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

---

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

Fructose-1,6-bisphosphate aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate lyase, EC 4.1.2.13) partitions between the microsomes and the cytosol when a rat liver homogenate is fractionated by differential centrifugation. Gel electrophoresis and immunodiffusion indicate that the one isozyme present in the liver of the young adult rat is found in both fractions. The association of the aldolase with membranes is differentially sensitive to a variety of metabolites and inorganic salts. In the absence of cellular salts, 1 mM fructose 1,6-bisphosphate or glucose 1,6-bisphosphate elutes 50% of the enzyme from the microsomes. About 9 mM Pi or citrate is necessary to produce the same effect. With other metabolites or inorganic salts higher concentrations are required. The fraction of total enzyme which partitions with the microsomes when a homogenate is submitted to high speed centrifugation, correlates inversely with the level of fructose 1,6-bisphosphate in the supernatant solution and this concentration is higher when the tissue concentration in the homogenate is greater. The Km for fructose 1,6-bisphosphate of 3 . 10(-4) for aldolase bound to microsomes is decreased to 6 . 10(-6) M when the enzyme is dissociated from the membranes with salt. These observations appear relevant to the ongoing discussion regarding the physiological relevance of the subcellular localization of glycolytic enzymes.
...
PMID:Reversible microsomal binding of hepatic aldolase. 679 27

Escherichia coli grown on gluconeogenic compounds as carbon sources produced two chemically and physically distinct types of fructose-1,6-biphosphate aldolases (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphatelyase, EC 4.1.2.13), while these bacteria produced only a single enzyme when grown on glucose or fructose. We have investigated this enzyme in several strains of Escherichia coli (Crookes, K-12, and B) grown on glucose, fructose lactate, pyruvate, alanine and glycerol by comparing chemical properties and mechanisms of action. Comparison of these mechanisms was accomplished by following the fate of 18O in the keto position of fructose 1,6-bisphosphate during the aldolase catalyzed cleavage reaction. The results show that the two enzymes have different mechanisms of action and are consistent with a Schiff-base mechanism for the one which was induced by gluconeogenic substrates and metal-chelate mechanism for the constitutive enzyme.
...
PMID:Comparison of the mechanisms of two distinct aldolases from Escherichia coli grown on gluconeogenic substrates. 699 35

Activities of 14 enzymes were determined in psoas muscle, smooth muscle, diaphragm, heart, brain, liver, kidney, spleen, pancreas, salivary glands, zygomatic gland, intestinal mucosa, subcellular fractions, and plasma of the dog. In pups, plasma activity of most enzymes was high, except iditol dehydrogenase (ID), glutamate dehydrogenase (GLD), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and D-fructose-1,6-diphosphate aldolase (ALS). Alkaline phosphatase (ALP), ALS, cholinesterase (CHS), creatine kinase (CK), alpha-hydroxybutyrate dehydrogenase (HBD), lactate dehydrogenase (LD), and malate dehydrogenase (MD) decreased significantly (P less than 0.01) with increasing age, but in dogs greater than 7 months, all enzymes except CK, HBD, and ALT revealed reasonably constant plasma values. Enzymes ALT, GLD, CHS, and ID are specific for liver, CK and ALS for muscle, HBD to some degree for myocardium, and alpha-amylase for pancreas. The ALP and gamma-glutamyltransferase were located in microsomes, GLD in mitochondria, MD and AST in mitochondria and cytoplasm, and isocitric dehydrogenase, LD, and the other enzymes only in cytoplasm.
...
PMID:Enzyme activities in the dog: tissue analyses, plasma values, and intracellular distribution. 703 2

The effect of daily intraperitoneal administration of Mn2+(4 mg/kg) was investigated on the metabolism of carbohydrates and certain enzymes involved in the oxidation of glucose in the rat liver and blood at the intervals of 30, 60 and 90 days after exposure. Mn2+ had no effect on the contents of blood reducing sugars and proteins, however the levels of pyruvic and lactic acids were reduced at 60 and 90 days after the metal treatment. The contents of liver glycogen and proteins remained unaffected while pyruvic acid content was decreased in Mn2+ treated rat liver throughout the experimental period. The activities of glycogen phosphorylase and lactate dehydrogenase decreased while that of phosphoglucoisomerase and glucose-6-phosphatase increased in the post mitochondrial supernatant at 60 and 90 days of Mn2+ exposure. The levels of hexokinase decreased and FDP-aldolase and fructose-1, 6-diphosphatase increased throughout the experimental period. The magnitude of alteration was found to be greater with the increase in the duration of Mn2+ treatment. Several of the mitochondrial enzymes in the liver were inhibited in the manganese exposed rats which may be responsible to inhibit the rate of dehydrogenation of Kreb cycle's intermediates along with the linked respiratory chain and eventually oxidation in the rat liver.
...
PMID:Effects of manganese on carbohydrate metabolism and mitochondrial enzymes in rats. 713 26

Microfilariae of bovine filarial parasite Setaria cervi are equipped with the enzymes of glycolysis, pentose phosphate and PEP-succinate pathways and thus resemble the adult form in its metabolic pattern. Malate dehydrogenase was the most active enzyme in microfilariae followed by lactic dehydrogenase and fumarase, while phosphoglucoisomerase, PEP-carboxykinase and FDP-aldolase were comparatively less active. The very low ratio of PK/PEPCK in S. cervi microfilariae indicates active fixation of CO2 into PEP to produce oxalacetate. Centperazine and diethylcarbamazine significantly inhibited PEP-carboxykinase, fumarate reductase and succinic dehydrogenase, suggesting that these antifilarials probably exert microfilaricidal action by blocking the PEP-succinate pathway.
...
PMID:Setaria cervi: enzymes in microfilariae and in vitro action of antifilarials. 715 43

The toxic effects of i.p. administered n-hexane and n-heptane on biochemical processes in rat liver, as indicated by the increase in alkaline phosphatase activity and decrease in FDP aldolase activity, and their reflection on blood chemistry, were studied. Serum cholinesterase activity and albumin and cholesterol content showed statistically significant decreases with the increase in FDP aldolase activity. The significance of the findings is discussed.
...
PMID:Toxicity of n-hexane and n-heptane: some biochemical changes in liver and serum. 716 75

Fructose 1,6-bisphosphate aldolase [EC 4.1.2.13] in rat liver was found to be bound to the intracellular membraneous structures such as microsomes and nuclear membranes when the animals were fasted for 48 hr or administered tryptophan. Upon refeeding the rats the aldolase was released into the cytosol. The membrane-bound aldolase was almost inactive, showing about 50-fold larger Km and a smaller Vmax (37%) as compared with those of the free enzyme. The enzyme was released cooperatively from the membrane by exposure to fructose 1,6-bisphosphate, glyceraldehyde 3-phosphate or dihydroxyacetone phosphate at low concentrations. Apparent desorption constants (Kd, concentrations necessary for 50% desorption of enzyme) for fructose 1,6-bisphosphate of the enzymes bound to microsomes, mitochondria and nuclei were estimated to be 8 X 10(-5), 6.1 X 10(-6), and 4.8 X 10(-6)M, respectively, at pH 7.3. With the microsome-bound enzyme Kd values of 3.9 X 10(-4), 4.1 X 10(-4), 2.7 X 10(-3), 1.1 X 10(-2) and 2.0 X 10(-2) M were obtained for glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, fructose 1-phosphate, fumarate, and KCl, respectively. Strong cooperativities were observed in the enzyme desorption by the substances which showed large Kd values.
...
PMID:Membrane-bound fructose 1,6-bisphosphate aldolase: catalytic activity and mechanisms of desorption. 738 24

A stable overexpression E. coli strain containing the plasmid pKEN 2 for the production of the Zn(2+)-dependent FDP aldolase from E. coli has been developed. Approximately 14,000 U of the enzyme (specific activity = 23.3 U/mg) can be obtained from 4-L of growth medium. The enzyme was isolated, purified to homogeneity and used for the studies of stability, substrate specificity and metal ion replacement and dissociation. Crystals of the enzyme have been obtained for structural analysis. This E. coli strain was deposited with the American Type Culture Collection (ATCC #77472).
...
PMID:Cloning, overexpression and isolation of the type II FDP aldolase from E. coli for specificity study and synthetic application. 789 77

We studied the alteration of aldolase isozymes in the serum and tissues of patients with cancer and other diseases using radioimmunoassays specific for aldolase A, B, and C subunits. Aldolase B was predominantly found in adult liver, where aldolase A and C were distinctly low. Aldolase A and B showed almost the same concentration in fetal liver, while in neonatal liver aldolase B protein concentrations were much higher than aldolase A. In contrast, aldolase A was the predominant isozyme found in hepatoma and gastric cancer tissues, whereas aldolase B was distinctly low in hepatoma tissues, and extremely low in gastric cancer tissues. These results suggest that the aldolase A is a more fetal type of liver isozyme than the aldolase B and C, and aldolase B is a more differentiated type of liver isozyme than aldolase A and C. Serum FDP aldolase activities were elevated in half of patients with liver diseases, all patients with muscle diseases and a few patients with cancer. Serum aldolase A levels were elevated in patients with muscle diseases and cancer, but not elevated in patients with liver diseases. In contrast, serum aldolase B levels were elevated in patients with liver disease, but not elevated in patients with muscle diseases and other diseases without liver injury. Serum aldolase B levels showed a trend to decrease in cancer patients with normal GPT levels. Serum aldolase A/B ratios were significantly increased in cancer patients with normal GPT levels, whereas they showed the decreased levels in patients with liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Alteration of aldolase isozymes in serum and tissues of patients with cancer and other diseases. 804 42

Fructose 1,6-bisphosphate aldolase catalyzes the reversible cleavage of fructose 1,6-bisphosphate and fructose 1-phosphate to dihydroxyacetone phosphate and either glyceraldehyde 3-phosphate or glyceraldehyde, respectively. Catalysis involves the formation of a Schiff's base intermediate formed at the epsilon-amino group of Lys229. The existing apo-enzyme structure was refined using the crystallographic free-R-factor and maximum likelihood methods that have been shown to give improved structural results that are less subject to model bias. Crystals were also soaked with the natural substrate (fructose 1,6-bisphosphate), and the crystal structure of this complex has been determined to 2.8 A. The apo structure differs from the previous Brookhaven-deposited structure (1ald) in the flexible C-terminal region. This is also the region where the native and complex structures exhibit differences. The conformational changes between native and complex structure are not large, but the observed complex does not involve the full formation of the Schiff's base intermediate, and suggests a preliminary hydrogen-bonded Michaelis complex before the formation of the covalent complex.
...
PMID:Crystal structure of human muscle aldolase complexed with fructose 1,6-bisphosphate: mechanistic implications. 1004 22


<< Previous 1 2 3 4 5 6 Next >>

---