By sulfur substitution of the N-5 atom in flavins and flavocoenzymes a flavin analog is obtained, Sthiaflavin, which is found to be isoelectronic and isosteric with natural flavin in the fully reduced and half-reduced states, but not in the oxidized state. Among the three ‘redox shuttles’ characterizing the flavin system, viz. upper le-, lower leand 2eshuttle, only the second one is retained in...

The human branched-chain aminotransferase (hBCAT) isoenzymes are CXXC motif redox sensitive homodimers central to glutamate metabolism in the central nervous system. These proteins respond differently to oxidation by H(2)O(2), NO, and S-glutathionylation, suggesting that the redox potential is distinct between isoenzymes. Using various reduced to oxidized glutathione ratios (GSH:GSSG) to alter ...

The flavin-dependent monooxygenase from yeast (yFMO) oxidizes biological thiols such as cysteine, cysteamine, and glutathione. The enzyme makes a major contribution to the pools of oxidized thiols that, together with reduced glutathione from glutathione reductase, create the optimum cellular redox environment. We show that the activity of yFMO, as a soluble enzyme or in association with the ER ...

We propose the very first "Nernstian biosupercapacitor", a biodevice based on only one redox polymer: poly(vinyl imidazole-co-allylamine)[Os(bpy)2 Cl], and two biocatalysts. At the bioanode PQQ-dependent glucose dehydrogenase reduces the Os3+ moieties at the polymer to Os2+ shifting the Nernst potential of the Os3+ /Os2+ redox couple to negative values. Concomitantly, at the biocathode the redu...

The redox potentials of electron transfer proteins vary over a wide range, even when the type of redox center is the same. Rees [Proc. Natl. Acad. Sci. USA (1985) 82, 3082-3085] proposed that this variation of redox potential partly reflects the different net charges of the proteins, and he presented a linear correlation between these two properties for 36 proteins. A review of the factors that...

a new hydroxylamine sensor has been fabricated by immobilizing oxadiazol denvative at the surface ol aglassy carbon electrode (gce) modified by multi-wall carbon nanotube (mivcnt). the adsorbed thin illms oroxadiazol derivative on the mwcnt modified gce show a pair of peaks with surface confined characierisnus.the oxadiazol derivative mwcni (omwcnt) modified gce shows highly catalytic activity ...

Catalytic conversion of carbon dioxide (CO2) into value-added chemicals and fuels can not only mitigate global warming but also alleviate the energy crisis caused by fossil fuel depletion. Redox potential is a key thermodynamic quantity CO2 reduction reactions, while currently, standard (25°C, 1 atm, M) available for application. Herein, it first time to report influence temperature (0–1000°C),...

The effect of redox potential on xylitol production by Candida parapsilosis was investigated. The redox potential was found to be useful for monitoring the dissolved oxygen (DO) level in culture media, especially when the DO level was low. An increase in the agitation speed in a 5 L fermentor resulted in an increased culture redox potential as well as enhanced cell growth. Production of xylitol...

Divalent silver is stabilized in concentrated sulphuric acid and oleums. The formal redox potential of the Ag(II)/Ag(I) redox pair is markedly dependent on the Hammett acidity function and it reaches +2.90 V vs. NHE in 33% oleum thus rivalling E° for the F2/2F(-) redox pair (+2.87 V).