Adenosine triphosphatase (ATPase) activity in the rectal papillae of Calliphora has been studied by biochemical and histochemical techniques. The microsomal fraction contained a Mg-activated ATPase with a pH optimum of 8-o. The enzyme was not stimulated by the addition of Na+ plus K+ and was insensitive to ouabain. Histochemical studies using modifications of the Wachstein-Meisel method showed ...

The membrane adenosine triphosphatase (E.C. 3.6.1.3) from Escherichia coli has been solubilized with Triton X-100 and purified to near homogeneity. The purified enzyme has a sedimentation coefficient of 12.9S in a sucrose gradient, corresponding to a molecular weight of about 360,000. On electrophoresis in gels containing sodium dodecyl sulfate, it dissociates into subunits with apparent molecu...

Deamination of DNA bases can create missense mutations predisposing humans to cancer and also interfere with other basic molecular genetic processes; this deamination generates deoxyinosine from deoxyadenosine. In Escherichia coli, the highly conserved endonuclease V is involved in alternative excision repair that removes deoxyinosine from DNA. However, its exact activities and roles in humans ...

Adenosine and inosine are both key intracellular energy substrates for nucleotide synthesis by salvage pathways, especially during ischemic stress conditions. Additionally they both possess cell protective and cell repair properties. The objective of this study is to detect potential advantages of the combination of adenosine and inosine versus each drug alone, in terms of ventricular function,...

BACKGROUND The inhibitory effect of adenosine on platelet aggregation is abrogated after the addition of adenosine-deaminase. Inosine is a naturally occurring nucleoside degraded from adenosine. OBJECTIVES The mechanisms of antiplatelet action of adenosine and inosine in vitro and in vivo, and their differential biological effects by molecular modeling were investigated. RESULTS Adenosine (...

RNA-specific adenosine deaminase (ADAR)-mediated adenosine-to-inosine (A-to-I) editing is a critical arm of the antiviral response. However, mechanistic insights into how A-to-I RNA editing affects viral infection are lacking. We posited that inosine incorporation into RNA facilitates sensing of nonself RNA by innate immune sensors and accordingly investigated the impact of inosine-modified RNA...

1. Cystamine (2,2'-diaminodiethyl disulphide) caused an unmasking of mitochondrial adenosine triphosphatase and a leakage of Mg(2+) from the mitochondria, and decreased the stimulation of adenosine triphosphatase by 2,4-dinitrophenol. When Mg(2+) was added, cystamine potentiated the activation of adenosine triphosphatase by 2,4-dinitrophenol. 2. Cystamine was without effect on the adenosine tri...

Globally, over 4% of the world population is affected by hepatitis C virus (HCV) infection. The current standard of care for hepatitis C infection is combination therapy with pegylated interferon and ribavirin for 48 weeks, which yield a sustained virological response in only a little over half of the patients with genotype 1 HCV. We investigated the clinical importance of pharmacogenetics in t...

BACKGROUND AND AIMS The thiopurines are widely used in the treatment of inflammatory bowel disease, but are limited by poor dose-effect relationship. The objective was to assess the ability of a novel assay, determining the mono-, di-, and triphosphates, of thioguanine as well as methylthioinosine as individual metabolites in erythrocytes, to predict clinical outcome compared to a routine assay...

1. The initial rapid phase of ATP hydrolysis by bovine heart submitochondrial particles or by soluble F1-ATPase is insensitive to anion activation (sulphite) or inhibition (azide). 2. The second slow phase of ATP hydrolysis is hyperbolically inhibited by azide (Ki approximately 10(-5) M); the inosine triphosphatase activity of submitochondrial particles or F1-ATPase is insensitive to azide or s...