E. S. Kuznetsova

Structural-functional characteristics of a new bioregulator isolated from bovine pigmented epithelium tissue

A new bioregulator operating in ultralow doses corresponding to 10−17 mg/ml has been isolated from tissue of pigmented epithelium of bovine eyes. It has been established that the functional basis of this bioregulator is a complex of a low molecular weight regulatory peptide (4372 Da) and a modulator consisting of a mixture of proteins with molecular weights of 14.980–66.283 kDa. It has been shown that the regulatory peptide is responsible for membranotropic activity of the bioregulator, and the modulator proteins are responsible for biological action in ultralow doses. The data demonstrate an interrelation between nanocondition of the bioregulator and its ability to show activity in ultralow doses.

Effect of surface chemistry of carbon sorbents on high-performance liquid chromatography and mass-spectrometric analysis of amino acids

The work shows a complex approach to analyzing amino acids using carbon sorbents with different surface areas, including molecular-statistical calculations, high-performance liquid chromatography, and mass spectrometry with matrix-activated and surface-activated laser desorption/ionization (MALDI, SALDI). An analysis of the thermodynamic adsorption characteristics (TACs) of a series of proteinogenic amino acids and their isomers on graphitized thermal carbon black (GTCB) is carried out. A satisfactory correlation is established between experimental characteristics of amino-acid retention on the Hypercarb carbon sorbent and TACs of these particles calculated using the molecular statistics method. It is found in the identification of amino acids using the MALDI method in the chromato-mass-spectrometric modification in the off-line mode that the application of carbon sorbents as a support results in an increase in the intensity of the registered protonated molecular ions and adducts with alkali cations compared to a conventional experimental technique on a stainless-steel surface.

The influence of an intramolecular H-bond on the adsorption of sulfur-containing amino acids on graphitized thermal carbon black

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

Influence of the structures of hydrogen-bonded dimeric molecules on their adsorption at graphitized thermal carbon

This study is devoted to the influence of the structures of hydrogen-bonded dimeric molecules on their adsorption at graphitized thermal carbon (GTC). The thermodynamic adsorption characteristics (TACs) of amino acid dimers and dimers of amino acids with acetic acid and formamide at GTC were determined. The results obtained for the adsorption of dimeric molecules at the carbon sorbent were compared with the calculated data for the molecules of the corresponding amino acids at GTC. The geometric parameters of dimeric molecules were varied to analyze the influence of the hydrogen bond lengths on the TACs of the compounds under study.

Methodological features of mass-spectrometric studies of oxidized metal surfaces

Clustering of silver halides under the conditions of photoionization has previously been studied by laser desorption/ionization mass spectrometry. Some features of desorption/ionization of silver halides from different metal surfaces (stainless steel and different partially oxidized aluminum alloys) are discussed in this study. The data on the m/z values determination accuracy, resolving power, ionization efficiency, and distortion of isotope distribution in the studies of oxidized surfaces are statistically generalized. It is shown that the results can be used to gain insight into the chemical nature and morphology of examined surfaces and, in particular, to plot diagrams for distribution of analyzed compounds over the surfaces.

MALDI-TOF mass spectrometric identification of novel intercellular space peptides

We performed the matrix-assisted laser desorption/ionisation, time-of-flight mass spectrometry (MALDI-TOF) analysis of the peptides entering into the composition of not yet explored bioregulators derived from the extracellular matrix of the tissues of the various organs of the mammals, and also plants and fungi. The study included 15 different mammalian tissues, 13 species of plants, and 2 species of fungi. Exploring the bioregulators derived from eye tissues, we demonstrated that their composition includes peptide components with the same values of the molecular weight. The composition of the bioregulators derived from the tissues of various organs of mammals or different species of plants and fungi includes the peptides with different values of molecular weight. Obtained data indicate the growing evidence of the assumptions about the major function of the bioregulators of this group—their involvement in the regulation of tissue-organ homeostasis in the biological systems.

Molecular statistical calculations of the adsorption of proline and its hydroxy derivatives on graphitized thermal carbon black

The thermodynamic characteristics of adsorption of proline and its hydroxy derivatives on the surface of graphitized thermal carbon black (GTCB) were calculated. The arrangement of hydroxyl groups in the amino acid molecule was shown to influence their adsorption on GTCB. The influence of internal rotation angles in proline and its hydroxy derivative molecules on their adsorption on GTCB was studied.

Comparative analysis of the adsorption of the stereoisomers of hydroxy- and dihydroxyproline at graphitized thermal soot

The thermodynamic characteristics of the adsorption of proline and its derivatives at graphitized thermal soot (GTS) were determined. It was found that the arrangement of the hydroxy groups in the amino acid molecule influences its adsorption at GTS. The thermodynamic characteristics of the adsorption of the stereoisomers of hydroxy- and dihydroxyproline at GTS were calculated. The influence of the internal rotation angles in the molecules of proline and its derivatives on their adsorption at GTS was studied.

Molecular statistics calculations of thermodynamic characteristics of the adsorption of isomeric amino acids on graphitized thermal black

Thermodynamic characteristics of the adsorption of several isomeric amino acids on graphitized thermal black (GTB) are calculated by a molecular statistics method. Parameters of the potential function of the intermolecular pair interaction between an O atom of amino acid and a C atom of graphite are calculated.

Inorganic and Organic Clusters Formed upon Surface-Assisted Laser Desorption/Ionization

Examples of cluster formation from inorganic and organic compounds upon surface-assisted laser desorption/ionization have been considered. It has been shown that the cluster formation is especially efficient upon ionization of silver halides. The addition of silver salts to salts of other metals, in particular, lead and nickel salts and sodium stannate, leads to the formation of mixed clusters. The peak intensities of the ions of such clusters are higher than those of the clusters of initial salts, thereby indicating a higher efficiency of their formation. Nonpolar amino acids and short-chain peptides predominantly form adducts with alkali-metal ions.