• BMB Reports
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• v.29 no.2
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• pp.146-150
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• 1996

A 2.1 kb cDNA clone for rat transketolase was isolated from rat liver ${\lambda}gt11$ cDNA library and its sequence was determined. The predicted rat transketolase (655 amino acids with $M_r$ 71,186) is highly similar (92%) to that of the human enzyme except that it contains an extra 32 amino acids at its N-terminus. Although it is less similar (<27%) to transketolases from non-mammalian species, the functional motifs such as the catalytic sites and thiamine binding domain are well conserved in the rat enzyme. Southern blot analysis of genomic DNA verified that transketolase appears to be derived from a single gene. Immunoblot and Northern blot analyses suggested that hepatic transketolase was activated pretranslationally by a 2.1-fold while little change was observed in brain enzyme, indicating a tissue-specific pretranslational activation during postnatal development.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1389-1396
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• 2014

The entire nucleotide sequence of the TKL1 gene encoding transketolase (TKL) in an erythritol-producing yeast of Candida magnoliae was determined by degenerate polymerase chain reaction and genome walking. Sequence analysis revealed an open reading frame of C. magnoliae TKL1 (CmTKL1) that spans 2,088 bp and encodes 696 amino acids, sharing 61.7% amino acid identity to Kluyveromyces lactis TKL. Functional analysis showed that CmTKL1 complemented a Saccharomyces cerevisiae tkl1 tkl2 double mutant for growth in the absence of aromatic amino acids and restored transketolase activity in this mutant. An enzyme activity assay and RT-PCR revealed that the expression of CmTKL1 is induced by fructose, $H_2O_2$, and KCl. The GenBank accession number for C. magnoliae TKL1 is KF751756.

• Journal of Community Nutrition
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• v.2 no.2
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• pp.141-145
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• 2000

The present study was conducted to assess the dietary and nutritional status of thiamin in fourty-two elderly women. Dietary intake was determined by 24hour recall method and nutritional status of thiamin was determined by measurement of transketolase activity in erythrocytes. Average dietary intake of energy and thiamin were found to be low, and not more than 78% and 63.2% of Recommended dietary allowances(RDA) respectively. Transketolase activity in erythrocytes was distributed in the range of 0.227-0.589mU/mgHb and the mean value and 0.434mU/mgHb. The mean value of Thiamin pyrophosphate effect(TPP effect) was 24.0% and the range was from 9.36% to 83.9%. It appeared that 95% of 42 elderly women were severely or marginally deficient in thiamin status, showing 22 persons to be above 20% and 18 persons to be 15-20% of TPP effect. Transketolase activity and TPP effect did not show any significant correlation with dietary thiamin intake.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.288-293
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• 1995

In the present study, we tested whether lead intoxication could change the thiamine content and the activity of transketolase, one of thiamine-dependent enzymes, in the brain of rats. It was also tested whether administration of excessive thiamine can reverse the toxic manifestation of lead in the lead intoxicated rats. Four groups of Wistar rats were prepared: 1) control group, 2) lead treated group, 3) lead plus thiamine treated group and 4) thiamine deficient group. Each group of animals was divided into three subgroups based on ages: 3, 7 and 16 weeks. Lead concentration, thiamine content and the activity of transketolase in three different brain regions, i.e.,, telencephalon, brain stem and cerebellum, were measured in each group. Lead concentrations in brain regions of the lead treated group were significantly higher than those of the control group, and those of the lead plus thiamine treated group were significantly decreased from those of the lead treated group. Thiamine contents in the brain regions of the lead treated group were significantly lower than those of the control group, and those of the lead plus thiamine treated group were recovered back to those of the control group. Activities of transketolase in the brain regions of the lead treated group and the thiamine deficient group were significantly lower than those of the control group, while those of the lead plus thiamine treated group were higher than the lead treated group. The results from the present study suggest that neurotoxicity following lead intoxication in rats may be mediated, at least in part, through the changes of thiamine status and consequently thiamine-dependent biochemical reactions such as theactivity of transketolase.

• Journal of Community Nutrition
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• v.5 no.3
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• pp.127-131
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• 2003

The present study was performed to assess nutritional status of thiamin in 104 elementary school children, living in rural areas of Chungbuk. Dietary intake was obtained by 24 hour recall method and blood was collected to analyze the transketolase activity in erythrocytes. Average dietary intake of thiamin was found to be adequate (1.l5mg, 109.2％ of RDA), even though dietary intake of energy was not more than 1,719kcal, 81.5％ of RDA. Transketolase activity in erythrocytes was distributed in the range of 0.294-0.744mU/mgHb and the mean value was 0.540mU/mgHb. The mean value of TPP effect was 7.9％ and the range was 0-77.4％. It appeared that 7.7％ of children were deficient in thiamin, severely or marginally. There were no significant correlations between transketolase activity and dietary thiamin intake, and between TPP effect and dietary thiamin intake. Mean DVS (Dietary variety score) of the children was 14.2${\pm}$3.2 and DVS was apparently correlated with thiamin intake.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.665-672
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• 2004

D-Ribose is a five-carbon sugar used for the commercial synthesis of riboflavin, antiviral agents, and flavor enhancers. Batch fermentations with transketolase-deficient B. subtilis JY1 were carried out to optimize the production of D-ribose from xylose. The best results for the fermentation were obtained with a temperature of $37^{\circ}C$ and an initial pH of 7.0. Among various sugars and sugar alcohols tested, glucose and sucrose were found to be the most effective for both cell growth and D-ribose production. The addition of 15 g/l xylose and 15 g/l glucose improved the fermentation performance, presumably due to the adequate supply of ATP in the xylose metabolism from D-xylulose to D-xylulose-5-phosphate. A batch culture in a 3.7-1 jar fermentor with 14.9 g/l xylose and 13.1 g/l glucose resulted in 10.1 g/l D-ribose concentration with a yield of 0.62 g D-ribose/g sugar consumed, and 0.25 g/l-h of productivity. Furthermore, the sugar utilization profile, indicating the simultaneous consumption of xylose and glucose, and respiratory parameters for the glucose and sucrose media suggested that the transketolase-deficient B. subtilis JY1 lost the glucose-specific enzyme II of the phosphoenolpyruvate transferase system.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.402-406
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• 1988

The aim of the presented paper was to elucidate the physiological background of ethanol inhibition on glucose uptake, ethanol production and cell growth in Z. mobilis. Data obtained from batch and continuous cultures showed that the rates of glucose uptake and ethanol production were not affected but growth rate was apparently reduced by ethanol produced. In order to know the effects of ethanol on the anabolism and the catabolism in Z. mobilis, enzyme activities of the Enter-Doudoroff pathway, viz. hexokinase, glucose 6-phosphate dehydrogenase, were analyzed with the cell grown at different concentration of ethanol produced. As results, it was found that the activities of the glucose kinase and the glucose 6-phosphate dehydrogenase were not affected greatly by the concentration of ethanol where the glucose uptake rates revealed a relatively constant value. However it was very interesting to note that transketolase, which is an essential enzyme to provide the important precursors for cell growth, was affected more apparently to reduce by increasing ethanol levels. Those results might suggest that the apparent reduction of growth rate at ethanol concentration above 20 g/$\ell$ would be caused by the reduction of the transketolase activity, which in turn provide less precursor for the cell growth.

• Journal of Nutrition and Health
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• v.32 no.2
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• pp.175-181
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• 1999

The prevalence of alcoholism among elderly population is reported to be high in rural areas in Korea. Chronic abuse of alcohol can lead to the development of vitamin B deficiency through inadequate intake, altered absorption and metabolism, and increased excretion. The present study was conducted to assess vitamin B1 and B2 status in seventeen alcohol dependent subjects who do not exhibit any clinical neurological symptoms. Vitamin B1 and B2 nutritional states were determined enzymatically by measurement of transketolase and glutathione reductase activities in erythrocytes, respectively. And dietary intakes of nutrients were determined by a 24-hr recall method. The mean percent activation of erythrocyte transketolase was significantly higher in alcoholics than in alcoholics than in control (p<0.05). The proportion of subjects with a low and borderline status of vitamin B1, was significantly higher in alcoholics than in control (p<0.05). The mean percent activation of erythrocyte glutathione reductase was not different between alcoholics and control. And the proportion of subjects with low and borderline status of Vitamin B2, was higher in alcoholics than in control (p<0.1). Vitamin B1 and B2 status were significantly decreased in alcoholics who were smoking cigarettes compared to non-smoking and non-alcoholic subjects(p<0.05). Whether vitamin supplementation improves the vitamin status of alcohol dependent subjects remains to be researched.

• Proceedings of the Korean Nutrition Society Conference
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• 1995.05c
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• pp.23-23
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• 1995

• Clinical and Experimental Reproductive Medicine
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• v.39 no.2
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• pp.58-67
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• 2012

Objective: Previously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD). Methods: We evaluated the loss-of-function of Tkt by microinjecting Tkt double-stranded RNAs (dsRNAs) into germinal vesicle-stage oocytes, and the oocytes were cultured in vitro to evaluate phenotypic changes during oocyte maturation. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression of other enzymes in the pentose phosphate pathway were determined after Tkt RNA interference (RNAi). Results: Despite the complete and specific knockdown of Tkt expression, GVBD occurred and meiosis was arrested at the metaphase I (MI) stage. The arrested oocytes exhibited spindle loss, chromosomal aggregation, and declined maturation promoting factor and mitogen-activated protein kinase activities. The modified expression of two enzymes in the pentose phosphate pathway, Prps1 and Rbks, after Tkt RNAi and decreased maturation rates were amended when ribose-5-phosphate was supplemented in the culture medium, suggesting that the Tkt and pentose phosphate pathway are important for the maturation process. Conclusion: We concluded that Tkt and its associated pentose phosphate pathway play an important role in the MI-MII transition of the oocytes' meiotic cell cycle, but not in the process of GVBD.