SEARCH · Search PubMed
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.
The influence of different triiodothyronine doses on aldolase metabolism in rat liver was studied after whole-body X-irradiation. The effect of the hormone on the rates of synthesis and degradation and on the time of functioning of the enzyme in the exposed body was shown to vary markedly in the irradiated and intact animals.
Serum levels of phosphohexose isomerase (PHI), aldolase (ALD) and hexokinase (HK) activities have been determined in 76 patients of carcinoma cervix, in search of proper diagnostic and prognostic parameters. All the three glycolytic enzyme levels studied were found to be significantly elevated in all the groups of malignancy and showed a relation to the clinical stage and tumor. Serum PHI levels were of best diagnostic significance even at an early stage of the disease. The enzyme levels correlated well with the prognosis of the disease.
A study was made of the effect of glucagon and hydrocortisone on aldolase metabolism in rat liver after total-body X-irradiation. The hormonal regulation of the enzyme metabolism in the exposed rats was shown to vary from that of intact animals.
A single total-body exposure of rats to gamma-rays in an absolutely lethal dose caused significant changes in the activity of fructosodiphosphate aldolase (ALD) and glucose-6-phosphate dehydrogenase (G-6-PDH) in the brain, liver, myocardium and skeletal muscles. The activity of ALD was mainly inhibited and that of G-6-PDH increased. Thus, the initial step of glycolysis was significantly inhibited and the key reaction of the pentose phosphate pathway enhanced in the irradiated body.
NADH has a corresponding binding site in aldolase, and can activate the reaction of the aldole cleavage of the substrate (fructose-1,6-bisphosphate). Unlike the considerable protection by the substrate, the similar effect of NADH on the sulphydryl enzyme groups is less pronounced, and may be attributed to single cysteine residue. The functionally related and spatially separated binding sites for NADH and substrate are suggested.
It has been ascertained that in the Lampetra planeri (Bloch) the muscle and liver aldolase level in the last larval period in which lipids are accumulated strongly increases; this may be due to an increased synthesis or diminished degradation of the enzyme.
The biosynthesis, spontaneous breakdown and lifetime of rat liver aldolase after a single injection of thyroid adreno-cortical hormones were studied. Triiodothyronine and hydrocortisone were shown to have a pronounced effect on the enzyme metabolism.
A simple screening procedure for the detection of glucose-phosphate isomerase (GPI), phosphofructokinase (PFK), aldolase (AL) and glyceraldehyde-3-phosphate dehydrogenase (GAPD) deficiencies in blood, is described. These enzymes catalyze the second, third, fourth, and sixth reactions in the Embden-Meyerhof pathway. The procedure is based on the conversion of glucose-6-phosphate to 1,3-diphosphoglycerate (1,3-DPG) which is catalyzed by the sequential action of the GPI, PFK, AL and GAPD. The presence of the enzyme activities is visually estimated by the reduction of NAD+ (non-fluorescent) to NADH (fluorescent) which occurs when 1,3-DPG is formed. Absence of fluorescence indicates the deficiency of anyone of the four enzymes, which are specified by using separately the PFK, AL and GAPD respective substrates.
Serum aldolase and hexokinase levels were determined in 197 serum samples. There were 152 breast carcinoma cases comprising 26 of group I, 82 of group II and 44 of group III, 25 normal healthy female subjects and 20 benign. Activity of both the enzymes was normal in benign group but significantly higher activities were observed in advanced disease as compared to controls (P less than .001). The enzyme activity levels showed good correlation to the groups of the disease.
The complete nucleotide sequence of rabbit muscle aldolase mRNA has been determined from recombinant cDNA clones and from a primer-extended cDNA synthesis on the mRNA template. The sequence is composed of 1375 nucleotides, exclusive of the poly(A) tails. The 5'-untranslated region contains 62 bases including a potential ribosome-binding site. The 3'-untranslated region is 221 bases long. The remaining 1092 nucleotides are in an open reading frame coding for 364 amino acids. There is a single methionine residue preceding the NH2-terminal proline. The deduced amino acid sequence corrects a number of discrepancies between published structures as well as assignments previously missed. The sequences of the cloned cDNAs suggests there may be microheterogeneity in the messenger RNA population.
A specific radioimmunoassay was developed for the quantification of human muscle type aldolase (M-ALD) in human serum. The method utilized the double antibody radioimmunoassay technique using radioiodinated M-ALD, chicken antibody to M-ALD and rabbit antibody to chicken IgG. The serum M-ALD values of 41 normal healthy subjects ranged from 130 to 210 ng/ml, average 171 +/- 39 ng/ml. In 76 noncancer hospital patients, excluding patients with muscle diseases, the serum M-ALD values ranged from 125 to 220 ng/ml, average 164 +/- 52 ng/ml. In contrast, 129 cancer patients had high serum M-ALD values of 586 +/- 926 ng/ml, ranging from 85 to 5,800 ng/ml. Eighty-six percent of the cancer patients showed serum M-ALD concentrations over the normal range. The measurement of M-ALD values in the serum of patients by radioimmunoassay may be a valuable laboratory test in the diagnosis and follow-up of cancer patients.
The effects of vanadate, an oxidized form of vanadium, on glucose metabolism of the lens in diabetic rats were studied. Five-week-old male Sprague-Dawley rats were rendered diabetic with intraperitoneal injection of streptozotocin (50 mg/kg). One week later, the diabetic rats were given 0.2 g/l NaVO3 -5g/l NaCl solution in drinking water ad libitum for 2 weeks and biochemical parameters in their lenses were determined. Blood glucose levels significantly decreased in the vanadate-administered diabetic rats (DV group), compared with the diabetic rats given no vanadate (D group). In the DV group, a significant decrease was observed in lens fructose content compared with the D group. Lens ketohexokinase activity tended to be higher and lens aldolase activity was significantly higher in the DV group than in the D group. These results indicate that vanadate accelerates the metabolic reaction from sorbitol pathway to glycolysis.
While it is well known that prolonged intense exercise raises serum enzyme activities, the effects of short duration intense exercise on enzyme activity changes have not been clearly described. Three successive standard 30 s Wingate anaerobic cycle ergometer tests separated by 6-8 min rest intervals were performed by competitive male middle- and long-distance runners or cyclists (no. = 33), and matched healthy control subjects (no. = 30). Immediately before and 6 h after the tests, blood samples were before and 6 h after the tests, blood samples were taken to assess the effects of exercise on serum creatine kinase (CK), lactate dehydrogenase (LD) and aldolase (ALS) enzyme activities. Serum CK activities were found to be significantly higher in athletes than in the controls, both before and 6 hours after the test (p < 0.001), as were ALS activities (p < 0.01 before and p < 0.05 after the test), whereas LD activities were significantly higher (p < 0.05) in the athletes only after the test. Following the test, increases in LD activities (p < 0.01) were observed in athletes and rises in CK activities (p < 0.05) were seen in the controls. Significant correlations between pre- and post-exercise serum enzyme activities were established for both groups. In conclusion, following a supramaximal exercise test, increases in serum LD activities of athletes and in CK activities of controls appear to be more pronounced, and increases in serum CK, LD and ALS activities seem to depend more on the duration of exercise than on its intensity.
We have shown, by kinetic, electrophoretical and immunological methods, the resurgence of two intestine fetal aldolases (A and C) in well-differentiated rat duodenal adenocarcinomas. Our findings demonstrate that the resurgence of fetal isozymes in cancer is a general phenomenon, occurring in intestine, as in liver and other tissues.
The human aldolase A gene is transcribed from three alternative promoters, clustered in a small 1.6-kb DNA domain. In transgenic mice, the upstream pN and the downstream pH promoters are ubiquitous, whereas the pM promoter, located between pN and pH, is activated specifically in fast skeletal muscles. A strong ubiquitous enhancer, lying upstream of the pH promoter, is necessary for both pN and pH ubiquitous activities, whereas a fast-muscle-specific enhancer, located upstream of the pM promoter, is required for pM-specific activation. In the present study, we use the transgenic mice model to further investigate the contribution of these two regulatory elements to the overall control of these three promoters. We confirm that the pM and pH promoters are activated independently of each other and, in particular, we show that the activation of pM in fast muscle is not responsible for the downregulation of the downstream pH in this tissue. By contrast, the pN promoter needs the presence of both enhancers to reproduce its correct pattern of activity and is unable to function autonomously in vivo.
Nine efficient aldolase antibodies were generated by using hapten 1. This hapten unites reactive immunization and the transition state analogue approach in a single molecule. Characterization of two of these antibodies reveals that they are highly proficient (up to 1000-fold better than any other antibody catalyst) and enantioselective catalysts for aldol and retro-aldol reactions and exhibit enantio- and diastereoselectivities opposite to that of antibody 38C2.
The potential of L-fuculose-1-phosphate aldolase (FucA) as a catalyst for the asymmetric aldol addition of dihydroxyacetone phosphate (DHAP) to N-protected amino aldehydes has been investigated. First, the reaction was studied in both emulsion systems and conventional dimethylformamide (DMF)/H2O (1:4 v/v) mixtures. At 100 mM DHAP, compared with the reactions in the DMF/H2O (1:4) mixture, the use of emulsion systems led to two- to three-fold improvements in the conversions of the FucA-catalyzed reactions. The N-protected aminopolyols thus obtained were converted to iminocyclitols by reductive amination with Pd/C. This reaction was highly diastereoselective with the exception of the reaction of the aldol adduct formed from (S)-N-Cbz-alaninal, which gave a 55:45 mixture of both epimers. From the stereochemical analysis of the resulting iminocyclitols, it was concluded that the stereoselectivity of the FucA-catalyzed reaction depended upon the structure of the N-Cbz-amino aldehyde acceptor. Whereas the enzymatic aldol reaction with both enantiomers of N-Cbz-alaninal exclusively gave the expected 3R,4R configuration, the stereochemistry at the C-4 position of the major aldol adducts produced in the reactions with N-Cbz-glycinal and N-Cbz-3-aminopropanal was inverted to the 3R,4S configuration. The study of the FucA-catalyzed addition of DHAP to phenylacetaldehyde and benzyloxyacetaldehyde revealed that the 4R product was kinetically favored, but rapidly disappeared in favor of the 4S diastereoisomer. Computational models were generated for the situations before and after C-C bond formation in the active site of FucA. Moreover, the lowest-energy conformations of each pair of the resulting epimeric adducts were determined. The data show that the products with a 3R,4S configuration were thermodynamically more stable and, therefore, the major products formed, in agreement with the experimental results.
A facile synthesis of 3R,5R-dihydroxy-L-homoproline as idulonic acid mimic, of which the carboxyl and 3-hydroxyl groups were protected, was attained using L-threonine aldolase-catalyzed reaction. Idulonic acid is a key acidic sugar of the b-FGF binding domain in heparin and heparan sulfate. Moreover, the synthetic precursor of N-acetyl-4-deoxy-D-mannosamine, which is a potent inhibitor of NeuAc synthase, was prepared from the side product of the enzymatic aldol condensation.