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 plasma membrane-rich fraction has been separated from liver cells and cells of two solid rat tumors. D23 hepatoma and MC7 sarcoma. On the basis of marker enzyme activity the membranes separating at the 31-41% interface on the discontinuous sucrose gradient were enriched 15- to 19-fold. No significant differences in the phospholipid (PL) composition of the three membrane fractions were observed. The PL fatty acid (FA) composition showed that the percentage of unsaturated FA in all three membranes was between 43 and 48%. However, the oleic acid:PUFA ratio was much greater from tumor membranes. Membrane cholesterol was also significantly lower for cells from both tumors compared with liver cells. The DPH fluorescence polarization of the membrane fractions showed that the membranes from cells of both tumors are significantly less ordered than those of liver at all temperatures measured (4-50 degrees C). The Mg2+ ATPase activity of the plasma membranes is inactivated by hyperthermia treatments. The enzyme from liver cells was more thermostable (LT50 = 53.86 degrees C) than that from cells of either D23 (LT50 = 47.51 degrees C) or MC7 (LT50 = 46.34 degrees C) tumors.
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PMID:Lipid composition of the membranes from cells of two rat tumors and its relationship to tumor thermosensitivity. 198

Modification of histidine residues, SH- and epsilon-NH2-groups of myosin from rat sarcoma-45 by specific reagents was studied. It was shown that diethylpyrocarbonate modifies histidine residues essential for the ATPase activity. A kinetic analysis of myosin epsilon-NH2-groups modification by 2,4,6-trinitrobenzene sulfonate revealed that myosin trinitrophenylation and its inactivation by Ca2(+)-ATPase occurs in two steps: a fast and a slow (Km = 2400 and 1.7 s-1 M-1, respectively). Two essential epsilon-NH2-groups of tumour myosin active sites react in the fast reaction. The relatively low concentrations of p-chloromercuribenzoic acid activate rat sarcoma-45 myosin Ca2(+)-ATPase and Mg2(+)-ATPase, whereas higher ones inhibit the enzyme. The data obtained suggest that two SH-groups, SH1 and SH2 are essential for the tumour myosin ATPase function.
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PMID:[Study of the modification of histidine residues, SH- and epsilon-NH2-groups of rat sarcoma-45 myosin by specific reagents]. 215 Mar 35

Growing rats and adult weight-stable mice bearing a transplantable methylcholanthrene-induced sarcoma were compared with animals with various states of malnutrition. Heart protein synthesis was measured in vivo. Myocardial RNA, myofibrillar protein composition and the Ca2+-activated ATPase activity in heavy chains of native myosin were measured. 'Fingerprints' were made from myosin by trypsin treatment to evaluate possible structural changes in the protein. Cardiac protein-synthesis rate was decreased by 20% in growing tumour-bearing rats, by 35% in protein-malnourished (rats) and by 47% in starved rats, compared with freely fed controls (P less than 0.05). Adult tumour-bearing mice showed no significant decrease in myocardial protein synthesis. Pair-weighed control mice had significantly depressed heart protein synthesis. Protein translational efficiency was maintained in both tumour-bearing rats and mice, but was decreased in several groups of malnourished control animals. The Ca2+-activated myosin ATPase activity was decreased in all groups of malnourished animals, including tumour-bearing mice and rats, without any evidence of a change in cardiac isomyosin composition. We conclude that loss of cardiac muscle mass in tumour disease is communicated by both depressed synthesis and increased degradation largely owing to anorexia and host malnutrition. Increased adrenergic sensitivity in hearts from tumour-bearing and malnourished animals is not communicated by increased Ca2+-activated ATPase activity. This may be down-regulated in all groups with malnutrition, without any observable alterations in the isomyosin profile.
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PMID:Protein synthesis, myosin ATPase activity and myofibrillar protein composition in hearts from tumour-bearing rats and mice. 248 44

Kinetic parameters of the inhibitory effect of vincristine on Mg2+ATPase activity containing in the actomyosin-like protein from rat sarcoma 45 and in actomyosin from rat skeletal muscle was studied. The alkaloid decreased the VM value for the reaction catalyzed by ATPase in presence of Mg2+ and EGTA and did not alter Km value for both contractile proteins. Inhibitory constants, calculated for the actomyosin from skeletal muscles and for the actomyosin-like protein from sarcoma 45, constituted 520 mcM and 250 mcM, respectively. Vincristine appears to inhibit Mg2+-ATPase containing in these contractile proteins studied by the non-competitive type, simultaneously with lowering of the activating effect of actin on the myosin-derived ATPase.
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PMID:[Effect of vincristine on Mg2+-ATPase activity of actomyosin-like protein from sarcoma-45 and actomyosin from rat skeletal muscle]. 252 43

Myosin was purified from rat tumour sarcoma-45 whose properties (effects of cations on ATPase activity, substrate specificity, temperature- and pH-optima, thermal stability, sensitivity of Mg2(+)-ATPase to F-actin, molecular mass, subunit composition) are similar to those of fast skeletal muscle myosin. Some parameters of the protein, namely, the levels of Ca2(+)- and K+, EDTA-ATPase activity, relative content of myosin light chains with Mr 16500 and the degree of tumoural myosin Mg2(+)-ATPase activation by F-actin, were significantly lower than those of skeletal muscle myosin.
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PMID:[Purification and biochemical characteristics of myosin from rat malignant sarcoma-45]. 253 71

For the purpose of clarifying cellular differentiation of epithelioid sarcoma, studies based on various methods were performed. Enzyme histochemical studies showed that epithelioid sarcoma tumor cells have characteristics intermediate between epithelial cells and the large plump cells of synovial sarcoma-incomplete epithelial differentiation. For alkaline phosphatase and adenosine triphosphatase particularly, positive cells and negative cells coexisted, as in the large plump cells of synovial sarcoma. Immunohistochemical studies for alpha 1-antitrypsin, alpha 1-antichymotrypsin, vimentin, and keratin also showed that epithelioid sarcoma tumor cells are very similar to the large plump cells of synovial sarcoma and have incomplete epithelial differentiation. For example, the examinations of serial sections and double staining methods revealed that keratin-positive cells are always vimentin-positive in epithelioid sarcoma and in the monophasic area of synovial sarcoma. Electron-microscopically, bundles of intermediate filaments and filopodia toward the intercellular lumen were observed, as in the monophasic area of synovial sarcoma. The results of enzyme-histochemical and immunohistochemical studies of non-neoplastic synovial lining cells, performed here for the first time, are also discussed.
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PMID:Cellular differentiation of epithelioid sarcoma. An electron-microscopic, enzyme-histochemical, and immunohistochemical study. 258 Apr 43

The nucleotide sequence of the Moloney murine sarcoma virus strain HT-1 (HT1MSV) mos gene differs from that of the cellular mos gene in three positions, but these are silent changes, and the amino acid sequence of the v-mos and c-mos open reading frames are identical. We have overproduced the mos HT1MSV (equivalent to c-mos) in Escherichia coli under the control of phage lambda promoter (pL). The E. coli p40mos protein thus obtained was partially purified and examined for several biochemical activities. We show that the p40mos binds ATP analog p-fluorosulfonylbenzoyladenosine and exhibits ATPase activity.
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PMID:Nucleotide sequence and biochemical activities of the Moloney murine sarcoma virus strain HT-1 mos gene. 299 45

Oncogenes of the ras family stimulate DNA synthesis when microinjected into quiescent mouse and hamster fibroblasts, as detected by in situ autoradiography. The molecularly cloned genomes of Harvey and Kirsten sarcoma viruses, the cloned Harvey ras gene, and the product of the v-ras gene, the p21v-rasH protein, stimulate DNA synthesis in quiescent cells. This stimulation is comparable to the stimulatory activity of the microinjected SV40 T-antigen-coding gene. The demonstration that these oncogenes can stimulate transient DNA synthesis in quiescent cells is relevant to understanding the mechanism by which these genes are able to transform cells in vitro and induce tumors in animals.
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PMID:Microinjected ras family oncogenes stimulate DNA synthesis in quiescent mammalian cells. 300 23

A case of alveolar soft part sarcoma was studied by light and electron microscopy and by electron microscopic enzyme histochemistry of adenosine triphosphatase (ATPase) and 5'nucleotidase(5'Nase). The tumor showed distinct alveolar pattern and diastase resistant PAS positive crystalline inclusions were found in the cytoplasm. Ultrastructurally, characteristic rhomboid crystals and dense granules were observed and they were positive for Mg++- and Ca++-ATPases but negative for 5'Nase. Tumor cell membrane also showed positive activity of ATPase in addition to 5'Nase. These results would support the myogenous derivation of alveolar soft part sarcoma.
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PMID:Adenosine triphosphatase activity of crystalline inclusions in alveolar soft part sarcoma. An ultrahistochemical study of a case. 301 8

A protein tyrosine kinase that phosphorylates both alpha and beta subunits of inactivated (Na+,K+)-ATPase from dog kidney was purified about 500-fold from Ehrlich ascites tumor cell membranes. The enzyme required divalent cations Mn2+, Mg2+, or Fe2+ but was inhibited by Cu2+ or Zn2+. The purified enzyme phosphorylated the beta subunit about five times faster than the alpha subunit of the (Na+,K+)-ATPase. The random polymer poly(Glu80Tyr20) was an excellent substrate while casein was only marginally phosphorylated. In contrast, the purified transforming gene product of Rous sarcoma virus phosphorylated all three substrates and the (Na+,K+)-ATPase was preferentially phosphorylated on the alpha subunit. The transforming gene product of Fujinami sarcoma visue and EGF receptor kinase from A431 cells phosphorylated (Na+,K+)-ATPase poorly whereas casein was an excellent substrate. The molecular weight of the partially purified protein tyrosine kinase from Ehrlich ascites tumor cells determined by gel filtration was about 60,000. One of two major phosphorylated phosphopeptides resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis had an Mr of 60 kDa, thus suggesting that it might be the autophosphorylated protein tyrosine kinase. A phosphatase that hydrolyzes phosphorylated histones or poly(Glu80Tyr20) was partially purified from the same membrane.
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PMID:A tyrosine-specific protein kinase from Ehrlich ascites tumor cells. 302 71


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