Search results for "Phosphorylation"
showing 10 items of 975 documents
Epigenetics, oxidative states and diabetes
2020
Abstract Although controlling a wide range of physiological cell functions, redox states unbalance during inflammation toward oxidative stress. Specific regions of our genome are extremely sensitive to both oxygen and reactive oxygen species, therefore modulating gene transcription in response to this specific epigenetic effect. Additional epigenetic mechanisms may include the alteration of the methylation states of DNA, protein and lipid nitration or modulation of specific microRNAs. A crucial role in finely tuning redox states is also played by mitochondria, where oxidative phosphorylation is epigenetically controlled. Diabetes, the most considerable “epigenetic” clinical disorder, exacer…
Electrochemical sensor for evaluating oxidative stress in airway epithelial cells
2021
Cigarette smoke exposure induces oxidative stress within the airways. Increased oxidative burden contributes to the pathogenesis of chronic lung disorders and is associated with aging and chronic inflammation. Airway epithelial cells highly contribute to Reactive Oxygen Species (ROS) generation within injured and inflamed lung tissues. Among ROS, hydrogen peroxide (H2O2) can be monitored in the extracellular space. Herein, we present an amperometric/voltammetric sensor based on gold nanoparticles and graphene oxide able to detect H2O2 with good sensitivity and selectivity. Using this sensor, H2O2 release was measured in conditioned medium from primary bronchial epithelial cells (PBEC), bron…
Oxidative Stress and DNA Damage in Obesity-Related Tumorigenesis
2014
Reactive oxygen species induce oxidative modification of critical macromolecules. Oxygen derived free radicals may act as potential cytotoxic intermediates inducing inflammatory and degenerative processes, or as signal messengers for the regulation of gene expression. This dual effect mainly depends on the availability of free radicals in terms of concentration, as well as on the environmental characteristics in which they are produced. The formation of free radicals has been proposed to be the linking factor between certain metabolic disturbances and cancer. Circulating mononuclear cells of patients with high cholesterol levels, insulin resistance, metabolic syndrome or obesity present low…
Forever Young: Structural Stability of Telomeric Guanine-Quadruplexes in Presence of Oxidative DNA Lesions
2020
AbstractHuman telomeric DNA (h-Telo), in G-quadruplex (G4) conformation, is characterized by a remarkable structural stability that confers it the capacity to resist to oxidative stress producing one or even clustered 8-oxoguanine lesions. We present a combined experimental/computational investigation, by using circular dichroism in aqueous solutions, cellular immunofluorescence assays and molecular dynamics (MD) simulations, that identifies the crucial role of the stability of G4s to oxidative lesions, related also to their biological role as inhibitors of telomerase, an enzyme overexpressed in most cancers associated to oxidative stress.
Oxidative cyclization of aldehyde thiosemicarbazones induced by potassium ferricyanide and by tris(p-bromophenyl)amino hexachloroantimoniate. A joint…
2005
The oxidative ring closure reaction of some aryl-substituted thiosemicarbazones induced by "bona fide" one-electron abstracting agents was investigated, by means of both experimental and computational techniques. The corresponding 1,2,4-triazole derivatives were the only cyclization products observed. The occurrence of two slightly different mechanistic pathways for the reaction is discussed.
The Effect of Light Intensity During Growth of Sinapis alba on the Electron-Transport and the Noncyclic Photophosphorylation
1975
The photosynthetic rate of Sinapis alba can be modified over a wide range by the light intensity during growth. Our present results indicate that there exist regulatory mechanisms in the field of photosynthetic primary reactions. We compared the effect of different light intensities during growth of Sinapis plants on the concentrations of soluble proteins, manganese and lipophilic plastid quinones, the electron flow from water to ferricyanide and noncyclic phosphorylation. We further determined the light dependence curves for the uncoupled electron transport with ferricyanide as electron acceptor and methylammonium-chloride as an uncoupler of photophosphorylation.
Molecular response to TBT stress in marine sponge Suberites domuncula: proteolytical cleavage and phosphorylation of KRS_SD protein kinase
2003
Abstract Marine sponges as sessile filter feeders are inevitably under a constant influence of changes in their environment. Mediation of extracellular signals and regulation of cellular response to environmental stress is a key function of cellular protein kinases. Expression, proteolytical cleavage and phosphorylation of stress-responsive KRS_SD protein kinase, in control and tributyl-tin (TBT) treated sponges were investigated. In control sponge, two KRS_SD proteins were expressed: KRS_SD1 (54 kDa) corresponding to KRS_SD calculated molecular weight, and KRS_SD2 (50 kDa). Exposure of sponges to TBT resulted in alteration of KRS_SD1 and KRS_SD2 expression levels and their phosphorylation …
One-Pot Oxidative C–H Activation/Aza-Prins-Type Reaction of Tertiary Alkynylamines: A Counter Ion-Induced Iminium Ion–Alkyne Cyclization
2021
Herein, the design and development of a new one-pot and metal-free oxidative C-H activation/aza-Prins type cyclization of alkynylamines is reported. The scope of this method was demonstrated by the preparation of ten new pyrido[2,1-a]isoquinolines in moderate to high yields (38-92%). Furthermore, a mechanistic proposal for the alkyne aza-Prins cyclization is described based on DFT calculations.
Oxidative DNA Damage Profiles in Mammalian Cells
1997
Reactive oxygen species (ROS) are formed inside cells not only under the influence of exogenous agents (visible light, ionizing radiation, and many oxidants such as peroxides or quinones), but also under normal (physiological) conditions as byproducts of oxygen metabolism and other cellular redox reactions (Pryor 1986; Halliwell and Gutteridge 1986; Sies 1986; Clayson et al. 1994). ROS such as hydroxyl radicals and singlet oxygen are a serious threat to the integrity of the cellular genome, since they efficiently react with DNA to generate many types of DNA modifications, at least some of which are pre- mutagenic (Breimer 1990; Halliwell and Aruoma 1991; Epe 1991; Feig et al. 1994). Steady-…
Carnitine transport in volume-overloaded rat hearts
1995
Carnitine concentration in tissue is generally related to mitochondrial volume-density and ability to oxidize fatty acids. The highest tissue carnitine has been detected in ventricular myocardium which, compared to other tissues, presents elevated rates of oxidative phosphorylation [1]. The ability of cardiac mitochondria to oxidize long chain fatty acids is also much higher when compared to skeletal muscle or liver sarcosomes (Table 1). Paradoxically enough, it has been known for many years [3–5] that the heart is missing γ-butyrobetaine hydroxylase [6, 7], the last enzyme of carnitine synthesizing pathway, and that in the myocardium of different species including man, the carnitine synthe…