Cytochrome c oxidase transfers electrons and protons for dioxygen reduction coupled with proton pumping. These electron and proton transfers are tightly coupled with each other for the effective energy transduction by various unknown mechanisms. Here, we report a coupling mechanism by a histidine (His-503) at the entrance of a proton transfer pathway to the dioxygen reduction site (D-pathway) o...

ESR spin-trapping method has been used for the study of radiation-induced radicals in· powdered dihydrothymine. Four approximately equal small proton couplings (AH' = 0.35 mT), a larger proton coupling (AH = 0.195 mT) and a nitrogen coupling (AN = = 0.295 mT) are attributed to the nitroxide radical formed by reaction of the spin trap with 6-dihydrothymyl radical upon dissolving of dihydrothymin...

Proton and oxygen-17 nmr relaxation rates of C D 3 1 7 O H as well as deuteron nmr relaxation rates of C H 3 O D were measured in mixtures with carbon tetrachloride at different compositions and temperatures. By varying the 1 0-content different contributions to the proton relaxation rate could be separated and from the 1 7 0 H dipolar interaction contribution the correlation time of the O H bo...

The use of line-shape decomposition techniques permitted the small 5-bond (5-J51') and 4-bond (4-J61') proton-proton coupling constants of a series of uracil nucleosides and nucleotides to be determined accurately. From an analysis of these coupling constants we have determined that the uracil base is in a predominantly anti conformation in aqueous solution and the mean position is not substant...

We perform phenomenological applications of modified gluon propagators and running coupling constants in scattering processes in Quantum Chromodynamics (QCD). The modified forms of propagators and running coupling constant are obtained by non-perturbative methods. The processes investigated includes the diffractive ones – proton-proton elastic scattering, light vector meson photo-production and...

The sensitivity of a nitroxide spin label to the polarity of its environment has been used to estimate the hydrophobic barrier of the proton channel of the transmembrane proton pump bacteriorhodopsin. By means of site-specific mutagenesis, single cysteine residues were introduced at 10 positions located at the protein surface, in the protein interior, and along the proton pathway. After reactio...

The NADPH oxidase is the main weapon of phagocytic white blood cells that are the first line of defence of our body against invading pathogens, and patients lacking a functional oxidase suffer from severe and recurrent infections. The oxidase is a multisubunit enzyme complex that transports electrons from cytoplasmic NADPH to molecular oxygen in order to generate superoxide free radicals. Elect...

A novel proton acceptor coupling reagent shows superiority to those described previously. The oxygen in the carbocation moiety confers more solubility to the reagent. Furthermore, it enhances coupling yields and decreases racemization, allowing the use of 1 equiv of base.