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)

The enzymology of methanol utilization in thermotolerant methylotrophic Bacillus strains was investigated. In all strains an immunologically related NAD-dependent methanol dehydrogenase was involved in the initial oxidation of methanol. In cells of Bacillus sp. C1 grown under methanol-limiting conditions this enzyme constituted a high percentage of total soluble protein. The methanol dehydrogenase from this organism was purified to homogeneity and characterized. In cell-free extracts the enzyme displayed biphasic kinetics towards methanol, with apparent Km values of 3.8 and 166 mM. Carbon assimilation was by way of the fructose-1,6-bisphosphate aldolase cleavage and transketolase/transaldolase rearrangement variant of the RuMP cycle of formaldehyde fixation. The key enzymes of the RuMP cycle, hexulose-6-phosphate synthase (HPS) and hexulose-6-phosphate isomerase (HPI), were present at very high levels of activity. Failure of whole cells to oxidize formate, and the absence of formaldehyde- and formate dehydrogenases indicated the operation of a non-linear oxidation sequence for formaldehyde via HPS. A comparison of the levels of methanol dehydrogenase and HPS in cells of Bacillus sp. C1 grown on methanol and glucose suggested that the synthesis of these enzymes is not under coordinate control.
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PMID:Methanol metabolism in thermotolerant methylotrophic Bacillus strains involving a novel catabolic NAD-dependent methanol dehydrogenase as a key enzyme. 267 21

The effect of the number of active groups of new affinity supports--odigose and odifil (ethylsulfo-activated agarose) on the retention of the specific activity of muscle aldolase was investigated. The active center of the enzyme includes lysine able to react with activated supports. The aldolase completely retained the specific activity after immobilization on the abovementioned relatively high-substituted supports, on which other enzymes, e.g. phosphorylase B, NAD-kinase from pigeon heart, were partially or completely inactivated. The aldolase was inactivated when being immobilized on more substituted supports. The enzyme specific activity completely retained if the high substituted supports were preliminary incubated at 37 degrees to destroy some diazo-groups.
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PMID:[Retention of specific activity of muscle aldolase after its immobilization on odigos and odifil (ethylsulfo-activated agarose)]. 274 Mar 1

The structural peculiarities of rabbit muscle aldolase accompanying enhancement of the aldolase activity in diabetes are described from the data of tryptophan phosphorescence at the room temperature and fluorescence polarization. It is shown that the pathology-concomitant conformational changes occur in both the hydrophobic part and NAD-binding site of the enzyme. The character of the structural changes in the hydrophobic part of the protein in diabetes and an increase in the enzymic activity are similar to that observed in normal aldolase after its interaction with NADH and are believed to be associated with the enhancement of the rigidity in the Trp-147 environment.
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PMID:[Structuro-functional characteristics of aldolase from rabbit muscles in diabetes]. 318 55

Dissimilation of L-fucose as a carbon and energy source by Escherichia coli involves a permease, an isomerase, a kinase, and an aldolase encoded by the fuc regulon at minute 60.2. Utilization of L-rhamnose involves a similar set of proteins encoded by the rha operon at minute 87.7. Both pathways lead to the formation of L-lactaldehyde and dihydroxyacetone phosphate. A common NAD-linked oxidoreductase encoded by fucO serves to reduce L-lactaldehyde to L-1,2-propanediol under anaerobic growth conditions, irrespective of whether the aldehyde is derived from fucose or rhamnose. In this study it was shown that anaerobic growth on rhamnose induces expression of not only the fucO gene but also the entire fuc regulon. Rhamnose is unable to induce the fuc genes in mutants defective in rhaA (encoding L-rhamnose isomerase), rhaB (encoding L-rhamnulose kinase), rhaD (encoding L-rhamnulose 1-phosphate aldolase), rhaR (encoding the positive regulator for the rha structural genes), or fucR (encoding the positive for the fuc regulon). Thus, cross-induction of the L-fucose enzymes by rhamnose requires formation of L-lactaldehyde; either the aldehyde itself or the L-fuculose 1-phosphate (known to be an effector) formed from it then interacts with the fucR-encoded protein to induce the fuc regulon.
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PMID:Cross-induction of the L-fucose system by L-rhamnose in Escherichia coli. 330 11

Changes in carbohydrate metabolism were studied in midgut gland, muscle, and gill tissues of marine prawn Penaeus indicus exposed to a sublethal concentration (0.3 ppm) of phosphamidon. A significant decrease in glycogen and pyruvate and an increase in lactate content were observed in all phosphamidon-exposed prawn tissues after 96 hr. An increase in phosphorylase a and aldolase activity levels suggested the increased formation of triose sugars during phosphamidon toxicity. LDH activity was considerably decreased and an increment in lactate content was observed which indicates reduced mobilization of pyruvate into the citric acid cycle. Glucose-6-phosphate dehydrogenase activity was considerably increased, suggesting the enhanced oxidation of glucose in the hexose monophosphate shunt pathway. Krebs cycle enzymes such as NAD-isocitrate dehydrogenase, succinate dehydrogenase, and malate dehydrogenase were found to be decreased, suggesting the impairment in mitochondrial oxidative metabolism due to the acute toxic impact of phosphamidon. Cytochrome-c oxidase and Mg2+ ATPase activity levels were also decreased considerably, suggesting impaired energy synthesis and breakdown during phosphamidon toxicity, as a result of reduced oxidation of glucose aerobically. The increase in acid and alkaline phosphatase activities indicates the enhanced breakdown of phosphate to release energy in view of inhibiton or impairment in the ATPase system during phosphamidon-induced stress. These results suggest that phosphamidon has a profound effect on the oxidative metabolism of prawn which results in the triggering of compensatory metabolic pathways for survivability.
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PMID:Modulation of carbohydrate metabolism in the selected tissues of marine prawn, Penaeus indicus (H. Milne Edwards), under phosphamidon-induced stress. 337 38

The aldolase A binding to the lecithin liposomes (Kd = 2.4 +/- 0.1 X 10(-3) M) has been shown by the fluorescence and tryptophan phosphorescence at the room temperature. The interaction is accompanied by an increase in the phospholipid bilayer microviscosity, and some conformational changes in the hydrophobic part of the enzyme, pronouncing themselves in Trp-147 environment rigidity, decrease. The observation of membrane viscosity vs. incubation time revealed practically instant enzyme-membrane interaction and no gradual incorporation. The accessibility of the NAD-binding domain of aldolase for NADH in the liposome presence remains unaltered.
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PMID:[Interaction of aldolase A with lecithin liposomes]. 339 75

Since red cells transport and metabolize acetaldehyde in vivo, the effects of acetaldehyde on human red cell enzyme activities were studied. Incubation of intact red cells or undiluted red cell lysates at 37 degrees C for 4 h with 1-10 mmol/l acetaldehyde decreased only GOT, GPT and aldolase activities among the 26 enzymes tested. No inhibition occurred at 4 degrees C or when acetaldehyde was incubated with dilute hemolysates. Incubation of lysates with other reducing substrates or with acetate inhibited aldolase but not GOT or GPT. Preincubation of lysates with cyanate or fluoride markedly decreased acetaldehyde-mediated transaminase inhibition but not aldolase inhibition. Addition of pyridoxal phosphate, the vitamin B6 transaminase coenzyme, to GOT and GPT assay mixes did not reverse acetaldehyde-mediated transaminase inhibition. These findings suggest that acetaldehyde-mediated aldolase inhibition results from oxidation of acetaldehyde while transaminase inhibition results from nonoxidative acetaldehyde metabolism. When 100-200 mumol/l acetaldehyde is added to lysates at 2-h intervals and when lysates are incubated with ethanol, alcohol dehydrogenase and an NAD-regenerating system, enzyme inhibition occurs at acetaldehyde levels approaching those seen in vivo. Thus, the role of acetaldehyde-mediated enzyme inhibition in the toxicity of alcohol abuse warrants further study.
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PMID:Effects of acetaldehyde on human red cell metabolism: evidence for the formation of enzyme inhibitors. 341 86

It is shown that the activity of aldolase synthesized in rabbit muscles under diabetes is higher than that at normal state. This fact is probably a result of some structural alterations in NAD-binding site with Trp-291 and -311 in it which overlaps a considerable part of C-terminal region of the protein. The hydrophobic part of the enzyme containing Trp-147 under diabetes seems to remain unaltered. This consideration is based on the longwave shift in aldolase fluorescence lambda max (from 320 to 324 nm) under this pathology, suggesting a transition of Trp-291 and -311 into more polar environment and is confirmed by the disappearance of the difference in lambda max in the NADH presence. The NADH-originated shift in lambda max position for the both proteins ended at the same wave-length at 314 nm. The position of lambda max at 324 nm resulting from possible structural modification of NAD-binding site under diabetes correlates with an increase in the Stern-Volmer quenching constant value (from 4359 to 7500 M-1 for aldolase under normal and diabetic states, respectively). These quenching data evidence in favour of the suggestion on the existence of two classes of tryptophanyls in the aldolase molecule.
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PMID:[Comparative study of the structural characteristics of aldolase in rabbit muscles in normal states and in alloxan diabetes]. 377 81

1. Enzymic evidence supporting the operation of the Entner-Doudoroff pathway in the anaerobic conversion of glucose into ethanol and carbon dioxide by Zymomonas mobilis is presented. 2. Cell extracts catalysed the formation of equimolar amounts of pyruvate and glyceraldehyde 3-phosphate from 6-phosphogluconate. Evidence that 3-deoxy-2-oxo-6-phosphogluconate is an intermediate in this conversion was obtained. 3. Cell extracts of the organism contained the following enzymes: glucose 6-phosphate dehydrogenase (active with NAD and NADP), ethanol dehydrogenase (active with NAD), glyceraldehyde 3-phosphate dehydrogenase (active with NAD), hexokinase, gluconokinase, glucose dehydrogenase and pyruvate decarboxylase. Extracts also catalysed the overall conversion of glycerate 3-phosphate into pyruvate in the presence of ADP. 4. Gluconate dehydrogenase, fructose 1,6-diphosphate aldolase and NAD-NADP transhydrogenase were not detected. 5. It is suggested that NAD is the physiological electron carrier in the balanced oxidation-reduction involved in ethanol formation.
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PMID:The route of ethanol formation in Zymomonas mobilis. 428 42

The enzyme activities involved in fructose metabolism were measured in samples of human liver. On the basis of U/g of wet-weight the following results were found: ketohexokinase, 1.23; aldolase (substrate, fructose-1-phosphate), 2.08; aldolase (substrate, fructose-1,6-diphosphate), 3.46; triokinase, 2.07; aldehyde dehydrogenase (substrate, D-glyceraldehyde), 1.04; D-glycerate kinase, 0.13; alcohol dehydrogenase (nicotinamide adenine dinucleotide [NAD]) substrate, D-glyceraldehyde), 3.1; alcohol dehydrogenase (nicotinamide adenine dinucleotide phosphate [NADP]) (substrate, D-glyceraldehyde), 3.6; and glycerol kinase, 0.62. Sorbitol dehydrogenases (25.0 U/g), hexosediphosphatase (4.06 U/g), hexokinase (0.23 U/g), and glucokinase (0.08 U/g) were also measured. Comparing these results with those of the rat liver it becomes clear that the activities of alcohol dehydrogenases (NAD and NADP) in rat liver are higher than those in human liver, and that the values of ketohexokinase, sorbitol dehydrogenases, and hexosediphosphatase in human liver are lower than those values found in rat liver. Human liver contains only traces of glycerate kinase. The rate of fructose uptake from the blood, as described by other investigators, can be based on the activity of ketohexokinase reported in the present paper. In human liver, ketohexokinase is present in a four-fold activity of glucokinase and hexokinase. This result may explain the well-known fact that fructose is metabolized faster than glucose.
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PMID:Enzymes of fructose metabolism in human liver. 438 49


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