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PubMed1987

Effect of dietary carbohydrate source on soluble protein glucose concentration and enzyme activity (aldolase) of European eels (Anguilla anguilla L.).

This study was undertaken to determine the influence of dietary carbohydrate sources: wheat meal, bread meal, soluble corn starch, native potato starch and sorghum meal, on soluble protein, enzyme activity (aldolase) and glucose concentration in muscle and liver of European eels (Anguilla anguilla). There was less soluble protein in both muscle and liver of eels fed 30% wheat meal or bread meal than the other experimental groups. However, eels fed 30% bread meal or soluble corn starch had a higher glucose concentration in muscle and liver than the other experimental groups. High enzyme activity (aldolase) was found in the liver of eels fed 30% wheat meal, bread meal or soluble starch.

Anguilla↗
PubMed1983

Age-dependent changes of protein structure. The properties of young and old rabbit aldolase are restored after reversible denaturation.

The significantly increased helical content is observed in muscle aldolase molecule of old rabbits. The unfolding and refolding of protein conformation followed by circular dichroism, fluorescence and enzyme activity showed the recovery of initial conformation after the denaturation. The protein folds into the form that existed prior to denaturation--"young" into "young" and "old" into "old"--the conformational differences between them being restored. This suggests that the primary structure modifications prior to the folding of the native protein conformation are the origin of the age-dependent differences of aldolase structure and function.

Aging↗
PubMed1992

Molecular analysis of common aldolase B alleles for hereditary fructose intolerance in North Americans.

The diagnosis of hereditary fructose intolerance (HFI) presents a difficult challenge that often involves procedures of high risk to the patient. A relatively noninvasive method that involves molecular analysis of common alleles would offer a decided advantage. The molecular defects in the aldolase B gene were studied in 31 HFI subjects (23 pedigrees, 47 apparently independent alleles) from the United States and Canada. We screened for the three most common European alleles by direct hybridization of allele-specific oligodeoxyribonucleotides (ASOs) to portions of the aldolase B gene that were amplified by PCR. Fifty-five percent of mutant North American alleles were A149P (ala149----pro), the most common mutation in the European population. The other two alleles, A174D (ala174----asp) and N334K (asn334----lys), represent 11 and 2% of North American alleles, respectively. Nine patients, representing 32% of independent alleles studied, had an HFI allele that was not of this common missense class. This North American allele distribution is significantly different from that in Europe, where 13% of HFI alleles are not of this type. Preliminary screening of amplified DNA with this set of ASOs indicated that 80% of symptomatic HFI patients can be identified in the American population by this simple genetic test.

Alleles↗
PubMed2004

Accessibility of N-acyl-D-mannosamines to N-acetyl-D-neuraminic acid aldolase.

N-Acetyl-D-neuraminic acid (NeuNAc) aldolase is an important enzyme for the metabolic engineering of cell-surface NeuNAc using chemically modified D-mannosamines. To explore the optimal substrates for this application, eight N-acyl derivatives of D-mannosamine were prepared, and their accessibility to NeuNAc aldolase was quantitatively investigated. The N-propionyl-, N-butanoyl-, N-iso-butanoyl-, N-pivaloyl-, and N-phenylacetyl-D-mannosamines proved to be as good substrates as, or even better than, the natural N-acetyl-D-mannosamine, while the N-trifluoropropionyl and benzoyl derivatives were poor. It was proposed that the electronic effects might have a significant influence on the enzymatic aldol condensation reaction of D-mannosamine derivatives, with electron-deficient acyl groups having a negative impact. The results suggest that N-propionyl-, N-butanoyl-, N-iso-butanoyl-, and N-phenylacetyl-D-mannosamines may be employed to bioengineer NeuNAc on cells.

Carbohydrate Conformation↗
PubMed2004

Mycobacterium avium-superoxide dismutase binds to epithelial cell aldolase, glyceraldehyde-3-phosphate dehydrogenase and cyclophilin A.

Mycobacterium avium complex (MAC) adheres, invades and multiplies inside epithelial cells. Earlier, we demonstrated two MAC protein adhesins, 25 and 31 kDa, binding with HEp-2 cells. The 25 kDa MAC adhesin was found to be superoxide dismutase (SOD). In this study, epithelial cell (HEp-2 and A549) ligands for MAC-SOD were identified by probing two-dimensional western blots of epithelial extracts with MAC proteins followed by monoclonal anti-MAC-SOD antibodies. Three epithelial cell proteins with molecular masses 43, 40 and 18 kDa, present in both membrane and cytosolic fractions, were found to bind with MAC-SOD. Based on the N-terminal amino acid sequences, the 43, 40 and 18 kDa epithelial proteins were identified as aldolase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and cyclophilin A (CypA), respectively. Furthermore, MAC-SOD was found to bind to purified rabbit muscle aldolase, GAPDH and recombinant CypA in western blotting.

Adhesins, Bacterial↗
PubMed2000

Lithium regulation of aldolase A expression in the rat frontal cortex: identification by differential display.

BACKGROUND: Substantial evidence indicates that lithium may exert its therapeutic effects through progressive adaptive changes at the level of gene expression; however, the study of lithium-regulated genes has been primarily undertaken with the "candidate gene" approach based on a specific testable hypothesis. The aim of our study was to identify lithium-regulated genes that would not be predicted a priori by the candidate gene approach. METHODS: Differential display polymerase chain reaction was used to isolate and identify messenger RNAs (mRNAs) that are differentially expressed in the frontal cortex of rats given lithium for 5 weeks to achieve plasma lithium concentrations of 0.6 to 0.9 mmol/L. RESULTS: A putative lithium-regulated complementary DNA fragment (LRG1) was identified. Northern blot analysis revealed that 5 weeks of lithium treatment, but not 1 week, significantly reduced LRG1 mRNA levels. LRG1 mRNA levels were similarly reduced by 5 weeks of carbamazepine, but not valproate administration. Sequence analysis and search of the GenBank database revealed that LRG1 is analogous to the sequence of the gene for rat aldolase A. CONCLUSIONS: These results demonstrate that chronic administration of lithium, but not short-term administration, down regulates the levels of aldolase A mRNA, suggesting this effect may play a role in mediating the therapeutic action of this agent.

Animals↗
PubMed1999

PKC-dependent phosphorylation of the p97 repressor regulates the transcription of aldolase A L-type promoter.

Expression of mouse aldolase A L-type mRNA is negatively modulated by a cis element (AldA-NRE), located within the aldolase A distal promoter (pL). AldA-NRE interacts with a 97-kDa repressor protein (p97), which binds DNA in a cell cycle-dependent manner. We demonstrate that the binding between AldA-NRE and p97 decreases during differentiation of human Caco-2 cells and is inversely correlated with L-type mRNA expression. Phosphorylation of the p97 repressor weakened its DNA binding activity in differentiated Caco-2 cells, while dephosphorylation enhanced the binding in proliferating cells. Stimulation of protein kinase C (PKC) in vivo decreased the binding of p97 to AldA-NRE and stimulated transcription, while inhibition of PKC stimulated p97 binding and downregulated transcription. These findings suggest that PKC is a mediator of the binding and silencing function of the p97/AldA-NRE repressor complex.

3T3 Cells↗
PubMed1988

Catalytic deficiency of human aldolase B in hereditary fructose intolerance caused by a common missense mutation.

Hereditary fructose intolerance (HFI) is a human autosomal recessive disease caused by a deficiency of aldolase B that results in an inability to metabolize fructose and related sugars. We report here the first identification of a molecular lesion in the aldolase B gene of an affected individual whose defective protein has previously been characterized. The mutation is a G----C transversion in exon 5 that creates a new recognition site for the restriction enzyme Ahall and results in an amino acid substitution (Ala----Pro) at position 149 of the protein within a region critical for substrate binding. Utilizing this novel restriction site and the polymerase chain reaction, the patient was shown to be homozygous for the mutation. Three other HFI patients from pedigrees unrelated to this individual were found to have the same mutation: two were homozygous and one was heterozygous. We suggest that this genetic lesion is a prevailing cause of hereditary fructose intolerance.

Alleles↗
PubMed1998

Interaction of phosphonomethyl analog of dihydroxyacetone phosphate with rabbit muscle aldolase.

Aldolase presents the same binding affinity for dihydroxyacetone phosphate and its phosphonomethyl analog, but the partition coefficient between the intermediates from the Michaelis complex to the eneamine is different. The effects of the structural modification of the triose phosphate substrate on the interaction with rabbit muscle aldolase are discussed in connection with the mechanistic pathway and the three-dimensional structure of the enzyme.

Animals↗
PubMed2001

A novel growth-related nuclear protein binds and inhibits rat aldolase B gene promoter.

The promoter of the rat aldolase B (AldB) gene that confers liver-specific transcription has an additional role. It functions in vivo as an origin region of DNA replication in the cells in which the gene is repressed (Zhao, Y., Tsutsumi, R., Yamaki, M., Nagatsuka, N., Ejiri, S., Tsutsumi, K., 1994. Initiation zone of DNA replication at the rat aldolase B locus encompasses transcription promoter region. Nucleic Acids Res. 22, 5385-5390). This promoter/origin region has multiple protein-binding sites and, thus, binding of a particular set of protein factors in AldB-expressing or non-expressing cells seems to correlate with functional switch of this promoter/origin region. In the present study, we characterized two closely related proteins, termed AlF-C1 and AlF-C2, which are assumed to be involved in repression of the AldB gene. These two proteins share an identical amino acid sequence except for a 47-residue-insertion in AlF-C1, and are members of a gene family including heterogeneous nuclear ribonucleoprotein (hnRNP) and CCAAT-binding factor subunit A (CBF-A) genes. Bacterially expressed AlF-C1 can bind sequence-specifically to the AldB gene promoter, whereas AlF-C2 can only weakly. Transfection experiments using mammalian expression vectors showed that AlF-C1 down-regulates the AldB gene promoter in rat hepatoma cells, while AlF-C2 had no or little effect. Expressions of mRNAs encoding these two proteins are enriched in fetal livers and in regenerating livers. These results implied that AlF-C1 and/or C2 is involved in growth-regulated repression of the AldB gene.

Amino Acid Sequence↗
PubMed2001

Interaction between phosphofructokinase and aldolase from Saccharomyces cerevisiae studied by aqueous two-phase partitioning.

Phosphofructokinase (EC 2.7.1.11) and aldolase (EC 4.1.2.13) have been highly purified from Saccharomyces cerevisiae by improved protocols. Partitioning of the enzymes in aqueous polymer two-phase systems was used to detect complex formation. The partition of each enzyme was found to be affected by the presence of the other enzyme. AMP affected the partition of the individual enzymes as well as the mixture of the two. The activities of the respective enzymes were stimulated in the putative complex in an AMP-dependent manner. Two strictly conserved residues belonging to an acidic surface loop of class II aldolases, are a potential site for electrostatic interaction with the positively charged regions close to the active site in phosphofructokinase.

Adenosine Monophosphate↗
PubMed1992

Effect of myotonia induced by anthracene-9-carboxylic acid on mitochondrial calcium, plasma creatinine-phosphokinase and aldolase activity in the rat.

The frequent association of myotonia with dystrophy and the knowledge that calcium is increased in injured skeletal muscle cells suggest a possible relationship between cell calcium and myotonic alterations. This investigation has been performed to study the role of calcium in experimental myotonia induced by anthracene-9-carboxylic acid (9-AC) in rats treated with several regimens of food and exercise. Thirty-two rats were divided into 4 groups of 8 rats each, one control and 3 experimental groups. The treatments included caffeine plus exercise (group 2), and a calcium-rich diet (group 3); these procedures were designed to increase intracellular calcium; another group was treated with 9-AC as a myotonia-inducer (group 4). The treatment for all groups lasted 60 days. No significant differences in plasma sodium, potassium, chloride and calcium between control and experimental groups were observed. Whole muscle calcium in wet tissue samples did no change with any treatment. On the contrary, mitochondrial calcium showed a significantly higher concentration in group 3 and 4. CPK and aldolase activities in groups 1, 2 and 3 were similar; but in group 4 these enzyme activities were significantly higher (p less than 0.05). The electrical and mechanical responses were not altered in any rat with any experimental treatment. Our data suggest that myotonia is a predisposing factor for an altered mitochondrial calcium homeostasis in this model; in addition, the enzyme activities of CPK and aldolase were increased in the rats of group 4 implicating that myotonia is a crucial factor in the development of enzymatic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

Slow reversible inhibitions of rabbit muscle aldolase with substrate analogues: synthesis, enzymatic kinetics and UV difference spectroscopy studies.

Various dihydroxyacetone-phosphate (DHAP) analogues bearing an aromatic ring or beta-dicarbonyl structures were synthesized. Their capacity to form a stabilized iminium ion or conjugated enamine in the reaction catalyzed by rabbit muscle aldolase (EC 4.1.2.13) were investigated by enzymatic kinetics and UV difference spectroscopic techniques. Whereas the aromatic derivative led to competitive inhibition without detectable iminium ion formation, slow reversible inhibitions of aldolase by beta-dicarbonyl compounds was shown to have taken place. Conjugated enamine formation at the active site of the enzyme was detected by their specific absorbances close to 317 nm.

Acetophenones↗
PubMed2006

Amperometric assay for aldolase activity: antibody-catalyzed ferrocenylamine formation.

Screening of new catalysts for aldolase activity is a major task in bioorganic chemistry. For this purpose, fast and convenient methods are required for the detection of the catalysts. We have developed the first amperometric assay for aldol or retro-aldol catalytic activity. A new ferrocene-aldol derivative was synthesized with redox activity significantly different from that of ferrocenylamine. It was shown that the reaction between aldolase antibody 38C2 and a ferrocene-aldol substrate generated free ferrocenylamine, which could be detected and quantified by simple electrochemical measurement. The amperometric assay was applied to perform a Michaelis-Menten analysis of catalytic antibody 38C2 in order to determine the enzymatic kinetic parameters.

Antibodies↗
PubMed1993

Halophilic class I aldolase and glyceraldehyde-3-phosphate dehydrogenase: some salt-dependent structural features.

Aldolase and glyceraldehyde-3-phosphate dehydrogenase from the extremely halophilic archaebacterium Haloarcula vallismortis are stable only in high concentrations of KCl present within the physiological environment. Data concerning the structural changes in the two enzymes as a result of lowering of salt concentration and changes in pH were obtained by monitoring the intrinsic protein fluorescence in the presence of quenchers. When the KCl concentrations were lowered below 2 M or in the presence of 6 M guanidine hydrochloride, the emission maximum shifted to a longer wavelength, indicating enhanced exposure of tryptophyl residues to the solvent. The spectral characteristics of the two proteins in guanidine hydrochloride and 0.4 M KCl were identical. However, these denatured states appear to be different than those observed after acid denaturation. Further perturbation of fluorescence was observed due to I-, and application of the Stern-Volmer law showed that the total fluorescence was available to the quenchers only in 0.4 M KCl solutions. The unfolding of proteins in 0.4 M KCl was a gradual process which was accompanied by a time-dependent loss in enzyme activity. The activity loss was complete within 30 min for aldolase whereas in the case of GAPDH nearly 3 h was required for the destruction of activity. For both enzymes, inactivation and protein denaturation were strongly correlated. The data on activity and thermostability measurements of the two enzymes in varying concentrations of KCl and potassium phosphate revealed that though both proteins are halophilic, the forces in the maintenance of their stability could be different.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylamide↗
PubMed1984

Suicide inactivation of fructose-1,6-bisphosphate aldolase.

2-Keto-4,4,4-trifluorobutyl phosphate (HTFP) was prepared from 3,3,3-trifluoropropionic acid. HTFP acts as an irreversible inhibitor of rabbit muscle aldolase: the loss of activity was time dependent and the inactivation followed a pseudo-first-order process. Values of 1.4 mM for the dissociation constant and 2.3 X 10(-2) s-1 for the reaction rate constant were determined. The kinetic constants do not depend on the enzyme concentration. No effect of thiols on the inactivation rate was detected. Only 1-2 mol of fluoride ions was liberated per inactivated subunit, indicative of a low partition ratio. Dihydroxyacetone phosphate protected the enzyme against the inactivation in a competitive manner, and glyceraldehyde 3-phosphate protected as if it formed a condensation product with HTPF. 5,5'-Dithiobis(2-nitrobenzoic acid) thiol titration showed the loss of one very reactive thiol group per enzyme subunit after inactivation. All those observations seem to agree with a suicide substrate inactivation of aldolase by HTPF.

Animals↗
PubMed1985

Complexes of muscle aldolase in equilibrium with fructose 1,6-bisphosphate.

Minimum values for the content of covalent intermediates in the equilibria of muscle aldolase with its cleavable substrates have been determined by acid denaturation/precipitation. Ribulose 1,5-bisphosphate, a nonsubstrate that binds well to aldolase in the native state, does not form a covalent complex that is acid precipitable. The insoluble protein complexes with substrates fructose 1,6-bisphosphate and sedoheptulose 1,7-bisphosphate, representing approximately 50% and approximately 60% of total bound substrate, are much more stable in acid and alkali than that with substrate 5-deoxyfructose 1,6-bisphosphate, suggesting that they have the form of protein-bound N-glycosides. Whether such complexes exist on the enzyme in the native state in addition to being formed subsequent to denaturation is unresolved. Both the acid-precipitable and nonprecipitable forms of fructose 1,6-bisphosphate are converted to triose phosphate products at the same rate, providing no kinetic evidence for a pool that is not on the main reaction path. Total fructose 1,6-bisphosphate liganded to enzyme returns to the free solution about 9 times for each net cleavage reaction. It is still not clear whether this is limited by the cleavage step or by release of glyceraldehyde phosphate.

Animals↗
PubMed1981

Liberation of the triosephosphate isomerase reaction intermediate and its trapping by isomerase, yeast aldolase, and methylglyoxal synthase.

When a mixture of triosephosphate isomerase (rabbit muscle) and dihydroxyacetone phosphate (DHAP) is quenched with acid, a compound is liberated, presumed to be the cis-enediol 3-phosphate, that decomposes to inorganic phosphate (Pi) and methylglyoxal [Iyengar, R., & Rose, I.A. (1981) Biochemistry (preceding paper is this issue)]. The decomposition can be prevented by rapid neutralization if a catalytic amount of fresh isomerase is present. Varying the time between acidification and rescue gave a half-life of the liberate compound of approximately 12-17 ms. Varying the concentration of enzyme used for rescue gave a minimum second-order rate constant for trapping of 10(9)M(-1)s(-1). These results add further evidence favoring a stepwise mechanism for the aldose-ketose isomerase reactions in which a chemically defined enzyme-bound intermediate is found. The high rate of trapping over a wide pH range indicates that the enediol phosphate, not the enediolate phosphate, is the intermediate. One property of the enzyme is to stabilize the intermediate with respect to its fragmentation in solution by greater than 1000-fold. Yeast aldolase is also able to rescue all of the isomerase intermediate, though higher concentrations of enzyme are required. Although different enantiotopic protons of DHAP are abstracted by isomerase and aldolase, both enzymes use the same enediol phosphate intermediate. Methylglyoxal synthase at a 50-fold greater concentration was unable to compete with triosephosphate isomerase for cis-enediol phosphate. Either the synthetase has a low V/K for the cis isomer or it uses the trans-enediol phosphate form specifically. A new strategy for the chemical and enzymological characterization of enzyme reaction intermediates is proved here based on the liberation of the intermediate from the reaction equilibrium and its recovery by fresh enzyme or another enzyme species.

Animals↗