Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.1.1.1 (alcohol dehydrogenase)
9,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intracellular products, not secreted from the microbial cell, are released by breaking the cell envelope consisting of cytoplasmic membrane and an outer cell wall. Hydrodynamic cavitation has been reported to cause microbial cell disruption. By manipulating the operating variables involved, a wide range of intensity of cavitation can be achieved resulting in a varying extent of disruption. The effect of the process variables including cavitation number, initial cell concentration of the suspension and the number of passes across the cavitation zone on the release of enzymes from various locations of the Brewers' yeast was studied. The release profile of the enzymes studied include alpha-glucosidase (periplasmic), invertase (cell wall bound), alcohol dehydrogenase (ADH; cytoplasmic) and glucose-6-phosphate dehydrogenase (G6PDH; cytoplasmic). An optimum cavitation number Cv of 0.13 for maximum disruption was observed across the range Cv 0.09-0.99. The optimum cell concentration was found to be 0.5% (w/v, wet wt) when varying over the range 0.1%-5%. The sustained effect of cavitation on the yeast cell wall when re-circulating the suspension across the cavitation zone was found to release the cell wall bound enzyme invertase (86%) to a greater extent than the enzymes from other locations of the cell (e.g. periplasmic alpha-glucosidase at 17%). Localised damage to the cell wall could be observed using transmission electron microscopy (TEM) of cells subjected to less intense cavitation conditions. Absence of the release of cytoplasmic enzymes to a significant extent, absence of micronisation as observed by TEM and presence of a lower number of proteins bands in the culture supernatant on SDS-PAGE analysis following hydrodynamic cavitation compared to disruption by high-pressure homogenisation confirmed the selective release offered by hydrodynamic cavitation.
...
PMID:Disruption of Brewers' yeast by hydrodynamic cavitation: Process variables and their influence on selective release. 1657 Mar 16

The influence of low temperature on soybean (Glycine max [L.] Merr. cv. Wells) energy transduction via mitochondrial respiration and dehydrogenases was investigated in this study during imbibition and germination. Mitochondria were isolated from embryonic axes of seeds treated at 10 and 23 C (control) by submergence in H(2)O for 6 hours and maintenance for an additional 42 hours in a moist environment. Arrhenius plots of initial respiration rates revealed that those from cold-treated axes had respiratory control (RC) ratios of near 1.0 above an inflection in the plot at 8 C. Arrhenius plots of control axes mitochondrial respiration showed RC ratios of 2.8 above and 5.0 below an inflection temperature of 12.5 C. Energies of activation for mitochondrial respiration between 20 and 30 C for the cold and control treatments were 7.8 and 15.6 kcal/mole, respectively. These data indicate possible differences in mitochondrial membranes, degree of mitochondrial integrity, and mitochondrial enzyme complement between the two treatments.Glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), glucose-6-phosphate dehydrogenase (G6P-DH), and NADP-isocitrate dehydrogenase (NADP-ICDH) were assayed from whole seeds and axes (after germination) during the 48 hours of temperature treatments. Activity of these dehydrogenases decreased during the first 6 hours with the exception of MDH. After germination at 23 C (48 hours) all five dehydrogenases increased in activity. Arrhenius plots of cotyledon dehydrogenase activities indicated that one inflection temperature between 6 and 18 C was present for each enzyme assayed. Differences were seen in Arrhenius plots of axes dehydrogenase activities with the two temperature treatments in the cases of GDH and MDH from mitochondrial pellets and with differences in enzyme extraction media. These data suggest that the temperature treatments yield differences in mitochondrial enzyme complement. There were no detectable inflection temperatures for the activities of G6P-DH and ADH extracted from axes. Arrhenius plots of NADP-ICDH activity indicated extreme cold sensitivity. The slopes of the plots for axes NADP-ICDH were very similar to those for mitochondrial respiration (23 C treatment) suggesting that this enzyme may limit mitochondrial respiration at low temperature in soybean tissues grown at moderate temperatures.
...
PMID:Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination. 1666 Jan 71

The Long-Evans Cinnamon (LEC) rat strain (Atp7b m/m), which accumulates copper in the liver due to mutations in the Atp7b gene, is a useful model for investigating the relationship between oxidative stress and hepatocarcinogenesis. To determine the effect of this mutation on oxidative stress marker genes, we performed oligonucleotide array analysis (Affymetrix), and compared the results in Atp7b m/m rats with those of a sibling line with the Atp7b w/w genotype. We focused our studies on the expression of the aldo-keto reductase 1 family B7 (AKR1B7)-like protein gene, since this gene codes for reductase enzymes involved in the detoxification of oxidizing compounds (e.g., aldehydes) and was differentially expressed in Atp7b m/m and Atp7b w/w rat liver. Akr1B7 mRNA expression was significantly increased in comparison with the expression of 4 other known oxidative stress responsive genes, haem-oxygenase-1 (HO-1), thioredoxin (Trx), aldehyde reductase (AKR1A1), and glucose-6-phosphate dehydrogenase (G6PDH). By searching binding motifs, five nuclear factor kappa B (NF-kappaB) binding sites were located in the 5'-upstream region of the akr1b7 gene. Transient co-transfection with both I-kappaBalpha and the Akr1b7 6 kb promoter (p6.0-AKR-Luc) inhibited luciferase activity of p6.0-AKR-Luc in HepG2 cells. Cuprous ion however did not affect the transcription activity induced by p6.0-AKR-luc. Gel-shift assay showed that the DNA binding activity of NF-kappaB increased in the livers of LEC rats, suggesting that the oxidative stress is mediated through NF-kappaB. The results indicate conclusively that in LEC rat liver, akr1b7 might be up-regulated by oxidative stress mediated through NF-kappaB, but not that mediated directly by copper.
...
PMID:Aldo-keto reductase 1 family B7 is the gene induced in response to oxidative stress in the livers of Long-Evans Cinnamon rats. 1696 78

Ethyl(R)-4-chloro-3-hydroxybutanoate ((R)-CHBE) are obtained by cetyltrimetylammonium bromide (CTAB) permeabilized fresh brewer's yeast whole cells bioconversion of ethyl 4-chloro-3-oxobutanoate (COBE ) in the presence of allyl bromide. The results showed that the activities of alcohol dehydrogenase (ADH) and glucose-6-phosphate dehydrogenase (G6PDH) in CTAB permeabilized brewer's yeast cells increased 525 and 7.9-fold, respectively, compared with that in the nonpermeabilized cells and had high enantioselectivity to convert COBE to (R)-CHBE. As one of co-substrates, glucose-6-phosphate was preprepared using glucose phosphorylation by hexokinase-catalyzed of CTAB permeabilized brewer's yeast cells. In a two phase reaction system with n-butyl acetate as organic solvent and with 2-propanol and glucose-6-phosphate as co-substrates, the highest (R)-CHBE concentration of 447 mM was obtained with 110-130 g/l of the CTAB permeabilized cells at optimized pH, temperature, feeding rate and the shake speed of 125 r/min. The yield and enantiomeric excess (ee) of (R)-CHBE reached 99.5 and 99%, respectively, within 6 h.
...
PMID:Bioconversion of ethyl 4-chloro-3-oxobutanoate by permeabilized fresh brewer's yeast cells in the presence of allyl bromide. 1704 5

The enzyme activity levels of alcohol, malate, isocitrate, glucose-6-phosphate and 6-phosphogluconate dehydrogenases were determined in mature maize scutella in a series of one to four doses of the long arm of chromosome 1, produced by the B-A translocation 1La. Although the Adh structural locus was varied, ADH levels did not exhibit a gene-dosage effect. The levels of G6PDH, 6PGDH and IDH were negatively correlated with the dosage of 1L. MDH was unresponsive. The esterase-8 enzyme, whose structural locus was demonstrated to be elsewhere in the genome, was also negatively correlated with 1L dosage. The portion of the B chromosome involved in the translocation was shown to have no effect on the enzyme levels. Measurements of cell size and hydrolysable DNA per mg dry weight revealed no change in the number of cells through the one, two and three dose series. The topic of enzyme alterations in aneuploids is reviewed.
...
PMID:A study of enzyme activities in a dosage series of the long arm of chromosome one in maize. 1724 47

Seeds of pea (Pisum sativum L.) were germinated for 5d by soaking in distilled water or 5mM cadmium nitrate. The relationships among cadmium stress, germination rate, changes in respiratory enzyme activities and carbohydrates mobilization were studied. Two cell fractions were obtained from embryonic axis: (1) mitochondria, used to determine enzyme activities of citric acid cycle and electron transport chain, and (2) soluble, to measure some enzyme activities involved in fermentation and pentose phosphate pathway. Activities of malate- and succinate-dehydrogenases (MDH, SDH) and NADH- and succinate-cytochrome c reductases (NCCR, SCCR) were rapidly inhibited, while cytochrome c oxidase (CCO) was unaltered by cadmium treatment. However, this stimulated the NADPH-generating enzyme activities of the pentose phosphate pathway, glucose-6-phosphate- and 6-phosphogluconate-dehydrogenases (G6PDH, 6PGDH), as well as enzyme activity of fermentation, alcohol dehydrogenase (ADH), with concomitant inhibition in the capacity of enzyme inactivator (INADH). Moreover, Cd restricted carbohydrate mobilization in the embryonic axis. Almost no glucose and less than 7% of control fructose and total soluble sugars were available in the embryo tissues after 5d of exposure to cadmium. Cotyledonary invertase isoenzyme activity was also inhibited by Cd. The results indicate that cadmium induces disorder in the resumption of respiration in germinating pea seeds. The contribution of Cd-stimulated alternative metabolic pathways to compensate for the failure in mitochondrial respiration is discussed in relation to the delay in seed germination and embryonic axis growth.
...
PMID:Respiratory metabolism in the embryonic axis of germinating pea seed exposed to cadmium. 1876 Apr 97

The effects of industrial storage on the changes of the cell viability and the activities of intracellular alcohol dehydrogenase (ADH) and glucose-6-phosphate dehydrogenase (G6PDH) in brewer's yeast, and the corresponding capacity for the bioconversion of ethyl-3-oxobutanoate (EOB) to ethyl (S)-3-hydroxybutanoate ((S)-EHB), were investigated. The viability of fresh brewer's yeast cells stored in industrial circulating cooling water at 1-2 degrees C showed 4 and 15% drop after the storage of 7 and 15 days, respectively, after which cells died rapidly. The pretreatment of the stored brewer's yeast cells by washing and screening significantly enhanced cell viability during industrial storage. The intracellular levels of ADH and G6PDH after permeabilization of these stored cells with cetyltrimetylammonium bromide (CTAB) were much higher, which showed only slight decrease within 2 weeks during the industrial storage. When the stored cells after the permeabilization treatment was used as the biocatalyst at 90-120 g/L, EOB was converted almost completely into enantiopure (S)-EHB with an enantiomeric excess (ee) more than 99% and a yield of over 96%, by fed-batch bioconversion of 560 mM EOB within 6 h.
...
PMID:Effects of industrial storage on the bioreduction capacity of brewer's yeast. 1885 7

Cyclophilins are conserved cis-trans peptidyl-prolyl isomerase that are implicated in protein folding and function as molecular chaperones. We found the expression of cyclophilin A, Cpr1, changes in response to exposure to yeast Saccharomyces cerevisiae to abiotic stress conditions. The effect of Cpr1 overexpression in stress responses was therefore examined. The CPR1 gene was cloned to the yeast expression vector pVTU260 under regulation of an endogenous alcohol dehydrogenase (ADH) promoter. The overexpression of Cpr1 drastically increased cell viability of yeast in the presence of stress inducers, such as cadmium, cobalt, copper, hydrogen peroxide, tert-butyl hydroperoxide (t-BOOH), and sodium dodecyl sulfate (SDS). The Cpr1 expression also enhanced the cell rescue program resulting in a variety of antioxidant enzymes including thioredoxin system (particularly, thioredoxin peroxidase), metabolic enzymes (glucose-6-phosphate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase), and molecular chaperones (Hsp104, Hsp90, Hsp60 and Hsp42). Thus, our study illustrates the importance of Cpr1 as a molecular chaperone that improves cellular stress responses through collaborative relationships with other proteins when yeast cells are exposed to adverse conditions, and it also premises the improvement of yeast strains.
...
PMID:A cyclophilin A CPR1 overexpression enhances stress acquisition in Saccharomyces cerevisiae. 2049 20

Aimed to understand the waterlogging tolerance and adaptation mechanisms of different tree species, a simulated field experiment was conducted to study the growth and energy-metabolic enzyme activities of one-year-old seedlings of Taxodium distichum, Carya illinoensis, and Sapium sebiferum. Three treatments were installed, i. e., CK, waterlogging, and flooding, with the treatment duration being 60 days. Under waterlogging and flooding, the relative growth of test tree species was in the order of T. distichum > C. illinoensis > S. sebiferum, indicating that T. distichum had the strongest tolerance against waterlogging and flooding, while S. sebiferum had the weakest one. Also under waterlogging and flooding, the root/crown ratio of the three tree species increased significantly, suggesting that more photosynthates were allocated in roots, and the lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) activities of the tree species also had a significant increase. Among the test tree species, T. distichum had the lowest increment of LDH and ADH activities under waterlogging and flooding, but the increment could maintain at a higher level in the treatment duration, while for C. illinoensis and S. sebiferum, the increment was larger during the initial and medium period, but declined rapidly during the later period of treatment. The malate dehydrogenase (MDH), phosphohexose (HPI), and glucose-6-phosphate dehydrogenase (G6PDH) -6-phosphogluconate dehydrogenase (6PGDH) activities of the tree species under waterlogging and flooding had a significant decrease, and the decrement was the largest for T. distichum, being 35.6% for MDH, 21.0% for HPI, and 22.7% for G6PDH - 6PGDH under flooding. It was suggested that under waterlogging and flooding, the tree species with strong waterlogging tolerance had a higher ability to maintain energy-metabolic balance, and thus, its growth could be maintained at a certain level.
...
PMID:[Effects of waterlogging on the growth and energy-metabolic enzyme activities of different tree species]. 2056 Mar 12

Abstract Isotope effects represent perhaps one of the most versatile tools available to investigators interested in the determination of reaction mechanism, particularly in the case of the mechanistic enzymologist. Interpretation of isotope effect data is somewhat more difficult for enzyme reactions, since the chemical or isotope-dependent step(s) is(are) normally not solely rate-limiting as they are for non-enzyme-catalyzed reactions. One can, however, take advantage of rate-limitation by multiple steps in an enzyme-catalyzed reaction to obtain information on a number of aspects of mechanism. In this paper, simple theory for the application of isotope effects to reaction mechanism is developed, and applied to organic reactions and those catalyzed by enzymes. Techniques used to measure isotope effects depend somewhat on the isotope used, that is radioisotope vs. stable isotope, or hydrogen isotope vs. heavier atoms. Techniques to be discussed include competitive and noncompetitive (or internal discrimination) measurements. In enzymecatalyzed reactions, information can be obtained on the order of addition of reactants and release of products, and this will be illustrated using the 6-phosphogluconate and alcohol dehydrogenase reactions. The use of multiple isotope effects can be used to distinguish between stepwise and concerted reactions, and this will be illustrated with the formate and glucose 6-phosphate dehydrogenase and malic enzyme reactions.
...
PMID:Mechanism from isotope effects. 2208 77


<< Previous 1 2 3 4 5 6 7 8 9 10

---