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PQQ AND Ubiquinone

Sofia Babanova, Ivana Matanovic, Madelaine Seow Chavez, Plamen Atanassov
In this study, the influence of two quinones (1,2- and 1,4-benzoquinone) on the operation and mechanism of electron transfer in PQQ-dependent glucose dehydrogenase (PQQ-sGDH) anodes has been determined. Benzoquinones were experimentally explored as mediators present in the electrolyte. The electrochemical performance of the PQQ-sGDH anodes with and without the mediators was examined and for the first time molecular docking simulations were used to gain a fundamental understanding to explain the role of the mediator molecules in the design and operation of the enzymatic electrodes...
June 24, 2015: Journal of the American Chemical Society
Nina V Doronina, Elena N Kaparullina, Yuri A Trotsenko
A newly isolated facultatively methylotrophic bacterium (strain 3t(T)) was investigated. Cells of the isolate were Gram-stain-negative, asporogenous, non-motile rods that multiplied by binary fission. The strain utilized methanol, methylamine and a variety of multicarbon compounds as carbon and energy sources. Growth occurred at pH 6.5-8.5 (optimally at 7.0-7.5) and at 10-45 °C (optimally at 30-37 °C). The major fatty acids of methanol-grown cells were C16 : 1ω7c and C16 : 0. The predominant phospholipids were phosphatidylethanolamine and phosphatidylglycerol...
January 2014: International Journal of Systematic and Evolutionary Microbiology
Saúl Gómez-Manzo, Alejandra Abigail González-Valdez, Jesús Oria-Hernández, Horacio Reyes-Vivas, Roberto Arreguín-Espinosa, Peter M H Kroneck, Martha Elena Sosa-Torres, Jose E Escamilla
The membrane-bound alcohol dehydrogenase of Gluconacetobacter diazotrophicus contains one pyrroloquinoline quinone moiety (PQQ), one [2Fe-2S] cluster, and four c-type cytochromes. Here, we describe a novel and inactive enzyme. ADHi, similarly to ADHa, is a heterodimer of 72- and 44-kDa subunits and contains the expected prosthetic groups. However, ADHa showed a threefold molecular mass as compared to ADHi. Noteworthy, the PQQ, the [2Fe-2S] and most of the cytochromes in purified ADHi is in the oxidized form, contrasting with ADHa where the PQQ-semiquinone is detected and the [2Fe-2S] cluster as well as the cytochromes c remained fully reduced after purification...
March 2012: FEMS Microbiology Letters
S Gómez-Manzo, J L Chavez-Pacheco, M Contreras-Zentella, M E Sosa-Torres, R Arreguín-Espinosa, M Pérez de la Mora, J Membrillo-Hernández, J E Escamilla
Several aldehyde dehydrogenase (ALDH) complexes have been purified from the membranes of acetic acid bacteria. The enzyme structures and the chemical nature of the prosthetic groups associated with these enzymes remain a matter of debate. We report here on the molecular and catalytic properties of the membrane-bound ALDH complex of the diazotrophic bacterium Gluconacetobacter diazotrophicus. The purified ALDH complex is a heterodimer comprising two subunits of 79.7 and 50 kDa, respectively. Reversed-phase high-pressure liquid chromatography (HPLC) and electron paramagnetic resonance spectroscopy led us to demonstrate, for the first time, the unequivocal presence of a pyrroloquinoline quinone prosthetic group associated with an ALDH complex from acetic acid bacteria...
November 2010: Journal of Bacteriology
J L Chávez-Pacheco, M Contreras-Zentella, J Membrillo-Hernández, R Arreguín-Espinoza, G Mendoza-Hernández, S Gómez-Manzo, J E Escamilla
Gluconacetobacter xylinus possesses a constitutive membrane-bound oxidase system for the use of ethanol. Its alcohol dehydrogenase complex (ADH) was purified to homogeneity and characterized. It is a 119-kDa heterodimer (68 and 41 kDa subunits). The peroxidase reaction confirmed the presence of haem C in both subunits. Four cytochromes c per enzyme were determined by pyridine hemochrome spectroscopy. Redox titrations of the purified ADH revealed the presence of four haem c redox centers, with apparent mid-point potential values (Em(7)) of -33, +55, +132 and +310 mV, respectively...
September 2010: Archives of Microbiology
Toshiharu Yakushi, Kazunobu Matsushita
Pyrroquinoline quinone-dependent alcohol dehydrogenase (PQQ-ADH) of acetic acid bacteria is a membrane-bound enzyme involved in the acetic acid fermentation by oxidizing ethanol to acetaldehyde coupling with reduction of membranous ubiquinone (Q), which is, in turn, re-oxidized by ubiquinol oxidase, reducing oxygen to water. PQQ-ADHs seem to have co-evolved with the organisms fitting to their own habitats. The enzyme consists of three subunits and has a pyrroloquinoline quinone, 4 heme c moieties, and a tightly bound Q as the electron transfer mediators...
May 2010: Applied Microbiology and Biotechnology
Burla Sashidhar, Krishna Kishore Inampudi, Lalitha Guruprasad, Anil Kondreddy, Kodetham Gopinath, Appa Rao Podile
Gram-negative bacteria membrane-bound glucose dehydrogenase (m-GDH) has pyrroloquinoline quinone [PQQ (2,7,9,-tricarboxyl-1H-pyrrolo[2,3-f]quinoline-4,5-dione)] as its prosthetic group, transferring electrons to ubiquinone (UQ) in the membrane. Based on the sequence homology of the C-terminal catalytic domain (151-796 amino acid residues) we have modeled the 3D structure of Escherichia coli GDH. The geometrical parameters of the homology model structure, validated using the Ramachandran plot, revealed 95.8% of residues in the allowed regions and 2...
2010: Journal of Molecular Microbiology and Biotechnology
Golam Mustafa, Yoshinori Ishikawa, Kazuo Kobayashi, Catharina T Migita, Seiichi Tagawa, Mamoru Yamada
Membrane-bound glucose dehydrogenase (mGDH) is a single integral protein in the respiratory chain in Escherichia coli which oxidizes D-glucose and feeds electrons to ubiquinol oxidase via bulk ubiquinone (UQ). mGDH contains a bound UQ, CoQ8, for its intramolecular electron transfer in addition to pyrroloquinoline quinone (PQQ) as a coenzyme. Pulse radiolysis analysis revealed that the bound UQ exists very close to PQQ at a distance of 11-13 angstroms. Studies on mGDH mutants with substitutions for amino acid residues around PQQ showed that Asp-466 and Lys-493, which are crucial for catalytic activity, interact with bound UQ...
2008: BioFactors
Kazunobu Matsushita, Yoshiki Kobayashi, Mitsuhiro Mizuguchi, Hirohide Toyama, Osao Adachi, Kimitoshi Sakamoto, Hideto Miyoshi
Quinoprotein alcohol dehydrogenase (ADH) of acetic acid bacteria is a membrane-bound enzyme that functions as the primary dehydrogenase in the ethanol oxidase respiratory chain. It consists of three subunits and has a pyrroloquinoline quinone (PQQ) in the active site and four heme c moieties as electron transfer mediators. Of these, three heme c sites and a further site have been found to be involved in ubiquinone (Q) reduction and ubiquinol (QH2) oxidation respectively (Matsushita et al., Biochim. Biophys...
October 2008: Bioscience, Biotechnology, and Biochemistry
Golam Mustafa, Catharina T Migita, Yoshinori Ishikawa, Kazuo Kobayashi, Seiichi Tagawa, Mamoru Yamada
Escherichia coli membrane-bound glucose dehydrogenase (mGDH), which is one of quinoproteins containing pyrroloquinoline quinone (PQQ) as a coenzyme, is a good model for elucidating the function of bound quinone inside primary dehydrogenases in respiratory chains. Enzymatic analysis of purified mGDH from cells defective in synthesis of ubiquinone (UQ) and/or menaquinone (MQ) revealed that Q-free mGDH has very low levels of activity of glucose dehydrogenase and UQ2 reductase compared with those of UQ-bearing mGDH, and both activities were significantly increased by reconstitution with UQ1...
October 17, 2008: Journal of Biological Chemistry
Golam Mustafa, Yoshinori Ishikawa, Kazuo Kobayashi, Catharina T Migita, M D Elias, Satsuki Nakamura, Seiichi Tagawa, Mamoru Yamada
The Escherichia coli membrane-bound glucose dehydrogenase (mGDH) as the primary component of the respiratory chain possesses a tightly bound ubiquinone (UQ) flanking pyrroloquinoline quinone (PQQ) as a coenzyme. Several mutants for Asp-354, Asp-466, and Lys-493, located close to PQQ, that were constructed by site-specific mutagenesis were characterized by enzymatic, pulse radiolysis, and EPR analyses. These mutants retained almost no dehydrogenase activity or ability of PQQ reduction. CD and high pressure liquid chromatography analyses revealed that K493A, D466N, and D466E mutants showed no significant difference in molecular structure from that of the wild-type mGDH but showed remarkably reduced content of bound UQ...
August 8, 2008: Journal of Biological Chemistry
Xue-Peng Yang, Liu-Jing Wei, Jian-Bin Ye, Bo Yin, Dong-Zhi Wei
A membrane-bound pyrroloquinoline quinine (PQQ)-dependent D-sorbitol dehydrogenase (mSLDH) in Gluconobacter oxydans participates in the oxidation of D-sorbitol to L-sorbose by transferring electrons to ubiquinone which links to the respiratory chain. To elucidate the kinetic mechanism, the enzyme purified was subjected to two-substrate steady-state kinetic analysis, product and substrate inhibition studies. These kinetic data indicate that the catalytic reaction follows an ordered Bi Bi mechanism, where the substrates bind to the enzyme in a defined order (first ubiquinone followed by D-sorbitol), while products are released in sequence (first L-sorbose followed by ubiquinol)...
September 15, 2008: Archives of Biochemistry and Biophysics
B González, S Martínez, J L Chávez, S Lee, N A Castro, M A Domínguez, S Gómez, M L Contreras, C Kennedy, J E Escamilla
In highly aerobic environments, Gluconacetobacter diazotrophicus uses a respiratory protection mechanism to preserve nitrogenase activity from deleterious oxygen. Here, the respiratory system was examined in order to ascertain the nature of the respiratory components, mainly of the cyanide sensitive and resistant pathways. The membranes of G. diazotrophicus contain Q(10), Q(9) and PQQ in a 13:1:6.6 molar ratios. UV(360 nm) photoinactivation indicated that ubiquinone is the electron acceptor for the dehydrogenases of the outer and inner faces of the membrane...
December 2006: Biochimica et Biophysica Acta
Kazuo Kobayashi, Golam Mustafa, Seiichi Tagawa, Mamoru Yamada
The membrane-bound quinoprotein glucose dehydrogenase (mGDH) in Escherichia coli contains pyrroloquinoline quinone (PQQ) and participates in the direct oxidation of D-glucose to D-gluconate by transferring electrons to ubiquinone (UQ). To elucidate the mechanism of ubiquinone reduction by mGDH, we applied a pulse radiolysis technique to mGDH with or without bound UQ8. With the UQ8-bound enzyme, a hydrated electron reacted with mGDH to form a transient species with an absorption maximum at 420 nm, characteristic of formation of a neutral ubisemiquinone radical...
October 18, 2005: Biochemistry
Hirohide Toyama, F Scott Mathews, Osao Adachi, Kazunobu Matsushita
Quino(hemo)protein alcohol dehydrogenases (ADH) that have pyrroloquinoline quinone (PQQ) as the prosthetic group are classified into 3 groups, types I, II, and III. Type I ADH is a simple quinoprotein having PQQ as the only prosthetic group, while type II and type III ADHs are quinohemoprotein having heme c as well as PQQ in the catalytic polypeptide. Type II ADH is a soluble periplasmic enzyme and is widely distributed in Proteobacteria such as Pseudomonas, Ralstonia, Comamonas, etc. In contrast, type III ADH is a membrane-bound enzyme working on the periplasmic surface solely in acetic acid bacteria...
August 1, 2004: Archives of Biochemistry and Biophysics
Christopher Anthony
This review summarises our current understanding of two of the main types of quinoprotein dehydrogenase in which pyrroloquinoline quinone (PQQ) is the only prosthetic group. These are the soluble methanol dehydrogenase and the membrane glucose dehydrogenase (mGDH). The membrane GDH has an additional N-terminal domain by which it is tightly anchored to the membrane, and a periplasmic domain whose structure has been modelled on the X-ray structure of the alpha-subunit of MDH which contains PQQ in the active site...
August 1, 2004: Archives of Biochemistry and Biophysics
M D Elias, Satsuki Nakamura, Catharina T Migita, Hideto Miyoshi, Hirohide Toyama, Kazunobu Matsushita, Osao Adachi, Mamoru Yamada
The membrane-bound pyrroloquinoline quinone (PQQ)-containing quinoprotein glucose dehydrogenase (mGDH) in Escherichia coli functions by catalyzing glucose oxidation in the periplasm and by transferring electrons directly to ubiquinone (UQ) in the respiratory chain. To clarify the intramolecular electron transfer of mGDH, quantitation and identification of UQ were performed, indicating that purified mGDH contains a tightly bound UQ(8) in its molecule. A significant increase in the EPR signal was observed following glucose addition in mGDH reconstituted with PQQ and Mg(2+), suggesting that bound UQ(8) accepts a single electron from PQQH(2) to generate semiquinone radicals...
January 23, 2004: Journal of Biological Chemistry
Andrew R Knaggs
This review covers the literature published during 2000 on the biosynthesis of compounds derived wholly or partly from intermediates on the shikimate pathway. Recent developments in the enzymology and genetics of the shikimate pathway arc also described. Enzymes involved in the biogenetic pathway to the aromatic amino acids are covered initially followed by sections dedicated to metabolites derived in some part from intermediates on the pathway. These include pyrrolnitrin. violacein. indole-3-acetic acid, coumarins, lignans, lignin, tannins, melanin, flavanoids, ubiquinone, TOPA quinone, PQQ, and tropanes...
February 2003: Natural Product Reports
G E Cozier, R A Salleh, C Anthony
The requirements for substrate binding in the quinoprotein glucose dehydrogenase (GDH) in the membranes of Escherichia coli are described, together with the changes in activity in a site-directed mutant in which His262 has been altered to a tyrosine residue (H262Y-GDH). The differences in catalytic efficiency between substrates are mainly related to differences in their affinity for the enzyme. Remarkably, it appears that, if a hexose is able to bind in the active site, then it is also oxidized, whereas some pentoses are able to bind (and act as competitive inhibitors), but are not substrates...
June 15, 1999: Biochemical Journal
P M Goodwin, C Anthony
Pyrrolo-quinoline quinone (PQQ) is the non-covalently bound prosthetic group of many quinoproteins catalysing reactions in the periplasm of Gram-negative bacteria. Most of these involve the oxidation of alcohols or aldose sugars. PQQ is formed by fusion of glutamate and tyrosine, but details of the biosynthetic pathway are not known; a polypeptide precursor in the cytoplasm is probably involved, the completed PQQ being transported into the periplasm. In addition to the soluble methanol dehydrogenase of methylotrophs, there are three classes of alcohol dehydrogenases; type I is similar to methanol dehydrogenase; type II is a soluble quinohaemoprotein, having a C-terminal extension containing haem C; type III is similar but it has two additional subunits (one of which is a multihaem cytochrome c), bound in an unusual way to the periplasmic membrane...
1998: Advances in Microbial Physiology
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