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Biomedical subjects

V D Lakhno

Publications and source records attributed to V D Lakhno.

8 recordsLinked to original sources
PubMed1994

Ferroelectric active models of ion channels in biomembranes.

Ferroactive models of ion channels in the theory of biological membranes are presented. The main equations are derived and their possible solutions are shown. The estimates of some experimentally measured parameters are given. Possible physical consequences of the suggested models are listed and the possibility of their experimental finding is discussed. The functioning of the biomembrane's ion channel is qualitatively described on the basis of the suggested ferroactive models. The main directions and prospects for development of the ferroactive approach to the theory of biological membranes and their structures are indicated.

Animals↗
PubMed1993

A polaron model for electron transfer in globular proteins.

Polaron models have been considered for the electron states in protein globules existing in a solvent. These models account for two fundamental effects, viz, polarization interaction of an electron with the conformational vibrations and the heterogeneity of the medium. Equations have been derived to determine the electron state in a protein globule. The parameters of this state show that it is an extended state with an energy of 2 eV. The electron transfer rate for cyt C self-exchange reaction has been calculated in the polaron model. Reorganization energy, tunneling matrix element and the rate constant have also been estimated. The results are compared with experimental data. The influence of model parameters on the significance of the data obtained has been studied. The potentialities of the model are discussed.

Electron Transport↗
PubMedDate not supplied

[Electron transfer between globular proteins. Evaluation of a matrix element].

The dependence of the matrix element of the probability of interprotein electron transfer on the mutual orientation of the donor and acceptor centers and the distance between them was calculated. The calculations were made under the assumption that electron transfer proceeds mainly by a collective excitation of polaron nature, like a solvated electron state. The results obtained are consistent with experimental data and indicate the nonexponential behavior of this dependence in the case when the distance transfer is less than 20 A.

Electron Transport↗
PubMedDate not supplied

[Electron transfer between globular proteins. Dependence of the rate of transfer on distance].

Based on the assumption that electron transfer between globular proteins occurs by a collective excitation of polaron type, the dependence of the rate of this process on the distance between the donor and acceptor centers with regard to their detailed electron structure was calculated. The electron structure of the heme was calculated by the quantum-chemical MNDO-PM3 method. The results were compared with experimental data on interprotein and intraglobular electron transfer. It is shown that, in the framework of this model, the electron transfer is not exponential and does not require a particular transfer pathway since the whole protein macromolecule is involved in the formation of the electron excited state.

Electron Transport↗
PubMedDate not supplied

[Hopping and superexchange mechanisms of charge transport to DNA].

A theory for charge transport in nucleobase sequences was constructed in which the hole migration proceeds via hopping between guanines. Each hop over the adenine-thymine (A-T) bridge connecting neighboring guanines occurs by means of the superexchange mechanism. The experimental data and theoretical results for various types of nucleobase sequences are compared.

DNA↗
PubMedDate not supplied

[Dynamics of charge transfer along an oligonucleotide at finite temperature].

The quantum-statistical approach was used to describe the charge transfer in nucleotide sequences. The results of numerical modeling for hole transfer in the GTTGGG sequence with background temperature noise are given. It was shown that, since guanine has an oxidation potential lower than thymine, the hole created at the G donor in this sequence passes through the thymine barrier into the guanine triplet (acceptor) at a time of approximately 10 ps at a temperature of 37 degrees C.

Base Sequence↗
PubMedDate not supplied

[Modeling of hole transfer dynamics in tetramer GAGG].

The hole transfer in the nucleotide sequence GAGG, where guanine G is a donor and the guanine doublet GG is an acceptor, was considered. It was shown that the relaxation of the hole on the acceptor is accompanied by rapid oscillations of the hole between the donor and the acceptor with an oscillation period of a few picoseconds. The calculated slow relaxation of the hole on the acceptor over a period of 2 ns was compared with experimental data.

Models, Chemical↗