Showing papers in "Archives of Biochemistry and Biophysics in 1992"

TL;DR: The mechanism appears to involve peroxynitrite initially reacting with the active site copper to form an intermediate with the reactivity of nitronium ion (NO2+), which then nitrates tyrosine on a second molecule of superoxide dismutase.

TL;DR: The formation of a relatively long lived, strong oxidant from the reaction of nitric oxide and superoxide in activated macrophages may contribute to inflammatory cell-mediated tissue injury.

TL;DR: It is proposed that peroxynitrite anion is more stable in the cis conformation, whereas only a higher energy species in the trans conformation can fit in the active site of Cu,Zn superoxide dismutase.

TL;DR: The hydroxyl radical scavengers mannitol, ethanol, and benzoate did not significantly affect toxicity while dimethyl sulfoxide enhanced peroxynitrite-mediated killing, indicating that exogenous transition metals were not required for toxicity.

TL;DR: The possibility of a cooperative interaction between fat-soluble antioxidants is examined in a membrane model in this article, where a combination of beta-carotene and alpha-tocopherol results in an inhibition of lipid peroxidation significantly greater than the sum of individual inhibitions.

TL;DR: There were interindividual differences in carotenoid levels of the different tissue types, but liver, adrenal gland, and testes always contained significantly higher amounts of thecarotenoids than kidney, ovary, and fat; carOTenoids in brain stem tissue were below the detection limit.

TL;DR: The number of recent published observations for each of these cations is so staggering that it would put the writer in a quandary to write a small review not only on their cellular control but also on individual compo- nents, organelles, or enzymes involved in specific steps of this control.

TL;DR: When the conjugated keto-carotenoids are added to rat liver microsomes undergoing radical-initiated lipid peroxidation under air, they are as effective as alpha-tocopherol in inhibiting this process.

TL;DR: It was found in model experiments that in postmortem tissue neither oxidation nor reduction of ubiquinone occurs, and high levels of reduction could be observed in human tissues, with the exception of brain and lung.

TL;DR: The purified product exhibited antibacterial activity against several gram-positive bacterial strains, including the food pathogen Listeria monocytogenes, and the amino acid sequence and arrangement of the disulfide bonds were determined.

TL;DR: Reactions of oleic and linoleic acids with myeloperoxidase, hydrogen peroxide, and chloride gave chlorohydrin products identical to those with HOCl, which could be significant in neutrophil-mediated cytotoxicity.

TL;DR: Results provide strong evidence that P450 1A1 catalyzes the hydroxylations of E2 at the C-2, C-15 alpha, and C-6 alpha positions in incubations with microsomes from TCDD-treated MCF-7 cells, but suggest TCDd may also induce a cytochrome P450 E2 4-hydroxylase that is distinct from P450 2A1 or P 450 1A2.

TL;DR: An unexpected finding was the presence at position -403 to -385 of a putative dioxin responsive element, a sequence found to be responsible for the induction of transcription of the cytochrome P450IA1 gene (CYPIA1) and other genes involved in detoxification/activation of polycyclic aromatic hydrocarbons.

TL;DR: In this article, the authors found that the sensitivity of NR to inhibition by millimolar concentrations of magnesium was increased when the leaves were returned to darkness, and the NR rapidly became sensitive to Mg2+ inhibition.

TL;DR: It was found that CA074 methyl ester caused selective inactivation of the intracellular cathepsin B of human gingival fibroblasts in culture, in contrast to other available agents, and it is suggested that CA74 methyl Ester will be of value in the elucidation of the biological functions of cathePSin B.

TL;DR: It is shown by Northern blot analysis that human HO-2 is encoded by two transcripts and is a single-copy gene as judged by Southern blot analysis and evidence based on Northern blot and sequence analysis of a cDNA representing the larger transcript that the transcripts differ in the 3' untranslated region is provided.

TL;DR: CYP2A6 is largely or entirely responsible for catalyzing the 7-hydroxylation of coumarin in human liver microsomes, which implies that environmental factors may be responsible for the large variation in CYP2A 6 levels in humans, although genetic factors may also be important.

TL;DR: Analysis of synovial fluids and serum of age-matched animals revealed the presence of aggrecan core protein peptides corresponding in size to those detected in vitro, thus indicating the cleavage observed in explant culture is the same as that which occurs in vivo.

TL;DR: The results suggest that Ca+ channel blockers and antioxidants, although inactive on oxidative stress-induced Ca2+ release from intracellular stores, prevent the increased influx apparently related to a membrane thiol oxidation.

TL;DR: The effect of calcium on annexin V-membrane binding is proposed to be due to the formation of phospholipid-calcium complexes, to which the protein binds, rather than to an allosteric effect ofcium on protein-phospholipids affinity.

TL;DR: It is suggested that L-propionyl carnitine protects the heart by a dual mechanism: it is an efficient fuel source and an antiradical agent.

TL;DR: Enhanced levels of catalase did not prolong the life span of flies, nor did they provide improved protection against oxidative stress induced by hyperoxia or paraquat treatment, however, enhanced resistance to hydrogen peroxide was observed in the overexpressors.

TL;DR: Findings indicate that high concentrations of TNF alpha induce an oxidant stress in isolated hepatocytes, and the antioxidants mannitol and benzoate, as well as the iron chelator deferoxamine, reduced the extent of T NF alpha-induced oxidant effects in hepatocyte, which indicates that the oxidant Stress may involve hydroxyl radical generation.

TL;DR: A mathematical model based on diffusion-limited aggregation was developed to describe the kinetics of aggregation and showed that β(1–40) aggregated end-to-end in solution, reaching average molecular weights greater than 4 × 106 after 13 days.

TL;DR: It is found that incubation of A6 cell microsomes from dexamethasone-induced cells with antibodies against family 3A proteins specifically inhibited corticosterone 6 beta-hydroxylase activity, suggesting that toad kidney A6 cells express a family 2A P450 that is immunochemically, functionally, and genetically related to the mammalian liver 3Aprotein.

TL;DR: The formation of ubiquitin-conjugated microsomal protein which correlates with P450 2E1 loss suggests that ubiquitination may represent a proteolytic signal for the rapid and selective proteolysis of certain labilized conformations of P4502E1 from the endoplasmic reticulum.

TL;DR: These concepts, when applied to published data on double mutants of delta 5-3-ketosteroid isomerase, staphylococcal nuclease, tyrosyl-tRNA synthetase, glutathione reductase, and subtilisin, provide deeper insights into the independent, cooperative, anticooperative, or antagonistic interactions of amino acid residues in the binding of substrates, activators, and inhibitors and in promoting catalysis.

TL;DR: Thioperoxyl radicals, RSOO.

TL;DR: It is concluded that in vitro seed XG-ase can transfer cleavage products of XG to XG oligosaccharides via endotransglycosylation reactions, thereby reducing XG M(r) without hydrolysis.