Pavel E. Kuznetsov

Optical properties of aqueous morphine solutions

We have studied morphine action on mobility and structure of water by means of fluorescent investigations and light scattering analysis. Wave-like concentration dependences have been plotted in the both cases. Theoretical description of the discovered effect has been made based on the formalism of N.N.Bogolubov.

Computer design of tetrapeptide CCK-4 analogues

In this paper we propose a theoretical method of estimation of biological activity of tetrapeptide cholecystokinin (CCK- 4) analogues according to their structure. The method is based on the prospective mechanism of CCK-4 interaction with CCK-2 receptor. Electron and structural properties of CCK-4 are taken into account. The relationship structure-activity for CCK-4 analogues with the known pharmacological profile have been studied using the model of the ligand-receptor interaction.

Quantum-chemical and experimental modeling of hydrogen peroxide generation in heterogenous aqueous surroundings, which contain dibenzo-p-dioxines or their analogues

A hypothetical molecular mechanism of previously unknown way of toxic action of dibenzo-p-dioxin derivatives has been suggested and demonstrated on the basis of quantum-chemical investigations. The main stages of this process are as follows: protonization of oxygen atom of dioxin ring on the surface of biomembrane; interaction of dioxin with oxygen of oxidized cytochrome P-450; as a result, this xenobiotic becomes a catalyst in the generation of active forms of oxygen (H2O2, O2-, 3O2, etc.). The process may become cyclic if the initial state of dibenzo-p-dioxin is restored. In this case dibenzo-p-dioxines can be considered as carriers of electrons. The hypothesis we are coming up with has been tested by means of comparatively simple experimental models based on the well-known chemical model of cytochrome P-450. Generation of hydrogen peroxide in heterogeneous aqueous media containing dioxanes derivatives has been experimentally proven.

Optical methods in modeling nicotine effect on the surface water of cell membranes

Fluorescence and spectrophotometric methods have been used for investigation of nicotine action on the state and mobility of the surface water. The surfaces of membranes and proteins were simulated with the help of liposomes and ultradispersive diamonds consequently. Nicotine was shown to reduce the stability of liposomes and to change the aggregative ability of ultradispersive diamonds. The wave-like curves for the nicotine concentration dependences of the pointed features were observed. Such shape of responses was suggested to be due to the changing in structure and dynamics of water hydrogen bonds net near the surface of the model systems induced by nicotine molecules. The surface water phase was supposed to be one of signal elements ofthe ligand receptor recognition process.

Computer simulation of structure and mobility of water hydrogen bonds net in aqueous solutions of some chemical compounds

Computer simulation of aqueous solutions of some biological active and inactive compounds has been carried out. Molecular dynamics method and TIP3P potential were used. The parameters of hydrogen bonds net were calculated by using the developed computer program. The simulation showed that relatively large clusters of water molecules appeared and the average number of hydrogen bonds decreased in the aqueous solutions of biological active compounds. It points to the fact that these compounds may induce the phase k-transition in the surrounding water. Molecular mechanisms ofthese effects are discussed.

Optical methods for creating delivery systems of chemical compounds to plant roots

Spectrophotometric and fluorescence methods have been used for creation and investigation of various systems of target delivery of chemical compounds to roots of plants. The possibility of using liposomes, incrusted by polysaccharides of the external surface of nitrogen-fixing rizospheric bacteria Azospirillum brasilense SP 245, and nanoparticles incrusted by polysaccharides of wheat roots, as the named systems has been shown. The important role of polysaccharide-polysaccharide interaction in the adsorption processes of bacteria on wheat roots has been demonstrated.

Computer simulation and experimental study of the polysaccharide-polysaccharide interaction in the bacteria Azospirillum brasilense Sp245

We have studied the conformational properties and molecular dynamics of polysaccharides by using molecular modeling methods. Theoretical and experimental results of polysaccharide-polysaccharide interactions are described.