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Cardiovascular Disease and Oxidative Stress
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Marco Fernandes, Alisha Patel, Holger Husi
Xanthine oxidase (XO), a form of xanthine oxidoreductase, is important in the catabolism process of purines such as uric acid (UA) (Schuchardt et al., 2017). It readily donates electrons to diatomic oxygen yielding O2− and H2O2. UA is the final end-product of the purine catabolism and is formed from xanthines and hypoxanthines, and XO may be responsible for most of the ROS production (Berry and Hare, 2004). The catalytic reaction on how it generates ROS is shown in three separate, but relatable chemical reactions: Xanthine + NAD+ + H2O ↔ urate + NADHHypoxanthine + NAD+ + H2O ↔ xanthine + NADHXanthine + H2O + O2 ↔ urate + H2O2
In vitro diagnostics for early detection of bacterial wound Infection
Published in Maximilian Lackner, Philipp Stadler, Wilhelm Grabow, Handbook of Online and Near-real-time Methods in Microbiology, 2017
Gregor Tegl, Andrea Heinzle, Eva Sigl, Georg M. Guebitz
A pH-changing compound accumulated in response to the host immune response in uric acid, which is produced by xanthine oxidase (XO) from purine derivatives (Fernandez et al. 2012). Disposable pH sensors for urate detection were produced by Phair et al. and were based on SPEs; they could successfully detect urate in buffer and blood samples (Phair et al. 2011). Further developments of carbon fiber sensors and pad-imprinted carbonuric acid composite electrodes proved a sensitive detection of pH changes caused by uric acid in complex media, like artificial wound fluid, serum and blister fluid. However, these systems are lacking a definite proof on human wound fluid samples of infected wounds.
Monocotyledons I
Published in Donald H. Les, Aquatic Monocotyledons of North America, 2020
Economic importance: food: Cooked Pistia plants have been eaten in India as a famine food; medicinal: Worldwide, Pistia stratiotes has been used to treat numerous ailments. It is regarded as an effective antioxidant, bronchodilator, diuretic, and emollient, and as having antidiabetic, antimicrobial, antifungal, antiprotease, antitumor, and diuretic properties. Various leaf extracts are thought to lessen cellular injury by reducing levels of harmful superoxides, nitric oxide radicals, and free radicals. Ethanolic extracts prevent uric acid formation by inhibiting xanthine oxidase (a strategy used to treat gout). The extracts also are antipyretic and can alleviate fevers. The foliage is used as a disinfectant and in various remedies to treat dysentery, eczema, inflammation, leprosy, parasites, piles, syphilis, tuberculosis, and ulcers. Ash made from the leaves is used as a cure for ringworm; cultivation:Pistia stratiotes is one of the most widely distributed ornamental pond and water garden plants worldwide. The typical species and a variegated form are distributed commercially; misc. products:Pistia plants have been used to synthesize gold nanoparticles, to generate biogas, and as a bio-sorbent for removal of crude oil from saltwater and metals in industrial applications. They also have been evaluated as a means of removing heavy metals, pharmaceuticals, personal care product residues, and radioisotopes from natural and wastewaters; weeds:Pistia stratiotes is regarded as a noxious weed in North America and throughout its nonindigenous (and even native) range elsewhere. The state of Florida alone expends several million dollars annually on control measures. The recent discovery of Pistia in more northern localities (e.g., Great Lakes) has raised question whether the plants might be able to persist at higher latitudes as the global climate continues to warm; however, such seems unlikely for these surface plants unless abnormally warm, ice-free waters become available throughout the winter; nonindigenous species:Pistia stratiotes presumably is nonindigenous to North America although impassioned arguments have been made for its indigenous status, based primarily on fossil evidence. In any case, aggressive Florida populations already were present in the St. John’s River and Suwanee River before 1765. The species has been disseminated widely across the globe due to the continuing sales and careless disposal of cultivated water garden specimens.
Structural and activity changes of xanthine oxidase induced by cetyltrimethylammonium bromide and its Gemini homologue bis(cetyldimethylammonium)hexane dibromide: a comparative study
Published in Journal of Dispersion Science and Technology, 2023
Xanthine oxidase (XOD) plays an important role in tissue and vascular injuries, inflammatory diseases, cardiac disorders, and metabolic arthritis.[8,9] The harmful effects of XOD are mainly due to the reduction of molecular oxygen associated with the XOD catalyzed oxidation of xanthine to uric acid.[10] The by-products of the above reaction, superoxide anion, and hydrogen peroxide, oxidize the cellular components of a cell. These reduced forms of molecular Oxygen are primarily responsible for the damaging role of the enzyme.[9–11] XOD, a complex molybdoflavoprotein, is made of two identical polypeptide chains, each chain is composed of an N-terminal domain containing two iron-sulfur centers (Fe/S I and Fe/S II), a central flavin adenine dinucleotide (FAD) domain, and a C-terminal molybdopterin-binding domain with the four redox centers aligned in an almost linear fashion.[12–14] In the process of the oxidation of a substrate the Mo(VI) of the active site gets reduced to Mo(IV).[15] The extra electrons released cascade down to the molybdenum, iron-sulfur [Fe2–S2] clusters, flavin and finally to an electron acceptor such as O2.[12,13]
Potential adverse cardiac remodelling in highly trained athletes: still unknown clinical significance
Published in European Journal of Sport Science, 2018
Luigi Gabrielli, Marta Sitges, Mario Chiong, Jorge Jalil, María Ocaranza, Silvana Llevaneras, Sebastian Herrera, Rodrigo Fernandez, Rodrigo Saavedra, Fernando Yañez, Luis Vergara, Alexis Diaz, Sergio Lavandero, Pablo Castro
After extreme exercise effort, plasma levels of markers of oxidative stress increase (La Gerche et al., 2012), suggesting a pro-oxidative environment that likely outstrips the buffering capacity of the system that promote oxidative-dependent biomolecules damage (e.g. ROS-dependent oxidation of intracellular lipid, proteins and DNA) and leads to a loss of redox homeostatic balance (D'Autreaux & Toledano, 2007). The intracellular accumulation of these damaged biomolecules might play a role in both acute and chronic cardiomyocyte dysfunction after excessive physical exercise (Figure 1(D)). There are several sources of oxidative molecules that might contribute to the oxidative environment during physical exercise including mitochondria, xanthine oxidase and NADPH oxidase enzymes (Morales, Pedrozo, Lavandero, & Hill, 2014).
Effect of cetyltrimethylammonium bromide and its gemini homologue bis(cetyldimethylammonium)butane dibromide on activity of xanthine oxidase
Published in Journal of Dispersion Science and Technology, 2018
Xanthine oxidase (XO), a complex molybdoflavo protein, is a key enzyme in purine metabolism that has attracted lots of attention because of its potential role in tissue and vascular injuries, as well as in inflammatory diseases and chronic heart failure.[8,9] It catalyzes the oxidation of hypoxanthine to xanthine and that of xanthine to uric acid with concomitant reduction of molecular oxygen.[10] This last step results in the production of superoxide anion and hydrogen peroxide, two reactive oxygen species that have been associated with the potential damaging role of the enzyme.[91011] The enzyme is a homodimer, each monomer is composed of an N-terminal domain containing two iron–sulfur centers (Fe/S I and Fe/S II), a central flavin adenine dinucleotide (FAD) domain, and a C-terminal molybdopterin-binding domain with the four redox centers aligned in an almost linear fashion.[121314] Substrate oxidation occurs at the molybdenum site, which becomes reduced from Mo(VI) to Mo(IV) in the process.[15] The catalytic cycle is completed by electron transfer from molybdenum to the [Fe2–S2] clusters and then to the flavin, where the electrons are donated to an acceptor such as O2.[12,13]