Read by QxMD icon Read


Kazuhiro Saihara, Ryosuke Kamikubo, Kazuto Ikemoto, Koji Uchida, Mitsugu Akagawa
Pyrroloquinoline quinone (PQQ), a redox-active o-quinone found in various foods and mammalian tissues, has received an increasing amount of attention because of a number of health benefits that can be attributed to its ability to enhance mitochondrial biogenesis. However, its underlying molecular mechanism remains incompletely understood. We have now established that the exposure of mouse NIH/3T3 fibroblasts to a physiologically relevant concentration of PQQ significantly stimulates mitochondrial biogenesis...
December 19, 2017: Biochemistry
Partha Pratim Chakraborty, Shinjan Patra, Rana Bhattacharjee, Subhankar Chowdhury
Currently available glucose test strip enzymes include glucose oxidase (GOD) and glucose dehydrogenase (GDH). In GDH-based glucometers, glucose oxidation can be catalysed by different cofactors: nicotinamide adenine dinucleotide (GDH-NAD), flavin adenine dinucleotide (GDH-FAD), pyrroloquinolinequinone (GDH-PQQ) and mutant GDH-PQQ. GOD-based and GDH-NAD-based glucometers are substrate-specific and do not react with sugars other than glucose. GDH-FAD reacts with xylose only in addition to glucose. GDH-PQQ is not glucose-specific; in addition to glucose, it reacts with different other sugars and produces falsely high values of capillary glucose in the presence of such substances...
May 12, 2017: BMJ Case Reports
Aishwarya Mahadevan, Sandun Fernando
An improved glycerol biosensor was developed via direct attachment of NAD(+)-glycerol dehydrogenase coenzyme-apoenzyme complex onto supporting gold electrodes, using novel inorganic iron (II) sulfide (FeS)-based single molecular wires. Sensing performance factors, i.e., sensitivity, a detection limit and response time of the FeS and conventional pyrroloquinoline quinone (PQQ)-based biosensor were evaluated by dynamic constant potential amperometry at 1.3V under non-buffered conditions. For glycerol concentrations ranging from 1 to 25mM, a 77% increase in sensitivity and a 53% decrease in detection limit were observed for the FeS-based biosensor when compared to the conventional PQQ-based counterpart...
June 15, 2017: Biosensors & Bioelectronics
Mitsugu Akagawa, Kenji Minematsu, Takahiro Shibata, Tatsuhiko Kondo, Takeshi Ishii, Koji Uchida
Pyrroloquinoline quinone (PQQ), a redox-active o-quinone, is an important nutrient involved in numerous physiological and biochemical processes in mammals. Despite such beneficial functions, the underlying molecular mechanisms remain to be established. In the present study, using PQQ-immobilized Sepharose beads as a probe, we examined the presence of protein(s) that are capable of binding PQQ in mouse NIH/3T3 fibroblasts and identified five cellular proteins, including l-lactate dehydrogenase (LDH) A chain, as potential mammalian PQQ-binding proteins...
May 27, 2016: Scientific Reports
Ismaila Emahi, Paige R Gruenke, Dana A Baum
In vitro selection or SELEX has allowed for the identification of functional nucleic acids (FNAs) that can potentially mimic and replace protein enzymes. These FNAs likely interact with cofactors, just like enzymes bind cofactors in their active sites. Investigating how FNA binding affects cofactor properties is important for understanding how an active site is formed and for developing useful enzyme mimics. Oxidoreductase enzymes contain cofactors in their active sites that allow the enzymes to do redox chemistry...
December 2015: Journal of Molecular Evolution
Jian Zhang, Sunitha Meruvu, Yudhishtar Singh Bedi, Jason Chau, Andrix Arguelles, Robert Rucker, Mahua Choudhury
Sirtuin (Sirt) 1 and Sirt 3 are nicotinamide adenine dinucleotide ((+))-dependent protein deacetylases that are important to a number of mitochondrial-related functions; thus, identification of sirtuin activators is important. Herein, we hypothesize that pyrroloquinoline quinone (PQQ) can act as a Sirt1/Sirt3 activator. In HepG2 cell cultures, PQQ increased the expression of Sirt1 and Sirt3 gene, protein, and activity levels (P < .05). We also observed a significant increase in nicotinamide phosphoribosyltransferase gene expression (as early as 18 hours) and increased NAD(+) activity at 24 hours...
September 2015: Nutrition Research
Shay Mailloux, Yulia V Gerasimova, Nataliia Guz, Dmitry M Kolpashchikov, Evgeny Katz
Molecular computing based on enzymes or nucleic acids has attracted a great deal of attention due to the perspectives of controlling living systems in the way we control electronic computers. Enzyme-based computational systems can respond to a great variety of small molecule inputs. They have the advantage of signal amplification and highly specific recognition. DNA computing systems are most often controlled by oligonucleotide inputs/outputs and are capable of sophisticated computing as well as controlling gene expressions...
May 26, 2015: Angewandte Chemie
Janet B Matsen, Song Yang, Lisa Y Stein, David Beck, Marina G Kalyuzhnaya
Methane utilizing bacteria (methanotrophs) are important in both environmental and biotechnological applications, due to their ability to convert methane to multicarbon compounds. However, systems-level studies of methane metabolism have not been carried out in methanotrophs. In this work we have integrated genomic and transcriptomic information to provide an overview of central metabolic pathways for methane utilization in Methylosinus trichosporium OB3b, a model alphaproteobacterial methanotroph. Particulate methane monooxygenase, PQQ-dependent methanol dehydrogenase, the H4MPT-pathway, and NAD-dependent formate dehydrogenase are involved in methane oxidation to CO2...
2013: Frontiers in Microbiology
Uraiwan Masud, Kazunobu Matsushita, Gunjana Theeragool
The cytosolic NAD⁺-dependent alcohol dehydrogenases (NAD⁺-ADHs) are induced in the quinoprotein ADH-(PQQ-ADH) defective Acetobacter pasteurianus SKU1108 mutant during growth in an ethanol medium. The adhI and adhII genes, which encode NAD⁺-ADH I and ADH II, respectively, of this strain have been cloned and characterized. Sequence analyses have revealed that the adhI gene consists of 1029 bp coding for 342 amino acids, which share 99.71% identity with the same protein from A. pasteurianus IFO 3283. Conversely, the adhII gene is composed of 762 bp encoding for a polypeptide of 253 amino acids, which exhibit 99...
November 2011: Journal of Bioscience and Bioengineering
Daniel H Haft
BACKGROUND: Enzymes in the radical SAM (rSAM) domain family serve in a wide variety of biological processes, including RNA modification, enzyme activation, bacteriocin core peptide maturation, and cofactor biosynthesis. Evolutionary pressures and relationships to other cellular constituents impose recognizable grammars on each class of rSAM-containing system, shaping patterns in results obtained through various comparative genomics analyses. RESULTS: An uncharacterized gene cluster found in many Actinobacteria and sporadically in Firmicutes, Chloroflexi, Deltaproteobacteria, and one Archaeal plasmid contains a PqqE-like rSAM protein family that includes Rv0693 from Mycobacterium tuberculosis...
January 11, 2011: BMC Genomics
Chiu-Yeh Tsai, Su-Chu Lee, Chi-Chih Hung, Jia-Jung Lee, Mei-Chuan Kuo, Shang-Jyh Hwang, Hung-Chun Chen
OBJECTIVE: False elevation of blood glucose levels measured by glucose dehydrogenase pyrroloquinoline quinone (GDH-PQQ)-based glucose self-monitoring systems; glucometer) in peritoneal dialysis (PD) patients using icodextrin solution has been well documented. However, adverse hypoglycemic events caused by misreadings for blood glucose are still being reported. We aimed to study blood glucose levels measured simultaneously using different methods in PD patients with switching of icodextrin, and throughout daily exchanges either using icodextrin or not...
May 2010: Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis
Uraiwan Masud, Kazunobu Matsushita, Gunjana Theeragool
The adhS gene which encodes the smallest subunit, subunit III, of quinoprotein alcohol dehydrogenase (PQQ-ADH) from Acetobacter pasteurianus SKU1108 has been cloned and characterized. The role of this subunit on the function of PQQ-ADH was investigated by construction of adhS gene disruptant and mutants. The adhS gene disruptant completely lost its PQQ-ADH activity and acetate-producing ability but retained acetic acid toleration. In contrast, this disruptant grew well, even better than the wild type, in the ethanol containing medium even though its PQQ-ADH activity and ethanol oxidizing ability was completely lost, while NAD(+)-dependent ADH (NAD(+)-ADH) was induced...
March 31, 2010: International Journal of Food Microbiology
T P Pirog, Iu V Korzh, T A Shevchuk
Four types of alcohol- and acetaldehyde dehydrogenases were found in the cells of strain Rhodococcus erythropolis EK1 grown on ethanol. They are as follows: NAD-, NADP-, pyroquinoline quinone (PQQ)- and 4-nitroso-N,N-dimethyl aniline (NDMA)-dependent enzymes. Activity of NAD- and NADP+ -dependent alcohol dehydrogenases, as well as PQQ and NDMA-dependent acetaldehyde dehydrogenases was low and made up 3-11 nmol x min(-1) x mg(-1) of protein. Ethanol oxidation in the given strain is realized by NDMA-dependent alcohol dehydrogenase, which activity reached its maximum value (up to 15 nmol x min(-1) x mg(-1) of protein) in the early exponential growth phase...
January 2009: Mikrobiolohichnyĭ Zhurnal., Mikrobiologichny Zhurnal
S Achmann, M Hermann, F Hilbrig, V Jérôme, M Hämmerle, R Freitag, R Moos
An amperometric enzyme-based sensor-system for the direct detection of formaldehyde in air is under investigation. The biosensor is based on a native bacterial NAD(+)- and glutathione-independent formaldehyde dehydrogenase as biorecognition element. The enzyme was isolated from Hyphomicrobium zavarzinii strain ZV 580, grown on methylamine hydrochloride in a fed-batch process. The sensor depends on the enzymatic conversion of the analyte to formic acid. Released electrons are detected in an amperometric measurement at 0...
May 15, 2008: Talanta
Hope A Johnson, Bradley M Tebo
Manganese(II)-oxidizing bacteria play an integral role in the cycling of Mn as well as other metals and organics. Prior work with Mn(II)-oxidizing bacteria suggested that Mn(II) oxidation involves a multicopper oxidase, but whether this enzyme directly catalyzes Mn(II) oxidation is unknown. For a clearer understanding of Mn(II) oxidation, we have undertaken biochemical studies in the model marine alpha-proteobacterium, Erythrobacter sp. strain SD21. The optimum pH for Mn(II)-oxidizing activity was 8.0 with a specific activity of 2...
January 2008: Archives of Microbiology
Hirohide Toyama, Eriko Nishibayashi, Megumi Saeki, Osao Adachi, Kazunobu Matsushita
PqqC/D converts the biosynthetic intermediate purified from a pqqC mutant to pyrroloquinoline quinone (PQQ), and both NAD(P)H and cytosolic fraction, named as activating factor (ActF), are required to show its higher production. Dithiothreitol alone, as well as ActF plus NAD(P)H, enhanced the PQQ production by PqqC/D. Thioredoxin-thioredoxin reductase system with NADPH showed similar effect. PqqC/D made a tight complex with PQQ, however, in the presence of dithiothreitol, PQQ was dissociated from the protein...
March 2, 2007: Biochemical and Biophysical Research Communications
K A Bauerly, D H Storms, C B Harris, S Hajizadeh, M Y Sun, C P Cheung, M A Satre, A J Fascetti, E Tchaparian, R B Rucker
Pyrroloquinoline quinone (PQQ) added to purified diets devoid of PQQ improves indices of perinatal development in rats and mice. Herein, PQQ nutritional status and lysine metabolism are described, prompted by a report that PQQ functions as a vitamin-like enzymatic cofactor important in lysine metabolism (Nature 422 [2003] 832). Alternatively, we propose that PQQ influences lysine metabolism, but by mechanisms that more likely involve changes in mitochondrial content. PQQ deprivation in both rats and mice resulted in a decrease in mitochondrial content...
November 2006: Biochimica et Biophysica Acta
Astrid-Mette Husøy, Grete Rustan Knudsen, Micaela Thierley, Einar Svarstad
BACKGROUND: Recent reports have indicated that icodextrin may interfere with glucose assays when patients are treated with icodextrin for peritoneal dialysis (PD). We wished to examine whether icodextrin interfered with plasma glucose, as measured with new instruments commonly used for glucose measurements in Norway. MATERIAL AND METHODS: Serum and plasma glucose were measured in a diabetic patient (type II) who had started PD with icodextrin. Serum glucose was measured simultaneously in venous blood using the laboratory reference method (hexokinase), and compared with eight point of care testing (POCT) glucometers...
September 7, 2006: Tidsskrift for Den Norske Lægeforening: Tidsskrift for Praktisk Medicin, Ny Række
María F Luna, Cecilia E Bernardelli, María L Galar, José L Boiardi
Periplasmic glucose oxidation (by way of a pyrrolo-quinoline-quinone [PQQ]-linked glucose dehydrogenase [GDH]) was observed in continuous cultures of Gluconacetobacter diazotrophicus regardless of the carbon source (glucose or gluconate) and the nitrogen source (N(2) or NH(3)). Its synthesis was stimulated by conditions of high energetic demand (i.e., N(2)-fixation) and/or C-limitation. Under C-excess conditions, PQQ-GDH synthesis increased with the glucose concentration in the culture medium. In batch cultures, PQQ-GDH was actively expressed in very early stages with higher activities under conditions of N(2)-fixation...
March 2006: Current Microbiology
Estrella Maestre, Ioanis Katakis, Arántzazu Narváez, Elena Domínguez
A multianalyte flow electrochemical cell (MAFEC) for bioanalysis is constructed, characterised and used for simultaneous carbohydrate analysis incorporating mediated amperometric enzyme electrodes. Although multidetection schemes can be addressed with microfabricated systems, it is demonstrated that a "meso" analytical device of low cost can give answers to traditional simultaneous multianalysis problems, being robust, and easy to construct and operate. The cell operates as a radial flow thin-layer device and can achieve mass transport controlled response for fast electrochemical reactions...
November 15, 2005: Biosensors & Bioelectronics
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"