Academic literature on the topic 'NADH molecules'
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Journal articles on the topic "NADH molecules"
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Wos, M. L., and P. C. Pollard. "Cellular nicotinamide adenine dinucleotide (NADH) as an indicator of bacterial metabolic activity dynamics in activated sludge." Water Science and Technology 60, no. 3 (July 1, 2009): 783–91. http://dx.doi.org/10.2166/wst.2009.393.
Full textAbstract:
In this study, native fluorescent nicotinamide adenine dinucleotide (NADH) was used as a direct indicator of bacterial metabolic activity in activated sludge. Specific NADH concentration was dynamic and varied between 106–108 molecules per bacterial cell. Low concentrations (106–107 NADH molecules cell−1) indicate efficient bacterial metabolic activity while high concentrations (107–108 NADH molecules cell−1) indicate inefficient bacterial metabolic activity. Specific [NADH] did not correlate to changes in dissolved organic carbon, but increases correlated to decreases in oxygen uptake rates. Perhaps a lack of oxygen as the terminal electron acceptor prevented efficient reoxidization of NADH to NAD+, which resulted in an accumulation of NADH within the cells. Also, significant amounts of NADH were released and accumulated into the extracellular medium of metabolically active E. coli cells in log phase. Such overflow metabolism may be the product of favourable conditions. Thus, the flux of both specific intracellular and extracellular [NADH] indicates the dynamics of bacterial metabolic activity in activated sludge.
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Tsai, Hsieh-Chin, Cheng-Hung Hsieh, Ching-Wen Hsu, Yau-Heiu Hsu, and Lee-Feng Chien. "Cloning and Organelle Expression of Bamboo Mitochondrial Complex I Subunits Nad1, Nad2, Nad4, and Nad5 in the Yeast Saccharomyces cerevisiae." International Journal of Molecular Sciences 23, no. 7 (April 6, 2022): 4054. http://dx.doi.org/10.3390/ijms23074054.
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Mitochondrial respiratory complex I catalyzes electron transfer from NADH to ubiquinone and pumps protons from the matrix into the intermembrane space. In particular, the complex I subunits Nad1, Nad2, Nad4, and Nad5, which are encoded by the nad1, nad2, nad4, and nad5 genes, reside at the mitochondrial inner membrane and possibly function as proton (H+) and ion translocators. To understand the individual functional roles of the Nad1, Nad2, Nad4, and Nad5 subunits in bamboo, each cDNA of these four genes was cloned into the pYES2 vector and expressed in the mitochondria of the yeast Saccharomyces cerevisiae. The mitochondrial targeting peptide mt gene (encoding MT) and the egfp marker gene (encoding enhanced green fluorescent protein, EGFP) were fused at the 5′-terminal and 3′-terminal ends, respectively. The constructed plasmids were then transformed into yeast. RNA transcripts and fusion protein expression were observed in the yeast transformants. Mitochondrial localizations of the MT-Nad1-EGFP, MT-Nad2-EGFP, MT-Nad4-EGFP, and MT-Nad5-EGFP fusion proteins were confirmed by fluorescence microscopy. The ectopically expressed bamboo subunits Nad1, Nad2, Nad4, and Nad5 may function in ion translocation, which was confirmed by growth phenotype assays with the addition of different concentrations of K+, Na+, or H+.
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Qi, Xiangying, Kaiqi Wang, Liping Yang, Zhenshan Deng, and Zhihong Sun. "The complete mitogenome sequence of the coral lily (Lilium pumilum) and the Lanzhou lily (Lilium davidii) in China." Open Life Sciences 15, no. 1 (December 31, 2020): 1060–67. http://dx.doi.org/10.1515/biol-2020-0102.
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AbstractBackgroundThe mitogenomes of higher plants are conserved. This study was performed to complete the mitogenome of two China Lilium species (Lilium pumilum Redouté and Lilium davidii var. unicolor (Hoog) cotton).MethodsGenomic DNA was separately extracted from the leaves of L. pumilum and L. davidii in triplicate and used for sequencing. The mitogenome of Allium cepa was used as a reference. Genome assembly, annotation and phylogenetic tree were analyzed.ResultsThe mitogenome of L. pumilum and L. davidii was 988,986 bp and 924,401 bp in length, respectively. There were 22 core protein-coding genes (including atp1, atp4, atp6, atp9, ccmB, ccmC, ccmFc, ccmFN1, ccmFN2, cob, cox3, matR, mttB, nad1, nad2, nad3, nad4, nad4L, nad5, nad6, nad7 and nad9), one open reading frame and one ribosomal protein-coding gene (rps12) in the mitogenomes. Compared with the A. cepa mitogenome, the coding sequence of the 24 genes and intergenic spacers in L. pumilum and L. davidii mitogenome contained 1,621 and 1,617 variable sites, respectively. In the phylogenetic tree, L. pumilum and L. davidii were distinct from A. cepa (NC_030100).ConclusionsL. pumilum and L. davidii mitogenomes have far distances from other plants. This study provided additional information on the species resources of China Lilium.
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Cronholm, T. "Hydrogen transfer between ethanol molecules during oxidoreduction in vivo." Biochemical Journal 229, no. 2 (July 15, 1985): 315–22. http://dx.doi.org/10.1042/bj2290315.
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Rates of exchange catalysed by alcohol dehydrogenase were determined in vivo in order to find rate-limiting steps in ethanol metabolism. Mixtures of [1,1-2H2]- and [2,2,2-2H3]ethanol were injected in rats with bile fistulas. The concentrations in bile of ethanols having different numbers of 2H atoms were determined by g.l.c.-m.s. after the addition of [2H6]ethanol as internal standard and formation of the 3,5-dinitrobenzoates. Extensive formation of [2H4]ethanol indicated that acetaldehyde formed from [2,2,2-2H3]ethanol was reduced to ethanol and that NADH used in this reduction was partly derived from oxidation of [1,1-2H2]ethanol. The rate of acetaldehyde reduction, the degree of labelling of bound NADH and the isotope effect on ethanol oxidation were calculated by fitting models to the found concentrations of ethanols labelled with 1-42H atoms. Control experiments with only [2,2,2-2H3]ethanol showed that there was no loss of the C-2 hydrogens by exchange. The isotope effect on ethanol oxidation appeared to be about 3. Experiments with (1S)-[1-2H]- and [2,2,2-2H3]ethanol indicated that the isotope effect on acetaldehyde oxidation was much smaller. The results indicated that both the rate of reduction of acetaldehyde and the rate of association of NADH with alcohol dehydrogenase were nearly as high as or higher than the net ethanol oxidation. Thus, the rate of ethanol oxidation in vivo is determined by the rates of acetaldehyde oxidation, the rate of dissociation of NADH from alcohol dehydrogenase, and by the rate of reoxidation of cytosolic NADH. In cyanamide-treated rats, the elimination of ethanol was slow but the rates in the oxidoreduction were high, indicating more complete rate-limitation by the oxidation of acetaldehyde.
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Jeong, Kang Hwa, Hyun Jin Lee, Young Woo Park, and Jae Young Lee. "Structural Basis of Redox-Sensing Transcriptional Repressor Rex with Cofactor NAD+ and Operator DNA." International Journal of Molecular Sciences 23, no. 3 (January 29, 2022): 1578. http://dx.doi.org/10.3390/ijms23031578.
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The transcriptional repressor Rex plays important roles in regulating the expression of respiratory genes by sensing the reduction–oxidation (redox) state according to the intracellular NAD+/NADH balance. Previously, we reported on crystal structures of apo, NAD+-bound, and NADH-bound forms of Rex from Thermotoga maritima to analyze the structural basis of transcriptional regulation depending on either NAD+ or NADH binding. In this study, the crystal structure of Rex in ternary complex with NAD+ and operator DNA revealed that the N-terminal domain of Rex, including the helix-turn-helix motif, forms extensive contacts with DNA in addition to DNA sequence specificity. Structural comparison of the Rex in apo, NAD+-bound, NADH-bound, and ternary complex forms provides a comprehensive picture of transcriptional regulation in the Rex. These data demonstrate that the conformational change in Rex when binding with the reduced NADH or oxidized NAD+ determines operator DNA binding. The movement of the N-terminal domains toward the operator DNA was blocked upon binding of NADH ligand molecules. The structural results provide insights into the molecular mechanism of Rex binding with operator DNA and cofactor NAD+/NADH, which is conserved among Rex family repressors. Structural analysis of Rex from T. maritima also supports the previous hypothesis about the NAD+/NADH-specific transcriptional regulation mechanism of Rex homologues.
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Kolappan, Subramaniapillai, David L. Shen, Renee Mosi, Jianyu Sun, Ernest J. McEachern, David J. Vocadlo, and Lisa Craig. "Structures of lactate dehydrogenase A (LDHA) in apo, ternary and inhibitor-bound forms." Acta Crystallographica Section D Biological Crystallography 71, no. 2 (January 23, 2015): 185–95. http://dx.doi.org/10.1107/s1399004714024791.
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Lactate dehydrogenase (LDH) is an essential metabolic enzyme that catalyzes the interconversion of pyruvate and lactate using NADH/NAD+as a co-substrate. Many cancer cells exhibit a glycolytic phenotype known as the Warburg effect, in which elevated LDH levels enhance the conversion of glucose to lactate, making LDH an attractive therapeutic target for oncology. Two known inhibitors of the human muscle LDH isoform, LDHA, designated1and2, were selected, and their IC50values were determined to be 14.4 ± 3.77 and 2.20 ± 0.15 µM, respectively. The X-ray crystal structures of LDHA in complex with each inhibitor were determined; both inhibitors bind to a site overlapping with the NADH-binding site. Further, an apo LDHA crystal structure solved in a new space group is reported, as well as a complex with both NADH and the substrate analogue oxalate bound in seven of the eight molecules and an oxalate only bound in the eighth molecule in the asymmetric unit. In this latter structure, a kanamycin molecule is located in the inhibitor-binding site, thereby blocking NADH binding. These structures provide insights into LDHA enzyme mechanism and inhibition and a framework for structure-assisted drug design that may contribute to new cancer therapies.
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Kim, Youngnyun, L. O. Ingram, and K. T. Shanmugam. "Dihydrolipoamide Dehydrogenase Mutation Alters the NADH Sensitivity of Pyruvate Dehydrogenase Complex of Escherichia coli K-12." Journal of Bacteriology 190, no. 11 (March 28, 2008): 3851–58. http://dx.doi.org/10.1128/jb.00104-08.
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ABSTRACT Under anaerobic growth conditions, an active pyruvate dehydrogenase (PDH) is expected to create a redox imbalance in wild-type Escherichia coli due to increased production of NADH (>2 NADH molecules/glucose molecule) that could lead to growth inhibition. However, the additional NADH produced by PDH can be used for conversion of acetyl coenzyme A into reduced fermentation products, like alcohols, during metabolic engineering of the bacterium. E. coli mutants that produced ethanol as the main fermentation product were recently isolated as derivatives of an ldhA pflB double mutant. In all six mutants tested, the mutation was in the lpd gene encoding dihydrolipoamide dehydrogenase (LPD), a component of PDH. Three of the LPD mutants carried an H322Y mutation (lpd102), while the other mutants carried an E354K mutation (lpd101). Genetic and physiological analysis revealed that the mutation in either allele supported anaerobic growth and homoethanol fermentation in an ldhA pflB double mutant. Enzyme kinetic studies revealed that the LPD(E354K) enzyme was significantly less sensitive to NADH inhibition than the native LPD. This reduced NADH sensitivity of the mutated LPD was translated into lower sensitivity of the appropriate PDH complex to NADH inhibition. The mutated forms of the PDH had a 10-fold-higher Ki for NADH than the native PDH. The lower sensitivity of PDH to NADH inhibition apparently increased PDH activity in anaerobic E. coli cultures and created the new ethanologenic fermentation pathway in this bacterium. Analogous mutations in the LPD of other bacteria may also significantly influence the growth and physiology of the organisms in a similar fashion.
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Liao, Yuqin, Ruiyun You, Min Fan, Shangyuan Feng, Dechan Lu, and Yudong Lu. "Determination of NADH by Surface Enhanced Raman Scattering Using Au@MB@Ag NPs." Australian Journal of Chemistry 74, no. 10 (2021): 722. http://dx.doi.org/10.1071/ch21178.
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Nicotinamide adenine dinucleotide (NADH) is an important coenzyme involved in various metabolic processes of living cells. As an important biomarker, NADH is associated with breast cancer and Alzheimer’s disease. In this paper, silver plated gold core–shell nanoparticles containing Raman signal molecules were synthesised on the basis of bare gold. Using the Raman peak corresponding to the 4-mercaptobenzonitrile (MB) silent region C≡N vibration for quantification, while avoiding competition with the precious metal surface binding site to be measured, it can also be free from the interference of endogenous biomolecules. On the one hand, it can correct the working curve, on the other hand, it can avoid competing with the binding site. Compared with the core–shell structure prepared here, the limit of detection (LOD) for NADH was only 10−5 M for bare gold and the LOD for the core–shell structure prepared on the basis of bare gold was 3.3 × 10−7 M. In terms of correction, with Rhodamine 6G (R6G) as a Raman signalling molecule, the R2 value before SERS detection and correction is only 0.9405, and the R2 value after correction increases to 0.9853. The unique fingerprint peak of SERS was used to realise the quantitative detection of NADH, which realizes the detection of NADH in complex biological samples of serum and provides the possibility for expanding the early diagnosis of breast cancer.
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Tedokon, M., K. Suzuki, Y. Kayamori, S. Fujita, and Y. Katayama. "Enzymatic Assay of Inorganic Phosphate with Use of Sucrose Phosphorylase and Phosphoglucomutase." Clinical Chemistry 38, no. 4 (April 1, 1992): 512–15. http://dx.doi.org/10.1093/clinchem/38.4.512.
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Abstract We developed a new enzymatic method for the assay of inorganic phosphate (Pi) by using sucrose phosphorylase (SP; EC 2.4.1.7) and phosphoglucomutase (PGM; EC 5.4.2.2). Pi is transferred to sucrose by SP, producing alpha-D-glucose 1-phosphate (G1P) and alpha-D-fructose. G1P is transphosphorylated by PGM in the presence of alpha-D-glucose 1,6-bisphosphate to form alpha-D-glucose 6-phosphate, which is oxidized by NAD+ and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) to form 6-phosphogluconate (6PG) and NADH. Finally, the oxidation of 6PG by NAD+, catalyzed by 6-phosphogluconic dehydrogenase (EC 1.1.1.44), yields D-ribulose 5-phosphate and NADH. Thus two molecules of NADH are formed for each molecule of Pi, and the reaction is monitored at 340 nm. The Km values of SP for Pi and sucrose were 4.44 and 5.31 mmol/L, respectively. The best buffer was 1,4-piperazinediethanesulfonic acid (PIPES) at 50 mmol/L and pH 6-7. Implementing this method with a Cobas-Bio centrifugal analyzer allowed us to measure Pi accurately and precisely.
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Ruiz, Lorena, Miguel Gueimonde, Patricia Ruas-Madiedo, Angela Ribbera, Clara G. de los Reyes-Gavilán, Marco Ventura, Abelardo Margolles, and Borja Sánchez. "Molecular Clues To Understand the Aerotolerance Phenotype of Bifidobacterium animalis subsp. lactis." Applied and Environmental Microbiology 78, no. 3 (November 18, 2011): 644–50. http://dx.doi.org/10.1128/aem.05455-11.
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ABSTRACTOxygen is one of the abiotic factors negatively affecting the survival ofBifidobacteriumstrains used as probiotics, mainly due to the induction of lethal oxidative damage. Aerobic conditions are present during the process of manufacture and storage of functional foods, and aerotolerance is a desired trait for bifidobacteria intended for use in industry. In the present study, the molecular response ofBifidobacterium animalissubsp.lactisIPLA4549 to aerobic conditions is presented. Molecular targets affected by oxygen were studied using two-dimensional electrophoresis (2DE) and quantitative reverse transcriptase (qRT) PCR. Globally, oxygen stress induced a shift in the glycolytic pathway toward the production of acetic acid with a concomitant increase in ATP formation. Several changes in the expression of genes coding for enzymes involved in redox reactions were detected, although the redox ratio remained unaltered. Interestingly, cells grown under aerobic conditions were characterized by higher activity of coproporphyrinogen III oxidase, which can directly detoxify molecular oxygen, and by higher NADH oxidase specific activity, which can oxidize NADH using hydrogen peroxide. In turn, this is in agreement with the glycolytic shift toward acetate production, in that more NADH molecules may be available due to the lower level of lactic acid formation. These findings further our ability to elucidate the mechanisms by whichB. animaliscopes with an oxygen-containing atmosphere.
Dissertations / Theses on the topic "NADH molecules"
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Liang, Pingping. "Gold Nanoparticle-Based Colorimetric Sensors for Detection of DNA and Small Molecules." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2595.
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Biosensors have proven to be a powerful tool for detecting diverse targets, such as proteins, DNA, and small molecules representing disease biomarkers, toxins, drugs and their metabolites, environmental pollutants, agrichemicals, and antibiotics with high sensitivity and specificity.
The major objective of the research described in this dissertation was to develop low cost, low sample volume, highly sensitive and specific AuNP-based colorimetric sensor platforms for the detection of DNA and small molecules. With this in mind, we propose an instrument-free approach in chapter three for the detection of NADH with a sensor constructed on a paper substrate, based on the target-induced inhibition of AuNP dissolution. The successful detection of this important molecule opens the door to numerous possibilities for dehydrogenase characterization, because NAD+/NADH are essential cofactors for more than 300 dehydrogenase enzymes. To further increase the sensitivity of our hybridization-based assay for DNA detection, we developed an enzyme-assisted target recycling (EATR) strategy in chapter four and have applied such an EATR-based colorimetric assay to detect single-nucleotide mismatches in a target DNA with DNA-functionalized AuNPs. This assay is based on the principle that nuclease enzymes recognize probe–target complexes, cleaving only the probe strand. This results in target release, enabling subsequent binding to and cleavage of another probe molecule. When the probe is conjugated onto AuNPs, complete cleavage from the AuNP surface produces a detectable signal in high ionic strength environments as the nanoparticles undergo aggregation. With such enzyme-assisted amplification, target detection can occur with a very low nM detection limit within 15 minutes. The extent of DNA loading on the AuNP surface plays an important role in the efficiency of DNA hybridization and aptamer-target assembly. Many studies have shown that high surface-coverage is associated with steric hindrance, electrostatic repulsive interactions and elevated surface salt concentration, whereas low surface-coverage can result in nonspecific binding of oligonucleotides to the particle surface. In chapter five, we investigated DNA surface coverage effects, and apply this optimization in conjunction with a highly-specific aptamer to develop a sensitive colorimetric sensor for rapid cocaine detection based on the inhibition of nuclease enzyme activity.
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Stinson, Jelynn A. "The Electroanalytical Performance of Sonogel Carbon Titanium (IV) Oxide Electrodes versus Conducting Polymer Electrodes in the Electrochemical Detection of Biological Molecules." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1181068417.
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Roeschlaub, Carl Andrew. "The design and synthesis of novel reductively activated molecular sensors." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843218/.
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NADH and NADPH are ubiquitous biological reducing agents essential for both respiration and biosynthesis. The discovery that increased pentose-phosphate pathway activity in cervical cancer cells leads to increased levels of NAD(P)H, emphasises the need for a sensitive detection system as an indication of cellular viability and vitality. The remit of this project was to design and synthesise a novel molecular sensor system whose emissive properties are "switched on" upon reduction by NAD(P)H. Research using the reducible, non-fluorescent dye, resazurin, has shown that, in the presence of a non-enzymic electron transfer agent phenazinium methosulphate (PMS)-NADH can effect reduction to the highly fluorescent dye resorufin. Mechanistic studies have shown that the reduction proceeds via a two-electron hydride transfer to the heterocyclic mediator, followed by a one electron transfer to the dye and disproportionation to furnish the final fluorescent product. It has been shown that direct reduction by NADH does not occur and that the reaction depends upon there being an electron transfer agent present. A new type of reagent for the detection of NAD(P)H has been synthesised, comprising a reducible heterocycle and a masked fluorophore. It has been shown that reduction of the precursor conjugate by NADH results in the release of a detectable fluorescent moiety methylumbelliferone. The synthesis of an analogous conjugate probe containing a known hindered dioxetane moiety is described. Prepared using a previously unreported route, the key vinyl ether intermediate is generated via a Wadsworth-Emmons reductive coupling of an alkoxy phosphonate to 2-adamantanone. Reduction by NADH and subsequent cleavage of a conjugate ether link generates an electron rich phenolate substituted dioxetane which is metastable, resulting in emission from the generated excited product. Work towards a dioxetane containing functionalised alkyl group for conjugation to a fluorophore is also outlined.
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Wos, Melissa Louise, and n/a. "Methods For Understanding Bacterial Metabolic Activity In Activated Sludge." Griffith University. School of Environmental Engineering, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20061031.151641.
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Biological wastewater treatment relies on the diverse and complex metabolic activities of bacteria to remove pollutants. Its success depends on the metabolic efficiency of the bacteria. Activated sludge models use parameters that attempt to depict bacterial growth and metabolic processes. However, current methods do not separate metabolic activity from growth and maintenance. As a result, activated sludge processes are misinterpreted or over-simplified. Alternative methods for gauging bacterial activity have been proposed and include the measurements of cellular derived compounds that relate specifically to energy cycling and include Nicotinamide Adenine Dinucleotide [NADH]. To date, NADH has been largely measured within activated sludge using commercial online fluorimeters with in situ probes. However, this current method provides a measure of the 'bulk' (raw) fluorescence within the system, resulting in difficulties when interpreting fluorescence data and poor sensitivity for detecting changes in intracellular [NADH]. This study has developed a more reliable method for estimating intracellular [NADH] and thus metabolic activity within activated sludge systems. Separating extracellular from intracellular [NADH] in samples was crucial because NADH was released and accumulates in the extracellular environment at a concentration of 200 ~M immediately following bacterial death or lysis. This concentration did not decline overtime. This not only caused high background fluorescence but also reduced the sensitivity of detection for changes in intracellular [NADH]. In particular, considerably higher [NADH] values to those from the extracellular suspensions were obtained following extraction of the intracellular material, suggesting that the cell membranes were not being penetrated by the excitable light source. Of the extraction procedures examined, filtration followed by extraction of the intracellular material with a hot Tris buffer was the most efficient and was recommended for accurate estimates of intracellular [NADH] in situ. In addition, standards were used to quantify NADH (moles per cell and/or unit volume) from unknown samples. The limits of detection were found to be 1.058 - 353 uM, whereas concentrations above 353 jAM self-quenched. Sample concentrations were always within these limits of detection. Hence, the sensitivity, reliability and experimental application of the original method was improved upon and able to be used for the direct measurement of microbial metabolic activity, something that has not been demonstrated before now. This study found that bacteria have between 106~ I 08 NADH molecules per cell depending on their metabolic state. A highly metabolically active bacterial cell had between 1O6~ tO7 NADH molecules, while a less active bacterial cell had between to7 -to8 NADH molecules. These measurements of metabolic activity were simultaneously monitored alongside other measures of bacterial growth, such as the incorporation of radiolabelled thymidine into DNA as a direct measure of DNA replication (new cell synthesis), the incorporation of radiolabelled leucine into protein as a direct measure of protein synthesis, oxygen uptake rates (OUR) as a direct measure of respiration, ATP as a measure of potential energy and dissolved organic carbon (DOC) as a measure of substrate assimilation. As OUR deceased, bacterial growth (using both the thymidine and leucine assays), specific [NADH] and specific [ATP] increased. High OUR and substrate oxidation rates simultaneous with low specific [NADH] indicated high rates of electron transport and thus efficient metabolic activity. Also, low OUR and substrate oxidation rates simultaneous with high specific [NADHI indicated inefficient rates of electron transport, therefore inhibiting oxidative phosphorylation (ATP production). A lack of oxygen as the terminal electron acceptor did not efficiently reoxidise NADH to NAD and resulted in an accumulation of NADH within the cell. Thus, a measure of low specific [NADHI was linked to the efficient rate of reoxidation of NADH to NAD* and reflects high metabolic efficiency. DNA and protein syntheses were coupled following substrate enrichment (glucose or acetate), indicating that bacteria were in balanced growth. However, DNA and protein syntheses became uncoupled once substrate was depleted, indicating unbalanced growth. An average Leu:TdR ratio of 7.4 was determined for activated sludge and was comparable to values published from marine systems. This ratio increased during log growth phase and decreased during stationary growth phases. Specific growth rates determined using the [3HITdR and [3H]Leu assay yielded values ranging from 2 - 10.5 d' and from 2.5 - 6 d1, respectively and were comparable to published values. Changes in OUR, NADH, ATE', DNA replication and protein synthesis were statistically ordinated using multidimensional scaling, and changes (in magnitude and direction) in bacterial metabolic activity were observed. Such methods enable the tracing of where bacteria divert their energies, such as to growth or maintenance and thus provide a greater understanding of bacterial behaviour in activated sludge. While studying anoxic and anaerobic conditions were beyond the scope of this work, the use of such methods to monitor bacterial metabolic activity under such conditions is warranted.
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Wos, Melissa Louise. "Methods For Understanding Bacterial Metabolic Activity In Activated Sludge." Thesis, Griffith University, 2005. http://hdl.handle.net/10072/367303.
Full textAbstract:
Biological wastewater treatment relies on the diverse and complex metabolic activities of bacteria to remove pollutants. Its success depends on the metabolic efficiency of the bacteria. Activated sludge models use parameters that attempt to depict bacterial growth and metabolic processes. However, current methods do not separate metabolic activity from growth and maintenance. As a result, activated sludge processes are misinterpreted or over-simplified. Alternative methods for gauging bacterial activity have been proposed and include the measurements of cellular derived compounds that relate specifically to energy cycling and include Nicotinamide Adenine Dinucleotide [NADH]. To date, NADH has been largely measured within activated sludge using commercial online fluorimeters with in situ probes. However, this current method provides a measure of the 'bulk' (raw) fluorescence within the system, resulting in difficulties when interpreting fluorescence data and poor sensitivity for detecting changes in intracellular [NADH]. This study has developed a more reliable method for estimating intracellular [NADH] and thus metabolic activity within activated sludge systems. Separating extracellular from intracellular [NADH] in samples was crucial because NADH was released and accumulates in the extracellular environment at a concentration of 200 ~M immediately following bacterial death or lysis. This concentration did not decline overtime. This not only caused high background fluorescence but also reduced the sensitivity of detection for changes in intracellular [NADH]. In particular, considerably higher [NADH] values to those from the extracellular suspensions were obtained following extraction of the intracellular material, suggesting that the cell membranes were not being penetrated by the excitable light source. Of the extraction procedures examined, filtration followed by extraction of the intracellular material with a hot Tris buffer was the most efficient and was recommended for accurate estimates of intracellular [NADH] in situ. In addition, standards were used to quantify NADH (moles per cell and/or unit volume) from unknown samples. The limits of detection were found to be 1.058 - 353 uM, whereas concentrations above 353 jAM self-quenched. Sample concentrations were always within these limits of detection. Hence, the sensitivity, reliability and experimental application of the original method was improved upon and able to be used for the direct measurement of microbial metabolic activity, something that has not been demonstrated before now. This study found that bacteria have between 106~ I 08 NADH molecules per cell depending on their metabolic state. A highly metabolically active bacterial cell had between 1O6~ tO7 NADH molecules, while a less active bacterial cell had between to7 -to8 NADH molecules. These measurements of metabolic activity were simultaneously monitored alongside other measures of bacterial growth, such as the incorporation of radiolabelled thymidine into DNA as a direct measure of DNA replication (new cell synthesis), the incorporation of radiolabelled leucine into protein as a direct measure of protein synthesis, oxygen uptake rates (OUR) as a direct measure of respiration, ATP as a measure of potential energy and dissolved organic carbon (DOC) as a measure of substrate assimilation. As OUR deceased, bacterial growth (using both the thymidine and leucine assays), specific [NADH] and specific [ATP] increased. High OUR and substrate oxidation rates simultaneous with low specific [NADH] indicated high rates of electron transport and thus efficient metabolic activity. Also, low OUR and substrate oxidation rates simultaneous with high specific [NADHI indicated inefficient rates of electron transport, therefore inhibiting oxidative phosphorylation (ATP production). A lack of oxygen as the terminal electron acceptor did not efficiently reoxidise NADH to NAD and resulted in an accumulation of NADH within the cell. Thus, a measure of low specific [NADHI was linked to the efficient rate of reoxidation of NADH to NAD* and reflects high metabolic efficiency. DNA and protein syntheses were coupled following substrate enrichment (glucose or acetate), indicating that bacteria were in balanced growth. However, DNA and protein syntheses became uncoupled once substrate was depleted, indicating unbalanced growth. An average Leu:TdR ratio of 7.4 was determined for activated sludge and was comparable to values published from marine systems. This ratio increased during log growth phase and decreased during stationary growth phases. Specific growth rates determined using the [3HITdR and [3H]Leu assay yielded values ranging from 2 - 10.5 d' and from 2.5 - 6 d1, respectively and were comparable to published values. Changes in OUR, NADH, ATE', DNA replication and protein synthesis were statistically ordinated using multidimensional scaling, and changes (in magnitude and direction) in bacterial metabolic activity were observed. Such methods enable the tracing of where bacteria divert their energies, such as to growth or maintenance and thus provide a greater understanding of bacterial behaviour in activated sludge. While studying anoxic and anaerobic conditions were beyond the scope of this work, the use of such methods to monitor bacterial metabolic activity under such conditions is warranted.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental Engineering
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Tur, Jared. "Cardiovascular regulation by Kvβ1.1 subunit." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6596.
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Heterologous expression systems such as COS-7 cells have demonstrated the profound effects of KCNAB1-3 or Kvβ1-3 proteins on voltage gated potassium channels (Kv) channels. Indeed, in the presence of these β-subunits transiently expressed Kv channels are often modulated in multiple ways. Kv channel membrane expression is often increased in the presence of β-subunits. In addition, non-inactivating Kv currents suddenly become fast-inactivating and fast-inactivating channels become even faster. While much research has demonstrated the profound effects the β-subunits in particular the Kvβ1 subunit have on transiently expressed Kv currents little to date is known of the physiological role it may play. One study demonstrated that by “knocking out” Kvβ1 cardiomyocyte current changes were noted including a decrease in the Ito,f current. While this novel finding demonstrated a key cardiac physiological role of the Kvβ1 subunit it left many unanswered questions as to determine the cardiovascular regulation the Kvβ1 subunit provides. Indeed, cardiac arrhythmias and other electrical abnormalities within the heart such as long QT present patients with many unfortunate unknowns. Many of these incidences occur often abruptly with cardiac electrical abnormalities. Genetic research has begun to shine light on key cardiovascular genes in particular those coding for ion channels and auxiliary subunits or β-subunits. Kv channels and their β-subunits have gained particular notoriety in their key responsibility in restoring the resting membrane potential known as the repolarization phase. Indeed genetic manipulation and physiological examination of Kv channels and recently their β-subunits has demonstrated profound physiological results including prolonged QT durations within mice altered functional activity during physiological cycles such as estrus. While initial findings of Kvβ1 have demonstrated profound cellular and cardiomyocyte current alterations much still remains unknown. Therefore, this work hypothesizes that the Kvβ1 subunit provides a profound cardiovascular role in regulation and redox sensing at the physiological and pathophysiological level in both males and females. This work identifies a sex-based difference in cardiovascular regulation by Kvβ1 as well as demonstrated a profound redox sensing ability during altered metabolic states seen in pathophysiological conditions.
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Ilic, Stefan. "Utilizing NAD+/NADH Analogs for the Solar Fuel Forming Reductions." Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1499262103862098.
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Pereira, Cristiane Ribeiro. "Modulação das vias de sinalização intracelulares pelo sistema NAD(P)H oxidase em melanoma humano." Universidade do Estado do Rio de Janeiro, 2007. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9429.
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Fundação de Amparo à Pesquisa do Estado do Rio de JaneiroEvidências têm mostrado que as espécies reativas de oxigênio (ROS) geradas pela NAD(P)H oxidase são importantes moduladores de diversas funções celulares como migração, crescimento, proliferação e sobrevivência. Estudos recentes demonstraram o envolvimento da atividade da NAD(P)H oxidase no crescimento e sobrevivência de células de melanoma. Neste trabalho, investigamos o efeito da inibição da NAD(P)H oxidase por difenileneiodônio (DPI) sobre o crescimento das células de melanoma humano MV3 e observamos que este composto reduziu o crescimento destas células em aproximadamente 50%. A inibição da NAD(P)H oxidase induziu mudanças no formato celular, com arredondamento, diminuição do espraiamento e descolamento celular. Esta redução foi acompanhada por um rearranjo do citoesqueleto de actina, diminuição da fosforilação no resíduo Tyr397 da quinase de adesão focal (FAK) e redução na associação de FAK com actina e com a tirosina quinase c-Src. Isto indica que a inibição da geração de ROS está modulando negativamente vias de sinalização ativadas por integrinas, o que freqüentemente conduz a um tipo particular de morte celular conhecida por anoikis. Comprovando a ocorrência deste fenômeno, observamos que a inibição da atividade da NAD(P)H oxidase aumentou a apoptose das células de melanoma e induziu a ativação da caspase-3. Nossos resultados mostram ainda que a inibição da viabilidade celular por DPI foi revertida com o pré-tratamento das células MV3 com um inibidor de tirosina fosfatases (ortovanadato de sódio). Em resumo, este estudo mostra que a geração de ROS por NAD(P)H oxidase está envolvida nos mecanismos de sobrevivência em células de melanoma, uma vez que afetam as vias de sinalização dependentes de FAK-Src, através da inibição da atividade de proteína tirosina fosfatases.
NAD(P)H oxidase-derived reactive oxygen species (ROS) have emerged as critical mediators of several cell functions as diverse as migration, growth, proliferation and survival. Recent evidence has show that NAD(P)H oxidase activity is essential to melanoma proliferation and survival. We reported that NAD(P)H oxidase inhibitor diphenyleneiodonium (DPI) inhibited melanoma growth. NAD(P)H oxidase inhibition induced changes in cell shape with cell spreading decrease, rounding up and detachment. These phenomena were accompanied by rearrangement of actin network and a decrease in both focal adhesion (FAK) phosphorylation in Tyr397 residue and in FAK association to actin and c-Src, indicating that inhibition of ROS generation would down- modulate integrin-mediated signaling, what often results in a particular type of apoptotic cell death, known as anoikis. We observed that NAD(P)H oxidase inhibitor induced apoptosis in melanoma cells with activation of caspase-3. We results show that the effects promoted by NAD(P)H oxidase inhibition on melanoma growth were completely abolished by the pre-treatment of MV3 cells with the protein tyrosine phosphatases inhibitor sodium orthovanadate. In conclusion, our results strongly suggest that ROS generated by NAD(P)H oxidase complex transmit cell survival signals in melanoma cells through the FAK-Src pathway, probably inhibiting protein tyrosine phosphatases.
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Chen, Ye Grace. "The Discovery and Characterization of NAD-Linked RNA." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10447.
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Over the past few decades, RNA has emerged as much more than just an intermediary in biology’s central dogma. RNA is now known to play a variety of catalytic, regulatory and defensive roles in living systems as demonstrated through the discoveries of ribozymes, riboswitches, microRNAs, small interfering RNAs, Piwi-interacting RNAs, small nuclear RNAs, clusters of regularly interspaced short palindromic repeat RNAs and long non-coding RNAs. In contrast to the functional diversity of RNA, the chemical diversity has remained primarily limited to canonical polyribonucleotides, the 5’ cap on mRNAs in eukaryotes, modified nucleotides and 3’-aminoacylated tRNAs. This disparity coupled with the powerful functional properties of small molecule-nucleic acid conjugates led us to speculate that novel small molecule-RNA conjugates existed in modern cells, either as evolutionary fossils or as RNAs whose functions are enabled by the small molecule moieties. We developed and applied a nuclease-based screen coupled with high-resolution liquid chromatography/mass spectrometry analysis to detect novel small molecule-RNA conjugates, broadly and sensitively. We discovered NAD-linked RNA in two types of bacteria and further characterized the small molecule and RNA in Escherichia coli. The NAD modification is found on the 5’ end of RNAs between 30 and 120 nucleotides long, and is surprisingly abundant at around 3,000 copies per cell. Subsequent experiments to characterize further NAD-linked RNA have been undertaken, including sequencing the RNAs to which NAD is attached and elucidating the biological functions of the small molecule-RNA conjugate. The development and application of a screen to detect novel nucleotide modifications that is independent of structure or biological context has the potential to increase our understanding of the functional and chemical diversity of RNA. The discovery and biological characterization of NAD-linked RNA can provide new examples of RNA biology and offer insight into the RNA world.
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Marques, Isabel Maria Medeiros. "Molecular biology charactersation of mitochondrial NADH dehydrogenase." Doctoral thesis, Instituto de Ciências Biomédicas Abel Salazar, 2007. http://hdl.handle.net/10216/7281.
Full textBooks on the topic "NADH molecules"
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Erdner, Deana L. Characterization of ferredoxin and flavodoxin as molecular indicators of iron limitation in marine eukaryotic phytoplankton. Woods Hole, Mass: Woods Hole Oceanographic Institution, 1997.
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Schnorr, Kirk Matthew. Molecular analysis of the barley NADH nitrate reductase gene and its cDNA. 1990.
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The molecular and biochemical characterization of the MLRQ subunit of NADH: Ubiquinone oxidoreductase in the human mitochondrial respiratory chain. Ottawa: National Library of Canada, 2001.
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Miller, Philip. Molecular characterization of the gene, mRNAS, precursor proteins, and mature subunits involved in the synthesis of the NADP-specific glutamate dehydrogenase isoenzymes in Chlorella sorokiniana. 1994.
Find full textBook chapters on the topic "NADH molecules"
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Sukharev, V. I., and N. L. Vekshin. "NADH binds in the mitochondrial respiratory chain far from flavins of flavoproteins." In Spectroscopy of Biological Molecules: New Directions, 177–78. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4479-7_78.
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Noguchi, N., M. Tachikawa, and H. Takahashi. "One-Electron Photooxidation Of Nadh: Laser Photolysis, Time-Resolved Raman And Ab Initio Mo Calculation Study." In Spectroscopy of Biological Molecules: Modern Trends, 161–62. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5622-6_71.
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Yang, Yue, and Anthony A. Sauve. "Assays for Determination of Cellular and Mitochondrial NAD+ and NADH Content." In Methods in Molecular Biology, 271–85. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1433-4_15.
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Mhamdi, Amna, Frank Van Breusegem, and Graham Noctor. "Measurement of NAD(P)H and NADPH-Generating Enzymes." In Methods in Molecular Biology, 97–106. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2469-2_7.
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Brown, J. M. "NaCH." In Landolt-Börnstein - Group II Molecules and Radicals, 1–2. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/11313410_36.
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Hung, Yin Pun, and Gary Yellen. "Live-Cell Imaging of Cytosolic NADH–NAD+ Redox State Using a Genetically Encoded Fluorescent Biosensor." In Methods in Molecular Biology, 83–95. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-622-1_7.
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Froehlich, Stephan J., Carlo A. Lackerbauer, Guenter Rudolph, Jan Rémi, Soheyl Noachtar, Werner J. Heppt, Annette Cryer, et al. "NASH." In Encyclopedia of Molecular Mechanisms of Disease, 1434–35. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_6453.
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Jiang, Fan. "NADPH Oxidase." In Encyclopedia of Molecular Pharmacology, 1–4. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-21573-6_10023-1.
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Jiang, Fan. "NADPH Oxidase." In Encyclopedia of Molecular Pharmacology, 1072–75. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-57401-7_10023.
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Buvelot, Hélène, Vincent Jaquet, and Karl-Heinz Krause. "Mammalian NADPH Oxidases." In Methods in Molecular Biology, 17–36. New York, NY: Springer New York, 2019. http://dx.doi.org/10.1007/978-1-4939-9424-3_2.
Full textConference papers on the topic "NADH molecules"
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Barabash, Y., M. A. Zabolotny, and T. Zabolotnaya. "Influence of the mm-range electromagnetic radiation on the rheologic properties of aqueous NADH solution." In XV International School on Spectroscopy of Molecules and Crystals, edited by Galina A. Puchkovska and Sergey A. Kostyukevych. SPIE, 2002. http://dx.doi.org/10.1117/12.486665.
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Webb, Watt W. "Multiphoton Microscopy MPM: Imaging Spectra and Dynamics of Molecular Function Deep in Living Tissues." In In Vivo optical Imaging at the NIH. Washington, D.C.: Optica Publishing Group, 1999. http://dx.doi.org/10.1364/ivoi.1999.msi3.
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Multiphoton Excitation (MPE) of fluorescence provides the optimum photophysics for microscopic imaging deep in living tissue with minimal photodamage, to depths so far ~ 400 µm. Tissue autofluorescence excited by two-photon or three-photon absorption to ultra-violet energies can provide specific indications of disease. Useful autofluorescence of serotonin (5HT), melatonin, indolamine breakdown products, NADH, collagen, elastin, and a number of yet-to-be-identified molecular species, some of which identify disease states are already being imaged routinely. For research in model animals, genetic constructs that label specific molecules with mutants of Green Fluorescent Protein (GFP) can be imaged deep in tissue with MPM. MPM excitation of GFP mutants at nanomolar concentrations for Fluorescence Correlation Spectroscopy (FCS) provides a robust, internally calibrated, new measure of pH in cells and tissues. Fluorescent labels that penetrate tissue can be usefully imaged in living animals and thick tissue cultures; for example, thioflavins in the beta amyloid plaques of Alzheimer’s Disease are being imaged deep in living transgenic mouse brains. Multiphoton imaging spectroscopy and fluorescence lifetime imaging (FLIM) provides useful molecular identification diagnostics. Some applications are shown in order to illustrate capability. However, the potential of MPM for in vivoimaging has barely been explored, and this technology should be regarded as providing a fertile opportunity that is yet to be fully exploited for biomedical research and for clinical applications.
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Stewart, Hazel, Ted Hupp, and David J. Birch. "NADPH as a potential intrinsic probe for tumour margin estimation." In Molecular-Guided Surgery: Molecules, Devices, and Applications IV, edited by Greg Biggs, Brian W. Pogue, and Sylvain Gioux. SPIE, 2018. http://dx.doi.org/10.1117/12.2287414.
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Balu, Mihaela, Amaan Mazhar, Carole K. Hayakawa, Richa Mittal, Tatiana B. Krasieva, Karsten König, Vasan Venugopalan, and Bruce J. Tromberg. "In Vivo Multiphoton NADH Fluorescence Reveals Depth-Dependent Keratinocyte Metabolism in Human Skin." In Optical Molecular Probes, Imaging and Drug Delivery. Washington, D.C.: OSA, 2013. http://dx.doi.org/10.1364/omp.2013.mt1c.5.
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Bower, Andrew J., Joanne Li, Eric J. Chaney, Marina Marjanovic, and Stephen A. Boppart. "High-Speed Two-Photon Fluorescence Lifetime Imaging Microscopy of NADH for Label-Free Metabolic Imaging." In Optical Molecular Probes, Imaging and Drug Delivery. Washington, D.C.: OSA, 2017. http://dx.doi.org/10.1364/omp.2017.oms2d.5.
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Ganapathy, Ramanan, and Ahmet Aykaç. "Depolymerisation of High Molecular Weight Chitosan and Its Impact on Purity and Deacetylation." In 6th International Students Science Congress. Izmir International Guest Student Association, 2022. http://dx.doi.org/10.52460/issc.2022.048.
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Chitosan (poly[β-(1-4)-2-amino-2-deoxy-d-glucopyranose]) is a non-toxic and biocompatible cationic polysaccharide produced by partial deacetylation of chitin isolated from naturally occurring crustacean shells. Its low solubility limits its application, improving the solubility by reducing the molecular weight, increases its wide application in food, agriculture, pharmaceutical and other technical applications. Low molecular weight chitosan, acts as a potent biotic elicitor, induce plant defense responses, activating different pathways that increase the crop resistance to diseases. Antimicrobial activity of chitosan inversely proportional to its molecular weight. Chitosan degradation has many techniques, ultrasound, electron beam plasma, solution plasma, cavitation, mechanical, microwave, photo irradiated and chemical. Chemical depolymerization can be affected utilizing alkalis (NaOH, KOH), sodium nitrite, sodium hypochlorite, hydrogen peroxide etc. In our study we used chemical method to reduce molecular weight of chitosan, utilizing sodium nitrite at various concentrations. During depolymerization its impact on purity of chitosan was studied. Depolymerized chitosan molecular weights were ascertained by intrinsic viscosity method, its purity was measured by UV-Vis method.
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Chan, C., and S. Baek. "Model Based Surface Design to Incorporate the Effect of Soluble Cues." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53439.
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Many disease states such as obesity and Type 2 diabetes are polygenic and involve multiple organs with inter-related metabolic and vascular abnormalities, and furthermore are risk factors for other diseases such as nonalcoholic steatohepatitis (NASH), cardiovascular or Alzheimer’s diseases. Tissue engineering is attempting to address these diseases from the perspective of developing “spare” or “replacement” parts. Cell and tissue engineering integrates cellular and molecular biology with the principles and methods of chemical and mechanical engineering to develop biological substitutes that can restore, maintain, or control tissue function.
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Stadler, M., L. Rappez, T. Alexandrov, and M. Heikenwälder. "Identification of Molecular Mechanisms by which NASH-derived Inflammation alters Hepatic Lipid Metabolism." In 35. Jahrestagung der Deutschen Arbeitsgemeinschaft zum Studium der Leber. Georg Thieme Verlag KG, 2019. http://dx.doi.org/10.1055/s-0038-1677187.
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Gorbunova, I. A., M. K. Danilova, M. E. Sasin, and O. S. Vasutinskii. "The Influence of Microenvironmental and Molecular Conformational Effects on Quantum Yield in NADH and FAD in Water-Alcohol Solutions." In 2022 International Conference Laser Optics (ICLO). IEEE, 2022. http://dx.doi.org/10.1109/iclo54117.2022.9839974.
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Berechet, Mariana Daniela, Demetra Simion, Maria Stanca, Ciprian Chelaru, Cosmin-Andrei Alexe, and Maria Rapa. "The influence of alkaline extraction on some keratin hydrolysates properties." In The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.ii.3.
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Keratin is a fibrous protein abundant in nature, being the component of wool, hair, hooves, horns, feathers, and claws. Keratin is one of the most valuable natural biopolymers due to its chemical versatility and biological performance. At the molecular level, keratin is distinguished from other biopolymers by its high concentration of cysteine-containing sulfur. Two keratin hydrolysate batches were obtained in alkaline medium, at a constant concentration of 8% NaOH and 75°C (KerNa875), 85°C (KerNa885), and 95°C (KerNa895), and at a fixed temperature of 99°C and different concentrations of NaOH, i.e. 3% (KerNa399), 5% (KerNa599), and 8% (KerNa899), respectively. Physical-chemical analyses showed that the protein content ranging between 83.60% for KerNa875 and 88.88% for KerNa399, while the total nitrogen was found 13.83% and 14.67% in the case of KerNa875 and KerNa399, respectively. Dynamic light scattering analysis showed that the particle sizes decreased with the increased concentration in the reaction medium. The average particle size was between 1352 nm and 1771 nm for the samples obtained at a temperature of 99°C and with lower values between 463.3 nm and 571.6 nm for the samples obtained with 8% NaOH. The Fourier transform infrared (FT-IR) spectra evidenced the specific bands of keratin-specific proteins and sulfur compounds. Experiments were also performed to evaluate the antioxidant activity and the growth of Tamino and Mirastar wheat plants by applying the treatments with 3% and 5% concentrations of KerNa899 on wheat seeds. These experiments showed an improvement in the wheat plant growth during 10 days of observation compared to control sample. The results recommend the potential use for keratin hydrolysates in the medical, pharmaceutical, cosmetics fields, and also as fertilizers in agriculture.
Reports on the topic "NADH molecules"
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Sadka, Avi, Mikeal L. Roose, and Yair Erner. Molecular Genetic Analysis of Citric Acid Accumulation in Citrus Fruit. United States Department of Agriculture, March 2001. http://dx.doi.org/10.32747/2001.7573071.bard.
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The acid content of the juice sac cells is a major determinant of maturity and fruit quality in citrus. Many citrus varieties accumulate acid in concentrations that exceed market desires, reducing grower income and consumer satisfaction. Pulp acidity is thought to be dependent on two mechanisms: the accumulation of citric acid in the vacuoles of the juice sac cells, and acidification of the vacuole. The major aim of the project was to direct effort toward understanding the mechanism of citric acid accumulation in the fruit. The following objectives were suggested: Measure the activity of enzymes likely to be involved in acid accumulation and follow their pattern of expression in developing fruit (Sadka, Erner). Identify and clone genes which are associated with high and low acid phenotypes and with elevated acid level (Roose, Sadka, Erner). Convert RAPD markers that map near a gene that causes low acid phenotype to specific co dominant markers (Roose). Use genetic co segregation to test whether specific gene products are responsible for low acid phenotype (Roose and Sadka). Objective 1 was fully achieved. Most of the enzymes of organic acid metabolism were cloned from lemon pulp. Their expression was studied during fruit development in low and high acid varieties. The activity and expression of citrate synthase, aconitase and NADP-isocitrate dehydrogenase (IDH) were studied in detail. The role that each enzyme plays in acid accumulation and decline was evaluated. As a result, a better understanding of the metabolic changes that contribute to acid accumulation was achieved. It was found that the activity of the mitochondrial aconitase is greatly reduced early in high-acid fruits, but not in acidless ones, suggesting that this enzyme plays an important role in acid accumulation. In addition, it was demonstrated that increases in the cytosolic forms of aconitase and NADP-IDH towards fruit maturation play probably a major role in acid decline. Our studies also demonstrated that the two mechanisms that contribute to fruit acidity, vacuolar acidification and citric acid accumulation, are independent, although they are tightly co-regulated. Additional, we demonstrated that sodium arsenite, which reduce fruit acidity, causes a transient inhibition in the activity of citrate synthase, but an induction in the gene expression. This part of the work has resulted in 4 papers. Objective 3 was also fully achieved. Using bulked segregant analysis, three random amplified polymorphic DNA (RAPD) markers were identified as linked to acitric, a gene controlling the acidless phenotype of pummelo 2240. One of them, which mapped 1.2 cM from acitric was converted into sequence characterized amplified region (SCAR marker, and into co dominant restriction length polymorphism (RFLP) marker. These markers were highly polymorphic among 59 citrus accessions, and therefore, they should be useful for selecting seedling progeny heterozygous for acitric in nearly all crosses between pummelo 2240 and other citrus genotypes. This part of the project resulted in one paper. Objective 4 was also fully achieved. Clones isolated by the Israeli group were sent to the American laboratory for co segregation analysis. However, none of them seemed to co segregate with the low acid phenotype. Both laboratories invested much effort in achieving the goals of Objective 2, namely the isolation of genes that are elevated in expression in low and high acid phenotypes, and in tissue cultures treated with arsenite (a treatment which reduces fruit acidity). However, conventional differential display and restriction fragment differential display analyses could not identify any differentially expressed genes. The isolation of such genes was the major aim of a continuation project, which was recently submitted.
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Smulson, Mark E. The Molecular Biological Basis for the Response of Poly(ADP-RIB) Polymerase and NAD Metabolism to DNA Damage Caused by Mustard Alkylating Agents. Fort Belvoir, VA: Defense Technical Information Center, July 1996. http://dx.doi.org/10.21236/ada319494.
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Horwitz, Benjamin A., and Barbara Gillian Turgeon. Fungal Iron Acquisition, Oxidative Stress and Virulence in the Cochliobolus-maize Interaction. United States Department of Agriculture, March 2012. http://dx.doi.org/10.32747/2012.7709885.bard.
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Our project focused on genes for high affinity iron acquisition in Cochliobolus heterostrophus, a necrotrophic pathogen of maize, and their intertwined relationship to oxidative stress status and virulence of the fungus on the host. An intriguing question was why mutants lacking the nonribosomal peptide synthetase (NRPS) gene (NPS6) responsible for synthesis of the extracellular siderophore, coprogen, are sensitive to oxidative stress. Our overall objective was to understand the mechanistic connection between iron stress and oxidative stress as related to virulence of a plant pathogen to its host. The first objective was to examine the interface where small molecule peptide and reactive oxygen species (ROS) mechanisms overlap. The second objective was to determine if the molecular explanation for common function is common signal transduction pathways. These pathways, built around sensor kinases, response regulators, and transcription factors may link sequestering of iron, production of antioxidants, resistance to oxidative stress, and virulence. We tested these hypotheses by genetic manipulation of the pathogen, virulence assays on the host plant, and by following the expression of key fungal genes. An addition to the original program, made in the first year, was to develop, for fungi, a genetically encoded indicator of redox state based on the commercially available Gfp-based probe pHyper, designed for animal cell biology. We implemented several tools including a genetically encoded indicator of redox state, a procedure to grow iron-depleted plants, and constructed a number of new mutants in regulatory genes. Lack of the major Fe acquisition pathways results in an almost completely avirulent phenotype, showing how critical Fe acquisition is for the pathogen to cause disease. Mutants in conserved signaling pathways have normal ability to regulate NPS6 in response to Fe levels, as do mutants in Lae1 and Vel1, two master regulators of gene expression. Vel1 mutants are sensitive to oxidative stress, and the reason may be underexpression of a catalase gene. In nps6 mutants, CAT3 is also underexpressed, perhaps explaining the sensitivity to oxidative stress. We constructed a deletion mutant for the Fe sensor-regulator SreA and found that it is required for down regulation of NPS6 under Fe-replete conditions. Lack of SreA, though, did not make the fungus over-sensitive to ROS, though the mutant had a slow growth rate. This suggests that overproduction of siderophore under Fe-replete conditions is not very damaging. On the other hand, increasing Fe levels protected nps6 mutants from inhibition by ROS, implying that Fe-catalyzed Fenton reactions are not the main factor in its sensitivity to ROS. We have made some progress in understanding why siderophore mutants are sensitive to oxidative stress, and in doing so, defined some novel regulatory relationships. Catalase genes, which are not directly related to siderophore biosynthesis, are underexpressed in nps6 mutants, suggesting that the siderophore product (with or without bound Fe) may act as a signal. Siderophores, therefore, could be a target for intervention in the field, either by supplying an incorrect signal or blocking a signal normally provided during infection. We already know that nps6 mutants cause smaller lesions and have difficulty establishing invasive growth in the host. Lae1 and Vel1 are the first factors shown to regulate both super virulence conferred by T-toxin, and basic pathogenicity, due to unknown factors. The mutants are also altered in oxidative stress responses, key to success in the infection court, asexual and sexual development, essential for fungal dissemination in the field, aerial hyphal growth, and pigment biosynthesis, essential for survival in the field. Mutants in genes encoding NADPH oxidase (Nox) are compromised in development and virulence. Indeed the triple mutant, which should lack all Nox activity, was nearly avirulent. Again, gene expression experiments provided us with initial evidence that superoxide produced by the fungus may be most important as a signal. Blocking oxidant production by the pathogen may be a way to protect the plant host, in interactions with necrotrophs such as C. heterostrophus which seem to thrive in an oxidant environment.
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Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen, and Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils: Speciation, Transport, and Accumulation. United States Department of Agriculture, June 2011. http://dx.doi.org/10.32747/2011.7697103.bard.
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Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.