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)

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

A 39-year-old female with several past psychiatric hospitalization for schizophrenia was admitted to our hospital because of severe pain and swelling of her legs. A few days before onset, she had often sat down upon her heels in water closet, agitated and talking to herself for many hours. Two days before the admission, she had suffered from severe pain and swelling of her bilateral calf-muscles, and her urine became brownish. On admission, neurological findings revealed delirious state, moderate rigidity of limbs, hyporeflexia of legs, marked swelling and severe spontaneous pain in bilateral legs. She was afebrile with body temperature of 36.4 degrees C. Laboratory data showed marked increase of levels of serum CK to 163,000 U/1, myoglobin to 9,860 ng/ml and aldolase to 42.8 IU/1, and the diagnosis of rhabdomyolysis was made. Although she fell into acute renal failure, the renal function recovered after repeated hemodialysis. Several days after admission, swelling and pain of calf-muscles began to improve, and serum CK, myoglobin and aldolase decreased rapidly. One month later, she was able to walk on her own legs. In the literature, rhabdomyolysis associated with immobile posture caused by schizophrenia is extremely rare, and this is the first case reported in Japan. The relationship between rhabdomyolysis and schizophrenia was discussed.
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PMID:[A case of rhabdomyolysis following long time immobile posture caused by schizophrenia]. 259 45

The intrinsic fluorescence of lauryl maltoside solubilized bovine heart cytochrome c oxidase has been determined to arise from tryptophan residues of the oxidase complex. The magnitude of the fluorescence is approximately 34% of that from n-acetyltryptophanamide (NATA). This level of fluorescence is consistent with an average heme to tryptophan distance of 30 A. The majority of the fluorescent tryptophan residues are in a hydrophobic environment as indicated by the fluorescence emission maximum at 328 nm and the differing effectiveness of the quenching agents: Cs+, I-, and acrylamide. Cesium was ineffective up to a concentration of 0.7 M, whereas quenching by the other surface quenching agent, iodide, was complex. Below 0.2 M, KI was ineffective whereas between 0.2 and 0.7 M 15% of the tryptophan fluorescence was found to be accessible to iodide. This pattern indicates that protein structural changes were induced by iodide and may be related to the chaotropic character of KI. Acrylamide was moderately effective as a quenching agent of the oxidase fluorescence with a Stern-Volmer constant of 2 M-1 compared with acrylamide quenching of NATA and the water-soluble enzyme aldolase having Stern-Volmer constants of 12 M-1 and 0.3 M-1, respectively. There was no effect of cytochrome c on the tryptophan emission intensity from cytochrome c oxidase under conditions where the two proteins form a tight, 1:1 complex, implying that the tryptophan residues near the cytochrome c binding site are already quenched by energy transfer to the homes of the oxidase. The lauryl maltoside concentration used to solubilize the enzyme did not affect the fluorescence of NATA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection, characterization, and quenching of the intrinsic fluorescence of bovine heart cytochrome c oxidase. 301 Oct 84

The uptake and degradation of radiolabelled rabbit muscle fructose-bisphosphate aldolase (EC 4.1.2.13) was studied in HeLa cells microinjected by the erythrocyte ghost fusion system. Labelled aldolase was progressively modified by treatment with GSSG or N-ethylmaleimide (NEM) before microinjection to determine whether these agents, which inactivate and destabilize the enzyme in vitro, affect the half-life of the enzyme in vivo. Increasing exposure of aldolase to GSSG or NEM before microinjection increased the extent of aldolase transfer into the HeLa cells and decreased the proportion of the protein that could be extracted from the cells after water lysis. Some degradation of the GSSG- and NEM-inactivated aldolases was observed in the ghosts before microinjection; thus a family of radiolabelled proteins was microinjected in these experiments. In spite of the above differences, the 40 kDa subunit of each aldolase form was degraded with a half-life of 30 h in the HeLa cells. In contrast, the progressively modified forms of aldolase were increasingly susceptible to proteolytic action in vitro by chymotrypsin or by cathepsin B and in ghosts. These studies indicate that the rate of aldolase degradation in cells is not determined by attack by cellular proteinases that recognize vulnerable protein substrates; the results are most easily explained by a random autophagic process involving the lysosomal system.
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PMID:Degradation of native and modified forms of fructose-bisphosphate aldolase microinjected into HeLa cells. 322 14

Diffusion of angiotensin II, albumin and aldolase was studied through collagen membranes with swelling ratios between 4 and 15. The diffusion coefficient was measured from the time-lag for the onset of steady-state flux through the membrane. Binding of macromolecules to collagen was evaluated from the results of sorption studies conducted as a function of macromolecular concentration. Results presented indicate that the diffusion of macromolecules through collagen membrane is slowed by electrostatic and hydrogen bonding between individual macromolecular chains and collagen. The extent of adsorption is increased as the molecular weight of the diffusant increases. Diffusion of water soluble macromolecules through collagen occurs rapidly, suggesting that diffusion occurs through water filled channels as opposed to between collagen molecules. The results of these studies are useful in understanding diffusion through connective tissues and in the design of drug delivery systems based on collagen.
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PMID:Diffusivity of 125I-labelled macromolecules through collagen: mechanism of diffusion and effect of adsorption. 358 Apr 69

The number of rat liver autophagic vacuoles (AVs) was increased by separate injection of three different inhibitors--vinblastine, leupeptin, and chloroquine--of lysosomal protein degradation. The different mechanisms of action of the agents correlated to the ultrastructure of the AVs. Accumulation of the base chloroquine with ensuing influx of water into AVs caused a significant swelling. The leupeptin-induced AVs were processed into residual-body-like structures within a few hours of exposure in line with the presence of a leupeptinase in liver tissue. Vinblastine was the most efficient agent in increasing the occurrence of AVs. The effect of vinblastine lasted for the entire study period (36 hr) with continuous formation of nascent AVs. In addition, vinblastine caused the appearance of a subpopulation of AVs laden with VLDL particles. The term crinosomes was suggested for these hybrid organelles, since they seemed to evolve by fusion between secretory granules and lysosomes. In addition to sequestered cell organelles, the AVs harbored cytosolic enzyme activities (LDH and aldolase). Leupeptin was the only agent that caused a decrease in cathepsin B and L activities. Similarly, leupeptin impeded protein breakdown in isolated AVs, whereas vinblastine and chloroquine evoked an increase. In vivo, chloroquine and vinblastine block protein degradation. The reason for this discrepancy is probably that during in vivo exposure the substrate (cytoplasmic proteins) is built up in the AVs because degradation is retarded. Upon isolation of the AVs the inhibitor block is released, and proteolysis proceeds at enhanced rates over control due to excess of substrates. Leupeptin, on the other hand, caused a substantial inhibition of thiol proteinases; this block remained in the isolated AVs. Accordingly, leupeptin-induced AVs displayed decreased protein degradation following shorter exposure times. Later, when leupeptin was metabolized, catch-up proteolysis was noted. The differing mechanisms of action of the inhibitors were also apparent as regards lipid contents and lipolysis. Whereas chloroquine and vinblastine increased the amounts of cholesterol and triglycerides parallel to proteins, leupeptin had no such effect. Lipolysis proceeded at normal rate following leupeptin administration, which was not the case after vinblastine and chloroquine exposure. Leupeptin has no effect on acid lipases; therefore lipids do not accumulate in AVs of hepatocytes that are exposed to leupeptin.
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PMID:Comparison of different autophagic vacuoles with regard to ultrastructure, enzymatic composition, and degradation capacity--formation of crinosomes. 367 66

The influence of fructose-1,6-bisphosphate aldolase, as a membrane peripheral protein, on some electrical and transport properties of spherical lipid membranes was investigated. It was found that the association of the enzyme with the membrane did not effect markedly the electrical conductance or capacity of the membrane but decreased the water filtration coefficient and the cationic transferance number. The enzyme association also modifies temperature characteristics of the membrane parameters.
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PMID:Modification of some properties of spherical lipid membranes induced by the association with fructose-1,6-bisphosphate aldolase. 394 98

The activities of individual enzymes of the isoprenoid pathway from mevalonate kinase to squalene synthetase in homogenates of seeds germinated up to 32h were assayed. Changes in the activity of each enzyme were observed and compared with the activity at the 2h germination stage. Activities of alkaline phosphatase and fructose 1,6-diphosphate aldolase were similarly measured to provide a reference for changes in the general metabolic activity of seeds during imbibition of water. Water uptake reached a plateau after 12h. The reference enzymes almost doubled in activity between 2 and 8h and thereafter their activities steadily declined. All of the enzymes of the isoprenoid pathway increased in activity between 2 and 6h and, thereafter, with the exception of the prenyltransferase, their activities remained relatively constant. With the prenyltransferase activity the initial increase was followed by a short plateau between 6 and 9h and then a second increase to a maximum between 14 and 16h. After 16h the activity declined. The relative activities of the isoprenoid enzymes at 16h of germination were mevalonate kinase>phosphomevalonate kinase>pyrophosphomevalonate decarboxylase approximately isopentenyl pyrophosphate isomerase>squalene synthetase>isopentenyl pyrophosphate/dimethylallyl pyrophosphate prenyltransferase. The finding that the prenyltransferase may be the rate-limiting enzyme in squalene synthesis from mevalonate is discussed in relation to regulation of isoprenoid synthesis during pea-seed germination.
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PMID:Development of the activities of enzymes of the isoprenoid pathway during early stages of pea-seed germination. 434 63

A new crystal form of rabbit muscle aldolase shows that the molecule has 222 symmetry to at least 4-angstrom resolution, and hence that the gross conformation of the four subunits is the same. Comparison of the new form with a previously reported form establishes the number of molecules per unit cell, n, in the older form. For an independent check, the "crystal-volume and protein-content method" was developed to determine n without directly measuring the water content of the crystals.
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PMID:Subunit structure of aldolase. 509 18

The subcutaneous administration of chloropeptide, a hepatotoxic cyclic pentapeptide of Penicillium islandicum Sopp, induced a marked enlargement of hepatic weight in mice. Chemical analysis revealed an increment of water content. Biochemical investigation resulted in marked elevation of serum enzyme activities such as transaminases, alcohol dehydrogenase, fructose-1-phosphate aldolase and lactate dehydrogenase.
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PMID:Effects of chloropeptide on liver components and serum enzyme activities in mice. 616 65


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