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)

Isomyosin analyses by biochemical, immunochemical, and histochemical investigations have been carried out in five sheep following unilateral recurrent laryngeal nerve paralysis and direct functional electrostimulation of the denervated cricoarytenoid posterior muscle. Myosin light chains were identified by two-dimensional gel electrophoresis. Myosin heavy chains were analyzed by one-dimensional SDS-polyacrylamide gel electrophoresis. Slow myosin heavy chain was identified by orthogonal peptide mapping and immunochemistry. The stimulation effect at cellular level was determined using adenosine triphosphatase (ATPase) histochemistry. A dramatic increase of the type 1 fiber area (slow, fatigue-resistant fibers) could be seen after many weeks of an increasing regime of low-frequency direct electrical stimulation. Biochemically, the amount of slow myosin was always higher than in normal muscles. Some muscles were transformed almost completely to the slow type. At the time they were studied and with the methods employed, the expression of embryonic isomyosin was not observed. In conclusion, after numerous weeks of maintained functional activity, elicited by direct electrostimulation, the denervated muscle regionally showed areas of hypertrophy or at least lack of atrophy of slow myofibers without major signs of muscle damage.
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PMID:Isomyosin changes after functional electrostimulation of denervated sheep muscle. 297 27

Several approaches were adopted for the disruption and removal of the tegumental surface from protoscoleces of the horse strain of the hydatid organism, Echinococcus granulosus. The effectiveness of each method and the purity of subsequent microthrix-enriched fractions obtained by differential centrifugation were evaluated by electron microscopy, by the amount of protein released and by the degree of enrichment of surface plasma membrane marker enzymes. Incubation in saponin for 10 min produced the purest microtriche preparation, but in low yield; freeze/thawing, incubation in Triton X-100 for 10 min or in saponin for 20 min produced fractions containing significant amounts of relatively pure microtriches, but mild homogenization was a poor method for surface disruption and subsequent isolation of microtriches. Phosphodiesterase, adenosine triphosphatase (total and ouabain-inhibited), leucine aminopeptidase and glutamyltransferase were active in the protoscoleces but none were enriched in any of the microthrix fractions. In contrast, alkaline phosphatase, acid phosphatase, 5' nucleotidase and maltase were enriched significantly in all of the isolated microtriche preparations, which suggests that these enzymes are predominantly surface membrane bound. The protein profiles of the microthrix-enriched fractions, following SDS-PAGE, were basically similar, although there were some qualitative and quantitative differences in the proteins released by each isolation procedure. Three major PAS-staining components were present in all the preparations and these probably originated from the glycocalyx. One of these PAS-positive components, with an approximate molecular weight of 110 kDa, may be a glycoprotein specific to the horse strain of E. granulosus.
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PMID:Isolation, fractionation and partial characterization of the tegumental surface from protoscoleces of the hydatid organism, Echinococcus granulosus. 398 50

1. Two mutants of Escherichia coli K 12 were isolated which, although able to grow on glucose, are unable to grow with succinate or d-lactate as the sole source of carbon. 2. Genetic mapping of these mutants showed that they both contain a mutation in a gene (designated uncA) mapping at about minute 73.5 on the E. coli chromosome. 3. The uncA(-) alleles were transferred by bacteriophage-mediated transduction into another strain of E. coli and the transductants compared with the parent strain to determine the nature of the biochemical lesion in the mutants. 4. The mutants gave low aerobic growth yields when grown on limiting concentrations of glucose, but oxidase activities in membranes from both the mutants and the normal strain were similar. 5. Measurement of P/O ratios with d-lactate as substrate indicated that a mutation in the uncA gene causes uncoupling of phosphorylation associated with electron transport. 6. Determination of the Mg(2+),Ca(2+)-stimulated adenosine triphosphatase activities in the mutant and normal strains indicated that the uncA gene is probably the structural gene for Mg(2+),Ca(2+)-stimulated adenosine triphosphatase. 7. Mg(2+),Ca(2+)-stimulated adenosine triphosphatase therefore appears to be essential for oxidative phosphorylation in E. coli.
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PMID:Oxidative phosphorylation in Escherichia coli K12. Mutations affecting magnesium ion- or calcium ion-stimulated adenosine triphosphatase. 425 22

The actomyosin protein complex of Physarum polycephalum was prepared from vegetative and starved plasmodia. The yield of actomyosin per unit wet wt. was the same from both types of plasmodia. Myosin was resolved from the complex by gel filtration and purified by ion-exchange chromatography. The Ca(2+)-stimulated adenosine triphosphatase activities of myosin preparations from vegetative and starved plasmodia were not appreciably different. Synthesis of myosin de novo was shown to occur during the starvation phase of the life-cycle by the isolation of labelled myosin preparations from plasmodia starved in the presence of [2-(14)C]glycine. Fractionation of polyacrylamide gels after gel filtration of labelled myosin confirmed the presence of label in the adenosine triphosphatase-active myosin band. It is concluded that during starvation myosin synthesis continues although there is a net loss of approx. 50% of the total protein. Sodium dodecyl sulphate-polyacrylamide-gel electrophoresis of Physarum myosin showed the presence of low-molecular-weight components of the molecule, similar to those of muscle myosins. The content and composition of the free amino acid pool of Physarum was measured at various time-intervals during the vegetative and starvation phases of the life-cycle.
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PMID:The biosynthesis of plasmodial myosin during starvation of Physarum polycephalum. 427 85

1. Energy-linked and non-energy-linked transhydrogenase activities were assayed in membrane preparations from normal Escherichia coli K 12 and from various mutant strains. 2. The energy-linked transhydrogenase, which uses ATP as energy source, was dependent for activity on the presence of a functional Mg(2+)+Ca(2+)-stimulated adenosine triphosphatase. 3. Neither of the quinones formed by E. coli, namely ubiquinone-8 and menaquinone-8, was required for normal ATP-dependent energy-linked transhydrogenase activity. 4. The energy-linked transhydrogenase was inhibited by piericidin A at a site unrelated to the sites of inhibition of the electron-transport chain by piericidin A.
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PMID:The energy-linked transhydrogenase reaction in respiratory mutants of Escherichia coli K12. 433 91

In order to get precise information about the movement of plasma membrane proteins in cap formation, cyto- and bio-chemical analyses were made of the plasma membranes from non-capped areas of Ehrlich ascites tumor cells (EATCs) exposed to concanavalin A (Con A). Blebs formed by treatment with cytochalasin B (CB) of the non-capped areas of cells having a cap were isolated and used as the plasma membranes from non-capped areas (ConA-CB-bleb fraction). This bleb fraction was compared with a bleb fraction prepared from cells without ConA-treatment (CB-bleb fraction). Cytochemical analysis of ConA-CB-bleb fraction revealed a decreased in conA binding sites (ConA-BS) compared to the CB-bleb fraction. SDS polyacrylamide slab gel electrophoresis also revealed a decrease in the major components of ConA-BS of the ConA-CB-bleb fraction. The minor components of ConA-BS showed no distinct quantitative difference between the ConA-CB-bleb and CB-bleb fractions. NA+ K+-adenosine triphosphatase (ATPase), 5' nucleotidase (5'ND) and gamma-glutamyl transpeptidase (gamma-GTP) did not show any decrease in activity in the ConA-CB-bleb fraction, but the activity of D+-stimulated phosphatase (K-Pase) was decreased. The findings indicate that there are two types of plasma membrane glycoproteins in EATCs; one includes those participating in cap formation due to ConA, e.g. the major components of ConA-BS and K-Pase, and the other, those not participating in such cap formation, e.g. some minor components of ConA-BS, ATPase, 5'ND and gamma-GTP, which keep their places without moving.
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PMID:Movement of plasma membrane proteins of Ehrlich ascites tumor cells in relation to cap formation induced by concanavalin A: a study on the non-capped areas. 611 90

Electron spin resonance, enzymatic, and SDS-polyacrylamide gel electrophoretic investigations of erythrocyte membranes from patients with Alzheimer's disease were performed. Alterations in the physical state of membrane proteins in Alzheimer's disease erythrocytes were found by spin labeling studies. However, no alterations in membrane lipid fluidity or in the activities of membrane-bound sodium plus potassium-stimulated, magnesium-dependent adenosine triphosphatase or acetylcholinesterase could be demonstrated. Also, no changes in staining profiles of AD erythrocyte membrane proteins subjected to electrophoresis were observed. The altered conformation and/or organization of extraneural membrane proteins in Alzheimer's disease suggests the possibility that this disorder may have more widespread membrane involvement than was originally thought.
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PMID:Spin label and biochemical studies of erythrocyte membranes in Alzheimer's disease. 624 87

The molecular weight and stoichiometry of the subunits of the sodium- and potassium-activated adenosine triphosphatase. (Na,K)-ATPase, have been examined in four highly purified preparations of this enzyme: dog kidney, eel electroplax, dogfish rectal gland, and brine shrimp nauplius. The molecular weights of the subunits were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) at 10 different total acrylamide concentrations (%T) and by a gradient SDS-PAGE system, standardized with 16 molecular weight marker proteins of known primary structure. The molecular weight of the large (Na,K)-ATPase subunit (alpha subunit) was found to be reliably estimated by SDS-PAGE, whereas the small subunit (beta subunit) was not. The molecular weight of the alpha subunit was 97,000, 97,700, 104,200, and 97,800 for the dog, eel, dogfish, and brine shrimp (Na,K)-ATPase, respectively. The molecular weight of the beta subunit is overestimated by SDS-PAGE. Mass ratio analysis of the alpha and beta subunits separated by SDS-PAGE was determined by three techniques: total amino acid quantitation, gel scanning and dye elution of Coomassie blue-stained gels, and UV gel scanning. The former method, which provides the most reliable estimate of the mass ratio, gives an alpha/beta mass ratio of 2.41, 2.33, 2.91, and 2.44 for the dog, eel, dogfish, and brine shrimp preparations, respectively. Results of the mass ratio studies, the molecular weight analysis, and prior cross-linking studies clearly demonstrate that the quaternary structure of the (Na,K)-ATPase is an alpha 2 beta 2 tetramer in all four species. Based on all of the above data, a more reliable molecular weight estimate of the beta subunit is calculated as 40,200, 43,000, 35,800, and 40,100 for the dog, eel, dogfish, and brine shrimp preparations, respectively. These results now confirm that the molecular weight of the protein portion of the alpha subunit is near 100,000 and that of the beta subunit is near 40,000 and that the (Na,K)-ATPase holoenzyme is an alpha 2 beta 2 tetramer of molecular weight 274,000 to 280,000, regardless of species.
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PMID:Molecular weight and stoichiometry of the sodium- and potassium-activated adenosine triphosphatase subunits. 626 Jul 77

Several methods of purification of Na+,K+-adenosine triphosphatase (ATPase) have been previously described for a wide variety of tissues. In general, highest activity preparations have necessitated large amounts of tissue and many purification steps. This article describes a technique that allows partial purification of Na+,K+-ATPase from as few as 15 rat brains and should be of interest to investigators of the pharmacology of this particular enzyme system. In this modified version of the Jorgensen procedure (Biochim Biophys Acta 356:36--52, 1974) we purified the Na+,K+-ATPase from 15--90 rat brains, and obtained enzyme preparations with a mean specific activity of 552 +/- 37.6 mumol Pi/mg of protein/hr (95.5% ouabain sensitive). This "purified" enzyme had an activity ratio (Mg2+ + Na+ + K+)/(Mg2+ + Na+) of 47.4 +/- 12.3 SEM, compared to 3.29 +/- 0.17 SEM for the untreated microsomes. Ouabain inhibited the "purified" enzyme with an I50 of 6 X 10(-9) M. Ouabain binding (644 pmol/mg of protein) yielded a turnover number of 13,700 min-1. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis of the enzyme revealed predominantly the alpha and beta subunits with some minor contaminant bands. Previous methods of purification of rat brain Na+,K+-ATPase have employed sodium deoxycholate and high concentrations of NaI; the reported specific activity obtained was generally 150--350 mumol Pi/mg of protein/hr. We have employed higher SDS concentrations than in Jorgensen's technique for rabbit kidney but the procedure is simpler because sucrose gradients are not used. Final wash steps also include 10--20% glycerol in the media. These modifications have yielded Na+,K+-ATPase of significantly higher specific activity than previously reported for rat brain.
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PMID:A simple method for the purification of rat brain Na+,K+-adenosine triphosphatase (ATPase). 628 10

The isolation of basolateral membranes from rat proximal colonic epithelial cells is described. Cells were harvested using a technique combining chelation of divalent cations with mechanical dissociation. After homogenization, differential centrifugation yielded a 'crude' membrane fraction which was further purified using sucrose density centrifugation. The final membrane fraction was enriched 10-14-fold over homogenate in ouabain-sensitive sodium-potassium dependent adenosine triphosphatase and ouabain-sensitive potassium-dependent phosphatase specific activities. SDS-polyacrylamide gel electrophoresis of this membrane revealed at least 18 protein bands with molecular weights of 14600-200000. Phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, free cholesterol and fatty acids were the major lipid components of this membrane. The predominant fatty acids were palmitic (16:0), oleic (18:1), stearic (18:0) and linoleic (18:2) acid. Membranes and their liposomes were studied, using the lipid soluble fluorophore 1,6-diphenyl-1,3,5-hexatriene (DPH), by steady-state fluorescence polarization. The fluorescence anisotropy was greater in the intact membranes compared to their liposomes, indicating greater fluidity in the liposomes. Compositional studies suggested that the high fluidity of this membrane was due to its low ratios of protein/lipid (w/w), cholesterol/phospholipid (mol/mol), and sphingomyelin/phosphatidylcholine (mol/mol).
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PMID:Isolation and partial characterization of basolateral membranes from rat proximal colonic epithelial cells. 683 Jul 71


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