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

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A site-directed mutation in the gene which codes for the c-subunit of the F1F0-ATPase, resulting in the substitution of Ala-25 by Tyr, has been constructed and characterized. A plasmid carrying the mutation was used to transform strain AN943 (uncE429). The resulting strain is unable to grow on succinate as sole carbon source and possesses an uncoupled growth yield. Membranes prepared from the mutant possess low levels of ATPase activity and are proton-impermeable. The F1-ATPase activity was found to be inhibited by 80% when bound to the membrane. When carried on a plasmid, the mutation is dominant in complementation tests with all mutant unc alleles tested and when transformed into wild-type strain AN346, the mutation results in an uncoupled phenotype. A mutant which overcomes this dominance was isolated and found to possess an 11-amino-acid deletion extending from Ile-55 to Met-65 within the c-subunit. These results are discussed in relation to the previously isolated Ala-25 to Thr mutant (Fimmel, A.L., Jans, D.A., Hatch, L., James, L.B., Gibson, F. and Cox, G.B. (1985) Biochim. Biophys. Acta 808, 252-258) and in relation to a previously proposed model for the F0 (Cox, G.B., Fimmel, A.L., Gibson, F. and Hatch, L. (1986) Biochim. Biophys. Acta 849, 62-69).
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PMID:The F1F0-ATPase of Escherichia coli. The substitution of alanine by tyrosine at position 25 in the c-subunit affects function but not assembly. 252 60

We studied the testis of Wistar rats weighing 280-300 gms. following the administration of a single, acute intracardiac dose of methionine-enkephalin (100 microliters of 50% met-enkephalin solution), or a chronic intramuscular dose (50 microliters of 40% met-enkephalin solution). Rats were sacrificed at 15, 30 and 60 minutes following acute injection. Those on chronic treatment were injected once daily for 10 or 20 days. For the study, we utilized 105 male Wistar rats; 30 comprised the control group, and 75 comprised the study group. The following staining methods were used: 1) succinate dehydrogenase, 2) lactate dehydrogenase, 3) ATPase, 4) acid phosphatase, 5) alkaline phosphatase. We observed marked histoenzymological changes in the rat testis. Particularly noteworthy was a marked change in the energy pathways consisting of a decreased activity of aerobic pathways (decreased SDH activity), increased anaerobic activity (increased LDH activity), and consequently, decreased cellular energy stores (decreased ATPase activity). Similarly, changes were observed in other nonspecific enzymes that led to a fall in acid phosphatase activity and a rise in alkaline phosphatase activity.
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PMID:[Effects of met-enkephalin on the testis. III. Histoenzymatic study]. 253 59

The effect of vitamin A deficiency on the intestinal absorption of nutrients and the activities of brush border enzymes were studied in albino rats. Intestinal uptakes of D-glucose, L-methionine, L-tryptophan and L-histidine were significantly greater in vitamin A-deficient animals than in controls. The specific activities of total adenosine triphosphatase (ATPase), ouabain-sensitive ATPase, maltase and sucrase in the intestinal mucosa of vitamin A-deprived rats were 121, 124, 131 and 134 per cent respectively, of the corresponding values in control animals. The DNA content of the small intestine in vitamin A-deficient rats was 36.5 per cent lower than in control rats. The stimulation in digestive and absorptive capacity appears to be an adaptive change in vitamin A-deficiency which decreases the intestinal cell population.
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PMID:Effect of vitamin A deficiency on rat intestinal digestive & absorptive functions. 253 19

The rates of incorporation of [35S]methionine into Na+/K+ ATPase, actin (beta- and gamma-isoforms), and total protein of the preimplantation rabbit blastocyst were determined between Days 4 and 7 of development. Blastocyst proteins were metabolically radiolabelled with [35S]methionine and subsequently analysed by co-isolation with purified Na+/K+ ATPase using two-dimensional polyacrylamide gel electrophoresis, immunoprecipitation, immunoblotting, fluorography, and liquid scintillation spectroscopy. The rate of [35S]methionine incorporation into acid-soluble total protein increased 24-fold between Days 4 and 6 post coitum (p.c.), then diminished approximately 79% on Day 7. In-vitro incorporation of [35S]methionine was linear at each stage of blastocyst development. [35S]methionine incorporation rates were unaffected by low free intracellular methionine concentration (less than 0.06 mM) and stage-related differences in blastocoele volume. Analysis of beta- and gamma-actin synthesis revealed patterns of [35S]methionine incorporation rates which were similar to those of total protein. In contrast, synthesis of blastocyst Na+/K+ ATPase was characterized by a 90-fold increase (P less than 0.001) in the rate of [35S]methionine incorporation between Days 4 and 6 p.c. The results demonstrate that Na+/K+ ATPase is actively synthesized at a high and increasing rate during preimplantation development in the rabbit at a period which is characterized by rapid fluid accumulation by the blastocyst.
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PMID:Synthesis of Na+/K+ ATPase by the preimplantation rabbit blastocyst. 253 12

(Na+,K+)ATPase activity of rat liver plasma membranes was evaluated in female rats feeding an ethanol containing diet for 46 days (total ethanol ingested, 59.7 g/100 g body wt). Determinations were performed at the end of ethanol treatment or at various times after stopping treatment. (Na+,K+)ATPase and 5'-nucleotidase activities exhibited a 8- and 1.4-fold decrease, respectively, at the end of ethanol ingestion. In contrast no modifications of Mg2+-ATPase activity were observed. There also occurred, in ethanol-treated rats, release of sorbitol dehydrogenase into the blood, fat accumulation in liver cells, and decrease in reduced glutathione (GSH) liver content. A decrease in (Na+,K+)ATPase activity was also found in plasma membranes isolated from hepatocyte suspensions after a 2-hr incubation with 50 mM ethanol or 1 mM acetaldehyde (ACA), in conditions that caused a great fall in hepatocyte GSH content but did not cause cell death. After the cessation of ethanol administration, there occurred a progressive recovery of (Na+,K+)ATPase activity, GSH and triacylglycerol content, and release of sorbitol dehydrogenase. These parameters reached control values 12 hr after ethanol withdrawal. S-Adenosyl-L-methionine (SAM), L-methionine, and N-acetylcysteine (NAC), given to rats during ethanol treatment, prevented the decrease in (Na+,K+)ATPase activity and GSH content. They also reduced steatosis and liver necrosis. The efficiency of these compounds decreased in this order: SAM, methionine, NAC. SAM accelerated the recovery of all parameters studied after ethanol withdrawal, and also protected (Na+,K+)ATPase activity and GSH content of isolated hepatocytes from the deleterious effect of ethanol. These SAM effects were prevented by 1-chloro-2,4-dinitro-benzene, a compound which depletes cell GSH. Treatment of isolated hepatocytes with [35S]SAM led to the synthesis of labeled GSH. The total amount and specific activity of labeled GSH underwent a significant increase, in the presence of 2 mM ethanol or 0.5 mM ACA, which indicates a marked stimulation of GSH synthesis by ethanol and ACA. These data indicate that ethanol intoxication may inhibit (Na+,K+)ATPase activity; an effect that does not seem to depend on cell necrosis. SAM, methionine, and NAC exert various degrees of protection toward ethanol-induced cell injury, which are related to the efficiency of these compounds in maintaining a high GSH pool.
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PMID:Inhibition by ethanol of rat liver plasma membrane (Na+,K+)ATPase: protective effect of S-adenosyl-L-methionine, L-methionine, and N-acetylcysteine. 253 5

Molecular genetic evidence indicates that there should be three different (Na+ + K+)-stimulated ATPase (Na,K-ATPase) alpha subunit isozymes in the brain where previously only two ("alpha" and "alpha(+)") were resolved as proteins. To detect and identify alpha 1, alpha 2, and alpha 3 isozymes, polypeptides made by cell-free translation (Schneider, J.W., Mercer, R.W., Gilmore-Hebert, M., Utset, M.F., Lai, C., Greene, A., and Benz, E.J., Jr. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 284-288) were analyzed by gel electrophoresis and proteolytic fingerprinting. Synthetic alpha 1 comigrated with tissue alpha 1, while alpha 2 and alpha 3 comigrated with the leading and trailing edges, respectively, of tissue "alpha(+)." Proteolytic fingerprints of newborn rat brain Na,K-ATPase labeled in vivo with L-[35S]methionine indicated the presence of alpha 1 and alpha 3, and a low level of alpha 2. Monoclonal antibodies were characterized by the electrophoretic mobility of their antigens and by their ability to recognize the Na,K-ATPases of kidney, brain, and skeletal muscle. The antibodies were used to assess isozyme expression in the brain. All three isozymes increased in abundance during development from the 18-day fetus to the adult. Small changes were seen in the relative level of expression of alpha 1 and alpha 3 at different developmental ages, while alpha 2 expression increased markedly between the neonate and adult. In adult brain, all three isozymes were found in all brain regions examined. We conclude that all three isozymes are expressed as proteins and that their expression and distribution must be under complex control. No single developmental age or macroscopic brain region provides an exclusive source of any of the isozymes.
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PMID:Identification of three isozyme proteins of the catalytic subunit of the Na,K-ATPase in rat brain. 254 71

At least three types of mRNA of the catalytic subunit of Na,K-ATPase namely alpha-,alpha+- and alpha 3-isoforms are identified in different tissues. Only two of them alpha and alpha+ have well known structural and catalytic properties. Here we present immunochemical data indicating that the alpha 3 protein really exists in pig and human kidney, and human brain. Crude membrane fractions and purified membrane-bound Na,K-ATPases were immunoblotted with alpha 3-specific antibodies raised against the synthetic peptide corresponding to the unique sequence of this isoform. The mature alpha 3-subunit is shown to include the sequence GDKKDDKSSPK followed by the initiating methionine residue. Nephron collecting tubules are proposed to specifically contain Na,K-ATPase alpha 3-isoform.
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PMID:Immunodetection of Na,K-ATPase alpha 3-isoform in renal and nerve tissues. 254 11

Ribonucleic acid was isolated from the fundic gastric mucosae of rats and rabbits by cesium chloride centrifugation of guanidine isothiocyanate-denatured mucosal homogenates, and poly A+ RNA was recovered from the pellets by oligodeoxythymidine column selection. When added to rabbit reticulocyte lysates, this poly A+ RNA stimulated [35S]methionine incorporation into trichloroacetic acid-precipitable material. Fluorographic analysis of the lysates showed protein synthesis to be dominated by polypeptides with molecular weights from 40,000 to 50,000, presumably prepepsinogen isoforms. Immune precipitation of the lysates with monoclonal antibodies directed against the gastric H+,K+-adenosine triphosphatase yielded bands at 94 kilodaltons and more diffuse banding at 180 kilodaltons. Further purification of the poly A+ RNA on sucrose gradients eliminated prepepsinogen messenger RNA; nascent H+,K+-adenosine triphosphatase synthesized by purified messenger RNA consisted of polypeptides with molecular weights between 88,000 and 94,000. The study indicates that cell-free translation of gastric mucosal messenger RNA may provide a useful model for analysis of gastric H+,K+-adenosine triphosphatase biosynthesis and processing.
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PMID:Cell-free synthesis of rat and rabbit gastric proton pump. 255 Mar 9

Partially purified Na,K-ATPase from whole nauplii at various stages of development, analyzed by SDS-PAGE, reveals a polydisperse beta and two alpha subunits (denoted alpha 1 and alpha 2). In the absence of Ca2+, ATP-inhibitable fluorescein isothiocyanate (FITC) labeling is restricted to the alpha subunit of this enzyme, even in crude naupliar homogenates. The intensity of the alpha-specific fluorescent signal (i.e., the sum of the yield from both alpha isoforms) is proportional to Na,K-ATPase activity during development. FITC-labeled subunits were detected at 8 hr of development prior to the detection of measurable Na,K-ATPase activity. The alpha 2/alpha 1 ratio changed from an initial value of 1.25 to a peak of 1.75 at 32 hr of development, then reverted to a ratio of 1.25 by 42 hr, and remained constant thereafter. Pulse chase studies with 35S-methionine indicated that the developmental increase in enzyme activity is coincident with amino acid incorporation into the alpha subunits, implying that enzyme synthesis is active during enzyme accumulation.
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PMID:Isoforms of Na,K-ATPase in Artemia saline: I. Detection by FITC binding and time course. 255 Jun 49

The Na,K-ATPase alpha 3 isoform of the catalytic subunit has been isolated from pig kidney microsomes. The procedure employs immunoaffinity chromatography on Sepharose 4B covalently coupled with monospecific antibodies a-II against the synthetic peptide including the putative alpha 3 N-terminus. The structural analysis provides unambiguous proof that the isolated protein corresponds to the third transcript for the alpha 3 isoform. The N-terminal amino acid sequence determined. Met-Gly-Asp-Lys-Lys-Asp-Asp, shows that unlike the alpha 1 and alpha 2 proteins, the mature Na,K-ATPase isoform lacks post-translational proteolytic processing.
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PMID:Immunoaffinity isolation of Na,K-ATPase alpha 3 isoform from pig kidney. 255 92


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