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 primary structure of the muscle aldolase molecule was studied as affected by semilethal doses of valine administered the abdominal cavity of the rabbits after a long fasting. It is established that in spite of differences in the amino acid composition of the protein, uniformity of the peptides distribution in the process of bromo-cyanogen fragments elution and the total amount of amino acid residues in the identical fragments are maintained. Changes are found only in the point-replacements by amino acids in C-fragment of the molecule (asparagine is replaced by valine and threonine by serine).
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PMID:[Changes in the primary structure of rabbit muscle aldolase under the influence of valine against a background of prolonged fasting]. 102 17

Generation of antibodies and direct protein sequencing were used to identify and characterize proteins associated with highly purified synaptic vesicles from rat brain. A protein doublet of low abundance of 119 and 124 kDa apparent molecular mass [synaptic vesicle-associated phosphoprotein with a molecular mass of 120 kDa (SVAPP-120)] was identified using polyclonal antibodies. SVAPP-120 was found to copurify with synaptic vesicles and to be enriched in the purified synaptic vesicle fraction to the same extent as synapsin I. Like synapsin I, SVAPP-120 is not an integral membrane protein because it was released from synaptic vesicles by high salt concentrations. This protein was demonstrated to be brain specific, and its distribution in various brain regions paralleled the distribution of synapsin I and synaptophysin. During the postnatal development of the rat cortex and cerebellum, its expression correlated with synaptogenesis. SVAPP-120 was demonstrated to be a phosphoprotein both in vivo and in vitro. It was shown to be phosphorylated on serine and to a lesser extent on threonine residues. These results provide evidence that SVAPP-120 represents a novel synaptic vesicle-associated phosphoprotein. In addition, aldolase, a glycolytic enzyme, and alpha c-adaptin, a clathrin assembly-promoting protein, were identified on purified synaptic vesicles by direct protein sequencing.
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PMID:A novel synaptic vesicle-associated phosphoprotein: SVAPP-120. 207 93

Pyridoxal kinase displays high catalytic activity in the presence of metallothionein. The apoprotein of metallothionein as well as the peptide LYS-CYS-THR-CYS-CYS-ALA exert a strong inhibitory effect upon pyridoxal kinase by sequestering free Zn ions. Several steps intervene in the process of pyridoxal kinase activation, i.e. binding of Zn ions by ATP and interaction of Zn-ATP with the enzyme; but direct interaction between metallothionein and pyridoxal kinase (protein association) could not be detected by emission anisotropy measurements. Since the concentration of free Zn++ in mammalian tissues is lower than 10(-9)M, it is postulated that the concentration of metallothionein regulates the catalytic activity of pyridoxal kinase. The mechanism of reconstitution of the metalloenzyme yeast aldolase in the presence of metallothionein was also investigated.
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PMID:Modulation of the catalytic activity of pyridoxal kinase by metallothionein. 284 38

Steady-state kinetic measurements have shown that 8-azido-1,N6-ethenoadenosine 5'-triphosphate (8-N3-epsilon ATP) can be noncovalently bound to rabbit muscle fructose 1,6-bisphosphate aldolase with Ki = 0.075 mM at pH 8.5. This binding is purely competitive with substrate and occurs at the strong binding site for mononucleotides. Photoaffinity labeling of aldolase in the presence of 8-azido-1,N6-ethenoadenosine 5'-triphosphate results in inactivation of the enzyme. Aldolase is protected against modification in the presence of the inhibitors hexitol 1,6-bisphosphate or ATP. The labeling is saturable, and a good correlation is observed between the loss of enzymatic activity and the incorporation of 8-N3-epsilon ATP into aldolase. In addition, aldolase loses its ability to bind to phosphocellulose following modification. Digestion of labeled protein with trypsin, chymotrypsin, and cyanogen bromide revealed substantial modification of peptide 259-269. Thr-265 was identified as the residue that was covalently modified by 8-N3-epsilon ATP. On the basis of these results and other data we propose a model for the mononucleotide binding site.
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PMID:Photoaffinity labeling of rabbit muscle fructose-1,6-bisphosphate aldolase with 8-azido-1,N6-ethenoadenosine 5'-triphosphate. 365 92

Inability to grow on deoxyribonucleosides as the sole carbon source is characteristic of deo mutants of Escherichia coli. Growth of deoC mutants, which lack deoxyribose 5-phosphate aldolase, is reversibly inhibited by deoxyribonucleosides through inhibition of respiration. By contrast, deoB mutants are not sensitive to deoxyribonucleosides, and deoxyribose 5-phosphate aldolase and thymidine phosphorylase are present at normal levels but are not inducible by thymidine. Organisms with the genotype deoB(-)thy(-) or deoC(-)thy(-) are able to grow on low levels of thymine, whereas deoB(+)thy(-) or deoC(+)thy(-) strains require high levels of thymine for growth. The deoB and deoC mutations are transducible with and map on the counterclockwise side of the threonine marker. They are closely linked to deoA, a gene determining thymidine phosphorylase. Merodiploids heterozygous for either the deoB or deoC genes are resistant to deoxyribonucleosides and, in combination with the thy mutation, require high levels of thymine for growth. Cultures of thy(+)deoC(-) mutants are inhibited by thymidine until this compound has been completely degraded and excreted as deoxyribose and thymine, whereupon growth promptly resumes at a normal rate. The inhibition of respiration in deoC strains and the induction of thymidine phosphorylase and deoxyribose 5-phosphate aldolase in the wild-type organism are considered to result from the accumulation of deoxyribose 5-phosphate.
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PMID:Characteristics of the deo operon: role in thymine utilization and sensitivity to deoxyribonucleosides. 487 28

Some experimental and clinical studies were done from the metabolic viewpoint to elucidate the characteristics of myonephropathic-metabolic syndrome. In experimental dogs with their femoral arteries ligated and two third of femoral muscles divided, aldolase and myoglobin showed remarkable increase without significant changes in electrolytes. Slight increase of GPT and GOT was observed. Amino acids showed elevation in urea, taurin, leucin, isoleucin, valine, threonine, 3-methylhistidine, phenylalanine, histidine, lysine, methionine, tyrosine and anserin and decrease in glutamine, alanine, glycine, proline, carnosine, citrullin and arginine. In patients with acute arterial occlusion, potassium, GOT, LDH, CPK, lactate and pyruvate increased moderately and myoglobin showed remarkable increase and aldolase slight increase. Amino acids showed remarkable increase in 3-methylhistidine and beta-amino-isobutyric acid and moderate increase in phenylalanine and arginine. These results revealed that measurement of free amino acid concentration, especially that of methylhistidine as well as myoglobin, pyruvate, lactate and some other enzymes might be of great help to predict the prognosis of patients with acute arterial occlusion of the extremities.
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PMID:[Metabolic study on acute arterial occlusion of the extremities]. 667 89

A 2061 bp cDNA encoding a goldfish (Carassius auratus) aldolase was isolated from a goldfish brain library. The deduced 362 amino acid sequence is more similar to vertebrate brain (aldolase C) and muscle aldolases (aldolase A) than to the liver isozymes (aldolase B). Northern blot analysis indicates strong expression of the mRNA in brain but not in liver or muscle, which indicates that this is aldolase C rather than aldolase A. Analysis of all known vertebrate aldolase amino acid sequences reveals five residues; Leu-57, Arg-314, Thr-324, Glu-332, and Gly-350 that are present exclusively in aldolase Cs. The goldfish clone possesses all five residues. The residues are primarily located in the carboxyl-terminal region of the enzyme and may play a role in determining the neuronal isozyme-specific properties of the enzyme. Furthermore, the existence of an aldolase C in a teleost fish has implications with respect to the timing of genome duplication events that are thought to have been critical in vertebrate evolution.
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PMID:Identification of neuronal isozyme specific residues by comparison of goldfish aldolase C to other aldolases. 921 52

A low-specificity L-threonine aldolase (L-TA) gene from Pseudomonas sp. strain NCIMB 10558 was cloned and sequenced. The gene contains an open reading frame consisting of 1,041 nucleotides corresponding to 346 amino acid residues. The gene was overexpressed in Escherichia coli cells, and the recombinant enzyme was purified and characterized. The enzyme, requiring pyridoxal 5'-phosphate as a coenzyme, is strictly L specific at the alpha position, whereas it cannot distinguish between threo and erythro forms at the beta position. In addition to threonine, the enzyme also acts on various other L-beta-hydroxy-alpha-amino acids, including L-beta-3,4-dihydroxyphenylserine, L-beta-3,4-methylenedioxyphenylserine, and L-beta-phenylserine. The predicted amino acid sequence displayed less than 20% identity with those of low-specificity L-TA from Saccharomyces cerevisiae, L-allo-threonine aldolase from Aeromonas jandaei, and four relevant hypothetical proteins from other microorganisms. However, lysine 207 of low-specificity L-TA from Pseudomonas sp. strain NCIMB 10558 was found to be completely conserved in these proteins. Site-directed mutagenesis experiments showed that substitution of Lys207 with Ala or Arg resulted in a significant loss of enzyme activity, with the corresponding disappearance of the absorption maximum at 420 nm. Thus, Lys207 of the L-TA probably functions as an essential catalytic residue, forming an internal Schiff base with the pyridoxal 5'-phosphate of the enzyme to catalyze the reversible aldol reaction.
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PMID:Gene cloning, nucleotide sequencing, and purification and characterization of the low-specificity L-threonine aldolase from Pseudomonas sp. strain NCIMB 10558. 946 92

The gene encoding low specificity D-threonine aldolase, catalyzing the interconversion of D-threonine/D-allo-threonine and glycine plus acetaldehyde, was cloned from the chromosomal DNA of Arthrobacter sp. strain DK-38. The gene contains an open reading frame consisting of 1,140 nucleotides corresponding to 379 amino acid residues. The enzyme was overproduced in recombinant Escherichia coli cells and purified to homogeneity by ammonium sulfate fractionation and three-column chromatography steps. The recombinant aldolase was identified as a pyridoxal enzyme with the capacity of binding 1 mol of pyridoxal 5'-phosphate per mol of subunit, and Lys59 of the enzyme was determined to be the cofactor binding site by chemical modification with NaBH4. In addition, Mn2+ ion was demonstrated to be an activator of the enzyme, although the purified enzyme contained no detectable metal ions. Equilibrium dialysis and atomic absorption studies revealed that the recombinant enzyme could bind 1 mol of Mn2+ ion per mol of subunit. Remarkably, the predicted amino acid sequence of the enzyme showed no significant similarity to those of the currently known pyridoxal 5'-phosphate-dependent enzymes, indicating that low specificity D-threonine aldolase is a new pyridoxal enzyme with a unique primary structure. Taken together, low specificity D-threonine aldolase from Arthrobacter sp. strain DK-38, with a unique primary structure, is a novel metal-activated pyridoxal enzyme.
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PMID:A novel metal-activated pyridoxal enzyme with a unique primary structure, low specificity D-threonine aldolase from Arthrobacter sp. Strain DK-38. Molecular cloning and cofactor characterization. 964 21

Trichloroethylene (TCE) shows several types of toxicities, some of which may be the result of bioactivation. Oxidation by P450s yields the electrophile TCE oxide. We previously analyzed N(6)-acyllysine adducts formed from the reaction of TCE oxide with proteins [Cai, H., and Guengerich, F. P. (2000) Chem. Res. Toxicol. 13, 327-335]; however, we had been unable to measure ester adducts under the prolonged conditions of proteolysis and derivatization. Protein amino acid adducts were directly observed by mass spectrometry during the reaction of TCE oxide with the model polypeptides insulin and adrenocorticotropic hormone (ACTH, residues 1-24). The majority (80%) of the protein adducts were unstable under physiological conditions and had a collective t(1/2) of approximately 1 h, suggesting that they are ester type adducts formed from reactions of Cys, Ser, Tyr, or Thr residues with intermediates formed in TCE oxide hydrolysis. Synthetic O-acetyl-L-Ser and O-acetyl-L-Tyr had half-lives of 1 h and 10 min at pH 8.0, respectively, similar to the stabilities of the protein adducts. The effects of TCE oxide adduct formation on catalytic activities were examined with five model enzymes. No recovery of catalytic activity was observed during the reaction of TCE oxide with two model enzymes for which the literature suggests roles of a Lys, rabbit muscle aldolase and glucose-6-phosphate dehydrogenase. However, in the cases of papain (essential Cys residue in the active site), alpha-chymotrypsin (critical Ser residue), and D-amino acid oxidase (essential Cys and Tyr residues), time-dependent recoveries of enzyme activity were observed following reaction with TCE oxide or either of two model nucleophiles (dichloroacetyl chloride and acetic formic anhydride), paralleling the kinetics of removal of adducts from insulin and ACTH. Formation of adducts ( approximately 2%) was detected in the direct reaction of TCE oxide with 2'-deoxyguanosine, but not with the other three nucleosides found in DNA. During the reaction of TCE oxide with a synthetic 8-mer oligonucleotide, formation of adducts was observed by mass spectrometry. However, the adducts had a t(1/2) of 30 min at pH 8.5. These results indicate the transient nature of the adducts formed from the reaction of TCE oxide with macromolecules and their biological effects.
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PMID:Reaction of trichloroethylene oxide with proteins and dna: instability of adducts and modulation of functions. 1117 May 8


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