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)

10 sera were studied from patients with primary biliary cirrhosis (PBC), that were anomalous in their reactivity against mitochondrial antigens as detected by Western blotting. They had low reactivity against the major, M2 reactive antigen (Mr for beef heart mitochondria, 74 Kd) but reacted against an antigen of Mr 52 Kd (species independent) which was apparently inaccessible in submitochondrial particles (SMP) on ELISA and which was not present in chloroform-released ATPase preparations. In all respects this differed from the characteristics of the M2 antigens and it is concluded that these sera are detecting predominantly the M4-reactive antigen.
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PMID:Discrimination between M2 and M4 antimitochondrial antibodies in primary biliary cirrhosis. 355 42

1. Ox-brain microsomes were incubated with [gamma-(32)P]ATP under various conditions. After the reaction, which was stopped with trichloroacetic acid, a small amount of phosphate remained bound to the washed precipitate. 2. Properties of the bound phosphate were studied by treatment with buffers and solvents. 3. The Na(+)-dependent increment in bound phosphate, predominant at low ATP concentration and features of which suggest involvement in the concomitant adenosine-triphosphatase activity, was rapidly released in both circumstances. 4. In aqueous media the labile phosphate was released entirely as inorganic phosphate at faster rates with increasing alkalinity. 5. In acidified chloroform-alcohol mixtures the released phosphate appeared both as inorganic phosphate and different single (32)P-labelled organic phosphates, which were tentatively identified as the relevant mono-alkyl phosphates, presumably derived by acid-catalysed alcoholysis of a labelled microsomal component, or components. 6. The labile phosphate corresponded to the P exchangeable with non-radioactive ATP added during the enzyme reaction. 7. The possible molecular nature of the labile fraction of the bound phosphate is discussed.
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PMID:Properties of phosphate bound to cerebral microsomes during adenosine-triphosphatase activity. 422 17

A low-molecular-weight protein synthesized in yeast mitochondria was purified. The protein was identified as a component of the rutamycin-sensitive ATPase. The amino-acid composition of the purified protein shows an extremely large preponderance of nonpolar residues, which may account for its solubility in chloroform-methanol. Indirect evidence suggests that this component is involved in the conferral of rutamycin sensitivity and may also have a function in the assembly of the ATPase complex.
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PMID:Assembly of the mitochondrial system. Purification of a mitochondrial product of the ATPase. 427 31

1. Polyribosomes and ribosomal subunits from rat liver were adsorbed on a cellulosic ion-exchange adsorbent, freeze-dried and extracted with organic solvents. The activity of extracted particles in peptide elongation was tested in the presence of purified peptideelongation factors. 2. Chloroform-methanol mixture (2:1, v/v) extracted 1.87+/-0.15 pmol of cholesteryl 14-methylhexadecanoate/pmol of the smaller ribosomal subunit and 0.92+/-0.11 pmol/pmol of the larger subunit. 3. In the presence of transferase I, extracted polyribosomes and 40S subunits bound more phenylalanyl-tRNA than did control non-extracted particles. The same binding as in control mixtures was obtained with extracted particles supplemented with cholesteryl 14-methylhexadecanoate in quantities corresponding to those extracted. 4. The polymerization of phenylalanine was greatly decreased with extracted polyribosomes and subunits and addition of the cholesteryl ester could not fully restore the original activity. 5. Extraction significantly decreased the activity of the P site of peptidyl transferase and normal activity was recovered after the addition of the ester. The A site of peptidyl transferase in extracted polyribosomes showed an increased activity when compared with non-extracted polyribosomes. 6. Cholesteryl 14-methylhexadecanoate apparently affects the function of the ribosomal A site and peptidyl transferase site and probably also that of the guanosine triphosphatase site and P site. The presence of different amounts of the ester in polyribosomes may be one of the mechanisms modulating peptide elongation at the ribosomal level.
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PMID:Influence of cholesteryl 14-methylhexadecanoate on some ribosomal functions required for peptide elongation. 459 29

A nonspecific nucleoside triphosphatase was partially purified from skin and cutaneous melanoma tumors from Sinclair swine using chloroform precipitation, hydrophobic, ion-exchange and affinity chromatography techniques. The enzyme was not stimulated by Na+, K+ or Mg2+ but it was inhibited by EDTA. The enzyme was not inhibited by quercetin, proflavin, azide or ovabain. The enzyme exhibited optimal activity over a pH range of 8-9 and the activation energy was 10.4 and 9.8 kcal/mol for dUTP and ATP, respectively. The apparent Km of the enzyme for dUTP and dTTP was approximately 20 mumol/l while the apparent Km for dATP, ATP, dCTP, CTP and UTP was in the range of 65-80 mumol/l.
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PMID:Purification and properties of a nucleoside triphosphatase from Sinclair swine. 609 41

The mitochondrial Mg2+-activated adenosine triphosphatase (ATPase; EC 3.6.1.4) from the insect flagellate Crithidia fasciculata ATCC 11745 has been extracted from the membrane by chloroform treatment and purified to electrophoretic homogeneity by a method involving ammonium sulphate fractionation, gel filtration on Sephadex G-200 and DEAE-cellulose chromatography. The molecular weight of the native enzyme, determined by gel filtration, was about 350 000. Five subunits were detected by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate, with molecular weights of 54 000, 45 000, 35 000, 20 000 and 10 000. The membrane-bound, but not the soluble (F1) ATPase was inhibited by oligomycin and leucinostatin. Both forms of the enzyme were strongly inhibited by the antibiotic efrapeptin and the trypanocidal drug suramin. The inhibition by efrapeptin was of the mixed type, with double-reciprocal plots intersecting below the abscissa, as in the case of the enzyme present in beef heart submitochondrial particles. Suramin, on the other hand, acted as a non-competitive inhibitor of the membrane-bound ATPase and as a strictly competitive inhibitor of the purified F1 ATPase.
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PMID:Mg2+-activated adenosine triphosphatase from Crithidia fasciculata: purification and inhibition by suramin and efrapeptin. 611 95

Chloroform-released ATPase from ox heart mitochondria contains significant amounts of inhibitor protein. There is a correlation between processes that affect the interactions between the inhibitor protein and the ATPase molecule and the ability of MgATP to induce an inhibition of ATPase activity. Evidence is presented suggesting that the endogenous inhibitor protein is involved in the process of MgATP-induced inhibition of soluble ATPase activity.
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PMID:Involvement of the endogenous inhibitor protein in the MgATP-induced inhibition of soluble mitochondrial adenosine triphosphatase activity. 621 Nov 69

Periodate-oxidized ATP (o-ATP) was prepared as an affinity label of nucleotide binding sites on the chloroform-released ox heart mitochondrial ATPase. In the presence of MgSO4, o-ATP is a substrate for the ATPase. It can act as a reversible, competitive inhibitor of ATPase activity and can also induce an irreversible inhibition of ATPase activity. In parallel with the irreversible inhibition, covalent incorporation of [3H]o-ATP occurs. ATPase has about 1.05 mol of o-ATP bound per mol of ATPase when the enzyme is 50% inhibited. Most of the covalently bound o-ATP is associated with the alpha and beta subunits and is equally distributed between them. The incorporation of o-ATP into the ATPase is reduced, and the irreversible inhibition induced by o-ATP can be prevented totally by MgADP, MgATP, EDTA/ATP, or EDTA. The location, number, and the functional significance of the o-ATP binding sites are discussed. o-ATP can decompose to form an adenosine-containing compound and the tripolyphosphate anion in a beta-elimination reaction mechanism. The structures of the adenine-containing compound and its borohydride reduction product were determined. The adenine-containing elimination product inhibited the mitochondrial ATPase activity at a rate greater than that observed with o-ATP. The nature and mechanism of the inhibition of ATPase activity exerted by o-ATP and the elimination product were examined. The significance of the beta-elimination reaction to the use of periodate-oxidized nucleotides as affinity labels of nucleotide binding sites on other proteins is discussed.
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PMID:Interactions between the mitochondrial adenosinetriphosphatase and periodate-oxidized adenosine 5'-triphosphate, an affinity label for adenosine 5'-triphosphate binding sites. 621 60

Interaction of N,N'-dicyclohexylcarbodiimide (DCCD) with ATPase of Mycobacterium phlei membranes results in inactivation of ATPase activity. The rate of inactivation of ATPase was pseudo-first order for the initial 30-65% inactivation over a concentration range of 5-50 microM DCCD. The second-order rate constant of the DCCD-ATPase interaction was k = 8.5 X 10(5) M-1 X min(-1). The correlation between the initial binding of [14C]DCCD and 100% inactivation of ATPase activity shows 1.57 nmol DCCD bound per mg membrane protein. The proteolipid subunit of the F0F1-ATPase complex in membranes of M. phlei with which DCCD covalently reacts to inhibit ATPase was isolated by labeling with [14C]DCCD. The proteolipid was purified from the membrane in free and DCCD-modified form by extraction with chloroform/methanol and subsequent chromatography on Sephadex LH-20. The polypeptide was homogeneous on SDS-acrylamide gel electrophoresis and has an apparent molecular weight of 8000. The purified proteolipid contains phosphatidylinositol (67%), phosphatidylethanolamine (18%) and cardiolipin (8%). Amino acid analysis indicates that glycine, alanine and leucine were present in elevated amounts, resulting in a polarity of 27%. Cysteine and tryptophan were lacking. Butanol-extracted proteolipid mediated the translocation of protons across the bilayer, in K+-loaded reconstituted liposomes, in response to a membrane potential difference induced by valinomycin. The proton translocation was inhibited by DCCD, as measured by the quenching of fluorescence of 9-aminoacridine. Studies show that vanadate inhibits the proton gradient driven by ATP hydrolysis in membrane vesicles of M. phlei by interacting with the proteolipid subunit sector of the F0F1-ATPase complex.
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PMID:Purification and functional properties of the DCCD-reactive proteolipid subunit of the H+-translocating ATPase from Mycobacterium phlei. 622 56

A method is described for the purification of rat liver F1-ATPase by a modification of the chloroform extraction procedure originally described by Beechey et al. (Biochem. J. (1975) 148, 533). Purified liver membrane vesicles are extracted with chloroform in the presence of ATP and EDTA. The procedure yields pure F1 in only 2-3 h without the necessity of ion-exchange chromatography. The enzyme exhibits the alpha, beta, gamma, delta, and epsilon bands characteristic of F1-ATPase. It has a high ATPase specific activity, and is reconstitutively active, catalyzing high rates of ATP synthesis. Significantly, it can be readily crystallized. If desired, the enzyme can be passed over a gel filtration column to place it in a stabilizing phosphate-EDTA buffer, lyophilized and stored indefinitely at -20 degrees C.
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PMID:Proton ATPase of rat liver mitochondria: a rapid procedure for purification of a stable, reconstitutively active F1 preparation using a modified chloroform method. 623 96


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