Showing papers in "Archives of Biochemistry and Biophysics in 1995"

TL;DR: Against propagating lipid peroxyl radical species, epicatechin and catechin are as effective as ECG and EGCG, the least efficacious being EGC and GA.

TL;DR: Transnitrosation and acceleration of disulfide formation suggest mechanisms of regulation of protein function through the intermediacy of nitrosothiols, and support the notion that biological activities of S-nitrosOTHiols may be associated with heterolytic as well as homolytic mechanisms of decomposition.

TL;DR: The current status of experiments that relate to both the role of the cellular process and to the reactivity of selected proteins that participate in the cellular processes are discussed, including glutathione, a molecule of central interest in every aspect of protein S-thiolation and dethiolation.

TL;DR: The results suggest that ONOO- or ONOO(-)-generating systems induce nitration of tyrosine (or tyrosines residues in proteins) via intermediate formation of tyrosyl radicals and .NO2.

TL;DR: Using stopped-flow with spectrophotometric detection, HOCl was found to react very rapidly with glutathione and ascorbate and less rapidly with taurine, and evidence could be found for the formation of reactive free-radical intermediates in these reactions, in support of an electrophilic mechanism.

TL;DR: A transient adaptation to the oxidative stress of hydrogen peroxide (H2O2) exposure in several mammalian cell lines is reported, finding no significant increases in transcription or translation of the classical antioxidant enzymes catalase, glutathione peroxidase, phospholipid hydroperoxide glutathion peroxIDase, Cu, Zn superoxide dismutase, or Mn superoxide Dismutase.

TL;DR: The results suggest that peroxynitrite is far more toxic to E. coli than nitric oxide or its by products from aerobic oxidation.

TL;DR: It is concluded that .NO can play a potent oxidant-protective role in the vessel wall by inhibiting lipoxygenase-dependent lipid and lipoprotein oxidation through termination of lipid radical chain propagation reactions catalyzed by alkoxyl (LO.) and LOO.

TL;DR: DNA damage caused by peroxynitrite can be rationalized as caused by a powerful oxidant, HOONO*, which is formed during the decomposition of peroxlynitrite to nitrite.

TL;DR: These newly synthesized nonphosphorous lipids, in addition to the sulfo- and the ornithine lipid also found in R. sphaeroides grown under optimal conditions, take over the role of phosphoglycerolipids in phosphate-deprived cells.

TL;DR: The quantitative and dynamic importance of oxidative, reductive, and nonoxidative routes in the metabolism and detoxification of 4-HNE is described.

TL;DR: Findings suggest that human liver microsomal arachidonic acid metabolism is catalyzed principally by CYP2C enzymes, and that the human Liver microsomes have substantial EET-epoxide hydrolase activity.

TL;DR: It was concluded that beta-carotene is less potent as an antioxidant than alpha-tocopherol because beta- carotenes is less reactive toward peroxyl radical thanalpha-tocaperol and the stable beta- Carotene radical reacts with oxygen to give beta-Carotene peroxy radical which is not stable but able to attack lipid to continue chain oxidation.

TL;DR: It is suggested that the greater affinity of the guanidino cation for sulfate in GAGs is probably due to stronger hydrogen bonding and a more exothermic electrostatic interaction, which can be rationalized by soft acid, soft base concepts.

TL;DR: An impact load was applied to full-depth circular samples of articular cartilage in vitro and the effects of impact energy and velocity on matrix integrity and chondrocyte viability were studied.

TL;DR: Using this technique, mu-calpain activity in Molt-4 cells was found to decrease progressively with A23187 treatment, as a reflection of autolytic inactivation.

TL;DR: It is suggested that cytochrome b5 plays a role in regulating the activities of P450c17 to optimize the balance between sex hormone synthesis and glucocorticoid synthesis, and in human testes which contains a high b5/P450 ratio, 17 alpha-hydroxyprogesterone can serve as an intermediate in testosterone production.

TL;DR: The fungal-elicited production of a (+)-delta-cadinene synthase is consistent with a role for this enzyme as the first committed step in the pathways leading to the related phytoalexins gossypol and lacinilene C in cotton.

TL;DR: This work believes it can recognize five, or perhaps six, clans of serine peptidases that are homologous, although some of the similarities are in the "twilight zone" and the relationships cannot be proven by rigorous statistical methods.

TL;DR: Results suggest that caffeic acid acts synergistically with alpha-tocopherol, extending the antioxidant capacity of LDL by recycling alpha-ocopherol from thealpha-tocopheroxyl radical, and p-coumaric acid decreases the peroxidation chain rate.

TL;DR: Observations support the assertion that aminoguanidine is a mechanism-based inactivator of the nitric oxide synthase isoforms and exhibits marked specificity for the inactivation of the inducible isoform.

TL;DR: It is demonstrated that the exposure of T cells to sublethal levels of oxidant stress acutely stimulates the MAP kinase cascade and suggested that this activation may involve PKC-dependent and -independent pathways as well as inhibition of certain protein phosphatases.

TL;DR: Production of hydroxyl radicals (HO.) by substrate-supplemented beef heart submitochondrial particles was studied by electron paramagnetic resonance in conjunction with the spin trap 5,5'-dimethyl-1-pirroline-N-oxide (DMPO) and formation during mitochondrial electron transfer is discussed in terms of oxidative damage of mitochondrial DNA and the implications for mitochondrial functions and aging.

TL;DR: The results imply that when quantitating superoxide by the cytochrome c3+ reduction method, the existence of a simultaneous generation of nitric oxide and peroxynitrite may lead to an underestimation of the rates of superoxide production.

TL;DR: Inactivation of the three NOS isozymes with NMMA and NNA reveals active-site differences between the isoforms, suggesting that inactivation occurs at or near the active site.

TL;DR: It is proposed that Cyp 2C8 is one of the human cytochrome P450 isoforms responsible for the metabolism of endogenous arachidonic acid pools, and the chirality of the products match that of the enantiomers present, in vivo, in human kidney cortex.

TL;DR: The results provide clear evidence for hydroxyl radical formation from Cu1+ and H2O2 (either added or formed during the autoxidation of reduced copper) and a variety of copper chelators inhibit formation of carbon-centered radical adducts of 4-POBN.

TL;DR: The first step in the biosynthesis of taxol in Pacific yew is the cyclization of the universal diterpene precursor geranylgeranyl pyrophosphate to taxa-4(5),11(12)-diene, which is then elaborated to taxol and related compounds by a complex series of reactions involving oxidations and side-chain acylations.

TL;DR: It is concluded that one-electron reduction of ubiquinone-10 by superoxide ion resulting in the formation of Ubisemiquin one-10 radicals caused redox-cycling of alpha-tocopherol from its phenoxyl radical, thus preventing loss ofalpha-ocopherol.