Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.4.1.2 (acetyl-CoA carboxylase)
 2,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The enzyme activities responsible for carboxylation reactions in cell extracts of the gastric pathogen Helicobacter pylori have been studied by H14CO3- fixation and spectrophotometric assays. Acetyl coenzyme A carboxylase (EC 6.4.1.2) and malic enzyme (EC 1.1.1.40) activities were detected, whereas pyruvate carboxylase (EC 6.4.1.1), phosphoenolpyruvate carboxylase (EC 4.1.3.1) and phosphoenolpyruvate carboxykinase (EC 4.1.1.49) activities were absent. However, a pyruvate-dependent, ATP-independent, and avidin-insensitive H14CO3- fixation activity, which was shown to be due to the isotope exchange reaction of pyruvate:flavodoxin oxidoreductase (EC 1.2.7.1), was present. The purified enzyme is composed of four subunits of 47, 36, 24, and 14 kDa. N-terminal sequence analysis showed that this enzyme is related to a recently recognized group of four-subunit pyruvate:ferredoxin oxidoreductases previously known only from hyperthermophiles. This enzyme from H. pylori was found to mediate the reduction of a number of artificial electron acceptors in addition to a flavodoxin isolated from H. pylori extracts, which is likely to be the in vivo electron acceptor. Indirect evidence that the enzyme is capable of in vitro reduction of the anti-H. pylori drug metronidazole was also obtained.
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PMID:Identification of carboxylation enzymes and characterization of a novel four-subunit pyruvate:flavodoxin oxidoreductase from Helicobacter pylori. 760 66

The hypothesis is advanced that NADP(+)-malic enzyme (ME; EC 1.1.1.40) is an important activity in regulating the extent of lipid accumulation in filamentous fungi. In Mucor circinelloides, a fungus capable of accumulating only 25% (w/w, dry wt) lipid, even under the most propitious conditions, ME disappears 15-20 h after nitrogen exhaustion, coincident with the cessation of lipid accumulation. In contrast, ME in Mortierella alpina, a fungus capable of accumulating 50% (w/w, dry wt) lipid, remains active for over 60 h after N-exhaustion during which time lipid accumulation continues. No other enzyme activity studied, including the lipogenic enzymes acetyl-CoA carboxylase, fatty acid synthase, diacyglycerol acyltransferase, ATP: citrate lyase and the NADPH-generating enzymes glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and NADP+:isocitrate dehydrogenase, demonstrated any correlation with the accumulation of storage lipid in either fungus. Full activity of ME is restored in Mr. circinelloides within 4 h by adding NH4+ to the cultures, but this is prevented by adding cycloheximide as an inhibitor of protein synthesis. This suggests that the decrease in ME activity occurs due to down-regulation of the ME gene.
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PMID:The role of malic enzyme in the regulation of lipid accumulation in filamentous fungi. 1046 57

Several nondigestible but fermentable dietary carbohydrates are able to regulate lipemia and triglyceridemia in both humans and animals. The mechanism of their serum lipid-lowering effect remains to be elucidated. Oligofructose, which is a mixture of nondigestible and fermentable fructans, can decrease triacylglycerol in VLDL when given to rats. The triacylglycerol-lowering action of oligofructose is due to a reduction of de novo fatty acid synthesis in the liver through inhibition of all lipogenic enzymes, namely acetyl-CoA carboxylase (EC 6.4.1.2), fatty acid synthase, malic enzyme (EC 1.1.1.40), ATP citrate lyase (EC 4.1.3.8), and glucose-6-phosphate dehydrogenase (EC 1.1.1.49). Our results suggest that oligofructose decreases lipogenic enzyme gene expression. Postprandial insulin and glucose concentrations are low in the serum of oligofructose-fed animals and this could explain, at least partially, the metabolic effect of oligofructose. Moreover, some events occurring in the gastrointestinal tract after oligofructose feeding could be involved in the antilipogenic effect of this fructan: the production of propionate through fermentation, a modulation of the intestinal production of incretins (namely glucose-dependent insulinotropic peptide and glucagon-like peptide-1), or the modification of the availability of digestible carbohydrates. Recent studies showed that the hypotriglyceridemic effect of fructans also occurs in humans.
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PMID:Effects of fructans-type prebiotics on lipid metabolism. 1115 57


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