Iu Ia Ivanov

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The interaction of Fe(II) and Fe(III) with the 'high-affinity Mn-binding site' in Mn-depleted photosystem II (PSII) was investigated using diphenilcarbazide (DPC)/2,6-dichlorophenol-indophenol (DCIP) inhibition assay. Fe(III) was ineffective in the inhibition of DPC-DCIP reaction while Fe(II) decreased the rate of DCIP photoreduction supported by DPC in the(More)
Egg yolk phosphatidylcholine monolamellar liposomes (1000 A in diameter) loaded with cytochrome c were placed into an external solution, in which superoxide radicals, O2-., were generated by a xanthine-xanthine oxidase system. The penetration of the superoxide radicals across the liposomal membrane was detected by cytochrome c reduction in the inner(More)
The effects of pro-oxidants (Fe2+, CCl4) and antioxidants (alpha-tocopherol, propyl gallate) on hydroxylation of polycyclic hydrocarbon benz(a)pyrene and on the NADPH-cytochrome P-450-reductase reaction were studied. The role of allyl radicals formed in the fatty acid chains in discussed. The binding of O2 to free radicals, i. e. formation of peroxy(More)
The stabilizing effect of alpha-tocopherol on the enzymatic system of Ca2+ transport in sarcoplasmic reticulum (SR) membranes of rabbit skeletal muscle was studied. Exogenous fatty acids (e. g. arachidonic) cause destabilization of the enzymatic Ca2+ transport system by decreasing the thermal stability of Ca2+-dependent ATPase and the Ca2+-transport ability(More)
Chloroplasts isolated from pea seadlings grown on water containing 45Ca2+ were treated with local anesthetic tetracaine. Addition of tetracaine inactivated the electron transport activity of donor side photosystem II. This inhibition was accompanied by 45Ca2+ release from the chloroplast membranes as the whole and destroyed by osmotic shock. No such effect(More)
A model description of the Mössbauer spectrum (80 K) of native membranes of the thermophilic cyanobacterium Synechococcus elongatus is suggested on the basis of the known values of quadrupole splitting (deltaE(Q)) and isomer shift (deltaFe) for the iron-containing components of the photosynthetic apparatus. Using this approach, we found that heating the(More)
The prostaglandin F2 alpha (in concentration 1,4 or 14 microM) has been shown to induce the current fluctuations across the bilayers under the action on the planar bilayer membranes from the soya total phospholipids. The current fluctuations depend on the potential, their number expresses indistinctly and corresponds to the conductivity jumps across the(More)