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)

Previous investigations have documented a reduced activity of the sodium-potassium-stimulated adenosine triphosphatase enzyme (Na+,K+ ATPase) in platelet membranes of allergic subjects. The purpose of this study was to determine if the reduced Na+,K+ ATPase activity was due to an enzyme inhibitor. Na+,K+ ATPase activity of a particulate fraction of sonicated platelets was determined by spectrophotometry in asymptomatic adults with and without allergy. The Na+,K+ ATPase level (mean, nanomoles per microgram of protein per minute; +/- STD) of allergic subjects (0.9 +/- 1.3) was lower (p less than 0.001) than that of nonallergic subjects (3.9 +/- 1.6). In contrast, when the same platelet fractions were frozen before assay, Na+,K+ ATPase was higher (p less than 0.005) in allergic subjects (6.0 +/- 1.4) than in nonallergic subjects (3.6 +/- 2.0). An inhibitor of canine kidney Na+,K+ ATPase was detected in the buffer in which these platelet fractions were frozen, allergic subjects (0.5% +/- 0.4% inhibition per microgram of protein) compared to nonallergic subjects (0.04% +/- 0.08%; p less than 0.005). The level of inhibition correlated positively with the postfreezing increase in platelet membrane Na+,K+ ATPase, suggesting a freezing-induced displacement of an inhibitor from the membrane. Plasma from these same subjects inhibited Na+,K+ ATPase activity of normal platelets, allergic subjects (70% +/- 31% inhibition) compared to nonallergic subjects (13% +/- 16%; p less than 0.001). These data suggest that the transport-enzyme defect observed in platelets from allergic subjects was due to a circulating Na+,K+ ATPase inhibitor. In vivo Na+,K+ ATPase inhibition in allergy could have profound effects on intracellular cation concentrations and broad implications for pathogenesis.
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PMID:A circulating inhibitor of the platelet Na+,K+ adenosine triphosphatase (ATPase) enzyme in allergy. 184 56

Human papillomavirus type 6b (HPV-6b) is one of the most common causes of human genital warts, an important sexually transmitted disease. Discovery of antiviral therapies for this condition has been hampered by the inability to propagate the virus using standard tissue culture techniques and through difficulties in expressing sufficient recombinant viral proteins in vitro. Replication of papillomavirus DNA requires two viral proteins, E1 and E2. In an effort to establish assays to discover compounds active against this virus, we have co-expressed HPV-6b E1 and E2 proteins in insect cells. We demonstrate that the two proteins form a heteromeric complex which can be purified by sequence-specific DNA affinity chromatography. We also demonstrate that the complex has both E1-associated ATPase and ATP-dependent DNA helicase activity and report further characterization of these functions.
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PMID:Characterization of the helicase and ATPase activity of human papillomavirus type 6b E1 protein. 876 Apr 30