Redox property

In this study, perovskite BaTiO3 and SrTiO3 catalysts were prepared using the sol-gel method for oxidative coupling of methane (OCM). Characterization of catalysts was investigated by X-ray diffraction for crystal properties, physical N2 adsorption to determine specific surface area, and temperatureprogrammed techniques to examine the redox properties and acid–base strength.

6p vikwong 29-09-2024 1 1   Download

The signaling properties of the gasotransmitter molecule hydrogen sulfide (H2S), which is endogenously generated in plant cells, are mainly observed during persulfidation, a protein post-translational modification (PTM) that affects redox-sensitive cysteine residues. There is growing experimental evidence that H2S in higher plants may function as a mechanism of response to environmental stress conditions.

7p partimesinhvien 08-05-2020 31 0   Download

It has been discovered that many oxides can disperse spontaneously onto the supported surfaceto form a monolayer. When the catalysts are up to the monolayer, the oxide remains on the support as amorphous phase or in other words, it is well dispersed. Above the monolayer, X-ray diffractrograms indicate the presence of crystalline oxide. The monolayer of MeOx/TiO2 catalysts (Me = Mo, Co, Ni) were determined by X-ray Diffraction (XRD). The selective oxidations of hydrocarbon on oxide catalysts are known to proceed by a redox mechanism (Mars-van Krevelen mechanism).

6p uocvong03 24-09-2015 76 7   Download

A new functionalized conducting poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-3-acetic acid-1,4-naphthoquinone) with electroactive quinone group was studied by in situ Raman spectroscopy. The Raman results confirmed a good reversible transformation between two structures: quinoid and hydroquinoid ones during reduction-oxidation processes.

5p uocvong03 24-09-2015 29 3   Download

This study is focused on the synthesis of a polyindole doped by indole-3 butyric acid (PI-IBA). IR analyze indicated that the linkage positions of indole involves the position 2 and 3 of the monomer and the insertion of IBA in the polymer backbone. Polyindole IBA doped was incorporated into epoxy resin for protection anticorrosion of carbon steel. The electrochemical impedance measurements show a significantly improvement of protective properties in presence of PI-IBA in comparison with pure epoxy and epoxy containing polyindole coating.

6p uocvong01 24-09-2015 49 4   Download

One of the subjects of Ni-MH batteries studies is justly the electrochemically active material for the positive electrode-hydroxide nickel. This hydroxide Ni(OH)2 has been prepared in laboratory by chemical sedimentation from NiCl2 and NaOH solutions. The obtained product has been examined using different techniques, such as X ray Diffraction (XRD), Scanning Electronic Microscope (SEM) and electrochemical polarisation (cyclic voltammetry CV). The obtained results of obtained Ni(OH)2 show -type crystal, with grains of about 15 µm.

5p uocvong01 24-09-2015 50 4   Download

The dinitrogenase component proteins of the conventional Mo nitrogenase (MoFe protein) and of the alternative Fe-only nitrogenase (FeFe protein) were both isolated and purified from Rhodobacter capsulatus, redox-titrated according to the same procedures and subjected to an EPR spectroscopic comparison. In the course of an oxidative titration of the MoFe protein (Rc1Mo) three significant S ¼ 1/2 EPR signals deriving from oxidized states of the P-cluster were detected: (1) a rhombic signal (g ¼ 2.07, 1.96 and 1.

12p system191 01-06-2013 31 4   Download

Thecaa3-oxidase from Thermus thermophilushas been studied with a combined electrochemical, UV/VIS and Fourier-transform infrared (FT-IR) spectroscopic approach. In this oxidase the electron donor, cytochromec, is covalently bound to subunit II of the cytochrome c oxidase. Oxidative electrochemical redox titrations in the visible spectral range yielded a midpoint potential of )0.01 ± 0.01 V (vs. Ag/AgCl/3MKCl, 0.218 V vs. SHE¢) for the hemec.

9p research12 29-04-2013 49 3   Download

A new exocellular laccase was purified from the basidio-mycete C30. LAC2 is an acidic protein (pI¼3.2) prefer-entiallyproducedupona combined inductionby copper and p-hydroxybenzoate.The spectroscopic signature (UV/visible and EPR) of this isoform is typical of multicopper oxidases, but its enzymatic and physico-chemical properties proved to be markedly different from those of LAC1, the constitutive laccase previously purified from the same organism.

7p tumor12 22-04-2013 32 3   Download

Cytochrome P450BM3is a self-sufficient fatty acid mono-oxygenase consisting of a diflavin (FAD/FMN) reductase domain and a heme domain fused together in a single polypeptide chain. The multidomain structure makes it an ideal model system for studying the mechanism of electron transfer and for understanding P450 systems in general. Here we report the redox properties of the cyto-chrome P450BM3 wild-type holoenzyme, and its isolated FADreductase andP450 heme domains, when immobilized in a didodecyldimethylammonium bromide film cast on an edge-plane graphite electrode....

7p tumor12 20-04-2013 46 3   Download

The cytochromec nitrite reductase is isolated from the membranes of the sulfate-reducing bacteriumDesulfovibrio desulfuricansATCC 27774 as a heterooligomeric complex composedby two subunits (61 kDa and19 kDa) containing c-type hemes, encoded by the genes nrfA and nrfH, respectively. The extracted complex has in average a 2NrfA:1NrfH composition. The separation of ccNiR sub-units from one another is accomplished by gel filtration chromatography in the presence of SDS.

12p tumor12 20-04-2013 37 3   Download

Human novel reductase 1 (NR1) is an NADPH dependent diflavin oxidoreductase related to cytochrome P450reduc-tase (CPR). The FAD/NADPH- and FMN-binding domains of NR1 have been expressed and purified and their redox properties studied by stopped-flow and steady-state kinetic methods, and by potentiometry.

12p tumor12 20-04-2013 41 2   Download

Ferredoxin (flavodoxin)-NADP(H) reductases (FNR) are ubiquitous flavoenzymes that deliver NADPH or low potential one-electron donors (ferredoxin, flavodoxin) to redox-based metabolisms in plastids, mitochondria and bacteria. The plant-type reductase is also the basic prototype for one of the major families of flavin-containing electron transferases that display common functional and structural properties.

16p fptmusic 16-04-2013 39 2   Download

NMR and visible spectroscopy coupled to redox measurements were used to determine the equilibrium thermodynamic properties of the four haems in cytochrome c3 under conditions in which the protein was bound to lig-ands, the small anion phosphate and the protein rubredoxin with the iron in the active site replaced by zinc.

10p awards 06-04-2013 37 4   Download

Protein disulfide oxidoreductases are ubiquitous redox enzymes that catalyse dithiol–disulfide exchange reactions with a CXXC sequence motif at their active site. Adisulfide oxidoreductase, a highly thermostable protein, was isolated from Pyrococcus furiosus(PfPDO), which is characterized by two redox sites (CXXC) and an unusual molecularmass. Its 3D structure at high resolution suggests that it may be related to the multidomain protein disulfide-isomerase (PDI), which is currently known only in eukaryotes....

12p dell39 03-04-2013 35 3   Download

Inhibition of the mitochondrial adenine nucleotide translocator (ANT) by long-chain acyl-CoA esters has been proposed to contribute to cellular dys-function in obesity and type 2 diabetes by increasing formation of reactive oxygen species and adenosine via effects on the coenzyme Q redox state, mitochondrial membrane potential (Dw) and cytosolic ATP concentrations.

15p inspiron33 23-03-2013 55 4   Download

Two ORFs encoding a protein related to bacterial dimethylglycine oxidase were cloned from Pyrococcus furiosus DSM 3638. The protein was expressed in Escherichia coli, purified, and shown to be a flavoprotein amine dehydrogenase. The enzyme oxidizes the secondary aminesl-proline, l-pipecolic acid and sarcosine, with optimal catalytic activity towards l-proline.

18p galaxyss3 19-03-2013 58 4   Download

Adhesive properties of endothelial cells are influenced by the thioldisulfide balance. However, the molecular mechanism of this effect is unclear, although recent observations indicate that integrin receptors may be direct targets for redox modulation. The purpose of this study was to examine whether protein disulfide isomerase (PDI) is directly involved in this pro-cess.

11p media19 06-03-2013 58 3   Download

Much of the toxicity of Hb has been linked to its redox activity; Hb may generate reactive oxygen species, such as the superoxide anion. Superoxide is intrinsically toxic, and superoxide dismutase (SOD) provides important cellular protection. However, if the Hb molecule is located outside the red blood cell, the normal protection systems involving SOD and catalase are no longer closely associated with it, exposing Hb and its cellular surround

9p viettel02 20-02-2013 66 2   Download