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

---

Query: EC:1.1.1.41 (isocitrate dehydrogenase)
3,101 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 728 animals comprising of 633 rodents and 95 canids were examined for leishmanial parasites. Flagellates were isolated from 67 out of 111 (60.4%) Acomys subspinosus (spiny mouse), 12 out of 143 (8.4% ) Mastomys natalensis (multimammate rat), 2 out of 50 (4.0%) Lemniscomys striatus (striped mouse), 2 out of 6 (33.3%) Herpestes sanguineus (slender mongoose), 1 of 1 Helogale parvula (dwarf mongoose) and 1 out of 84 Canis familiaris (domestic dog). All isolates were characterized by Isoenzyme analysis using nine enzymes, namely, malate dehydrogenase (MDH), phosphoglucomutase (PGM), glucose phosphate isomerase (GPI), isocitrate dehydrogenase (ICD), nucleoside hydrolase (NH), glucose 6-phosphate dehydrogenase (G6PD), malic enzyme (ME), 6-phosphogluconate dehydrogenase (GPGD) and mannose phosphate isomerase (MPI). Enzyme profiles of these isolates were compared with those of five WHO Leishmania reference strains and five well characterized rodent trypanosomes of the subgenus Herpetosoma. The profiles of the isolates were found to be different from those of the Leishmania and Trypanosoma reference strains but the parasites were morphologically similar to rodent trypanosomes. These results suggest that Leishmania parasites were not among the isolates. The enzymes profiles of the three mongoose isolates were identical but differed from profiles of isolates from rodents and dog. This is the first time in Kenya that a high prevalence of nonpathogenic trypanosomes is reported in rodents and canids. From the epidemiological point of view, these trypanosomes must be differentiated from the pathogenic species of trypanosomes and Leishmania that infect man and other animals. The results of this study suggest that rodents do not seem to play a role as reservoirs of Leishmania parasites in Masinga Location, Kenya.
...
PMID:Isolation and characterization of flagellates from rodents and canids in Masinga, Machakos District, Kenya. 1216 Apr 24

Various inorganic and organic nitrogen sources were used to compare their effects on the lipogenesis and the activities of lipogenic enzymes (providing acetyl-CoA and donating NADPH) in gamma-linolenic acid-producing fungus Cunninghamella echinulata. Lipid accumulation was enhanced by organic nitrogen, among them the presence of corn-steep led to almost 40% oil in the biomass. While organic nitrogen increased activities of acetyl-CoA carboxylase (ACC) and malic enzyme (ME), ATP:citrate lyase (ACL) was rapidly enhanced by ammonium ion. The use of NaNO(3) resulted in high activities of glucose 6-phosphate dehydrogenase (GPD) and 6-phosphogluconate dehydrogenase (PGD). NADP-isocitrate dehydrogenase (NADP-ICD) was more active when the fungus utilized all inorganic N-compounds. The rise of nitrogen concentration in medium was accompanied with reduced lipid accumulation and a fall of ACL, ACC, and ME. In contrast, N-sufficient conditions favored biomass growth and elevated activities of GPD and PGD. Kinetic experiments also suggest that a significant portion of the required acetyl-CoA was being provided via ACL and ACC, and ME (probably coupled with GPD) channeled the NADPH into the fatty acid biosynthesis. The contribution of the lipogenic enzymes to metabolic pathways other than lipogenesis is also discussed.
...
PMID:Effect of nitrogen sources on the activities of lipogenic enzymes in oleaginous fungus Cunninghamella echinulata. 1250 58

Corynebacterium glutamicum is an important organism for the industrial production of amino acids such as lysine. In the present study time-dependent changes in the oxidative pentose phosphate pathway activity, an important site of NADPH regeneration in C. glutamicum, are investigated, whereby intracellular metabolite concentrations and specific enzyme activities in two isogenic leucine auxotrophic strains differing only in the regulation of their aspartate kinases were compared. After leucine limitation only the strain with a feedback-resistant aspartate kinase began to excrete lysine into the culture medium. Concomitantly, the intracellular NADPH to NADP concentration ratio increased from 2 to 4 in the non-producing strain, whereas it remained constant at about 1.2 in the lysine-producing strain. From these data the in'vivo flux through the pentose phosphate pathway was calculated. These results were used to approximate the total NADPH regeneration by glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and isocitrate dehydrogenase, which agreed fairly well with the calculated demands for biomass formation and lysine biosynthesis. The analysis allowed to conclude that NADPH regeneration in the pentose phosphate pathway is essential for lysine biosynthesis in C. glutamicum.
...
PMID:Changes of pentose phosphate pathway flux in vivo in Corynebacterium glutamicum during leucine-limited batch cultivation as determined from intracellular metabolite concentration measurements. 1264 24

Activities of several metabolic enzymes show distinct patterns of zonation along the intestinal tract of tilapia (Oreochromis niloticus), rainbow trout (Oncorhynchus mykiss) and copper rockfish (Sebastes caurinus). Zonation is species and enzyme specific, with different metabolic activities concentrated in specific areas, and few generalizations can be made. The rockfish show the smallest degree of zonation, with highest activities in the third quarter of the intestine, and shallow gradients to either side, and a general upswing in activity towards the distal end. In the trout, mitochondrial enzyme activities (citrate synthase, glutamate dehydrogenase, malate dehydrogenase) are highest in the pyloric caeca and decrease along the length of the small intestine. This pattern is accentuated for malic enzyme and glucose 6-phosphate dehydrogenase. These enzymes drop precipitously in activity after the first few sections of the small intestine, while other NADP-linked dehydrogenases (isocitrate dehydrogenase, and 6-phosphogluconate dehydrogenase) show moderate activity in pyloric caeca and peak toward the distal section of the small intestine. In tilapia, glutamate dehydrogenase shows a similar decrease as in trout, but citrate synthase peaks towards the distal sections. NADP-dependent dehydrogenases reveal distinct patterns, peaking in different sections of the intestine-malic enzyme in the proximal midsection, glucose 6-phosphate dehydrogenase in the distal mid-section, and isocitrate dehydrogenase in the anal section. Enzyme activities in the stomach of trout and tilapia also show zonation, with the midsection generally displaying the highest activities. A 5-day treatment of tilapia with an intraperitoneal cortisol deposit (25 mg kg(-1) wet mass) drastically alters metabolic performance along the gut in enzyme specific patterns, generally increasing enzyme activities in site-specific arrangements. Cortisol treatment also leads to the expected increases in activities of phosphoenolpyruvate carboxykinase, pyruvate kinase and aspartate aminotransferase in liver, but not in kidney. Aspartate aminotransferase is the only enzyme in brain significantly increased by cortisol treatment. Short-term food deprivation changes enzyme patterns, often resembling those observed after cortisol administration. We conclude that brain, liver and intestinal amino acid metabolism is an important target for cortisol action in fish and that metabolic zonation is a key factor to be reckoned with when analyzing physiological phenomena in the fish intestine.
...
PMID:Metabolic zonation in teleost gastrointestinal tract. Effects of fasting and cortisol in tilapia. 1278 63

An integrated study on cell growth, enzyme activities and carbon flux redistribution was made to investigate how the central metabolism of Escherichia coli changes with the knockout of genes in the oxidative pentose phosphate pathway (PPP). Mutants deficient in glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were constructed by disrupting the zwf and gnd genes and were grown in minimal media with two different carbon sources, such as glucose or pyruvate. It was shown that the knockout of either gnd or zwf gene did not affect the cell growth rate significantly, but the cellular metabolism was changed. While the specific substrate uptake rate and the specific carbon dioxide evolution rate for either mutant grown on glucose were higher than those obtained for the parent strain, these two rates were markedly decreased in mutants grown on pyruvate. The measurement of enzyme activities implied a significant change in metabolism, when alternative pathways such as the Entner-Doudoroff pathway (EDP) and the malic enzyme pathway were activated in the gnd mutant grown on glucose. As compared with the parent strain, the activities of phosphoglucose isomerase were increased in mutants grown on glucose but decreased in mutants grown on pyruvate. The metabolic flux redistribution obtained based on 13C-labeling experiments further indicated that the direction of the flux through the non-oxidative PPP was reversed in response to the gene knockout. Moreover, the knockout of genes caused an increased flux through the tricarboxlic acid cycle in mutants grown on glucose but caused a decrease in the case of using pyruvate. There was also a negative correlation between the fluxes through malic enzyme and isocitrate dehydrogenase in the mutants; and a positive correlation was found between the fluxes through malic enzyme and phosphoenolpyruvate carboxylase.
...
PMID:Global metabolic response of Escherichia coli to gnd or zwf gene-knockout, based on 13C-labeling experiments and the measurement of enzyme activities. 1466 Nov 15

An integrated study of cell growth characteristics, enzyme activities and protein expression patterns was carried out to investigate how the central metabolism of Escherichia coli changes upon knockout of the isocitrate dehydrogenase (ICDH) gene (icd) in the tricarboxylic acid cycle. Deletion of the icd gene led to reduced specific growth rate and reduced specific glucose consumption rate. The reduced specific growth rate in the icd mutant was due mainly to the lower intracellular ATP/ADP ratio as well as to the lower NADPH/NADP(+) ratio compared with those in the parent strain. However, the specific carbon dioxide evolution rate was found to be higher in the icd mutant strain compared to the parent E. coli. This may be due to the higher activity of 6-phosphogluconate dehydrogenase, phosphoenol pyruvate carboxykinase and NADP(+)-dependent malic enzymes. The glyoxylate pathway was also utilized, as evidenced by the significant upregulation of isocitrate lyase and malate synthase activity in the icd mutant E. coli. The appearance of the glyoxylate pathway caused lower acetate production. Of 21 proteins showing altered expression levels, 17 were successfully identified with the aid of MALDI-TOF mass spectrometry. The results showed that the abolition of ICDH activity significantly affected the respiratory system and electron transport chain, as evidenced by the significant downregulation of proteins encoded by the genes nuoE, nuoH, cydA and cyoA in icd mutant E. coli compared to the parent.
...
PMID:Metabolic regulation analysis of icd-gene knockout Escherichia coli based on 2D electrophoresis with MALDI-TOF mass spectrometry and enzyme activity measurements. 1522 Dec 31

Protein carbonylation is an irreversible oxidative modification that increases during organism aging and bacterial growth arrest. We analyzed whether the heat shock regulon has a role in defending Escherichia coli cells against this deleterious modification upon entry into stationary phase. Providing the cell with ectopically elevated levels of the heat shock transcription factor, sigma32, effectively reduced stasis-induced carbonylation. Separate overproduction of the major chaperone systems, DnaK/DnaJ and GroEL/GroES, established that the former of these is more important in counteracting protein carbonylation. Deletion of the heat shock proteases Lon and HslVU enhanced carbonylation whereas a clpP deletion alone had no effect. However, ClpP appears to have a role in reducing protein carbonyls in cells lacking Lon and HslVU. Proteomic immunodetection of carbonylated proteins in the wild-type, lon, and hslVU strains demonstrated that the same spectrum of proteins displayed a higher load of carbonyl groups in the lon and hslVU mutants. These proteins included the beta-subunit of RNA polymerase, elongation factors Tu and G, the E1 subunit of the pyruvate dehydrogenase complex, isocitrate dehydrogenase, 6-phosphogluconate dehydrogenase, and serine hydroxymethyltranferase.
...
PMID:Defense against protein carbonylation by DnaK/DnaJ and proteases of the heat shock regulon. 1593 82

Isozyme phenotypes were determined for 101 strains of Gibberella fujikuroi and 2 strains of Gibberella nygamai that represent seven biological species (mating populations) isolated from a variety of plant hosts in dispersed geographic locations. Fourteen enzymes were resolved in one or more of three buffer systems. Two of the enzymes, arylesterase and acid phosphatase, were polymorphic within two or more biological species and are suitable for intraspecific studies of population variation. Six enzymes, alcohol dehydrogenase, aspartate aminotransferase, glucose-6-phosphate dehydrogenase, mannitol dehydrogenase, phosphoglucomutase, and phosphogluconate dehydrogenase, were monomorphic in all of the isolates examined. The remaining six enzymes, fumarase, glucose phosphate isomerase, glutamate dehydrogenase (NADP), isocitrate dehydrogenase (NADP), malate dehydrogenase, and triose-phosphate isomerase, could potentially be used to distinguish the different biological species. Mating populations C and D are the most similar, since the mating population C isolates examined had the same isozyme phenotype as did a subset of the isolates in mating population D. Mating population E is the least similar to the other taxa examined. Unique isozyme phenotypes are present but are composed of banding patterns shared among the biological species. This finding supports the hypothesis that these biological species, with the possible exception of mating populations C and D, are reproductively isolated from one another and that no significant gene flow is occurring between them. Isozyme analysis is a useful method to distinguish these closely related biological species. Examination of isozyme phenotypes is more rapid than the present technique, which is based on sexual crosses; can be applied to strains that are not sexually fertile; and is more sensitive than traditional morphological characters, which cannot distinguish more than three or four morphological groups among the seven biological species. While emphasizing the discreteness of the mating populations as biological entities, our isozyme data also reaffirm the close genetic relationship among these groups.
...
PMID:Isozyme Variation among Biological Species in the Gibberella fujikuroi Species Complex (Fusarium Section Liseola). 1653 23

Clinical and experimental studies have shown the adverse effects of excess glucocorticoid on testicular testosterone production. The NADPH co-enzyme has been recognized as an important factor that regulates several steps in steroidogenesis, while glucose oxidation acts as a limiting factor on testicular testosterone production. Nevertheless, the impact of excess corticosterone, the stress hormone on testicular NADPH availability and glucose oxidation is unknown. Therefore, the present study was designed to assess the specific effects of excess corticosterone on Leydig cell NADPH generating enzymes and glucose oxidation. Adult Wistar rats (200-250 g, b.w.) were treated with corticosterone-21-acetate (2 mg/ 100 g, b.w., i.m., twice daily) for 10 days and corticosterone-21-acetate plus luteinizing hormone (LH) (100 microg/kg b.w., i.m., daily) for 10 days. After the treatment period, experimental animals and controls were killed, blood was collected and the sera separated for testosterone assay. Testes were removed and Leydig cells were isolated, purified and used for estimating the specific activity of NADPH generating enzymes and 14C-glucose oxidation. Serum testosterone, Leydig cellular 14C-glucose oxidation and the specific activities of 6-phosphogluconate dehydrogenase (6-PGDH), NADP-isocitrate dehydrogenase (ICDH) and malic enzyme were significantly decreased in corticosterone-treated rats. Co-administration of LH with corticosterone maintained the specific activities of 6-PGDH and ICDH and 14C-glucose oxidation at control level. Nevertheless, serum testosterone and Leydig cellular malic enzyme activity showed a significant decrease in these rats. In conclusion, the inhibitory effects of excess corticosterone on Leydig cell steroidogenesis are mediated through impaired glucose oxidation and defective NADPH generation. Co-administration of LH with corticosterone failed to prevent the decrease in serum testosterone and Leydig cell malic enzyme activity, suggesting the dominant inhibitory effects of excess corticosterone.
...
PMID:Effects of excess corticosterone on NADPH generating enzymes and glucose oxidation in Leydig cells of adult rats. 1663 30

The symbiosis between legumes and rhizobia is characterised by the formation of dinitrogen-fixing root nodules. In natural conditions, nitrogen fixation is strongly impaired by abiotic stresses which generate over-production of reactive oxygen species. Since one of the nodule main antioxidant systems is the ascorbate-glutathione cycle, NADPH recycling that is involved in glutathione reduction is of great relevance under stress conditions. NADPH is mainly produced by glucose 6-phosphate dehydrogenase (G6PDH; EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGDH; EC 1.1.1.44) from the oxidative pentose phosphate pathway, and also by NADP(+)-dependent isocitrate dehydrogenase (ICDH; EC 1.1.1.42). In this work, 10 microM paraquat (PQ) was applied to pea roots in order to determine the in vivo relationship between oxidative stress and the activity of the NADPH-generating enzymes in nodules. Whereas G6PDH and 6PGDH activities remained unchanged, a remarkable induction of ICDH gene expression and a dramatic increase of the ICDH activity was observed during the PQ treatment. These results support that ICDH has a key role in NADPH recycling under oxidative stress conditions in pea root nodules.
...
PMID:NADPH recycling systems in oxidative stressed pea nodules: a key role for the NADP+ -dependent isocitrate dehydrogenase. 1689 92


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---