Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blood levels of vitamin B1, B2, B6, B12 and folic acid were measured in a group of 37 Dutch parturient women and their full term newborns. For the evaluation of the vitamin B1, B2 and B6 status also transketolase-, glutathion reductase- and transaminase activities with their respective activation ratios were measured. In the circulation of the newborn blood levels and enzyme activities were found 1.5-2.0 times higher compared with those of the mother. Interpretation of the data obtained from the mothers using criteria coming from a group of healthy adult blood donors, revealed a relatively high incidence of marginal vitamin status, especially for vitamins B6, B12 and folic acid. By means of the enzyme activation tests even higher percentages of cases were found within the marginal or deficient range. The actual extent of vitamin deficiency in pregnancy could not be estimated, however, secondary effects seem to be involved affecting both vitamin blood levels and enzyme activities.
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PMID:Evaluation of the vitamin status in pregnancy. Circulating blood levels and enzyme activation in a group of Dutch parturient women and their full term newborns. 63 6

The nutritional habits of 38 randomly selected single aged people with free choice of food have been investigated by the precise weighing method. Blood serum levels of the vitamins A, C, and E and of beta-carotene and biotin were analyzed, and the nutritional status with respect to the vitamins B1, B2, and B6 was examined by the transketolase-test, the glutathione-reductase-test, and the glutamic-acid-oxalo-acetic-transaminase-test. In relation to the desirable daily supply of nutrients and other dietary components the food was deficient in the vitamins B1, and B6 and in magnesium. For women an additional calcium-deficiency was demonstrated. The dietary fat content, however, was found to be high (44% of total calorie intake). The results of the blood analyses suggest an insufficient dietary supply of vitamin B1, partly also of the vitamins B6 and C. The total caloric intake was found to be rather low with respect to the age.
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PMID:[A nutritional survey of 38 single elderly persons with free choice of food]. 99 82

Measurements of the activity of transketolase in human erythrocyte lysates by an assay coupled to NADH oxidation indicate that interactions of assay substrates with hemoglobin can give rise to overestimations of transketolase activity. Three potential sources of error are identified. Thus, in lysates containing methemoglobin, NADH oxidation can be due firstly to methemoglobin reductase activity or secondly to the monooxygenase activity of methemoglobin, for which the substrate can be ribose 5-phosphate, a substrate also of transketolase. Thirdly, the addition of high concentrations of the transketolase cofactor, TDP, to an insufficiently buffered reaction mixture can cause the aggregation and precipitation of hemoglobin: a phenomenon that may be misconstrued as an enhanced increase in absorbance at 340 nm and hence as additional transketolase activity. Although the present study concentrates on these potential artefacts in assays of transketolase activity, the findings may well be relevant to the measurement of other enzyme activities in hemolysates by procedures based ultimately on the rate of consumption or production of NAD(P)H.
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PMID:Interactions with hemoglobin: a source of error in measurements of transketolase activity in hemolysates. 274 79

In 830 Viennese school children of both sexes, aged 11-12 years, plasma carotene, retinol and alpha-tocopherol, erythrocyte transketolase activity (alpha ETK), erythrocyte glutathione-reductase (alpha EGR) and erythrocyte glutamic acid oxalacetic acid transaminase (alpha EGOT) were determined. The mean alpha ETK value indicated inadequate thiamine supply. The vitamin status was better in boys and in children of higher socio-economic classes than in girls and in the low income group, with respect to beta-carotene, retinol, tocopherol, thiamine and riboflavin. The opposite situation was true in the case of pyridoxine where the girls and the children of lower socio-economic status showed lower values for alpha EGOT indicating a better vitamin B6 status. Eating habits of the children did not seem to affect the vitamin status, but in children with overweight higher values for retinol and thiamine were more frequent and a positive correlation was found between tocopherol values and serum cholesterol.
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PMID:The vitamin status of Viennese school children aged 11-12 years. 712 2

Thiamin, riboflavin, and pantothenic acid status were determined in 13 young women, ages 19-25, at the beginning and end of a 12-day confined study. 9 women were using (+OCA) oral contraceptives and the other 4 were not (-OCA). The subjects entered the metabolic unit during the 1st week of their menstrual cycle and were fed a constant formula diet containing 2.0 mg thiamin, 3.0 mg riboflavin, and 10 mg pantothenic acid. Prestudy intakes, estimated from 3-day dietary records, were about 1/2 of the thiamin, riboflavin, and pantothenic acid levels fed in the study, and were similar in both groups. Use of OCs did not appear to influence the activity of erythrocyte transketolase or erythrocyte glutahione reductase or the response of these enzymes to in vitro stimulation by their cofactors. The enzymes were responsive to the levels of thiamin and riboflavin fed during the study, however. In the +OCA group, erythrocyte transketolase and erythrocyte glutahione reductase stimulation by their cofactors was significantly decreased by day 12. At the beginning of the study, blood and urine pantothenic acid levels were significantly lower in the +OCA group than the -OCA group. These differences were no longer evident by the end of the study. The data show that when dietary intakes and times of sampling in the menstrual cycle are controlled, OCs do not cause significant changes in the biochemical parameters of thiamin, riboflavin, and pantothenic acid status.
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PMID:Effect of oral contraceptives agents on thiamin, riboflavin, and pantothenic acid status in young women. 736 2

Saccharomyces cerevisiae was metabolically engineered for xylose utilization. The Pichia stipitis CBS 6054 genes XYL1 and XYL2 encoding xylose reductase and xylitol dehydrogenase were cloned into S. cerevisiae. The gene products catalyze the two initial steps in xylose utilization which S. cerevisiae lacks. In order to increase the flux through the pentose phosphate pathway, the S. cerevisiae TKL1 and TAL1 genes encoding transketolase and transaldolase were overexpressed. A XYL1- and XYL2-containing S. cerevisiae strain overexpressing TAL1 (S104-TAL) showed considerably enhanced growth on xylose compared with a strain containing only XYL1 and XYL2. Overexpression of only TKL1 did not influence growth. The results indicate that the transaldolase level in S. cerevisiae is insufficient for the efficient utilization of pentose phosphate pathway metabolites. Mixtures of xylose and glucose were simultaneously consumed with the recombinant strain S104-TAL. The rate of xylose consumption was higher in the presence of glucose. Xylose was used for growth and xylitol formation, but not for ethanol production. Decreased oxygenation resulted in impaired growth and increased xylitol formation. Fermentation with strain S103-TAL, having a xylose reductase/xylitol dehydrogenase ratio of 0.5:30 compared with 4.2:5.8 for S104-TAL, did not prevent xylitol formation.
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PMID:Xylose-metabolizing Saccharomyces cerevisiae strains overexpressing the TKL1 and TAL1 genes encoding the pentose phosphate pathway enzymes transketolase and transaldolase. 853 86

Saccharomyces cerevisiae was transformed with the Pichia stipitis CBS 6054 XYL1 and XYL2 genes encoding xylose reductase (XR) and xylitol dehydrogenase (XDH) respectively. The XYL1 and XYL2 genes were placed under the control of the alcohol dehydrogenase 1 (ADH1) and phosphoglycerate kinase (PGK1) promoters in the yeast vector YEp24. Different vector constructions were made resulting in different specific activities of XR and XDH. The XR:XDH ratio (ratio of specific enzyme activities) of the transformed S. cerevisiae strains varied from 17.5 to 0.06. In order to enhance xylose utilisation in the XYL1-, XYL2-containing S. cerevisiae strains, the native genes encoding transketolase and transaldolase were also overexpressed. A strain with an XR:XDH ratio of 17.5 formed 0.82 g xylitol/g consumed xylose, whereas a strain with an XR:XDH ratio of 5.0 formed 0.58 g xylitol/g xylose. The strain with an XR:XDH ratio of 0.06, on the other hand, formed no xylitol and less glycerol and acetic acid compared with strains with the higher XR:XDH ratios. In addition, the strain with an XR:XDH ratio of 0.06 produced more ethanol than the other strains.
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PMID:Expression of different levels of enzymes from the Pichia stipitis XYL1 and XYL2 genes in Saccharomyces cerevisiae and its effects on product formation during xylose utilisation. 929 80

The contents of the vitamins B1 (27 ng/ml), B2 (57 ng/ml), A (1.3 micrograms/ml), and E (9.7 micrograms/ml) as well as beta-carotene (0.2 microgram/ml) in transitional human milk were determined for up to 35 women aged between 19 and 31 years. Additionally, the vitamin content in maternal and cord plasma as well as the erythrocytic transketolase- and glutathione-reductase activities of the water soluble vitamins were measured. Dietary recalls were evaluated for the nutritional intake of vitamins. Concerning the fat soluble vitamins, the breast fed newborns received the recommended amounts of the German Society of Nutrition (DGE) for this group. In contrast to this, the supply of the water soluble vitamins (B1: 13.5 micrograms/500 ml; B2: 28.5 micrograms/500 ml) attained only 5 to 10% of the recommendations for newborns during the first two weeks after parturition with breast feeding. Vitamin content of maternal plasma (B1: 6.1 +/- 2.8 ng/ml) and erythrocytic enzyme activities (alpha ETK: 0.86-1.62; alpha EGR: 1.08-1.75) indicated a low or sufficient intake, while the values in cord blood (B1: 19.8 +/- 6.5 ng/ml; alpha ETK: 0.62-1.62; alpha EGR: 1.01-1.47) were in accordance with a satisfactory supply.
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PMID:[Vitamin B1, B2, A and E and beta-carotene content in transitional breast milk and comparative studies in maternal and umbilical cord blood]. 945 42

The XYL1 and XYL2 genes from Pichia stipitis encoding xylose reductase (XR) and xylilitol dehydrogenase (XDH), respectively, were transformed into Saccharomyces cerevisiae. These two genes were placed in different directions under the control of the alcohol dehydrogenase I (ADHI) and phosphoglycerate kinase (PGK) promoters and inserted into the E. coli-yeast shuttle plasmid YEp24. Different recombinant S. cerevisiae strains were constructed with different specific activities of XR and XDH. The highest XR or XDH activities were obtained when the expressed gene was controlled by the PGK promoter and located downstream after the ADHI promoter-gene-terminator sequence. The XR/XDH ratio (ratio of specific enzyme activities of XR and XDH) in these recombinant S. cerevisiae strains varied from 17.5 to 0.06. In order to enhance xylose utilization, in the XYL1, XYL2 containing S. cerevisiae strains, the native TKL1 gene encoding transketolase and the TALI gene encoding transaldolase were also overexpressed, which showed considerably good growth on the xylose plate. Fermentation of the recombinant S. cerevisiae strains containing XYL1, XYL2, TKL1, and TAL1 were studied with mixtures of glucose and xylose. The strain with XR/XDH ratio of 0.06 consumed 3.25 g/L xylose and formed no xylitol and less glycerol and acetic acid, but more ethanol compared with the strains with a higher XR/XDH ratio.
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PMID:Effect on product formation in recombinant Saccharomyces cerevisiae strains expressing different levels of xylose metabolic genes. 963 Dec 57

The transcriptional control of two native promoters and one heterologous promoter and the production of a heterologous protein from these promoters were evaluated in the xylose-fermenting yeast Pichia stipitis cultivated on xylose and glucose as carbon sources, using the beta-xylanase II xyn2 gene of Trichoderma reesei. The xyn2 gene open reading frame was fused to the P. stipitis xylose reductase gene (XYL1) promoter, the P. stipitis transketolase gene (TKL) promoter and the Saccharomyces cerevisiae phosphoglycerate kinase gene (PGKI) promoter DNA sequences on episomal plasmids. The plasmids were transformed into Pichia stipitis and gene expression and beta-xylanase production monitored. The XYL1 promoter was shown to be inducible in the presence of xylose, as xyn2 transcription and beta-xylanase activity could be measured when the recombinant strain was cultivated on xylose but not when it was cultivated on glucose. TKL promoter expression was found to be constitutive when either glucose or xylose was used as sole carbon source. The PGK1 promoter did not promote xyn2 transcription in P. stipitis. The molecular size of the recombinant Xyn2 protein produced by P. stipitis was 20.7 kDa, which is similar to that of the native T. reesei Xyn2 protein. This indicates no or minimal glycosylation of the recombinant protein. The recombinant xyn2-expressing strain also yielded twice the amount of biomass yielded by the control strain when cultivated in medium containing 1% birchwood xylan as sole carbon source.
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PMID:Differential expression of the Trichoderma reesei beta-xylanase II (xyn2) gene in the xylose-fermenting yeast Pichia stipitis. 1176 99


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