[The effect of vitamin K deficiency in rats on various enzyme systems participating in energy metabolism]. / Vliianie nedostatochnosti vitamina K u krys na nekotorye fermentnye sistemy, uchastvuiushchie v énergoobespechenii.

In alimentary deficiency of vitamin K in rats, accompanied by an increase in the prothrombin time by 30%, activity of kidney creatine kinase and of blood serum alkaline phosphatase was unaltered, while the activity of alkaline phosphatase in small intestinal mucose was decreased by 20% and that of creatine kinase from skeletal muscles--by 10%. In vitamin K-deprived animals the rate of coupling between respiration and mitochondrial phosphorylation was decreased, which might be due to alteration in the NADH-dehydrogenase complex. Menadion reductase activity and cyanide-resistant respiration of mitochondria were unaltered in presence of menadion. Palmitic acid effectively activated of mitochondrial respiration in vitamin K-deprived animals (contrary to the control rats). This effect appears to occur as a result of structural alterations in mitochondria depending on vitamin K level in the organelles.

[Effect of platinum and palladium compounds on mitochondrial enzymatic systems]. / Vliianie soedinenii platiny i palladiia na fermentnye sistemy mitokhondrii.

Effect of platinum and palladium complexes on respiration and ATPase activity in bovine heart tissue as well as on respiration of submitochondrial particles was studied. The highest inhibitory activity was exhibited by the complexes of platinum and palladium with pi-ligands in internal coorhdinational sphere such as ethylene-C H4, norbornadiene-C7H8 and allyl-C3H5. The electron density at the central atom of the complex was not responsible for the inhibitory affect of platinum and palladium on mitochondria.

[Inhibition of nonenzymatic ATP hydrolysis by its binding with the cationic detergent micelles]. / Tormozhenie neenzimaticheskogo gidroliza ATP pri sviazyvanii s mitsellami kationnogo detergenta

The rate of ATP hydrolysis is shown to decrease sharply by its binding with mycelles formed from cetyltrimethyl ammonium bromide (CTAB) (pH 9.0, 20 degrees C). Under these conditions only trace amounts of hydrolytic products have been found in the reaction mixture after a two-months standing. In the absence of mycelles the ATP hydrolysis is practically completed in 7 days. The energies of ATP, ADP and Pi binding with mycelles and at the interface of the "octane - water" system with previously adsorbed CTAB have been measured. The estimates demonstrate that the binding of one negative charge of phosphate anion or that of nucleotides with CTAB at the interface of the "octane - water" system corresponds to the change in free energy, i.e. -3.5 ccal/mol. The sharp deceleration of ATP hydrolysis cannot be due to the shift in the equilibrium of ATP hydrolysis reaction towards the formation of the pyrophosphate bond under conditions when all reaction components are bound to the surface of the mycelles.

[Inhibitors of the slow stage of proton transfer in the link connecting respiration with mitochondrial phosphorylation]. / Ingibitory medlennoi stadii perenosa protona v zvene soprazheniia dykhaniia i fosforilirovaniia mitokhondrii

Electrophilic agents--derivatives of carbonic acids--are found to inhibit respiration, ATP synthesis and reverse electrone transport in intact mitochondria. The inhibition of respiration and ATPase was observed in intact mitochondria at 3 and 3u states (by Chance). Inhibitors concentrations, which caused 50% inhibition, were approximately the same. Sharp decrease of the effect of electrophilic inhibitors on respiration and ATPase activity in mitochondria and submitochondrial particles with substantially impaired coupling system was observed. The following conclusions are drawn on the basis of the data obtained: 1) electrophilic inhibitor attack the coupling site of respiration and ATP synthesis in mitochondria; 2) the reaction of the proton transport from the respiration proton pump to ATP synthetase is one of the slowest steps of the process of ATP-synthesis in mitochondria. A scheme of working the coupling system is suggested which includes the step of proton lateral diffusion.