Palmitoyl-CoA hydrolase (EC 3.1.2.2) and palmitoyl-L-carnitine hydrolase (EC 3.1.1.28) activities from rat liver were investigated. 1. Microsomal and mitochondrial-matrix palmitoyl-CoA hydrolase activities had similar pH and temperature optima, although the activities showed different temperature stability. They were inhibited by Pb2+ and Zn2+. The palmitoyl-CoA hydrolase activities in microsom...

Four DNA-dependent DNA polymerases, which include a soluble nuclear polymerase, the mitochondrial polymerase, and two polymerases associated with the smooth membrane fraction, have been partially purified from normal rat liver and a fast-growing Morris hepatoma, 1111, by previously published procedures. The membrane-associated enzymes have been designated as the 0.10 and 0.25 smooth membrane po...

Individual muscle fibers from the biceps of five individuals were analyzed for 10 different enzymes. For each person, lactic dehydrogenase and adenylokinase were first measured in 50 to 100 fibers. From each large group, 20 or more fibers, representing the full range of enzyme activity, were analyzed in duplicate for the other eight enzymes (glycogen phosphorylase, P-fructokinase, pyruvate kina...

BACKGROUND S-nitrosylation of mitochondrial enzymes involved in energy transfer under nitrosative stress may result in ATP deficiency. We investigated whether α-lipoic acid, a powerful antioxidant, could alleviate nitrosative stress by regulating S-nitrosylation, which could result in retaining the mitochondrial enzyme activity. METHODS In this study, we have identified the S-nitrosylated for...

Muscle contractions cause numerous disturbances in intracellular homeostasis. This makes it impossible to use contracting muscle to identify which of the many signals generated by contractions are responsible for stimulating mitochondrial biogenesis. One purpose of this study was to evaluate the usefulness of L6 myotubes, which do not contract, for studying mitochondrial biogenesis. A second pu...

Separation of Neurospora mitochondrial outer membranes from the inner membrane/ matrix fraction was effected by digitonin treatment and discontinuous density gradient centrifugation . The solubilization of four isoleucine-valine biosynthetic enzymes was studied as a function of digitonin concentration and time of incubation in the detergent . The kinetics of the appearance of valine biosyntheti...

Separation of Neurospora mitochondrial outer membranes from the inner membrane/matrix fraction was effected by digitonin treatment and discontinuous density gradient centrifugation. The solubilization of four isoleucine-valine biosynthetic enzymes was studied as a function of digitonin concentration and time of incubation in the detergent. The kinetics of the appearance of valine biosynthetic f...

Mitochondrial production of 2-hydroxyglutarate (2HG) can be catalyzed by wild-type isocitrate dehydrogenase 2 (IDH2) and alcohol dehydrogenase, iron-containing 1 (ADHFE1). We investigated whether biochemical background substrate concentration in breast cancer cells promote 2HG production. To estimate its role production, we quantified levels enantiomers using analytical approaches for metabolom...

Gene expression in eukaryotes is normally believed to be controlled by transcriptional regulators that activate genes encoding structural proteins and enzymes. To identify previously unrecognized DNA binding activities, a yeast proteome microarray was screened with DNA probes; Arg5,6, a well-characterized mitochondrial enzyme involved in arginine biosynthesis, was identified. Chromatin immunopr...

Two enzymes participating in 2'-deoxyadenosine (dAdo) metabolism: dAdo kinase (dAdoK EC 2.7.1.76) and adenosine deaminase (ADA, EC 3.5.4.4) were partially purified from rat liver mitochondria and cytosol and influence of nucleosides and nucleotides on the activity of these enzymes were investigated. Mitochondrial and cytosol dAdoK are separate proteins, while ADA from both subcellular fractions...