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Membrane redox

The yeast-mediated enzymatic biodegradation of azo dyes can be accomplished either by reductive reactions or by oxidative reactions. In general, reductive reactions led to cleavage of azo dyes into aromatic amines, which are further mineralized by yeasts. Enzymes putatively involved in this process are NADH-dependent reductases [24] and an azoreductase [16], which is dependent on the extracellular activity of a component of the plasma membrane redox system, identified as a ferric reductase [19]. Recently, significant increase in the activities of NADH-dependent reductase and azoreductase was observed in the cells of Trichosporon beigelii obtained at the end of the decolorization process [25]. [Pg.185]

Also ascomycetes yeast strains showed decolorizing behaviors due to extracellular reactions on polar dyes. The process occur when an alternative carbon and energy source is available. The involvement of an externally directed plasma membrane redox system was suggested in S. cerevisiae, the plasma membrane ferric reductase system participates in the extracellular reduction of azo dyes [25]. [Pg.201]

Recent development of mitochondrial theory of aging is so-called reductive hotspot hypothesis. De Grey [465] proposed that the cells with suppressed oxidative phosphorylation survive by reducing dioxygen at the plasma membrane rather than at the mitochondrial inner membrane. Plasma membrane redox system is apparently an origin of the conversion of superoxide into hydroxyl and peroxyl radicals and LDL oxidation. Morre et al. [466] suggested that plasma membrane oxidoreductase links the accumulation of lesions in mitochondrial DNA to the formation of reactive oxygen species on the cell surface. [Pg.947]

Asard. H.. A. Bcnczi. and R.J. Caubcrgs Plasma Membrane Redox Systems and Their Rale in Biological Stress and Disease. Kluwcr Academic Publishers. Noiwelt. MA. 1999. [Pg.467]

In principle, glucose oxidase could be oxidized directly at the electrode, which would be the ultimate electron acceptor. However, direct electron transfer between redox enzymes and electrodes is not possible because the FADH2/FAD redox centers are buried inside insulating protein chains (Heller, 1990). If it were not the case, various membrane redox enzymes with different standard potentials would equalize their potentials on contact, thus effectively shorting out the biological redox chains. The electron transfer rate is strongly dependent on the distance x between the electron donor and the electron acceptor. [Pg.228]

Plasma Membrane Redox-Linked Proton Transport 174... [Pg.169]

PLASMA MEMBRANE REDOX-LINKED PROTON TRANSPORT... [Pg.174]

Villalba JM and Navas P (2000) Plasma membrane redox system in the control of stress-induced apoptosis. Antioxidants and Redox Signaling 2,213-30. [Pg.457]

Crane, F. L., I. L. Sun, M. G. Clark, C. Grebing, and H. Low (1985b), Transplasma-Membrane Redox Systems in Growth and Development, Biochim. Biophys. Acta 861, 233-264. [Pg.255]

NADH to ferricyanide, which proceeds effectively in aeorbic conditions, stops completely in anaerobic conditions. It could be supposed that in anaerobic conditions no peroxides necessary for electron transport are formed. Thus, it could be assumed that one of FMN s functions is that it maintains in mitochondrial membrane a certain optimal concentration of peroxide radicals, which are needed as catalysts of the electron transport reaction during respiration. It was shown that the formation of peroxides with the participation of FMN disappears in acid media. On the other hand, when peroxides are formed the layer adjacent to the membrane becomes enriched in protons. Hence, it follows that the peroxide formation process might possibly be a self-regulating one, the rate of which cannot rise endlessly. This circumstance once more substantiates the supposition that this process might play a very important functional role in membrane redox reactions. [Pg.136]

A.A. Stuchebrukhov, Coupled electron and proton transfer reactions in proteins and computational challenges of membrane redox pumps. In Cundari, T. (ed.), Reviews in Computational Chemistry, Wiley-VCH, Weinheim (2007) [Invited review article]. [Pg.101]

As the cell membrane of microorganisms is non-conductive, how to transfer the electrons across the cell membrane (usually termed as extracellular electron transfer (EET)) is the key issue for MES. Eor the bioanode, extracellular electron transfer usually refers to outwards electron transfer, which is related to transportation of intracellular electrons to the solid electrode. To date, at least three electron transfer pathways have been explored, i.e., electron shuttle mediated electron transfer, outer membrane redox proteins mediated contact-based electron transfer, and conductive pili mediated electron transfer (Figure 5.5). ... [Pg.142]

Observational studies In a comparison of HBOC-201 and erythrocyte transfusion, the former caused mild platelet dysfunction, which may be caused by reactive oxygen molecules. In blood, there is redox hemostasis as a result of a trans-plasma membrane redox system in platelets. This hemostasis could be impaired by free radicals [23 ]. [Pg.512]

The capacity of the oxidase of Epstein-Barr virus immortalised B lymphocytes was decreased or abolishes in chronic granulomatous disease (Morel et al. 2000). Cytochrome fa.245, the major membrane redox component of the O2 " generating oxidase, was only slightly expressed in the membrane of Epstein-Barr virus immortahsed B lymphocytes. [Pg.440]

Around 1970 Stephen Hersey, using the same spectrophotometric methods at Emory University, demonstrated that cytochrome c is 25 times more abundant in oxyntic cells than in striated muscle, but he asserted that there are no ordinary respiratory chain members, including cytochrome c, in the cells cytoplasma. Consequently, Hersey was reduced to postulating an unspecified extramitochondrial redox system that acts in the cell s membrane to produce hydrogen ions. Hersey said the membrane redox system must ultimately use reduced equivalents supplied by mitochondria. [Pg.70]

Okada Y, Okajima H (2001) Antioxidant effect of capsaicin on lipid peroxidation in homogeneous solution, micelle dispersions liposomal membranes. Redox Rep 6 117-122... [Pg.4540]

It is clear that ferric chelates present in soil water are the natural electron acceptors for the inducible system (or turbo reductase) responsible for ferric reduction prior to iron uptake by dicotyledoneous and nongrass monocotyledoneous plants (Holden et al., 1991 Lesuisse and Labbe, 1992). In contrast, the natural electron acceptor of the so-called constitutive plasma membrane redox system both in plant and animal cells has not been completely defined. In addition to oxygen and iron-containing compounds, the semioxidized form of ascorbate, AFR, has been proposed as a natural electron acceptor (Goldenberg et al, 1983). [Pg.59]

Medina, M. A., and Schweigerer, L., 1993, A plasma membrane redox system in human retinoblastoma cells, Biochem. Mol. Biol. Int. 29 881-887. [Pg.79]

Medina, M. A., Castillo-Olivares, A., and Schwigerer, L., 1992, Plasma membrane redox activity correlates with N-myc expression in neuroblastoma cells, FEBS Lett. 311 99-101. [Pg.79]

Misra, P. C., Craig, T, and Crane, F. L., 1984, A link between transport and plasma membrane redox systems in carrot cells, J. Bioenerg. Biomembr. 16 143-152. [Pg.79]

Rodriguez-Aguilera, J. C., Navarro, F., Arroyo, A., Villalba, J. M., and Navas, P., 1993, Transplasma membrane redox system of HL-60 cells is controlled by cAMP, J. Biol. Chem. 268 26346-26349. [Pg.81]

Rubinstein, B., and Luster, D. G., 1993, Plasma membrane redox activity Components and role in plant processes, Anna. Rev. Plant Physiol. Plant Mol. Biol. 44 131-155. [Pg.81]

Plasma membranes of all cells investigated so far contain an electron transport system transferring electrons from NADH to an extracellular electron acceptor (for review, see Navas et al., 1994 and Chapter 4 of this volume). Electron transport across the plasma membrane is accompanied by release of protons from the cell, presumably due to an activation of the Na+/H+ antiport (Sun et a/., 1988). Since proton release and the concomitant increase in cytoplasmic pH have been connected to growth stimulation (Moolenar et al., 1983), it was proposed that the transplasma membrane redox system via proton release might also be involved in the regulation of proliferation. [Pg.96]


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See also in sourсe #XX -- [ Pg.262 ]




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Membranes redox-active

Plasma membrane redox potential

Plasma membrane redox system

Redox Electrode Kinetics at Membrane Bielectrodes

The Transplasma Membrane Redox System

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