Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ALDOLASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

Magnetic resonance imaging and serum aldolase concentration in eosinophilic fasciitis.

We report a 26-year-old man with eosinophilic fasciitis who presented with progressive joint contractures of all four limbs. In this patient, the serum aldolase concentration was elevated while the serum creatinine kinase concentration was normal. Magnetic resonance imaging showed gadolinium enhancement of fascial structures in the lower limbs. With the clinical improvement by the treatment with oral corticosteroid, the aldolase concentration was decreased, and the fascial hyperintensity on magnetic resonance images was reduced. The phenomenon of increased an aldolase concentration accompanied by a normal creatinine kinase concentration may be characteristic of eosinophilic fasciitis. Serial magnetic resonance images and serum aldolase concentration are useful for monitoring the therapeutic response in this condition.

Adrenal Cortex Hormones↗

Autoantibody to aldolase in acute and chronic hepatitis.

Sera from 82 patients with acute or chronic hepatitis and 40 chronic carriers of hepatitis B were examined by ELISA and immunoblotting for reactivity with the glycolytic enzyme aldolase. The results of the ELISA tests, expressed as a percentage of a positive control, were compared to those obtained with sera from 39 patients with rubella, 11 with cytomegalovirus infection and 74 healthy subjects. The ELISA reaction with sera, expressed as mean +/- standard deviation was, for 15 patients with hepatitis A, 58.3 +/- 20.5%; 15 with hepatitis B, 59.5 +/- 42.18; 23 with hepatitis non-A, non-B 51.1 +/- 34.4%; 11 with HBsAg positive chronic active hepatitis, 70.1 +/- 31.5%; and 17 with autoimmune chronic active hepatitis, 66.8 +/- 21.4%. All values were significantly (p less than 0.05-p - less than 0.001) higher than those obtained with sera from carriers of hepatitis B surface antigen, 25.6 +/- 27.2%; rubella, 21.1 +/- 20.0%; cytomegalovirus infection, 19.2 +/- 27.8%; or healthy subjects, 20.9 +/- 16.2%. In two randomly selected sera, reactivity with aldolase by ELISA was neutralized by absorption with the enzyme. Selected sera showing reactivity by ELISA reacted by immunoblotting with aldolase. The findings suggest that acute or chronic liver damage may provoke the production of autoantibodies to aldolase.

Acute Disease↗

Functional and molecular modelling studies of two hereditary fructose intolerance-causing mutations at arginine 303 in human liver aldolase.

We have identified a novel hereditary fructose intolerance mutation in the aldolase B gene (i.e. liver aldolase) that causes an arginine-to-glutamine substitution at residue 303 (Arg(303)-->Gln). We previously described another mutation (Arg(303)-->Trp) at the same residue. We have expressed the wild-type protein and the two mutated proteins and characterized their kinetic properties. The catalytic efficiency of protein Gln(303) is approx. 1/100 that of the wild-type for substrates fructose 1,6-bisphosphate and fructose 1-phosphate. The Trp(303) enzyme has a catalytic efficiency approx. 1/4800 that of the wild-type for fructose 1,6-bisphosphate; no activity was detected with fructose 1-phosphate. The mutation Arg(303)-->Trp thus substitution impairs enzyme activity more than Arg(303)-->Gln. Three-dimensional models of wild-type, Trp(303) and Gln(303) aldolase B generated by homology-modelling techniques suggest that, because of its larger size, tryptophan exerts a greater deranging effect than glutamine on the enzyme's three-dimensional structure. Our results show that the Arg(303)-->Gln substitution is a novel mutation causing hereditary fructose intolerance and provide a functional demonstration that Arg(303), a conserved residue in all vertebrate aldolases, has a dominant role in substrate binding during enzyme catalysis.

Amino Acid Substitution↗

[Studies on the activity of aldolase from rabbit muscles in the presence of liposomes].

Electronmicroscopic studies have been made on the structure of liposomes obtained by the method of Bangham [13] with subsequent ultrasonic desintegration. The effect of muscle aldolase on the structure of liposomes was also investigated. Parallel studies were made on the effect of storage of liposomes upon the activity of aldolase. It was shown that liposomes obtained from chromatographically pure egg lecithin present discrete partially aggregated bodies, 1.000-3.000 A in size, composed by concentric layers, which have a dimension of approximately 40 A and periodicity of about 70 A. Interaction of these particles with the protein results into their desintegration and enlargement, this process being accompanied by the formation of a "fringe" at the edge of the particles. Aldolase activity in these systems in higher than in control. During storage of phosphatide-aqueous system, obtained by the metod of Bungenberg de Jong, activation of aldolase is gradually replaced by its inactivation.

Animals↗

[Comparative studies of the properties of aldolase isoenzymes A-C in normal rabbit brain and in skeletal muscles from rabbits with E-avitaminosis dystrophy].

By means of fructose-1,6-diphosphate selective elution of aldolase isoenzymic forms from the phosphocellulose column the izoenzyme AC3 was isolated preparatively from the muscles rabbits with experimental E-avitaminosis muscular dystrophy. The specific activity of aldolase A4 and AC3 with pathology differs from that at normal state by fructose-1,6-diphosphate and fructose-1-monophosphate. As to the electrophoretic activity the isoenzymes A4 and AC3 are similar to the same isoforms at normal state. The values of the Michaelis constants and maximal rate are determined for aldolases A4, AC3 and C4 at normal state and for A4 and AC3 with E-avitaminosis. Differences in these parameters are found relative to two substrates for A4 aldolase and AC3-hybrid at normal state and with dystrophy.

Animals↗

[Study of purified aldolase from Saccharomyces cerevisiae, using irradiated fructose-1,6-diphosphate].

The interaction of an electromagnetic field with the enzymatic substrate-- the sodium salt of fructose-1,6-disphosphate--induces in the latter a new type of physical transition S leads to S. The enzyme, in this case Saccharomyces cerevisiae aldolase, is able to reveal this new state of the substrate by an increase in its specific activity within well established irradiation times. Each enzyme is characterized by the tm (minimal irradiation time of the substrate) a tau (fixed time period) parameters that delimit the two signals. Purified S. cerevisiae aldolase has tm=5 sec. and tau=20 sec., in contrast to muscle aldolase (represented by class I aldolase) which has tm=15 sec. and tau=30 sec. This may be attributed to the fact that most of the enzymatic systems in S. cerevisiae are made up of several distinct molecular forms, involved in more metabolic pathways than in the animal tissue, therefore with various responses to the phenomenon of perturbation of the substrates.

Culture Media↗

[Identification of recombinant aldolase of Plasmodium falciparum and its monoclonal antibody preparation].

OBJECTIVE: To identify the recombinant aldolase (ALD) of Plasmodium falciparum, and to develop monoclonal antibodies (McAbs) against the recombinant ALD. METHODS: ALD gene was amplified by PCR from genomic DNA of FCC1/HN strain, and expressed in E. coli DH5 alpha. BALB/c mice were immunized with the recombinant ALD of P. falciparum via celiac injection for 3 times with 2 weeks interval. Three days after a booster injection, spleen cells of the immunized mice were used for producing McAbs. The immune serum was tested by IFAT and Western blotting. RESULTS: BALB/c mice immunized with purified aldolase protein developed strong immune response to the antigen, and the titer of specific antibody reached 1:10(5) in all immune sera after the third immunization. Moreover, immune sera specifically recognized the cultured P. falciparum. Western blotting showed that the immune sera recognized specifically a Mr 41000 band of crude malaria antigen. No cross-reaction with human red cells was detected. Seven positive hybridoma cell lines were obtained after 3 rows of selection. All the McAbs' subclasses belong to IgG1. IFAT showed that only 4 McAbs could recognize the cultured P. falciparum. CONCLUSION: Plasmodial aldolase has been successfully expressed and purified, and the established hybridoma cell lines can secrete McAbs specific to the aldolase of P. falciparum.

Animals↗

Long-range effects and conformational flexibility of aldolase.

The conformational flexibility and long-range interactions in rabbit muscle aldolase induced by active-site ligand binding, cross-linking of the enzyme between Cys72 and Cys338, and removal of the C-terminal tyrosine residue were studied by following the changes in the microenvironments of Cys239 and Cys289 located outside the active site. It was found that substrates induced a conformational change in aldolase, which propagates from the active site to Cys239, which is located close to intersubunit contacts. The response of the enzyme is differential. Ligands having both C-1 and C-6 phosphates or C-1 phosphate only induce the enhancement of Cys239 reactivity, whereas those with C-6 phosphates only decrease Cys239 reactivity. This correlates well with a dramatic difference in kinetic parameters for a cleavage of fructose-1,6-P2 and fructose-1-P. Therefore, these changes can be interpreted as syncatalytic. Cross-linking of the aldolase subunit by an -S-S-bridge between Cys72 and Cys338 inactivates the enzyme, abolishes binding of active-site ligands, and induces a conformational change in the enzyme that can be detected far away (at Cys239 and Cys289) from the site of perturbation. Cys72 and Cys338 are not in the active site. This shows that the region of the active site and the environment of Cys72 and Cys338 are tightly coupled and that residues far away from the active site, through such coupling, can possess properties of active-site residues. Similar, although less dramatic changes are observed upon removal of the C-terminal tyrosine residue. In view of the results obtained in this paper, aldolase seems to be quite a flexible molecule, whose conformation is sensitive to the nature of a substrate bound to the enzyme and is able to transmit the information about a local perturbation over long distances within a molecule.

Animals↗

Carboxyl terminus region modulates catalytic activity of recombinant maize aldolase.

Site-directed mutagenesis was utilized to study the functional role of the COOH-terminal region in recombinant maize aldolase. A single mutation was created in each of the last nine amino acids of the COOH terminus and characterized kinetically. Point mutations in the COOH-terminal region were found to influence both the rate of fructose 1,6-bisphosphate and fructose 1-phosphate cleavage. Catalytic efficiency, kcat/Km, was not affected by the mutations within experimental error consistent with this region of the COOH terminus modulating product release. Concentrations of the carbanion-enamine enzyme intermediate complex produced upon substrate cleavage increased with the severity of the point mutation. A condensation assay was developed to directly measure fructose 1,6-bisphosphate synthesized by aldolases in the presence of high triose phosphate concentrations. The maximal rate of aldol condensation of triose phosphates, D-glyceralehyde-3-P and dihydroxyacetone-P, was affected by the point mutations to the same extent as the maximal rate of substrate cleavage. Interpretation of the data is consistent with point mutations in the COOH terminus predominantly affecting the proton exchange with the dihydroxyacetone-P enzymatic complex at the carbanion-enamine step and that this step is probably rate-limiting in the catalytic mechanism of recombinant maize aldolase. The role of the COOH-terminal region in aldolases is thus consistent with a sequence dependent modulation of catalytic activity.

Amino Acid Sequence↗

Site-specific modification or rabbit muscle aldolase with fluorescent probes.

The site-specific modification of rabbit muscle aldolase A by labeling of thiol residues of Cys-289 with 5-(2-((iodoacetyl)amino)ethyl)amino)naphthalene-1-sulfonic acid and Cys-239 with 5-iodoacetamidofluorescein or 4-dimethylamino-phenylazophenyl-4'-maleimide has been described. The method is based on the differences in kinetics of the chemical modification of aldolase thiols with the above reagents either in the presence or in the absence of a competitive inhibitor. The spectral properties of the doubly labeled aldolase derivatives were compared with those of the singly labeled enzyme. The doubly labeled aldolase derivatives exhibited full catalytic activity.

Animals↗

Structure of chicken aldolase C mRNA and its expression in the liver and brain during development.

Chicken aldolase B (liver-type) and C (brain-type) cDNAs were isolated and their nucleotide sequences determined. Southern blot analysis of chicken genomic DNA using the fragments of aldolase C cDNA suggested that the aldolase C gene is a single-copy gene. The quantification by Northern blot analysis of aldolase B and C mRNAs in the chicken liver and brain during development showed that in the liver, the B gene was progressively activated, while C gene expression was extinguished reciprocally. In the brain, the B gene was silent throughout the development, while the C gene was activated progressively, reaching a product level of more than 20-fold that of the 7-day-old embryo.

Amino Acid Sequence↗

Effect of patulin on the kinetic properties of the enzyme aldolase studied in rat liver.

The toxic nature of the secondary metabolite has been studied in rats. Changes in the concentration of a few key enzymes in carbohydrate metabolism have also been studied. In this, liver aldolase concentration was found to be significantly lowered. Since aldolase is one of the important bifunctional enzymes of glycolysis, it has been isolated and purified and studied on its kinetic properties were made. The kinetic studies did not show any significant variations in the properties of liver aldolase of normal and patulin treated animals. These results suggest that most probably, patulin toxicosis inhibits the biosynthesis of liver aldolase.

Adenosine Diphosphate↗

[Characteristics of mRNA and cDNA of fructose-1,6-diphosphate aldolase].

Problems concerning synthesis of fructose-1,6-diphosphataldolase A (EC 4.1.2.13) in vitro, and localization in a cell and sizes of mRNA of this enzyme are considered in the review. The following items are described: methods for production and properties of individual mRNA and cDNA of the aldolase isoenzymes; making of the amino acid sequence of the aldolase isoenzyme forms according to the nucleotide sequence of mRNA and cDNA and peculiarities of isoform structure in different tissues of animals; structure of mRNA and cDNA of FDP-aldolase in the norm and under pathology and mechanisms of the appearance of nonspecific enzyme isoforms. Regulation of protein biosynthesis under pathology is considered as exemplified by mRNA and cDNA of FDP-aldolase.

Animals↗

[Effect of gamma radiation on fructose-1,6-diphosphate aldolase activity in the erythrocytes of healthy persons after submaximal physical exertion].

The authors studied the effects of gamma radiation and submaximal physical exercise on aldolase activity in healthy men erythrocytes. Twelve men aged 20-22 were examined. They underwent physical exercise at doses of 2 W/kg body weight for 15 minutes. Erythrocytes were exposed to gamma radiation (500 Gy doses) from 60Co source. The activity of aldolase in erythrocytes was estimated by Fermognost test. The submaximal physical exercise was indicated to increase the aldolase activity. Gamma radiation at 500 Gy dose was found to increase aldolase enzymatic activity in erythrocytes both a rest and after submaximal physical exercise.

Adult↗

Tissue-specific expression of rat aldolase A mRNAs. Three molecular species differing only in the 5'-terminal sequences.

Three species of aldolase A mRNA (mRNAs I, II, and III) only differing in the structure of the 5'-terminal noncoding region were detected in rat tissues. The cDNA clones for mRNAs II and III were prepared from ascites hepatoma AH60C and sequenced. The mRNA II is 1393 nucleotides long excluding poly(A) tail, while the mRNA III is 1440 nucleotides long, some 50 nucleotides longer than the mRNA II. The mRNAs II and III differ in the sequence between -25 and the 5' termini from the previously reported skeletal muscle aldolase A mRNA (mRNA I, 1343 nucleotides long). By contrast, the residual 5' noncoding sequence (-24 to -1) and the coding and 3' noncoding sequences are common to all the mRNAs. By dot spot hybridization and S1 mapping the distribution of these mRNAs in the various tissues was determined. The mRNA I appears exclusively in a skeletal muscle and some in heart and hepatoma AH60C, whereas the mRNAs II and III appear more or less in all the tissues examined, implying that their appearances are under tissue-specific control. Furthermore, partial nucleotide sequence analysis of the fetal liver aldolase A mRNA supports that aldolase A mRNA that reappeared in hepatoma is really a resurgence of the gene product expressed in the fetus.

Amino Acid Sequence↗

[Stabilizing effect of oligomerization on aldolase protomers in rabbit muscles].

It is shown by the fluorimetric analysis that with the 1,2 M MgCl2-induced dissociation of rabbit muscle aldolase the tertiary structure of the resulted protomers (subunits) remains practically unchanged. Significant changes in the protomeric enzyme are provoked by subsequent addition of urea up to the concentration of 2,3 M, and are, evidently, manifested in a significant decrease in regularity of the hydrophobic part of aldolase and in possible transition of its Trp-147 into more polar environment. This transition is reflected in the longwave shift of the protein fluorescence maximum (lambda max) by 13 nm (from 320 to 333 nm). But the joint action of MgCl2 and urea does not lead to complete unfolding of the resulted protomeric enzyme. More deep structural alterations in the subunits occur on acidic dissociation, and lambda max shift in this case reaches 342 nm. Structural changes caused by MgCl2 and urea are concomitant with the increase of fluorescence quenchibility with NADH. Here a short-wave lambda max shift, being usually observed in native aldolase fluorescence quenching, is not registered. This mean that the photoselection of protein fluorophores does not occur. The results thus obtained produce an evidence that oligomerization endows aldolase protomers with enhanced stability.

Animals↗

[Comparative study of the structural characteristics of aldolase in rabbit muscles in normal states and in alloxan diabetes].

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.

Animals↗

[Characteristics of the molecular diversities of human and rat aldolase via starch and agar gel electrophoresis].

Content of aldolase isoenzymes was reinvestigated in human and rat tissues by means of agar and starch gel electrophoresis. Heterogeneity of the A type aldolase is established and possible causes of formation of the multiple forms of the enzyme are discussed. The ratio of various fractions of aldolase A was different in erythrocytes of newborn and aldult persons. The patterns of the aldolase isozyme spectra were characterized in blood sera of newborns, in acute hepatitis and myocardial infarction.

Adult↗