-gel double digestion with lysyl endopeptidase and endoproteinase Asp-N. Electrospray ionization quadrupole time-of-flight mass spectrometry determined the amino acid sequence of the peptide (m/z 1047.5) to be Glu(278)-Lys(283), where a photoproduct of azido-Q(2) was linked to the carboxylic side chain of I-Glu(280). This study demonstrated directly that the N-terminal region of periplasmic loop VI/VII (Q-loop) is a part of the quinol oxidation site and indicates that the 2- and 3-methoxy groups of the quinone ring are in the close vicinity of I-Glu(280).
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Affiliation(s)
- Yushi Matsumoto
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8503, Japan
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24
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Desmethylubiquinone Q2 from the Far-Eastern ascidian Aplidium glabrum: structure and synthesis. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2004.11.157] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Hyytiäinen M, Penttinen C, Keski-Oja J. Latent TGF-beta binding proteins: extracellular matrix association and roles in TGF-beta activation. Crit Rev Clin Lab Sci 2004; 41:233-64. [PMID: 15307633 DOI: 10.1080/10408360490460933] [Citation(s) in RCA: 243] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transforming growth factor betas (TGF-betas) are multifunctional and pleiotropic growth factors. Their major effects include inhibition of cell proliferation and enhancement of extracellular matrix production. TGF-betas are secreted from cells as latent complexes, consisting of mature dimeric growth factor, the latency-associated propeptide (LAP), and a distinct gene product, latent TGF-beta binding protein LTBP. The secreted complex is targeted to specific locations in the extracellular matrix by the appropriate LTBP. The latent complex needs subsequently to be activated. Most studies describing biological effects of TGF-beta have been carried out in cell cultures using high concentrations of active, soluble TGF-beta, where appropriate targeting of the growth factor is missing. However, TGF-beta is produced and secreted in vivo as a latent complex in a specific and targeted manner. Various experimental approaches have convincingly shown the importance of the activation of latent TGF-beta, as well as the importance of LTBPs as targeting molecules of the effects of TGF-beta. Essential steps in the activation appear to be cellular recognition of extracellular matrix-associated LTBPs and subsequent recognition of the associated latent TGF-beta. Cell recognition by specific molecules like integrins and proteolytic events involving plasminogen activation evidently play multifaceted roles in the regulation of TGF-beta activation.
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Affiliation(s)
- Marko Hyytiäinen
- Department of Virology, Haartman Institute and Helsinki University Hospital, University of Helsinki, Finland
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26
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Yamashoji S. Coenzyme Q1-catalyzed luminol chemiluminescent assay for rapid antimicrobial susceptibility testing of Mycobacterium bovis. Microbiol Immunol 2003; 47:191-8. [PMID: 12725288 DOI: 10.1111/j.1348-0421.2003.tb03386.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Coenzyme Q1 is herein proposed as the best catalyst among coenzymes Q and vitamins K for quinone-catalyzed luminol chemiluminescent assays applied to rapid determination of viability or rapid antimicrobial susceptibility tests of Mycobacterium bovis. Luminol chemiluminescence intensity (LCI) was determined 10 min after the incubation of M. bovis with coenzyme Q1, and was proportional to CFU (colony-forming unit)/ml in the range of 9,000 to 2,250,000. LCI depended on the the production of the superoxide anion (O2-) rather than H2O2 during a 10-min incubation of M. bovis with coenzyme Q1, as superoxide dismutase reduced LCI more effectively than catalase. The minimal inhibitory concentrations (MICs) of 10 kinds of antituberculous agents estimated on the basis of decrease in LCI after one or two days' cultivation were in good agreement with MICs determined by turbidity analysis, which requires upwards of 1 week to complete.
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Affiliation(s)
- Shiro Yamashoji
- Nikken Biomedical Laboratory, 23 Teigaien, Ohashibe, Kumiyama-cho, Kuze-gun, Kyoto 613-0046, Japan.
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27
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Samuel CS, Sakai LY, Amento EP. Relaxin regulates fibrillin 2, but not fibrillin 1, mRNA and protein expression by human dermal fibroblasts and murine fetal skin. Arch Biochem Biophys 2003; 411:47-55. [PMID: 12590922 DOI: 10.1016/s0003-9861(02)00710-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Relaxin modulates connective tissue remodeling by altering matrix molecule expression. We have found that relaxin specifically inhibits a microfibril component, fibrillin 2 (FBN2), without affecting fibrillin 1 (FBN1). Human dermal fibroblasts (HDFs) grown or stimulated to overexpress fibrillin expression were used to show that relaxin specifically down-regulated FBN2 mRNA and protein levels. Continuous exposure of HDFs to relaxin (30ng/ml) significantly (P<0.05) decreased fibrillin 2 protein (40%) while FBN1 protein expression was unchanged. Our in vitro studies were confirmed using relaxin null mice whereby the absence of relaxin was associated with increased FBN2 mRNA and protein in fetal skin from pregnant relaxin knockout mice. The regulation of FBN2 expression may be associated with functional changes in elastic tissues during development and growth.
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Affiliation(s)
- Chrishan S Samuel
- Molecular Medicine Research Institute, 525 Del Rey Avenue, Suite B, Sunnyvale, CA 94085, USA.
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28
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Miyoshi H. Probing the ubiquinone reduction site in bovine mitochondrial complex I using a series of synthetic ubiquinones and inhibitors. J Bioenerg Biomembr 2001; 33:223-31. [PMID: 11695832 DOI: 10.1023/a:1010735019982] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Studies of the structure-activity relationships of ubiquinones and specific inhibitors are helpful to probe the structural and functional features of the ubiquinone reduction site of bovine heart mitochondrial complex I. Bulky exogenous short-chain ubiquinones serve as sufficient electron acceptors from the physiological ubiquinone reduction site of bovine complex I. This feature is in marked contrast to other respiratory enzymes such as mitochondrial complexes II and III. For various complex I inhibitors, including the most potent inhibitors, acetogenins, the essential structural factors that markedly affect the inhibitory potency are not necessarily obvious. Thus, the loose recognition by the enzyme of substrate and inhibitor structures may reflect the large cavity like structure of the ubiquinone (or inhibitor) binding domain in the enzyme. On the other hand, several phenomena are difficult to explain by a simple one-catalytic site model for ubiquinone.
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Affiliation(s)
- H Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.
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29
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Hastings SF, Heathcote P, Ingledew WJ, Rigby SE. ENDOR spectroscopic studies of stable semiquinone radicals bound to the Escherichia coli cytochrome bo3 quinol oxidase. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:5638-45. [PMID: 10951225 DOI: 10.1046/j.1432-1327.2000.01643.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The putative oxidation of ubiquinol by the cytochrome bo3 terminal oxidase of Escherichia coli in sequential one-electron steps requires stabilization of the semiquinone. ENDOR spectroscopy has recently been used to study the native ubisemiquinone radical formed in the cytochrome bo3 quinone-binding site [Veselov, A.V., Osborne, J.P., Gennis, R.B. & Scholes, C.P. (2000) Biochemistry 39, 3169-3175]. Comparison of these spectra with those from the decyl-ubisemiquinone radical in vitro indicated that the protein induced large changes in the electronic structure of the ubisemiquinone radical. We have used quinone-substitution experiments to obtain ENDOR spectra of ubisemiquinone, phyllosemiquinone and plastosemiquinone anion radicals bound at the cytochrome bo3 quinone-binding site. Large changes in the electronic structures of these semiquinone anion radicals are induced on binding to the cytochrome bo3 oxidase. The changes in electronic structure are, however, independent of the electronic structures of these semiquinones in vitro. Thus it is shown to be the structure of this binding site in the protein, not the covalent structure of the bound quinone, that determines the electronic structure of the protein-bound semiquinone.
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Affiliation(s)
- S F Hastings
- School of Biological Sciences, University of St Andrews, Fife, UK
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30
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Rai T, Uchida S, Sasaki S, Marumo F. Isolation and characterization of kidney-specific CLC-K2 chloride channel gene promoter. Biochem Biophys Res Commun 1999; 261:432-8. [PMID: 10425202 DOI: 10.1006/bbrc.1999.1038] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CLC-K1 and CLC-K2 are highly homologous kidney-specific chloride channels, but they are expressed in the different nephron segments. To understand the molecular mechanisms of kidney-specific and nephron-segment-specific expression of CLC-K channel genes, the rat ClC-K2 gene promoter was cloned and compared with that of CLC-K1. In the 1.5-kb pair 5'-flanking region of the CLC-K2 gene, no TATA box was identified around the transcriptional start site, and the proximal region (-32 to -68) was characterized by a GA-rich motif that had a significant sequence similarity to that of the previously isolated CLC-K1 gene promoter. In contrast, the distal portion did not have significant sequence similarity to that of CLC-K1. Reporter gene assay and gel-retardation analysis revealed that the GA-rich motif and the binding of a specific protein(s) to this element were indispensable for the basal promoter activity of the CLC-K2 gene. These results suggest that the GA-rich element may have an important role in the promoter activities of the kidney-specific CLC-K1 and -K2 genes, but that the GA-element alone is not sufficient for the strict regulation of nephron-segment-specific expression of CLC-K1 and CLC-K2 genes.
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Affiliation(s)
- T Rai
- Second Department of Internal Medicine, Tokyo Medical and Dental University, School of Medicine, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
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31
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Miyoshi H, Niitome Y, Matsushita K, Yamada M, Iwamura H. Topographical characterization of the ubiquinone reduction site of glucose dehydrogenase in Escherichia coli using depth-dependent fluorescent inhibitors. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1412:29-36. [PMID: 10354491 DOI: 10.1016/s0005-2728(99)00009-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Membrane-bound glucose dehydrogenase in Escherichia coli possesses a binding site for ubiquinone as well as glucose, metal ion and pyrroloquinoline quinone. To probe the depth of the ubiquinone binding site in the membrane environment, we synthesized two types of fluorenyl fatty acids which bear an inhibitor mimic moiety (i.e., specific inhibitor capsaicin) close to the fluorene located at different positions in the alkyl tail chain; one close to the polar carbonyl head group (alpha-(3, 4-dimethoxyphenyl)acetyloxy-7-nonyl-2-fluoreneacetic acid, alpha-DFA), and the other in the middle of the chain (theta-(3, 4-dimethoxyphenyl)acetyloxy-7-ethyl-2-fluorenenonanoic acid, theta-DFA). Mixed lipid vesicles consisting of phosphatidylcholine (PC) and alpha-DFA or theta-DFA were prepared by sonication method, and fluorescent quenching against a hydrophilic quencher, iodide anion, was examined. The vesicles containing alpha-DFA were more susceptible to quenching than those containing theta-DFA, indicating that the fluorene and consequently capsaicin mimic moiety are located at different depths in the lipid bilayer depending upon the position of attachment to the alkyl tail chain. The purified glucose dehydrogenase was reconstituted into PC vesicles which consisted of PC and alpha-DFA or theta-DFA with various molar ratios. For both types of reconstituted vesicles, the extent of inhibition of short-chain ubiquinone reduction activity increased with increases in the molar ratio of fluorenyl fatty acid to PC. The ubiquinone reduction activity was more significantly inhibited in the reconstituted vesicles containing alpha-DFA compared to those containing theta-DFA. Our findings strongly suggested that the ubiquinone reduction site in glucose dehydrogenase is located close to the membrane surface rather than in the hydrophobic membrane interior.
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Affiliation(s)
- H Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
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32
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Miyazaki H, Uchida S, Takei Y, Hirano T, Marumo F, Sasaki S. Molecular cloning of CLC chloride channels in Oreochromis mossambicus and their functional complementation of yeast CLC gene mutant. Biochem Biophys Res Commun 1999; 255:175-81. [PMID: 10082675 DOI: 10.1006/bbrc.1999.0166] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have cloned two members of the CLC chloride channel family (OmCLC-3 and OmCLC-5) from gill cDNA libraries of the euryhaline tilapia Oreochromis mosammbicus. At the amino acid level, OmCLC-3 is 90.5% identical to rat CLC-3 and OmCLC-5 is 79.2% identical to rat CLC-5. Ribonuclease protection assay revealed that OmCLC-5 was mainly expressed in the gill, kidney, and intestine in both freshwater- (FW) and seawater- (SW) adapted tilapia. Although the mRNA of OmCLC-3 was broadly expressed in tissues of FW- and SW-adapted tilapia, the most intense signals were observed in the gill, kidney, intestine, and brain. Injection of OmCLC-3 and OmCLC-5 cRNAs into Xenopus oocytes did not elicit chloride currents, but these clones did functionally complement the gef1 phenotype of YPH250(gef), a yeast strain in which a single CLC channel (GEF1) has been disrupted by homologous recombination. These results clearly indicated that CLC channels closely related to the mammalian CLC-3, -4, and -5 subfamily exist also in tilapia and that OmCLC-3 and OmCLC-5 function as intracellular chloride channels.
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Affiliation(s)
- H Miyazaki
- Second Department of Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Tokyo, Bunkyo, 113-8519, Japan.
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Matsushita K, Yakushi T, Toyama H, Adachi O, Miyoshi H, Tagami E, Sakamoto K. The quinohemoprotein alcohol dehydrogenase of Gluconobacter suboxydans has ubiquinol oxidation activity at a site different from the ubiquinone reduction site. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1409:154-64. [PMID: 9878716 DOI: 10.1016/s0005-2728(98)00158-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Alcohol dehydrogenase (ADH) of acetic acid bacteria functions as the primary dehydrogenase of the ethanol oxidase respiratory chain, where it donates electrons to ubiquinone. In addition to the reduction of ubiquinone, ADHs of Gluconobacter suboxydans and Acetobacter aceti were shown to have a novel function in the oxidation of ubiquinol. The oxidation activity of ubiquinol was detected as an ubiquinol:ferricyanide oxidoreductase activity, which can be monitored by selected wavelength pairs at 273 and 298 nm with a dual-wavelength spectrophotometer. The ubiquinol oxidation activity of G. suboxydans ADH was shown to be two times higher in 'inactive ADH', whose ubiquinone reductase activity is 10 times lower, than with normal 'active' ADH. No activity could be detected in the isolated subunit II or subunit I/III complex, but activity was detectable in the reconstituted ADH complex. Inactive and active ADHs exhibited a 2-3-fold difference in their affinity to ubiquinol despite having the same affinity to ubiquinone. Furthermore, the ubiquinol oxidation site in ADH could be distinguished from the ubiquinone reduction site by differences in their sensitivity to ubiquinone-related inhibitors and by their substrate specificity with several ubiquinone analogues. Thus, the results strongly suggest that the reactions occur at different sites. Furthermore, in situ reconstitution experiments showed that ADH is able to accept electrons from ubiquinol present in Escherichia coli membranes, suggesting the ubiquinol oxidation activity of ADH has a physiological function. Thus, ADH of acetic acid bacteria, which has ubiquinone reduction activity, was shown to have a novel ubiquinol oxidation activity, of which the physiological function in the respiratory chain of the organism is also discussed.
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Affiliation(s)
- K Matsushita
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Yamaguchi 753, Japan.
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34
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Miyoshi H, Iwata J, Sakamoto K, Furukawa H, Takada M, Iwamura H, Watanabe T, Kodama Y. Specificity of pyridinium inhibitors of the ubiquinone reduction sites in mitochondrial complex I. J Biol Chem 1998; 273:17368-74. [PMID: 9651320 DOI: 10.1074/jbc.273.28.17368] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dual binding sites for pyridinium-type inhibitors in bovine heart mitochondrial complex I have been proposed (Gluck, M. R., Krueger, M. J., Ramsay, R. R., Sablin, S. O., Singer, T. P., and Nicklas, W. J. (1994) J. Biol. Chem. 269, 3167-3174). The marked biphasic nature of the dose-response curve for inhibition of the enzyme by MP-6(N-methyl-4-[2-(p-tert-butylbenzyl)propyl]pyridinium) makes this compound the first selective inhibitor of the two sites (Miyoshi, H., Inoue, M., Okamoto, S., Ohshima, M., Sakamoto, K., and Iwamura, H. (1997) J. Biol. Chem. 272, 16176-16183). Modifications of the structure of MP-6 show that a tert-butyl group on the benzene ring, a methyl group attached to the pyridine nitrogen atom, para-substitution pattern in the pyridine ring, and the presence of a branched structure in the spacer moiety are important for the selective inhibition. On the basis of the structural specificity, we synthesized a selective inhibitor, MP-24 (N-methyl-4-[2-methyl-2-(p-tert-butylbenzyl)propyl]pyridinium), which elicits greater selectivity. Characterization of the inhibitory behavior of MP-24 provided further strong evidence for the dual binding sites model.
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Affiliation(s)
- H Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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D'Arrigo C, Burl S, Withers AP, Dobson H, Black C, Boxer M. TGF-beta1 binding protein-like modules of fibrillin-1 and -2 mediate integrin-dependent cell adhesion. Connect Tissue Res 1998; 37:29-51. [PMID: 9643645 DOI: 10.3109/03008209809028898] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Human fibrillin, a major component of the extracellular matrix, exists as two highly homologous forms (fibrillin-1 and -2). Several modules of fibrillin are homologous to TGF-beta1 binding protein. Two of these modules, D25 (the 25th module of fibrillin-1 and -2 D segment) and D12 (the 12th module of fibrillin-2 D segment) contain the cell adhesion motif arginyl-glycyl-aspartyl (RGD). The ability of RGD to mediate adhesion to D25-1 and D12-2 was investigated using bacterially expressed fusion proteins. Human skin fibroblasts and murine L-cells were used in microassays of cell attachment and cell spreading on fibrillin fusion-protein substrata. Dose-dependent experiments and competitive inhibition by soluble RGD-containing peptides demonstrated that D25-1 and D12-2 mediate RGD-dependent cell adhesion. These results provide evidence for a cell adhesion function of fibrillin-2. Inhibition with anti-integrin antibodies showed that alpha(v) and beta3 integrins mediate adhesion to D25-1, while alpha3, alpha(v) and beta1 are involved in adhesion to D12-2. Binding of different receptors may elicit distinct cell signalling supporting the hypothesis that fibrillin-1 and fibrillin-2 have distinct roles.
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Affiliation(s)
- C D'Arrigo
- Department of Neuropathology, Institute of Neurology, London, UK
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Devars S, Hernandez R, Covian R, Garcia-Horsman A, Barquera B, Moreno-Sanchez R. The Content of Alternative Oxidase of Euglena Mitochondria is Increased by Growth in the Presence of Cyanide and is not Cytochrome o. J Eukaryot Microbiol 1998. [DOI: 10.1111/j.1550-7408.1998.tb05079.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Affiliation(s)
- S Jünemann
- Glynn Laboratory of Bioenergetics, Department of Biology, University College London, UK.
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Hayashi T, Miyahara T, Koide N, Kato Y, Masuda H, Ogoshi H. Molecular Recognition of Ubiquinone Analogues. Specific Interaction between Quinone and Functional Porphyrin via Multiple Hydrogen Bonds. J Am Chem Soc 1997. [DOI: 10.1021/ja9711526] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takashi Hayashi
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-01, Japan, and Department of Applied Chemistry, Nagoya Institute of Technology, Nagoya 466, Japan
| | - Takashi Miyahara
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-01, Japan, and Department of Applied Chemistry, Nagoya Institute of Technology, Nagoya 466, Japan
| | - Norihiro Koide
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-01, Japan, and Department of Applied Chemistry, Nagoya Institute of Technology, Nagoya 466, Japan
| | - Yukitoshi Kato
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-01, Japan, and Department of Applied Chemistry, Nagoya Institute of Technology, Nagoya 466, Japan
| | - Hideki Masuda
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-01, Japan, and Department of Applied Chemistry, Nagoya Institute of Technology, Nagoya 466, Japan
| | - Hisanobu Ogoshi
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-01, Japan, and Department of Applied Chemistry, Nagoya Institute of Technology, Nagoya 466, Japan
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Miyoshi H, Inoue M, Okamoto S, Ohshima M, Sakamoto K, Iwamura H. Probing the ubiquinone reduction site of mitochondrial complex I using novel cationic inhibitors. J Biol Chem 1997; 272:16176-83. [PMID: 9195916 DOI: 10.1074/jbc.272.26.16176] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A wide variety of N-methylpyridinium and quinolinium cationic inhibitors of mitochondrial complex I was synthesized to develop potent and specific inhibitors acting selectively at one of the two proposed ubiquinone binding sites of this enzyme (Gluck, M. R., Krueger, M. J., Ramsay, R. R., Sablin, S. O., Singer, T. P., and Nicklas, W. J. (1994) J. Biol. Chem. 269, 3167-3174). N-Methyl-2-n-dodecyl-3-methylquinolinium (MQ18) inhibited electron transfer of complex I at under microM order regardless of whether exogenous or endogenous ubiquinone was used as an electron acceptor. The presence of tetraphenylboron (TPB-) potentiated the inhibition by MQ18 in a different way depending upon the molar ratio of TPB- to MQ18. In the presence of a catalytic amount of TPB-, the inhibitory potency of MQ18 was remarkably enhanced, and the extent of inhibition was almost complete. The presence of equimolar TPB- partially reactivated the enzyme activity, and the inhibition was saturated at an incomplete level (approximately 50%). These results are explained by the proposed dual binding sites model for ubiquinone (cited above). The inhibition behavior of MQ18 for proton pumping activity was similar to that for electron transfer activity. The good correlation of the inhibition behavior for the two activities indicates that both ubiquinone binding sites contribute to redox-driven proton pumping. On the other hand, N-methyl-4-[2-methyl-3-(p-tert-butylphenyl)]propylpyridinium (MP6) without TPB- brought about approximately 50% inhibition at 5 microM, but the inhibition reached a plateau at this level over a wide range of concentrations. Almost complete inhibition was readily obtained at low concentrations of MP6 in the presence of TPB-. Thus MP6 appears to be a selective inhibitor of one of the two ubiquinone binding sites. With a combined use of MP6 and 2,3-diethoxy-5-methyl-6-geranyl-1,4-benzoquinone, we also provided kinetic evidence for the existence of two ubiquinone binding sites.
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Affiliation(s)
- H Miyoshi
- Department of Agricultural Chemistry, Kyoto University, Sakyo-ku, Kyoto 606, Japan.
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Hayashi T, Ogoshi H. Molecular modelling of electron transfer systems by noncovalently linked porphyrin–acceptor pairing. Chem Soc Rev 1997. [DOI: 10.1039/cs9972600355] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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