The fbcB and fbcC genes encoding cytochromes b and c1 of the bc1 complex were extended with a segment to encode a polyhistidine tag linked to their C-terminal sequence allowing a one-step affinity purification of the complex. Constructions were made in vitro in a pUC-derived background using PCR amplification. The modified fbc operons were transferred to a pRK derivative plasmid, and this was u...

BACKGROUND Eukaryotic cells have evolved various response mechanisms to counteract the deleterious consequences of oxidative stress. Among these processes, metabolic alterations seem to play an important role. RESULTS We recently discovered that yeast cells with reduced activity of the key glycolytic enzyme triosephosphate isomerase exhibit an increased resistance to the thiol-oxidizing reage...

due to some important applications of guanine electrode in scientific and technology research such as electro-chemical dna based biosensors, and a problem of high redox potential of guanine (0.81 v), our research study concentrates on reducing guanine redox potential by substituting cu, ag, au, ch3, c2h5 and cl on sites of 1, 2 and 9 of guanine. a 5.0% reduction of redox potential for 9-ag-guan...

The reactions of horse heart cytochrome c with Fe(ethylenediaminetetraacetate)2-, Co(1,10-phenanthroline)3(3+), Ru(NH3)6(2+), and Fe(CN)6(3-) have been analyzed within the formalism of the Marcus theory of outer-sphere electron transfer, including compensation for electrostatic interactions. Calculated protein self-exchange rate constants based on crossreactions are found to vary over three ord...

Cysteine sulfenic acids in proteins can be identified by their ability to form adducts with dimedone, but this reagent imparts no spectral or affinity tag for subsequent analyses of such tagged proteins. Given its similar reactivity toward cysteine sulfenic acids, 1,3-cyclohexadione was synthetically modified to an alcohol derivative and linked to fluorophores based on isatoic acid and 7-methox...

Abstract Rigid 1,3-disubstituted bicyclo[1.1.1]pentanes (BCPs) are linear bioisosteres for para -substituted benzene rings in drug development and can lead to an improved pharmacokinetic profile. The construction of BCPs commonly requires the cumbersome use labile [1.1.1]propellane solution, more stable reagents do not show versatile reactivity propellane itself. Here we report thianthrenium-ba...

Electron transport activity at the cell surface of intact oat seedlings (Avena sativa L. cv Garry) was examined by measuring the oxidation and/or reduction of agents in the medium bathing the roots. Oxidation of NADH with or without added electron acceptors and reduction of ferricyanide by an endogenous electron donor were detected. The activities appear to be due to electron transfer at, or ac...

A comparison is made between electrochemical and homogeneous redox reactivity for species involving the transfer of multiple electrons at a single thermodynamic potential. In the electrochemical case the coreactant is the electrode; in the homogeneous case it is any of several members of a homologous series of one-electron reagents. In the latter case it is shown that the slope of a plot of the...

A Bacillus subtilis sigM null mutant, lacking the extracytoplasmic function sigma(M) protein, was sensitive to paraquat (PQ), a superoxide-generating reagent, but not to the redox stress-inducing compounds hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide, or diamide. Surprisingly, a sigM mutant was only sensitive to superoxide-generating compounds with a dipyridyl ring such as PQ,...

Synthetically useful radical thiol-ene reactions can be initiated by visible light irradiation in the presence of transition metal polypyridyl photocatalysts. The success of this method relies upon the use of p-toluidine as an essential additive. Using these conditions, high-yielding thiol-ene reactions of cysteine-containing biomolecules can be accomplished using biocompatibile wavelengths of ...