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 possibility of interaction between purified rabbit muscle aldolase and D-glyceraldehyde-3-phosphate dehydrogenase was studied by rapid kinetic methods, by analyzing the kinetics of the consecutive reaction catalyzed by the coupled enzyme system. The Km of the intermediary product, glyceraldehyde 3-phosphate, produced by aldolase was determined in the coupled reaction for glyceraldehyde-3-phosphate dehydrogenase. Its value corresponds to that of the aldehyde (active) form of glyceraldehyde 3-phosphate, although in the given conditions the aldehyde leads to diol interconversion is faster than the enzymic reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase. We suggest that above a certain concentration of the enzymes the glyceraldehyde 3-phosphate produced by aldolase gets direct access to glyceraldehyde-3-phosphate dehydrogenase without participating in the aldehyde leads to diol interconversion which otherwise would occur if the substrate were to mix with the bulk medium.
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PMID:Kinetic evidence for interaction between aldolase and D-glyceraldehyde-3-phosphate dehydrogenase. 20 15

In 38 patients with chronic renal insufficiency of different degree of severity examinations of the stationary concentration of the adenine nucleotides in the erythrocytes were carried out. It was shown that in the red blood cells of uraemics a genuine increase of the concentration of these compounds occurs, in which case the adenosine triphosphate dominates absolutely as well as relatively. In individual cases erytho-cyctic ATP-values of more than 3 micron mol pro ml cells may be achieved. The increase of the ATP-concentration in the red blood cells correlates with the degree of severity of the renal insufficiency and the renal anaemia. The hyperphosphataemia occurring as a rule in renal insuficiency is of causal importance for the increase of ATP. By a consecutive increase of the intracellular phosphate level and by influence on different steps of enzymes (phosphofructokinase, aldolase, glycerin aldehyde phosphate dehydrogenase) and changed regulations it effected an activation of the glycolysis. The increase of the plasma adenine and plasma adenosine concentration plays apparantly an accessory role for the increase of the concentration of the adenine nucleotides existing in the erythrocytes. Together with an increased concentration of 2,3-diphosphogycerate (2,3-DPG) the increase of the ATP-level has an effect on the oxygen transport function function of haemoglobin in the sense of a facilitation of the O2-output. These processes explain the relative adaption of patients with chronic renal insufficiency to renal anaemias of partly high degree.
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PMID:[Adenine nucleotide- and 2,3-diphosphoglycerate metabolism in human erythrocytes in chronic kidney insufficiency]. 84 44

In Pseudomonas saccharophila 2-keto-3-deoxygalactonate-6-P aldolase (EC 4.1.2.21) is induced by growth on galatose while 2-keto-3-deoxygluconate-6-P aldolase (EC 4.1.2.14) is constitutive. These enzymes catalyze identical reactions except for the configuration fixed at C-4 during the condensation reaction. It was found with each enzyme that in a condensation between [3-3H3]pyruvate and D-glyceraldehyde-3-P, the respective condensation products were formed 8 to 10 times faster than tritium was released to water. Since pyruvate deprotonation is obligatory for condensation, the above result requires a hydrogen isotope effect in enolpyruvate formation, which must be then at least partially rate limiting for C--C synthesis. Further, condensation between D-glyceraldehyde-3-P and (3R)-[3-3H, 2H,H]pyruvate or (3S)-[3-3H, 2H,H]pyruvate, as catalyzed by each enzyme, enriched for (3R)- and (3S)-3-3H, 2H-labeled condensation product, respectively. Thus, each enzyme catalyzes C--C and C--H synthesis with retention of configuration at C-3. This shows that the active sites of both enzymes are asymmetric since solutes can only approach a single face of the bound pyruvyl enolate. In addition, the respective aldehyde specific portions of the two active sites must have opposite chiralities, with respect to each other, for correctly orienting the carbonyl faces of the incoming D-glyceraldehyde-3-P, to generate the correct configuration at C-4 of the respective condensation products.
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PMID:The sterochemistry at carbon 3 of pyruvate lyase condensation products. 2-Keto-3-deoxygluconate 6-phosphate and 2-keto-3-deoxygalactonate-6-phosphate aldolase of Pseudomonas saccharophila. 115 86

Pig muscle aldolase was covalently attached to a silica-based support possessing aldehyde functional groups. The activity of the immobilized enzyme was 37 U/g solid, and the specific activity calculated on a bound protein basis was 1.9 U/mg protein. The optimum pH for the catalytic activity was pH 7.5. The apparent optimum temperature was found to be 45 degrees C. The Km app value of the immobilized aldolase with D-fructose 1,6-diphosphate as substrate was 1.25 X 10(-4) M. The conformational stability was improved by the immobilization. The immobilized aldolase was used for the continuous splitting of D-fructose 1,6-diphosphate.
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PMID:Immobilization of pig muscle aldolase on a silica-based support. 255 62

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

Chemical analysis of enzyme reaction intermediates has been used to compare the liver and muscle isozymes of rabbit aldolase at equilibrium and in their steady states to determine if they have properties that favor the direction of flow of glycolytic intermediates in their tissues of origin. For both enzymes at saturating concentrations of fructose 1,6-P2, the sum of intermediates in the steady state agreed with the total active enzyme calculated to be present. The two half-reactions, characterized by fructose 1,6-bisphosphate(Fru-P2):aldehyde exchange and DHAP:proton exchange were found to be of different importance in determining the rate of reaction with Fru-P2 with the liver enzyme being much more limited in the processing of DHAP. The chemical interconversions within each half-reaction are generally rapid compared with the release of products. The greater sensitivity of liver aldolase to inhibition by aldehydes in Fru-P2 cleavage seems to be a normal consequence of the higher level of the eneamine of DHAP in the forward steady state with the liver enzyme and probably should not be ascribed to a greater intrinsic affinity. An earlier report (Grazi, E., and Trombetta, G. (1979) Eur. J. Biochem. 100, 197-202) purporting to show a special interaction of glyceraldehyde-3-P with liver enzyme prior to proton abstraction from DHAP could not be reproduced. Examples are presented from the data that validate the use of the analytical methods used for analysis of intermediates in the case of the Schiff's base aldolases.
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PMID:Concentration and partitioning of intermediates in the fructose bisphosphate aldolase reaction. Comparison of the muscle and liver enzymes. 380 4

Dihydroxyacetone phosphate (DHAP) in equilibrium with FDP aldolase of muscle is present in the form of two major covalent complexes. One, representing approximately 60% of total bound substrate, decomposes to Pi and methylglyoxal upon acid denaturation of the enzyme as first reported by Grazi and Trombetta [Grazi, E., & Trombetta, G. (1979) Biochem. J. 175, 361-365]. This is now shown to be the enzyme-eneamine phosphate reaction intermediate since Pi formation is prevented if the acid denaturation is done in the presence of potassium ferricyanide, an oxidant of the eneamine. The enzyme-eneamine aldehyde X Pi 6, presumed to be an intermediate of the slow methylglyoxal synthetase reaction of aldolase, must not be a significant source of the Pi produced upon denaturation and is probably not a significant component of the equilibrium. The oxidation product, the enzyme-imine of phosphopyruvaldehyde, is sufficiently stable in 1 N HCl, t1/2 = 76 min at 0 degree C, to be isolated with the trichloroacetic acid precipitated protein. A second covalent complex, approximately 20-24% of bound dihydroxyacetone [32P]phosphate, remains with the protein during acid denaturation and centrifugation. This acid-stable complex is formed rapidly and is chased rapidly by unlabeled substrate. Its stability in 1 N HCl is similar to that of the ferricyanide-oxidized derivative mentioned above. From this and its reactivity with cyanoborohydride in acid, this complex is thought to be the imine adduct of DHAP with aldolase 4 and/or the carbinolamine complex 3 present in the initial equilibrium. D-Glyceraldehyde 3-phosphate in the carbonyl form also forms an acid-precipitable complex with aldolase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Chemical trapping of complexes of dihydroxyacetone phosphate with muscle fructose-1,6-bisphosphate aldolase. 405 77

Pyridoxal phosphate can act as a specific photosensitizer for amino acid residues in rabbit muscle and spinach leaf aldolases, but the residues affected depend on the pH of the reaction. Below pH 8 one histidine residue per enzyme subunit is destroyed; above pH 8.5 there is little loss of histidine, and photoinactivation is associated with the destruction of specific tyrosine residues, particularly the COOH-terminal residues. Pyridoxal and 4-pyridinecarboxaldehyde are much less effective than pyridoxal phosphate at neutral pH, but are similar to pyridoxal phosphate in their photosensitizing activity at the higher pH. Compounds lacking the aldehyde group or the pyridine ring show little or no activity. A number of other enzymes, including alpha-glycerophosphate dehydrogenase, glucose-6-phosphate dehydrogenase, and yeast hexokinase, were also photoinactivated in the presence of pyridoxal phosphate; however, rabbit liver aldolase and two isomerases tested were completely resistant. The results suggest that certain enzymes, including rabbit muscle and spinach aldolases, but not rabbit liver aldolase, contain a specific site which interacts with pyridoxal phosphate, and that the conformation of this site changes in the pH range between 8.0 and 8.5
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PMID:Photoinactivation of aldolases by pyridoxal phosphate and its analogues. 527 95

The equivalence of the four dihydroxyacetone phosphate binding sites of aldolase was abolished by lowering the temperature. At pH 6.2 and -13 degrees C, four binding sites were detected by gel filtration; two sites with a Kdiss less than or equal to 0.1 microM, and a second set of sites with a Kdiss = 4 microM. The alteration of the binding was accompanied by the alteration of the catalytic activity. The low-affinity sites were incapable of catalyzing the cleavage of the (3S) C-H bond of dihydroxyacetone phosphate, and form only the ketimine phosphate intermediate. The high-affinity sites were still able to cleave the (3S) C-H bond of dihydroxyacetone phosphate; however, the eneamine phosphate intermediate formed was almost fully converted into the eneamine-aldehyde . . . phosphate intermediate, which was the prevailing species at the equilibrium. The mechanism of the half-of-the sites reactivity of aldolase at low temperature has been explained and the nonequivalence of sites in promoting catalysis has been utilized to dissect and characterize the individual partial reactions of the enzyme. In the course of these studies it has been shown that the rate of hydration-dehydration of dihydroxyacetone phosphate at -24 degrees C was too slow to measure.
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PMID:Fructose-1,6-bisphosphate aldolase from rabbit muscle: different catalytic behavior of the dihydroxyacetone phosphate binding sites at low temperature. 648 3

Hemoglobin A1 (HbA1) levels were significantly higher in healthy alcohol drinkers (HbA1 = 7.50%, n = 11) than in normal non-drinkers (HbA1 = 6.62%, n = 13). Ethanol was not able to change HbA1 level when ethanol was added to human whole blood in vitro. Acetaldehyde (AcCHO), although, markedly increased it. Glucose utilization in erythrocytes was stimulated by AcCHO. While it was completely blocked by sodium fluoride in the presence of AcCHO in the incubation medium, but sodium fluoride did not affect the formation of HbA1. AcCHO formed HbA1 with human purified hemoglobin in vitro. The level of HbA1 formed by AcCHO was significantly low when purified human hemoglobin used as a substrate in comparison with the use of whole blood. AcCHO and dihydroxyacetone phosphate reacted in the presence of aldolase. The reacted product, 5-deoxy-D-xylulose-1-phosphate, increased HhA1 level of human purified hemoglobin. It is suggested, the high level of HbA1 in healthy drinkers was caused by AcCHO, the first metabolite of ethanol. AcCHO formed addicts with human hemoglobin directly, and there might be other mechanisms of HbA1 formation due to AcCHO, such as 5-deoxy-D-xylulose-1-phosphate, which is the reacted product of AcCHO.
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PMID:[Mechanisms of high hemoglobin A1 in alcohol drinkers]. 651 Aug 86


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