The F-ATPase of chloroplasts couples proton flow to ATP synthesis, but is leaky to protons in the absence of nucleotides. This "proton slip" can be blocked by small concentrations of ADP or by inhibitors of the channel portion, CF0. We studied charge flow through the ATPase by flash spectrophotometry and analyzed the inhibition of proton slip by nucleotides, phosphate/arsenate, and insufficient...

Abstract The reaction of seventeen borane derivatives five-membered N-heterocyclic rings (BNHRs) with CO 2 has been studied by means DFT calculations. Several non-covalent complexes between the BNHRs and which evolve through a TS in single adduct for each BNHR have identified. calculated IRC allowed to identify complex involved case. stationary points reactions analyzed distortion/interaction p...

The reaction of gas-phase oxidation of 4-methylpyridine on individual V2O5, binary and ternary vanadium-oxide catalysts was studied. These catalysts were modified by additives of SnO2 and TiO2. It was found that modifying V2O5 leads to increase the activity of binary contacts. Upon transition from binary V2O5<...

Amino acid transport was studied in membrane vesicles of the thermophilic anaerobic bacterium Clostridium fervidus. Neutral, acidic, and basic as well as aromatic amino acids were transported at 40 degrees C upon the imposition of an artificial membrane potential (delta psi) and a chemical gradient of sodium ions (delta microNa+). The presence of sodium ions was essential for the uptake of amin...

Paramagnetic Cu(II) ions enhance nuclear spin relaxation in a distance-dependent fashion and can be used as a structural probe of proteins. Cu(II) can also serve as a functionally important ligand in proteins. Here we investigate the structural basis of Cu(II) inhibition of the influenza M2 proton channel through Cu(II)-induced paramagnetic relaxation enhancement (PRE). (13)C T(1) relaxation ra...

Abstract Wood is a hygroscopic material that can reach an equilibrium moisture content when ambient temperature and relative humidity are constant. Moisture affects all properties of wood, as well its preservative treatment. The behavior wood be attributed to the hydroxyl groups constituents. Since hemicellulose shows greatest water affinity, it considered main responsible for ingress into mass...

introduction proton therapy is used to treat malignant tumors such as melanoma inside the eye. proton particles are adjusted according to various parameters such as tumor size and position and patient’s distance from the proton source. the purpose of this study was to assess absorbed doses in eyes and various tumors found in the area of sclera and choroid and the adjacent tissues in radiotherap...