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)

Membrane preparations of erythrocytes from normal and P. chabaudi-infected mice and membrane preparations of P. chabaudi-infected and uninfected erythrocytes from infected mice and separated by zonal centrifugation were characterized by the pattern of proteins and extracted glycoproteins obtained by SDS-polyacrylamide gel electrophoresis and by the specific activities of membrane associated enzymes. The protein pattern of the membrane preparation of infected erythrocytes showed similar differences from membrane preparations of normal erythrocytes as those described by Weidekamm et al. for P. berghei. The pattern of glycoproteins extracted by the chloroform-methanol method showed characteristic differences as compared to the controls. A new band (PASi) with a molecular weight of about 165,000 corresponds with the protein band IIa. In membrane preparations of normal erythrocytes and of nonparasitized erythrocytes separated from parasitized erythrocytes by zonal centrifugation was no difference in specific activities of ATPase, adenylate kinase and acetylcholinesterase. Adenylate kinase activity was markedly increased and acetyl-cholinesterase activity was slightly increased in membrane preparations of infected cells. Specific activities of ATPase of membrane preparations of normal and parasitized erythrocytes did not show significant differences. There was a decrease in enzyme activity of ATPase and an increase of acetylcholinesterase in Triton X 100 containing samples. Specific activities of an acid phosphatase were lower in membrane preparations of parasitized cells than in the controls.
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PMID:Plasmodium chabaudi-infection of mice: specific activities of erythrocyte membrane-associated enzymes and patterns of proteins and glycoproteins of erythrocyte membrane preparations. 19 21

We have synthesized 2-nitro-5-azidobenzoyl (NAB) derivatives of ouabain as photoaffinity labels of the cardiac glyocoside binding site of Na, K-ATPase. [3HzNAB-ouabain was found to bind to the same number of sites on Na, K-ATPase (purified from pig kidney outer medulla) as ouabain (1.9 nmol/mg), with approximately the same affinity (Kk(ouabain)/Kd(NAB-ouabain) congruent to 1.6), and ouabain was fully competitive uith NAB-ouabain at these sites. NAB-ouabain binding and inhibition were reversible in the dark, but on exposure to ultraviolet light (310-370 nm) 30-40% of the binding and ihibition became irreversible; this binding was shown to be covalent by stability to trichloroacetic acid, organic solvents, and heat denaturation. Covalent labeling was prevented by photolysis of NAB-ouabain prior to the experiment, or by prior incubation of the enzyme with ouabain. On sodium dodecyl suffate-polyacrylamide gels of labeled Na,K-ATPase, about half of the covalently bound [3H]NAB-ouabain migrated with the large polypeptide (molecular weight congruent to 95 000), and half migrated with a small polypeptide (molecular weight congruent to 12 000); noncovalently bound NAB-ouabain (60-70% of total label) ran with the tracking dye. A similar labeling pattern was obtained utilizing NaI microsomes prepared from pig kidney outer medulla. The small polypeptide was characterized as an acidic proteolipid by extractability into acid chloroform/methanol; labeling of this component by NAB-ouabain is the first demonstration that it is directly associated with the Na,K-ATPase. The results of our characterization of NAB-ouabain show that it has the required specificity, covalency, and efficiency of labeling for application in structural studies of Na,K-ATPase subunit interactions.
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PMID:Characterization of a new photoaffinity derivative of ouabain: labeling of the large polypeptide and of a proteolipid component of the Na, K-ATPase. 21 Aug 2

Mitochondrial ATPase complex has been spin-labeled in the membrane using the inhibitor N-(2,2,6,6-tetramethylpeperidyl-1-OXYL)-N(cyclohexyl)carbodiimide (nccd). the amount of NCCD bound to mitochondrial fragments is 0.5 nmol/mg and cannot be dialyzed or extracted with ether, chloroform, or methanol. The electron paramagnetic resonance spectrum of NCCD bound to fragments is pH-sensitive, a greater label immobilization occurring at pH values lower or higher than 7. Ether extraction removes the ATPase inhibition by NCCD without detaching the label. This effect appears to be the consequence of the dislocation of some components of the ATPase complex. Removal of F1 natural inhibitor or of F1 does not affect the spectrum of NCCD bound to fragments, while the removal of oligomycin sensitivity-conferring protein produces an increase in the extreme splitting. Oligomycin sensitivity-conferring protein may thus interact with the NCCD binding component of the membrane. The isolation of the NCCD-binding proteolipid results in a large increase in the mobility of the label, but addition of dipalmitoyllecithin decreases the mobility of the label to the original level. Phospholipids are thus necessary to keep the NCCD-binding proteolipid in the native conformation.
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PMID:Molecular interactions of adenosine triphosphatase with the mitochondrial membrane as revealed by a spin label study. 23 75

The ATP-energy transducing system in membranes of Escherichia coli is inhibited by dicyclohexylcarbodiimide. The protein component of this complex with which carbodiimides covalently react to inhibit function was previously identified by labeling wild type and dicyclohexylcarbodiimide-resistant mutants with dicyclohexyl[14C]carbodiimide (Fillingame, R. H. (1975) J. Bacteriol. 124, 870-883). This specific carbodiimide-reactive protein has now been purified. The protein was extracted from the membrane with chloroform:methanol and chromatographed on DEAE-cellulose and hydroxypropyl Spehadex G-50 in this sulvent mixture. The resultant 700-fold purification yielded a protein that was homogeneous on dodecyl sulfate-acrylamide gel electrophoresis and virtually free of phospholipid. It remained soluble in neutral chloroform:methanol throughout the purification procedure. The amino acid composition of the purified protein was extraordinary in that only 16% of the amino acids present could be considered polar. Histidine, serine, cysteine, and tryptophan were not found. Abnormally high contents of methionine, glycine, alanine, and leucine were present. One mole of lysine and threonine were found/mole of dicyclohexyl[14C]carbodiimide bound. The minimum molecular weight based on the amino acid composition was 8400. The specific carbodiimide-reactive protein has also been purified without prior modification by dicyclohexylcarbodiimide. The unmodified protein eluted from DEAE-cellulose at a higher salt concentration than the dicyclohexylcarbodiimide-modified form, which suggested that the reaction with the carbodiimide neutralized the negative charge. Only one-third of the total carbodiimide-reactive protein in the membrane was modified by dicyclohexylcarbodiimide under conditions which maximally inhibited adenosine triphosphatase activity. These results rais the possibility that the carbodiimide-reactive protein may be present as an oligomer in the energy-transducing complex. The purification of the unmodified carbodiimide-reactive protein should permit assessment of tis biological function, particularly its role in the protein-translocation process that is catalyzed by this energy-transducing complex.
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PMID:Purification of the carbodiimide-reactive protein component of the ATP energy-transducing system of Escherichia coli. 78 71

The release of lipoteichoic acid and mesosomal vesicles to the supernatant buffer during the formation of spherical, osmotically fragile bodies was studied using Streptococcus faecalis ATCC 9790. Autolytic N-acetylmuramidase action was permitted to take place in exponential-phase cells incubated in a buffer which provides an exceptional degree of osmotic stabilization. Both lipoteichoic acid and mesosomal vesicles were relatively rapidly released to the supernatant buffer. Most of the cellular content of lipoteichoic acid (and mesosomal vesicles) was found in the supernatant buffer at incubation times when the cells still retained over 75% of their cell wall. [14-C]- or [3-H]glycerol was used as a label for both cellular lipoteichoic acids and lipid-glycerol. Glycerol in lipoteichoic acid was quantitated after phenol-water and chloroform-methanol treatments and identified by products of acid hydrolysis and its ability to be precipitated by (i) antibodies specific for the polyglycerol-phosphate backbone, (ii) antibodies to the streptococcal group D antigen, and (iii) concanavalin A. Evidence was obtained that lipoteichoic acid was not associated with isolated mesosomal vesicles. Centrifugation of supernates at 200,000 X g sedimented membranous (mesosomal) vesicles and nearly all of the lipid-glycerol present, whereas essentially all of the lipoteichoic acid remained in the supernatant. The sedimented mesosomal vesicles differed from protoplast membrane in their higher lipid-phosphorus to protein ratio and in the absence of detectable levels of two enzymatic activities found in protoplast membranes, adenosine triphosphatase and polynucleotide phosphorylase. Both types of membranes were found to contain DD-carboxypeptidase and LD-transpeptidase activities at nearly the same specific activities. No evidence was obtained for the association of autolytic N-acetylmuramidase activity with either type of membrane preparation.
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PMID:Cellular localization of lipoteichoic acid in Streptococcus faecalis. 80 56

The direct synthesis of bis]3-phenyl-5-oxoisoxazol-4-yl]pentamethineoxonol, which is shown to be the fluorescent probe OX-V (formerly MC-V), is described. The emission lifetime (0.9 +/- 0.1 ns) and the spectral properties of this dye in a number of systems are presented as well as the relative polarizations associated with the transition moments of the observable electronic transitions. The structure of OX-V was determined using elemental analysis and infrared and 1H nuclear magnetic resonance (NMR) spectroscopy. The use of the contact shift reagent, Eu(fod)3-d27, greatly facilitated the interpretation of the NMR results. In aqueous media, the anionic form of OX-V is present virtually exclusively due to the low solubility of the neutral species; formation of the latter species occurs when ethanol or methanol solutions of OX-V are acidiied. Both neutral and anionic dye forms can be detected in chloroform-ethanol solvents. The fluorescence intensity from excitation of the neutral species is an order of magnitude weaker than that from excitation of the anionic form and may result from the formation of excited anions due to the loss of a proton by the neutral species in the excited state. Polarization results indicate that the visible absorption of the dye is due to a single electronic transition. OX-V has been employed as a probe primarily in beef heart submitochondrial particles, reconstituted ATPase vesicles,a nd pigeon heart mitochondria. The energy-linked spectral changes of the probe in these preparations are described and mechanisms proposed for the spectral effects.
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PMID:Synthesis, structure determination, spectral properties, and energy-linked spectral responses of the extrinsic probe oxonol V in membranes. 99 Feb 68

The purified plasma membrane H(+)-ATPase of Schizosaccharomyces pombe and Saccharomyces cerevisiae display, in addition to the catalytic subunit of 100 kDa, a highly mobile component, soluble in chloroform/methanol. Chloroform/methanol extraction of S. cerevisiae plasma membranes led to isolation of a low molecular weight proteolipid identical to that present in purified H(+)-ATPase. NH2-terminal amino acid sequencing revealed a 38-residue polypeptide with a calculated molecular mass of 4250 Da. The polypeptide lacks the first two NH2-terminal amino acids as compared with the deduced sequence of the PMP1 gene (for plasma membrane proteolipid) isolated by hybridization with an oligonucleotide probe corresponding to an internal amino acid sequence of the proteolipid. The polypeptide is predicted to contain an NH2-terminal transmembrane segment followed by a very basic hydrophilic domain.
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PMID:Purification and complete sequence of a small proteolipid associated with the plasma membrane H(+)-ATPase of Saccharomyces cerevisiae. 153 82

The coated vesicle (H+)-ATPase is composed of two domains, a peripheral V1 domain containing the 73 (A subunit)-, 58 (B subunit)-, 40-, 34-, and 33-kDa subunits and an integral V0 domain containing the 100-, 38-, 19-, and 17 (c subunit)-kDa subunits (Adachi, I., Puopolo, K., Marquez-Sterling, N., Arai, H., and Forgac, M. (1990) J. Biol. Chem. 265, 967-973). In the present manuscript we characterize the V0 domain with respect to its structural and activity properties. Glycerol density gradient separation of solubilized coated vesicle membrane proteins reveals the presence of an excess of V0 domains which migrate with a molecular weight of 250,000 and contain the V0 polypeptides in the same stoichiometry as in the intact V1V0 complex. Like the c subunit in V1V0, the c subunit of the free V0 domain is labeled by [14C]N,N'-dicyclohexylcarbodiimide (DCCD) and is extracted by chloroform:methanol. In addition, a monoclonal antibody specific for the 100-kDa subunit of the intact (H+)-ATPase recognizes the 100-kDa subunit of V0. Tryptic cleavage of the V0 complex gives the same pattern of fragments for the 100- and 38-kDa subunits as in the intact complex, but with an increase in sensitivity, suggesting greater exposure of these subunits in free V0. Proton conduction was measured in reconstituted vesicles containing the V0 domain and in native vesicles stripped of V1. No DCCD-inhibitable proton conduction was observed in either preparation, suggesting that unlike the corresponding F0 domain of F1F0, the free V0 domain is not an open proton channel.
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PMID:Characterization of the V0 domain of the coated vesicle (H+)-ATPase. 153 40

Plasma membrane proteolipid (plasmolipin), which was originally isolated from kidney membranes, has also been shown to be present in brain. In this study, we examined the distribution of plasmolipin in brain regions, myelin, and oligodendroglial membranes. Immunoblot analysis of different brain regions revealed that plasmolipin levels were higher in regions rich in white matter. Plasmolipin was also detected in myelin, myelin subfractions, and oligodendroglial membranes. Immunocytochemical analysis of the cerebellum revealed that plasmolipin was localized in the myelinated tracts. Plasmolipin levels in myelin were enriched during five successive cycles of myelin purification, similar to the enrichment of myelin proteolipid apoprotein (PLP) and myelin basic protein (MBP). In contrast, levels of Na+,K(+)-ATPase and a 70-kDa protein were decreased. When myelin or white matter was extracted with chloroform/methanol, it contained, in addition to PLP, a significant amount of plasmolipin. Quantitative immunoblot analysis suggested that plasmolipin constitutes in the range of 2.2-4.8% of total myelin protein. Plasmolipin, purified from kidney membranes, was detected by silver stain on gels at 18 kDa and did not show immunological cross-reactivity with either PLP or MBP. Thus, it is concluded that plasmolipin is present in myelin, possibly as a component of the oligodendroglial plasma membrane, but is structurally and immunologically different from the previously characterized myelin proteolipids.
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PMID:Presence of the plasma membrane proteolipid (plasmolipin) in myelin. 169 42

A number of chemicals are known to potentiate the hepatotoxicity of carbon tetrachloride. The halocarbon trichloroethylene was shown in a previous study to enhance both carbon tetrachloride-induced toxicity and lipid peroxidation in isolated hepatocytes. In this study three other chlorocarbons have been investigated in order to determine whether this interaction was peculiar to trichloroethylene or common to chlorinated solvents. Hepatocyte suspensions were exposed to carbon tetrachloride at subthreshold levels of toxicity and various concentrations of 1,1,1-trichloroethane, tetrachloroethylene, and chloroform over an eightfold concentration range. Plasma membrane preparations were exposed to tetrachloroethylene and carbon tetrachloride and effects on Mg(2+)- and Na(+)-K(+)-ATPase activities determined. None of the treatments alone caused statistically significant toxicity. Combined treatments resulted in toxicity as demonstrated by potassium ion, alanine aminotransferase, and lactate dehydrogenase leakage from the cells on coincubation of carbon tetrachloride with each of the other halocarbons studied. Only tetrachloroethylene and chloroform were found to potentiate lipid peroxidation, however. In liver plasma membranes no changes in Na(+)-K(+)-ATPase were observed with any of the treatments and only the highest dose of tetrachloroethylene was able to inhibit Mg(2+)-ATPase activity. There was no increase in this inhibition on coincubation with carbon tetrachloride, which does not support involvement of ATPases in combined halocarbon toxicity. In conclusion, the data suggest a mechanism of action common to this class of chemical although its specific nature remains to be established.
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PMID:Potentiating effects of chlorinated hydrocarbons on carbon tetrachloride toxicity in isolated rat hepatocytes and plasma membranes. 182 22


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