[Dynamics of active transmembrane ion transfer in transport enzymes].

It has been shown that recent investigations of the electron density distribution and high resolution (approximately 0.5 nm) spatial structure of transport ATPases open new possibilities in the development of general models for the mechanisms of energy of ATP hydrolysis and its use for active transmembrane ion transfer.

[Functional variability of the autocorrelation structure of the EEG].

On an example of records EEG of 39 healthy subjects, the quantitative analysis of variability of the autocorrelation structure of one-second EEG segments was carried out on the basis of comparison of structural functions constructed for these segments. It was shown that more than 30% of cases, statistically significant sifferences were observed between the structural functions of successive one-second EEG segments shifted by 1-3 s, as compared to surrogate EEGs formed with the tangled random sequence of count points. On the basis of the obtained data, the index of nonstationarity of the EEG autocorrelation structure was proposed. This index can be used for the objective quantitative evaluation of the functional states of the human brain.

Binding of Fe3+ ions to halobacterial purple membranes as studied by Mössbauer spectroscopy.

Purple membranes (PM) from Halobacterium were reconstituted with 57Fe ions and investigated by Mössbauer spectroscopy within the temperature range from 5 to 300 K at the Fe/bacteriorhodopsin (BR) ratio 0.6-300. When the Fe/Br ratio was below 2, Fe3+ bonded to PM mostly as hydroxymonomeric particle [FeOH]2+.5H2O, the apparent charge of the iron ion being two. When the Fe/BR ratio exceeded two, the dimeric form [FeOH](2+)4.8H2O along with a cluster form dominated. The temperature dependences of the mean square displacement show that the mobility of Fe ions changes from the solid-state type to the quasi-diffusional one at temperatures approximately 200 and approximately 230 K for the dimeric or monomeric and cluster iron forms, respectively. The nature of the cation binding sites and their location on the PM surface are discussed. A possible role of the divalent cation binding to PM in the mechanism of BR proton pumping is suggested.

[Role of intermembrane electrical fields in electron and proton transport along the respiratory chain of mitochondria]. / O roli vnutrimembrannykh élektricheskikh polei v perenose élektronov i protonov po dykhatel'noi tsepi mitokhondrii.

Charged particles (electrons and protons) transport in the respiratory chain of mitochondria in the process of oxidative phosphorylation is considered. It is shown that no kinetic difficulties appear in such transport (including proton transport against the mean field of the membrane) because the free energy of redox processes with participation of cytochrome may be used for charge separation and formation of protons in the region of internal fields. These fields arise from separation of charges in heme and depend on the orientation of the heme plane in respect to the membrane surface, and they cause the initial stages of proton transport in the direction necessary for oxidative phosphorylation. It is also shown that conformation changes of the albumin chains which accompany reduction and oxidation of cytochromes determine the transport of charges along the respiratory chain.

[Effect of electrical fields on the kinetics of biological processes]. / Vliianie élektricheskikh polei na kinetiku biologicheskikh protesessov.

The general problem of the influence of local electrical fields in albuminous systems in vitro on kinetics of chemical transformations and transport of charged particles (electrons, ions) in these systems are considered. Local electrical fields change the activation energy and many stimulate a considerable change of the rate constant values for the process with heterolytic breaks of chemical bonds. Utilization of energy stored in the biological systems for active ion transport is discussed. It is shown in particular that the free energy of ATP hydrolysis may be utilized for initiating redox reactions and stored in the form of inner electrical field energy. This field may stimulate the drift transport of ions and also transport the mean electrical field of the biological membrane