Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mitochondria were isolated from whole homogenates of normal liver and Novikoff hepatomas using reorienting rate zonal centrifugation on sucrose gradients. The activities of several mitochondrial-specific enzymes and ultrastructure were compared in the two tissues. Our results indicate that cytochrome oxidase, lipoamide dehydrogenase, malate dehydrogenase, and succinate dehydrogenase activities are all higher in liver homogenates than in Novikoff hepatoma homogenates. Mitochondrial hexokinase, however, is much greater in the hepatoma than in liver. The activity of these enzymes in isolated mitochondria displayed a much different pattern. Both cytochrome oxidase and succinate dehydrogenase activities were higher in hepatoma mitochondria than in liver mitochondria. Lipoamide dehydrogenase and malate dehydrogenase, conversely, were higher in liver mitochondria. Hexokinase was found to be virtually absent in liver mitochondria but plentiful in hepatoma mitochondria. Ultrastructural studies have shown that the hepatoma mitochondria are much smaller in size, which results in a decreased rate of migration into the gradient. These studies have also shown that normal liver consists of predominantly "condensed" forms of mitochondria, whereas hepatoma contained a majority of "twisted" species. Experiments using 1% bovine serum albumin in the homogenization procedures and in the gradient have confirmed earlier observations that bovine serum albumin is essential for optimal isolation of neoplastic mitochondria.
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PMID:Characteristics of mitochondria isolated by rate zonal centrifugation from normal liver and Novikoff hepatomas. 624 94

Huntington disease (HD) fibroblasts subjected to stress exhibit an enzyme profile that is different from that exhibited by escapee (unaffected members of families with HD) or control fibroblasts. The specific activity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in normally cultured HD fibroblasts was not different from that in control and escapee fibroblasts. However, in escapee and control fibroblasts subjected to stress by withholding fresh medium, the specific activity of GAPDH in cells harvested by trypsinization increased greatly 3 weeks after withholding medium ( approximately 8-fold), but the increase was significantly less pronounced ( approximately 3-fold) in the HD fibroblasts. In contrast, only small changes occurred in the specific activity of lipoamide dehydrogenase (LADH) over the same time period, and the values were not significantly different among the three groups at any time point. The specific activity of hexokinase (HK) was significantly higher in the HD fibroblasts at 1-3 weeks after withholding fresh medium than in the escapee/control fibroblasts. Finally, the total yield of fibroblasts per culture flask (as judged by protein content) was significantly greater for the stressed HD fibroblasts than for the escapee and control fibroblasts at 2 and 3 weeks after withholding medium. The present results are in accord with the hypothesis that HD is a disease associated with latent, generalized metabolic abnormalities.
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PMID:Glyceraldehyde 3-phosphate dehydrogenase abnormality in metabolically stressed Huntington disease fibroblasts. 977 85

A Ca(2+)-dependent GalNAc/Man-specific lectin (CSL) from Cyclina sinensis was isolated, and its stimulatory action was characterized in yeast. CSL showed a potent effect on the production of ethanol by Saccharomyces cerevisiae. In this work, the changes in the protein expression profiles of S. cerevisiae after 24h of incubation with CSL were analyzed using label-free quantitative proteomics. A total of 1410 proteins were identified, but only 117 proteins showed significant differences in normalized volume (p<0.05). Among the latter proteins, 24 proteins were up-regulated, and 93 were down-regulated. Analysis of the proteome revealed that CSL triggered changes in the concentrations of some enzymes, such as increased expression of hexokinase, glyceraldehyde 3-phosphate dehydrogenase and enolase and decreased expression of dihydrolipoamide dehydrogenase and aldehyde dehydrogenase. These results indicate that CSL can cause some changes in the metabolic pathway involved in ethanol synthesis in S. cerevisiae. These data may help us understand the stimulatory mechanism of lectin in the fermentation process.
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PMID:Quantitative proteomic analysis of the effects of a GalNAc/Man-specific lectin CSL on yeast cells by label-free LC-MS. 2679 10