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

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Query: EC:4.1.2.13 (aldolase)
3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aldolase and triose phosphate isomerase both display strict specificity towards the enantiomers of [1-3H]glycerone 3-phosphate. The enantiomer generated from D-[1-3H]glyceraldehyde 3-phosphate produces 3HOH in the aldolase reaction, whilst the other enantiomer generated from D-[3-3H]fructose 1,6-bisphosphate is solely detritiated in the reaction catalyzed by triose phosphate isomerase. Advantage was taken of such a specificity to assess, in human erythrocytes exposed to either D-[3-3H]glucose or D-[3,4-3H]glucose, the extent of D-glyceraldehyde 3-phosphate sequential conversion to glycerone 3-phosphate and D-fructose 1,6-bisphosphate, relative to net glycolytic flux. At 37 degrees C and in the presence of 5.6 mM D-glucose, only 55% of the metabolites of D-[4-3H]glucose underwent detritiation in the reactions catalyzed by triose phosphate isomerase and aldolase. Such a percentage was further decreased at low temperature (8 degrees C) or lower concentrations of D-glucose (0.2 and 1.0 mM). However, when the erythrocytes were exposed to menadione, the increase in 3HOH production from either D-[3-3H]glucose or D-[3,4-3H]glucose indicated that the majority of the 3H atoms initially located on the C4 of D-glucose were recovered as 3HOH upon circulation through the pentose phosphate pathway. These findings suggest that, under physiological conditions, a large fraction of D-glyceraldehyde 3-phosphate generated from exogenous D-glucose may undergo enzyme-to-enzyme channelling in the glycolytic pathway.
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PMID:Interconversion of D-fructose 1,6-bisphosphate and triose phosphates in human erythrocytes. 159 48

Postmortem biochemical indices may provide a useful adjunct to morphological studies in the identification of antemortem brain insult. We studied 34 routine medico-legal cases categorising them into one of four diagnostic groups. There were 11 cases of head trauma, 7 of 'hypoxia' (3 hangings and 4 carbon monoxide or drug poisonings), 7 sudden cardiac deaths and 9 miscellaneous cases. Survival time and postmortem interval was known for each case. The degree of cranio-cerebral trauma was graded. Cerebro-spinal fluid (CSF) and vitreous humour were analysed for calcium, glucose, total proteins, aldolase, aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyltransferase (GGT), lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase BB isoenzyme (CK-BB). CK-BB was also measured in superior vena cava serum. In CSF there was a significant correlation between the severity of cranio-cerebral trauma and levels of aldolase, CK-BB, AST, ALT and total proteins. CSF CK-BB, median units/l (range), for the groupings of head trauma, hypoxia, sudden cardiac death and miscellaneous were respectively 823 (2-3431); 96 (2-187); 4 (2-25); 5 (1-69). Corresponding serum CK-BB levels were 240 (28-322); 390 (26-411); 180 (20-482); 79 (18-530).
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PMID:Efficacy of cerebro-spinal fluid biochemistry in the diagnosis of brain insult. 160 50

Optimal concentrations of the essential components for analyzing the activity of each enzyme associated with glycolysis and gluconeogenesis in rabbit periodontal ligament were examined, and enzyme assay systems for 15 enzymes including 22 reactions were established using triethanolamine buffer. Specific activities of all the enzymes, except for the gluconeogenic reaction of phosphoglycerate kinase, were systematically evaluated using the optimum buffer for each enzyme, since the activity of each enzyme varied depending on the buffer used. For glycolysis, the activity levels of hexokinase and 6-phosphofructokinase were very low, and consequently these enzyme reactions were inferred to be the rate-limiting steps. For gluconeogenesis, fructose 1,6-bisphosphatase and aldolase activities were extremely low, and the activities of glucose 6-phosphatase, phosphoenolpyruvate carboxykinase and pyruvate carboxylase were undetectable. These results suggest that the periodontal ligament may have no gluconeogenesis capability. With a rise in pH, the activities of the key enzymes of glycolysis gradually increased, and a specific "crossover" point was found between the activities of glyceraldehyde-phosphate dehydrogenase and phosphoglyceromutase. In addition, the activity of fructose 1,6-bisphosphatase, one of the key enzymes of gluconeogenesis, was markedly increased with a rise in pH, although pH changes had no effect on aldolase activity. Consequently, alkaline pH appeared to result in overall stimulation of glycolysis.
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PMID:Enzymatic regulation of glycolysis and gluconeogenesis in rabbit periodontal ligament under various physiological pH conditions. 165 53

Experiments on 156 rats maintained at ration with copper deficiency have demonstrated a decrease in the values of iodine metabolism in organs and tissues excluding the liver where a sharp increase in the concentration and content of inorganic iodine was observed. A disturbance in indices of carbohydrate and proteins metabolism in the organism of animals is marked. A direct relationship with a correlation coefficient equaling 0.87-1.00 is determined between changes in the concentration of protein-bound iodine in blood and concentration of glycogen in the liver, skeletal muscles, albumins, alpha 1-, alpha 2-globulins, urea concentration; an inverse relationship with glucose, activity of blood lipo-dehydrogenase and liver mitochondria, aldolase, concentration of pyruvic and lactic acids is established as well. It is concluded that copper deficiency can exert both a direct effect on metabolic processes (as data from literature testify) and an indirect one disturbing iodine metabolism, i. e. sharply decreasing protein-bound iodine production by the thyroid gland.
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PMID:[The effect of copper on the metabolism of iodine, carbohydrates and proteins in rats]. 169 3

The conditional lethal mutations ts8 and h8 are located in fda, the gene encoding aldolase, and they inhibit RNA synthesis upon shift to the nonpermissive temperature. We demonstrate that both mutations preferentially inhibit stable RNA synthesis and that this inhibition occurs at the level of transcription initiation. The susceptibility of a promoter to the inhibitory effects of ts8 is correlated with the ability of the promoter to be growth rate regulated. This effect is independent of relA and spoT function. Inhibition is dependent upon glucose metabolism past the generation of glucose-6-phosphate; however, the mechanism of this effect is unknown.
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PMID:Physiological effects of the fructose-1,6-diphosphate aldolase ts8 mutation on stable RNA synthesis in Escherichia coli. 171 36

Due to repeatedly described incidents in patients with undiscovered hereditary fructose intolerance, the application of fructose and sorbit-containing parenteral solutions is a topic vehemently discussed. This paper presents a survey of the literature dealing with the inborn defect of fructose-1-phosphate aldolase. The physiology and pathophysiology of fructose metabolism are described as well as the clinical appearance and diagnostic possibilities. The acute course of a fructose incompatibility is determined by a threatening decrease in the blood glucose level, which is attributed to the inhibition of several enzymes of glycolysis and gluconeogenesis by an intracellular accumulation of fructose-1-phosphate. Within hours a global functional breakdown of organs, which normally have the enzyme, occurs. The impairment of the liver function finds expression in a severe coagulopathy, the damage of the kidney leads to anuria. In chronic oral fructose supply, damage of the liver and small intestinal mucosa with corresponding gastrointestinal symptoms determine the clinical course. Concerning diagnosis, contrary to the liver biopsy and the fructose tolerance test, the mucosal biopsy with determination of fructose-1-phosphate aldolase activity has the advantage of greater specificity and is better tolerated by the patient. A total abstinence to fructose and sorbitol-containing solutions is not considered to be necessary when the rarity of the illness is taken into account and certain precautions are taken. These include a specific anamnesis of nutrition as well as a total abstinence from fructose and sorbitol in infants and in the unconscious patient. For clinical routine a simple fructose tolerance test is suggested.
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PMID:[Etiology, pathophysiology and clinical significance of hereditary fructose intolerance]. 176 34

Three cell lines established from human gliomas were found to differ in the capacity to phosphorylate the glycolytic enzyme pyruvate kinase in vitro. Phosphorylation in the glioblastoma cell line U-138 was more pronounced than in the glioma cell line Hs 683 and in the glioblastoma cell line A-172. All 3 cell lines showed similar pyruvate kinase isozyme patterns and expressed about 90% K-type and 10% M-type subunits. So, differences in pyruvate kinase phosphorylation could not be explained by differences in the availability of the appropriate substrate, being pyruvate kinase type K. As in gliomas, phosphorylation could specifically and almost completely be inhibited by fructose-1,6-bisphosphate. In order to investigate a potential physiological significance of the phosphorylation of pyruvate kinase, we have characterized these cell lines for several glycolytic parameters. In U-138 cells, the production of lactate appeared to be 2 times higher as compared with A-172 and Hs 683 cells under normal growth conditions and even 4 times higher under low glucose culture regime. The efflux of lactate correlated with the pyruvate kinase phosphorylation pattern in the cell lines. In none of the cell lines could the lactate production be stimulated by glutamine as additional energy source under low glucose culture conditions. The higher glycolytic flux in U-138 cells was not accompanied by higher glycolytic enzyme activities. The isozyme patterns of hexokinase, pyruvate kinase, aldolase, enolase and lactate dehydrogenase in the cell lines were nearly identical and resembled the patterns previously described for solid gliomas. However, the isozyme composition of phosphofructokinase in the cell lines differed from the situation in gliomas. While in gliomas the expression of L-type phosphofructokinase is favored, in the glioma cell lines, we found an increase in the expression of C-type subunits.
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PMID:Phosphorylation of pyruvate kinase and glycolytic metabolism in three human glioma cell lines. 179 9

Examinations of 176 children administered caries-preventing drugs for 2 years have shown that oral irrigation with 0.2% sodium fluoride solution, oral intake of fluorine in a dose of 1 mg, or of potassium orotate, or of calcium glucerophosphate improved the oral fluid resistance to carbohydrate action. Glycolytic enzyme activity of the oral fluid in these children was not augmenting during carbohydrate load, whereas in children not administered such preventive courses oral intake of 10% glucose solution resulted in essential elevation of salivary aldolase and lactate dehydrogenase activities, i.e. intensification of glycolytic processes, this leading to the development of acid potential in the oral cavity and, consequently, to a higher risk of caries development.
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PMID:[The carbohydrate-resistant mechanism of the action of caries-prophylactic agents on the oral fluid in children]. 179 7

Proteolysis of lactate dehydrogenase, aldolase and the synthetic substrate N-succinylalanylalanylalanyl-p-nitroanilide by proteinase K is inhibited by glucose-6-phosphate and fructose-1,6-biphosphate. Analysis of the kinetic data obtained with the synthetic substrate indicates that the inhibition is a mixed-type and that more than one inhibitor molecule binds to proteinase K. Glucose and fructose are ineffective as inhibitors. In the presence of 0.2-4 mM fructose-1,6-biphosphate, aldolase becomes more susceptible to proteolysis, probably as a result of a conformational change induced by the substrate.
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PMID:Inhibition of proteinase K by phosphorylated sugars. 181

To test the mechanism of action of fructose-1,6-bisphosphate (F-1,6-P2), experiments were conducted on isolated perfused rat hearts to measure the glycolytic rate supported by exogenous glucose with simultaneous measurement of oxygen consumption and the release of lactate and pyruvate. Glycolysis was assayed in terms of the release of tritiated water from [5-3H] glucose, a measure of the rate through the aldolase step. It was found that 5 mmol/L F-1,6-P2 reduced the glycolytic rate parallel to the decrease in oxygen consumption. The results suggest that the cardioprotective action of F-1,6-P2 is related to a substrate effect and a decrease in adenosine triphosphate consumption as indicated by a decrease in oxygen consumption in accordance with the recent demonstration of Ca2+ binding by F-1,6-P2.
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PMID:Effect of exogenous fructose-1,6-bisphosphate on glycolysis in the isolated perfused rat heart. 185 36


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