The investigation of structure–activity relationship of polyamine-targeted synthetic compounds from different chemical groups

Amino Acids - The polyamine (PA) metabolism is involved in cell proliferation and differentiation. Increased cellular PA levels are observed in different types of cancers. Products of PA oxidation...     

Conditioning adhesive contacts between the neutrophils and the endotheliocytes by Staphylococcus aureus

We have developed a model for evaluating the integral intercellular interactions in the “endotheliocyte‐neutrophil” system and have shown the high variability of adhesion contacts in different donors associated with different expression profiles of neutrophils. Two methods (forсe spectroscopy‐spectroscopy and scanning ion‐conductance microscopy) showed a decrease in the rigidity of the membrane‐cytoskeletal complex of neutrophils under the influence of Staphylococcus aureus 2879 M. Adding this strain to the “endotheliocyte‐neutrophil” system caused a statistically significant decrease in the adhesion force and adhesion work, which indicates a change in the expression profile and physicochemical properties of membranes of both types of interacting cells (neutrophils and endotheliocytes).     

Acclimation of Chlamydomonas reinhardtii to extremely strong light

Photosynthesis Research - Most photosynthetic organisms are sensitive to very high light, although acclimation mechanisms enable them to deal with exposure to strong light up to a point. Here we...     

Standardized Aronia melanocarpa extract regulates redox status in patients receiving hemodialysis with anemia

Molecular and Cellular Biochemistry - The aim of our study was to investigate the effects of one-month consumption of polyphenol-rich standardized Aronia melanocarpa extract (SAE) on redox status...     

Specific inhibition of proton pumping by the T315V mutation in the K channel of cytochrome ba3 from Thermus thermophilus

Cytochrome ba₃ from Thermus thermophilus belongs to the B family of heme-copper oxidases and pumps protons across the membrane with an as yet unknown mechanism. The K channel of the A family heme-copper oxidases provides delivery of a substrate proton from the internal water phase to the binuclear heme-copper center (BNC) during the reductive phase of the catalytic cycle, while the D channel is responsible for transferring both substrate and pumped protons. By contrast, in the B family oxidases there is no D-channel and the structural equivalent of the K channel seems to be responsible for the transfer of both categories of protons. Here we have studied the effect of the T315V substitution in the K channel on the kinetics of membrane potential generation coupled to the oxidative half-reaction of the catalytic cycle of cytochrome ba₃. The results suggest that the mutated enzyme does not pump protons during the reaction of the fully reduced form with molecular oxygen in a single turnover. Specific inhibition of proton pumping in the T315V mutant appears to be a consequence of inability to provide rapid (τ ~ 100 μs) reprotonation of the internal transient proton donor(s) of the K channel. In contrast to the A family, the K channel of the B-type oxidases is necessary for the electrogenic transfer of both pumped and substrate protons during the oxidative half-reaction of the catalytic cycle.     

Hydroperoxide-Reducing Enzymes in the Regulation of Free-Radical Processes

Biochemistry (Moscow) - The review presents current concepts of the molecular mechanisms of oxidative stress development and describes main stages of the free-radical reactions in oxidative stress....