Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of temperature on the activation energies of mitochondrial enzymes of the yeast Saccharomyces cerevisiae was examined. Non-linear Arrhenius plots with discontinuities in the temperature range 14-19 degrees C and 19-22 degrees C were observed for the respiratory enzymes and mitochondrial ATPase (adenosine triphosphatase) respectively. A straight-line Arrhenius plot was observed for the matrix enzyme, malate dehydrogenase. The activation energies of the enzymes associated with succinate oxidation, namely, succinate oxidase, succinate dehydrogenase and succinate-cytochrome c oxidoreductase, were in the range 60-85kJ/mol above the transition temperature and 90-160kJ/mol below the transition temperature. In contrast, the corresponding enzymes associated with NADH oxidation showed significantly lower activation energies, 20-35kJ/mol above and 40-85kJ/mol below the transition temperature. The discontinuities in the Arrhenius plots were still observed after sonication, treatment with non-ionic detergents or freezing and thawing of the mitochondrial membranes. Discontinuities for cytochrome c oxidase activity were only observed in freshly isolated mitochondria, and no distinct breaks were observed after storage at -20 degrees C. Mitochondrial ATPase activity still showed discontinuities after sonication and freezing and thawing, but a linear plot was observed after treatment with non-ionic detergents. The results indicate that the various enzymes of the respiratory chain are located in a similar lipid macroenvironment within the mitochondrial membrane.
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PMID:Phase transitions in yeast mitochondrial membranes. The effect of temperature on the energies of activation of the respiratory enzymes of Saccharomyces cerevisiae. 16 75

Isolated membrane fractions of Escherichia coli K-12 yielded complex immunoprecipitate patterns when Triton X-100 and sodium dodecyl sulfate extracts were examined by crossed immunoelectrophoresis with antienvelope immunoglobulins. Twelve of the 46 antigens in the immunoprecipitate patterns of inner (plasma) membranes were identified by zymograms and/or by the use of specific antisera. The following enzyme activities were detected in immunoprecipitates: 6-phosphogluconate dehydrogenase (EC 1.1.1.43); adenosine triphosphatase (EC 3.6.1.3); glutamate dehydrogenase (EC 1.4.1.4), two separate components; malate dehydrogenase (EC 1.1.1.37); dihydroorotate dehydrogenase (EC 1.3.3.1); succinate dehydrogenase (EC 1.3.99.1); lactate dehydrogeanse (EC 1.1.1.27); reduced nicotinamide adenine dinucleotide dehydrogenase (EC 1.6.99.3); protease (EC 3.4.21.1); and glycerol 3-phosphate dehydrogenase (EC 1.1.99.5). The corresponding immunoprecipitate pattern for isolated outer membranes consisted of at least 25 discrete antigens and differed strikingly from that obtained with inner membranes. Two major immunogens were identified as lipopolysaccharide and Braun lipoprotein. A protease-active immunoprecipitate was also detected in this fraction, but attempts to identify the Rosenbusch matrix protein in the crossed immunoelectrophoretic profile were unsuccessful.
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PMID:Immunochemical analysis of inner and outer membranes of Escherichia coli by crossed immunoelectrophoresis. 33 83

Whole sheets of plasma membrane, each with their attached flagellum, were purified from Trypanosoma brucei. The method devised for their isolation included a new technique of cell breakage that used a combination of osmotic stress followed by mechanical sheer and avoided the problem of extreme vesiculation as well as the trapping of organelles in cell 'ghosts'. The purified membranes all contained the pellicular microtubular array. The antigenic surface coat was completely released from the plasma membrane during the isolation procedure. The membranes had a very high cholesterol/phospholipid ratio (1.54). A large proportion (42%) of the cellular DNA was recovered in the plasma-membrane fraction unless a step involving deoxyribonuclease treatment, which decreased the DNA content to less than 13%, was included before secrose-density gradient centrifugation. This step also aided the separation of plasma membranes from other cellular components. The ouabain-sensitive Na+ + K+-stimulated adenosine triphosphatase and adenylate cyclase co-purified with the plasma membranes. Although 5'-nucleotidase was thought to be a plasma-membrane component, it was easily detached from the membrane. The purified membranes were essentially free of L-alanine-alpha-oxoglutarate aminotransferase, L-asparte-alpha-oxoglutarate aminotransferase, malate dehydrogenase, oligomycin-sensitive adenosine triphosphatase, glucose 6-phosphatase, Mg2+-stimulated p-nitrophenyl phosphatase and catalase.
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PMID:The isolation and partial characterization of the plasma membrane from Trypanosoma brucei. 48 94

The effect of dl-norgestrel (13 beta-ethyl-17 alpha-ethynyl-19-nortestosterone, Wy 3707) on the biochemical makeup of rabbit ovary and uterus was investigated. 20 adult, healthy virgin female rabbits either received olive oil only or olive oil plus 12 mcg of norgestrel/rabbit/day for 30 days. The animals were sacrificed 24 hours after the last treatment. In the ovary protein concentration and activities of glucose-6-phosphate dehydrogenase (G6PD), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) remained unaffected. However, in the uterus the level of protein was significantly elevated (p less than .01), the activities of G6PD and acid phosphatase were enhanced (p less than .05), and those of adenosine triphosphatase (ATPase) and alkaline phosphatase were diminished (p less than .05). LDH and MDH in the uterus remained unchanged. The effect of norgestrel at this antiovulatory dose in rabbits consisted of a disturbance in the biochemical constituents of the uterus leading to a lowering of the ATPase activity and an impairment of the anaerobic mechanism of the organ.
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PMID:Effect of di-norgestrel (13beta-ethyl-17alpha-ethynyl-19-nortestosterone, Wy 3707) on the reproductive organs of rabbit. 122 53

Chronic infection of woodchucks with woodchuck hepatitis virus (WHV) was associated with the development of hepatitis, foci of altered hepatocytes and hepatocellular adenomas and carcinomas. The cytomorphological and cytochemical analysis permitted the identification of three different types of focal lesions; namely, glycogen-storage foci, mixed-cell foci and intermediate-cell foci, each showing a characteristic pattern. The cells of the glycogen-storage foci had clear to acidophilic cytoplasm, and were overloaded with glycogen. They showed a marked elevation in the activity of glucose-6-phosphate dehydrogenase (G6PDH) and malate dehydrogenase (MDH), increased activity of succinate dehydrogenase (SDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and glycerol-3-phosphate dehydrogenase (G3PDH), reduction in the activity of glycogen phosphorylase (PHO), glucose-6-phosphatase (G6Pase), adenosine triphosphatase (ATPase) and adenyl cyclase (ADC), and unchanged activity of glycogen synthase (SYN) and gamma-glutamyl transferase (GGT). The mixed-cell foci mainly consisted of basophilic cells poor in glycogen, but were intermingled with cells containing glycogen. These foci were characterized by a marked decrease in activity of PHO, SYN, G6Pase, G6PDH, ATPase and ADC, and increased activity of GGT, SDH, MDH and GAPDH. The intermediate-cell foci consisted of cells with both basophilic and glycogenotic cytoplasmic compartments, and showed a similar enzyme histochemical profile to the mixed-cell foci, with slight differences in the degree of elevation or reduction of some enzymes. The phenotypic similarities and the close spatial relationship between the foci of altered hepatocytes, and the hepatocellular adenomas and carcinomas in WHV-infected woodchucks, suggest that these lesions are preneoplastic. The focal morphological and metabolic aberrations emerging during hepatocarcinogenesis in WHV-infected woodchuck, are in principle similar to those identified in the course of chemical hepatocarcinogenesis in various species. The focal metabolic aberrations apparently represent a general biological response of the liver parenchyma to oncogenic agents and are closely linked to neoplastic transformation of the hepatocytes.
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PMID:Phenotypic patterns of preneoplastic and neoplastic hepatic lesions in woodchucks infected with woodchuck hepatitis virus. 215 41

Administration of different doses of L-thyroxine (T4) and triiodo-L-thyronine (T3) in vivo in G. carnosus stimulated the activities of cytochrome oxidase, alpha-glycerophosphate dehydrogenase (alpha-GPDH), succinate dehydrogenase (SDH), and Mg2+ adenosine triphosphatase (Mg2+ ATPase) and inhibited the activity of malate dehydrogenase (MDH). While a low dose of thiouracil administration produced a stimulatory effect on cytochrome oxidase and alpha-GPDH activities, a higher dose of thiouracil significantly inhibited the activities of cytochrome oxidase, alpha-GPDH, SDH, Mg2+ ATPase, and MDH. Injection of T4 or T3 into thiouracil-treated animals significantly restored the stimulatory effect of thyroid hormones on oxidative enzyme activities. It is suggested that thyroid hormones in vivo increase and that thiouracil decreases the oxidative capacity of hepatic mitochondria of G. carnosus.
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PMID:Stimulation of oxidative metabolism by thyroid hormones in an apodan amphibian, Gegenophis carnosus (Beddome). 216 65

Oral administration of DEHP, 1000 mg/kg body weight, to rats daily from 6 to 15 day of gestation resulted in retardation of fetal growth and increase in fetal liver weight which contained significant quantities of DEHP. The activities of mitochondrial succinate dehydrogenase, malate dehydrogenase, cytochrome c oxidase and adenosine triphosphatase were decreased in fetal liver. The data indicate that exposure of mothers to DEHP during pregnancy could adversely affect the fetal livers by interfering with bioenergetics of the cell.
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PMID:Biochemical alterations in rat fetal liver following in utero exposure to di(2-ethylhexyl)phthalate (DEHP). 263 47

Fibers of the garter snake transversus abdominis muscle fall into three classes according to contraction speed: faster and slower twitch and tonic. To determine the relationship between these physiologically determined classes and established mammalian fiber types, individual fibers were assayed for key enzymes representing the major energy-generating pathways in vertebrate muscle. Five such enzymes were examined: lactate dehydrogenase, malate dehydrogenase, adenylokinase, fumarate hydratase, and beta-hydroxyacyl-CoA dehydrogenase. The muscle contained three principal metabolic fiber types. Fast-contracting twitch fibers had low-oxidative but high-glycolytic capacity and therefore resembled mammalian-type fast-twitch glycolytic (FG) fibers. Slower twitch fibers were high oxidative-high glycolytic, similar to mammalian-type fast-twitch, oxidative, glycolytic (FOG) fibers. Tonic fibers were high oxidative-low glycolytic; this metabolic profile is characteristic of type slow-twitch oxidative (SO) fibers in mammals. Activity of the enzyme adenylokinase, which in mammals correlates with contraction speed and myosin adenosine triphosphatase (ATPase) activity, separated these reptilian fibers into three groups that are similar but not identical to those delineated by oxidative and glycolytic enzymes. Adenylokinase and beta-hydroxyacyl-CoA dehydrogenase showed the widest range of activities in snake muscle and, therefore, the greatest ability to discriminate fiber types.
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PMID:Metabolic fiber types of snake transversus abdominis muscle. 273 94

The half-life of mitochondrial adenosine triphosphatase and the relative rate constants of protein degradation for several fractions of rat liver have been measured by the double-isotope technique. It has been shown that the apparent turnover rates of some mitochondrial enzymes, far apart in size, such as carbamoyl phosphate synthetase, glutamate dehydrogenase and malate dehydrogenase, are not related to molecular weight or to size of subunits. In view of the possibility that mitochondrial proteins are degraded by different mechanisms, it was of interest to determine the half-life of a protein tightly bound to the inner membrane such as adenosine triphosphatase. The rate constants of degradation for rats fed a basal diet and injected at three-day intervals with isotopic leucine were: homogenate, kd = 0.195 days-1; mitochondria, kd = 0.135 days-1; cytosol, kd = 0.140 days-1; microsomes, kd = 0.28 days-1; ATPase, kd = 0.275 days-1. The rate constants of the cellular fractions of liver of rats fed a high protein diet did not change or showed a small increase, compared with those of animals fed the basal diet, while those from rats on the protein-free diet showed a decrease. The rate constant for adenosine triphosphatase showed an increase with high-protein and a decrease with protein-free diet. A procedure for the purification of ATPase from a single liver of a rat is described.
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PMID:Turnover of adenosine triphosphatase from rat liver mitochondria. Effect of high-protein and low-protein diets. 621 5

Parietal cells in the luminal segments of mouse gastric glands show high activity of acid-secreting potassium-dependent adenosine triphosphatase (H+, K+-ATPase) and of nicotinamide adenine dinucleotide-linked isocitrate dehydrogenase (NAD-ICDHase) and malate dehydrogenase (MDHase) but low activity of succinate dehydrogenase (SDHase). This pattern of activity is reversed in the basal segments of the same glands. These results and previous morphological findings support the conclusion that luminal segment parietal cells are much more active in hydrochloric acid secretion than those of the basal segment. The origin of this zonation may be either cellular deterioration with age or some more specific form of regulation of parietal cell metabolism.
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PMID:Cytochemical evidence for functional zonation of parietal cells within the gastric glands of the mouse. 631 15


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