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

A plasma-membrane fraction was isolated from a post-nuclear extract of human neutrophils by centrifugation through a linear sucrose density gradient. This fraction exhibited a Ca2+-dependent adenosine triphosphatase (ATPase) activity that could be differentiated from mitochondrial or myosin ATPase and from plasma-membrane Mg2+-dependent ATPase. When assayed in the presence of [gamma-32P]ATP, the Ca2+-dependent ATPase reaction resulted in the formation of an acid-resistant hydroxylamine-sensitive bond between the gamma-[32P] phosphate group and a membrane protein subunit with an apparent mol.wt. of 135000. Half-maximal activating effect of Ca2+ was found at 82nM and 0.18 microM for the ATPase and the formation of the 32P-membrane complex respectively. Generation of the phosphorylated product attained the steady state at 0 degrees C by about 30s, and was rapidly reversed by ADP. These results suggest that the Ca2+-activated ATPase reaction occurs through the formation of a phosphoprotein intermediate, similar to that described for some Ca2+-dependent ATPase enzymes associated with Ca2+ transport. The possibility thus exists that the neutrophil Ca2+-dependent ATPase catalyses a process of Ca2+ extrusion from the cell, thereby participating in the regulation of several Ca2+-dependent neutrophil functions.
 ...
PMID:Calcium ion-dependent adenosine triphosphatase activity and plasma-membrane phosphorylation in the human neutrophil. 16 Feb 22

The biosynthesis of the Ca2+- and Mg2+-dependent adenosine triphosphatase of sarcoplasmic reticulum was studied in cell cultures of embryonic chick heart. Rates of synthesis were estimated from the incorporation of tritium-labeled leucine into the ATPase. Newly synthesized ATPase was isolated from cells by immunoprecipitation. Radioactive leucine incorporation into the ATPase was determined by gel electrophoresis of the immunoprecipitates and counting of gel slices containing the ATPase band. Accumulation of the ATPase was estimated from the concentration of Ca2+ and Mg2+-dependent, hydroxylamine-sensitive phosphoprotein in the whole cell membrane fraction of cultured cells. Embryonic heart cells cultured in a medium which permitted cell proliferation showed approximately linearly increasing rates of ATPase synthesis and accumulation/culture plate as the cells proliferated. When cells were cultured in a serum-free medium, cell proliferation was inhibited and there was no sustained increase in the rate of ATPase synthesis or accumulation. Inclusion of isoproterenol or dibutyryl cyclic AMP at concentrations of 10 microM up to 1 mM in serum-free culture medium failed to stimulate significantly ATPase synthesis.
 ...
PMID:Biosynthesis of the Ca2+- and Mg2+-dependent adenosine triphosphatase of sarcoplasmic reticulum in cell cultures of embryonic chick heart. 22 35

Peptides obtained from pepsin digestion of the phosphorylated and nonphosphorylated forms of a preparation of brain microsomal sodium-potassium-activated adenosine triphosphatase were treated at pH 5.4 with N-(n-propyl-2,3-(3)H) hydroxylamine of high specific activity, then separated by column chromatography, and further digested with pronase. A compound isolated in higher amounts from the phosphorylated enzyme than from the nonphosphorylated enzyme migrated with authentic L-glutamyl-gamma-propylhydroxamate in four chromatographic systems and on electrophoresis on paper at three different pH's. The acyl phosphate "intermediate" in the phosphorylated form of the adenosine-triphosphatase therefore appears to be an L-glutamyl-gamma-phosphate residue.
 ...
PMID:Sodium-potassium adenosine triphosphatase: acyl phosphate "intermediate" shown to be L-glutamyl-gamma-phosphate. 422 45

1. An ATPase (adenosine triphosphatase) preparation obtained from pig brain microsomes by treatment with sodium iodide showed four apparently different ouabain-sensitive activities under various conditions. They were (a) ouabain-sensitive Mg(2+)-stimulated ATPase, (b) K(+)-stimulated ATPase, (c) (Na(+),K(+))-stimulated ATPase and (d) Na(+)-stimulated ATPase activities. 2. These activities showed the same substrate specificity, ATP being preferentially hydrolysed and CTP slightly. AMP was not hydrolysed. 3. These activities were inhibited by low concentration of ouabain. The concentration producing 50% inhibition was 0.1mum for ouabain-sensitive Mg(2+)-stimulated ATPase, 0.2mum for K(+)-stimulated ATPase, 0.1mum for (Na(+),K(+))-stimulated ATPase and 0.003mum for Na(+)-stimulated ATPase activity. 4. The ouabain-sensitive ATPase activities were inactivated by N-ethylmaleimide but the insensitive ATPase activity was not. 5. The three ouabain-sensitive ATPase activities were inhibited about 50% by 1mm-Ca(2+), whereas the ouabain-sensitive Mg(2+)-stimulated ATPase activity was activated by the same concentration of Ca(2+). The preparation was treated with ultrasonics at 20kcyc./sec. The 2min. ultrasonic treatment inactivated the ATPase activities by 50%. 7. The temperature coefficient Q(10) was 6.6 for K(+)-stimulated ATPase activity, 3.7 for (Na(+),K(+))-stimulated ATPase and 2.6 for Na(+)-stimulated ATPase. 8. Organic solvents inactivated the ATPase activities, to which treatment the K(+)-stimulated ATPase was the most resistant. 9. The phosphorylation of the enzyme preparation became less dependent on Na(+) with decreasing pH. This Na(+)-independent phosphorylation at low pH was sensitive to K(+) and hydroxylamine as well as the Na(+)-dependent phosphorylation at neutral pH.
 ...
PMID:Comparison of some minor activities accompanying a preparation of sodium-plus-potassium ion-stimulated adenosine triphosphatase from pig brain. 423 88

Properties of (Ca2+ + Mg2+) adenosine triphosphatase (ATPase) in plasma membranes from boar epididymal spermatozoa are described. Enzyme activity is optimum at high pH and has a high affinity for Ca2+. It is not inhibited by the calmodulin antagonist trifluoperazine (TFP), but it is inhibited by low concentrations of Ca2+. Plasma membrane vesicles obtained by hypotonic lysis of intact sperm [mixed inside-out (IOV) and right side-out (ROV) vesicles] transport 45Ca2+ in the presence of oxalate. Similar to the Ca2+-stimulated Mg ATPase activity, transport is unaffected by TFP, but unlike the ATPase, transport is at an optimum rate near neutral pH and is completely inhibited by p-chloromercurphenylsulfonate (pCMS). When plasma membranes are labeled in the presence and absence of Ca2+ and Mg2+ with [gamma-32P]ATP, differences in the intensity of labeling and lability of bound 32P to alkali and hydroxylamine suggest that two polypeptides between 100-120K may be related to a transport ATPase. The addition of TFP at concentrations which stimulate net Ca2+ uptake in intact cells causes intense labeling of a single neutrally charged protein near 68K. These labeling patterns and the properties of (Ca2+ + Mg2+) ATPase identify particular plasma membrane proteins (PMPs) from the complex surface of these cells that may be involved in Ca2+-dependent functions and support the view that calmodulin is not directly involved in the regulation of ATP-driven Ca2+ efflux from boar spermatozoa.
 ...
PMID:Characterization of (Ca2+ + Mg2+) adenosine triphosphatase activity and calcium transport in boar sperm plasma membrane vesicles and their relation to phosphorylation of plasma membrane proteins. 615 5

The complete amino acid sequence of dicyclohexylcarbodiimide (DCC)-binding subunit of proton adenosine triphosphatase from glycolysing bacteria Streptococcus faecalis was established. Isolation of the protein from subbacterial particles was carried out by using extraction with a chloroform/methanol mixture and following gel-filtration on Sephadex LH-60 and Bio-gel P-30. To establish the primary structure, use was made of cyanogen bromide and hydroxylamine cleavages, trypsin and partial acid hydrolyses. Separation of the peptide fragments obtained from cyanogen bromide and hydroxylamine cleavages and partial acid hydrolysis was performed by gel-filtration on Bio-gel P-10 and reversed-phase HPLC. Peptide structures were determined mainly with the aid of 4-N,N-dimethylaminoazobenzene-4'-isothiocyanate. The polypeptide chain of the protein consists of 71 amino acid residues (mol. wt. 7291). The primary structure of the protein from S. faecalis shares all common features of the structural organization of other H+-ATPase DCC-binding subunits and shows a high degree of homology with the corresponding subunit of thermophilic bacterium PS-3. Inactivation of H+-ATPase with DCC was due to modification of Glu54 of the polypeptide chain.
 ...
PMID:[Primary structure of the dicyclohexylcarbodiimide-binding subunit of Streptococcus faecalis H+-ATPase]. 623 59