Short cell-penetrating peptides: a model of interactions with gene promoter sites.

Analysis of the main parameters of molecular mechanics (number of hydrogen bonds, hydrophobic and electrostatic interactions, DNA-peptide complex minimization energy) provided the data to validate the previously proposed qualitative models of peptide-DNA interactions and to evaluate their quantitative characteristics. Based on these estimations, a three-dimensional model of Lys-Glu and Ala-Glu-Asp-Gly peptide interactions with DNA sites (GCAG and ATTTC) located in the promoter zones of genes encoding CD5, IL-2, MMP2, and Tram1 signal molecules.

[The mechanisms of stimulation of cellular proliferation under the effect of L-amino acids in the tissue culture in young and old rats].

The statistical method of range correlation was used to analyse the correlation of individual characteristics of L-amino acids, as well as of the dipole moments of the first pair of the nucleotides of their codons to the biological activity of the amino acids, i.e. to the stimulation of the cellular proliferation. The experimental material was obtained in the organotypic tissues of ecto- and mesodermal genesis in young and old rats. It was demonstrated, that each of stimulating amino acids acts in the explants from old rats to 1,5-6 times rarely, as compared to the explants from young rats. The weak correlation was detected between the stimulation of the cellular proliferation and physical-chemical characteristics - hydrophobicity, dipole moment and isoelectrical point of the amino acids, - in many tissues, but high and moderate correlation was detected in the brain subcortical explants, cerebella and skin. However, the moderate close correlation was detected between the dipole moment of the first pair of the nucleotides of their codons and the stimulating activity for the explants of the brain subcortical structures (young and old rats), of cerebella and skin (young rats), Spearman correlation coefficient rS =0,52; 0,45; 0,60, 0,71 accordingly. The moderate close correlation was detected also for the explants of testis and cartilage. It can be suggested, that some physical-chemicaland biochemical characteristics of amino acids should correlate to their biological activity, especially in relation to the ectodermal tissue.

[Epigenetic aspects of peptide regulation of aging].

Endogenous short peptides presented in the cyto- and nucleoplasm, are products of specific proteolysis of nuclear proteins in the proteasome. They are short blocks in sequence of amino acid residues with charged side groups and are characterized by a high local concentration of electrostatic charges of opposite signs. The peptides are capable of complementarily binding to specific short sequences of nucleotides in DNA strands. This binding can significantly reduce the strength of proton bonds in DNA double helix structure and thus stimulate the process of chain separation required for genes transcription and replication. The aging of organisms is always followed by the decrease in methylation of the genome. Age-related decrease in methylation of repeated nucleotide sequences in the genome leads to an increase in site-specific binding of short peptides to DNA. In turn, the binding of peptide inhibits the hydrolysis of demethylated DNA regions by endonucleases. The experimental data on the peptide interaction with methylated DNA point to the participation of oligopeptides in the epigenetic regulation of the ageing.

Melting of DNA double strand after binding to geroprotective tetrapeptide.

Experimental relationship between the hyperchromic effect of DNA [poly(dA-dT):poly(dA-dT)] interacting with Ala-Glu-Asp-Gly peptide is presented by a saturation isotherm. The free DNA double strand is melting (the strands separate) at 69.5 degrees C and at higher energy expenditures (enthalpy increase by 976.4 kJ/mol b.p.) in comparison with melting of the DNA-peptide complex (28 degrees C and 444.6 kJ/mol b.p.). The detected regularities of melting of duplex DNA and the thermodynamic parameters of this process indicate the natural mechanism of interaction between DNA and regulatory peptides underlying functioning of the living matter.

Molecular mechanism of interaction between oligopeptides and double-stranded DNA.

Formation of Ala-Glu-Asp-Gly peptide complex with duplex DNA [poly(dA-dT):poly(dA-dT)] at neutral pH and ambient temperature was studied experimentally. Peptide binding to duplex DNA was associated with hyperchromic effect indicating local separation of the double helix. Energies of paired interactions between amino acid residues and nucleotide bases were compared with the energy of bond between two bases in the nucleotide pair (dA-dT). A new concept of interaction between two types of information-carrying molecules is put forward. This interaction underlies triggering of protein synthesis mechanism and can explain the emergence of life on the Earth.

Effect of regulatory peptides on gene transcription.

Experimental studies of geroprotective activity of synthetic oligopeptides and conformational analysis of the tetrapeptide Epithalon allowed us to hypothesize that regulatory oligopeptides directly initiate transcription of genes for vitally important proteins. Sequences of nucleotide pairs that can serve as binding sites for tetrapeptide Epithalon were identified in the promoter regions of retinal genes F379, telomerase, and RNA polymerase II.

[Blood group-specific variability of sialic acid contents in the chorionic gonadotrophin structure]. / Gruppospetsificheskie variatsii soderzhaniia sialovykh kislot v strukture khorionicheskogo gonadotropina.

Low-pressure ion-exchange chromatography was used for isolation of chorionic gonadotropin (hCG) from urine of pregnant women. The purified hCG-preparations from various blood group donors were shown to differ in their sialic acid content. The highly purified hCG-preparations after gel chromatography were analyzed in the reaction of hemagglutination and the preliminary results suggest their blood group specificity.

[Affinity chromatography of nucleoprotein complexes]. / Affinnaia khromatografiia nukleoproteinovykh kompleksov.

Affinity sorbent containing cellular membranes of the cerebral cortex was obtained by means of an inclusion into porous matrix of polyacrylonitrile. Sorption of model and natural nucleoprotein complexes on the obtained sorbent was studied by the method of affinity chromatography. Distribution coefficients were determined. Natural nucleoprotein complexes isolated from brain possess a greater selectivity of binding to the cellular membranes of the cerebral cortex than that from liver.

[Nucleoprotein complexes of yeast and their biological effect on T-lymphocytes]. / Nukleoproteinovye kompleksy drozhzhei i ikh biologicheskaia aktivnost' po otnosheniiu k T-limfotsitam.

Complexes of nucleic acids and acid nuclear proteins that are active toward human T-lymphocytes were isolated from cells of bakers' yeast Saccharomyces cerevisiae. The conditions of isolation of nucleoprotein complexes by acid extraction followed by microfiltration for concentration of macromolecular components were optimized. Gel filtration and electrophoresis were used to study the composition and molecular weights of components of the preparations obtained. It was shown that nucleoprotein complex had a molecular weight of 1430 kDa. However, only one zone was determined by electrophoresis of the protein component with a molecular weight of 30 kDa.

[Tissue-specific nucleoprotein complexes]. / Tkanespetsificheskie nukleoproteinovye kompleksy.

A method of isolation of native nucleorprotein complexes from cattle cerebral cortex, thymus, and liver was developed. Compositions of these complexes were studied by means of gel-chromatography and ion-exchange chromatography. These preparations were shown to consist of several fractions of proteins and their complexes differ by molecular mass and electro-chemical properties. Native nucleoprotein complexes revealed high tissue specific activity, which was not species-specific.

[Preparative isolation of gonadotropin and urokinase on carboxylic cation exchangers]. / Preparativnoe vydelenie gonadotropina i urokinazy na karboksil'nykh ka tionitakh.

Low-pressure ion-exchange chromatography was used for sequential isolation of chorionic gonadotropin and urokinase (EC 3.4.99.26) from urine of pregnant women. Theoretical analysis of electrostatic interactions of protein macromolecules with the sorptive surface of a carboxylic cation exchanger was performed. This analysis allowed us to optimize the pH values for selective sorption and reversible desorption of the target component on a cation exchanger with a selected acidity of functional groups. The use of carboxylic cation exchangers KM-2p and Biokarb-GM allowed us to obtain the preparations with purity not inferior to commercially available preparations.

[The effect of urokinase inhibitors on effective fibrinolytic activity of human urine]. / Vliianie ingibitorov urokinazy na éffektivnuiu fibrinoliticheskuiu aktivnost' mochi liudei.

The levels of fibrinolytic activity of human urine as a source of the thrombolytic enzyme urokinase in various volunteers differing in sex and age. The fibrinolytic activity was distinctly altered after mixing of urine obtained from various donor groups as a result of varying quantitative and qualitative contents of urokinase inhibitors in individual volunteers. The specific biological activity of urokinase was studied in the presence of various inhibitors. Prescreening of the initial raw material (urine) should be made to isolate the most effective samples of the thrombolytic enzyme urokinase.

[Arthrobacter proteinase and its effect on fibrin thrombi]. / Proteinaza artrobakterii i ee deistvie na fibrinobye tromby.

Arthrobacteria are producers of proteolytic enzymes. Optimal cultivation conditions were determined for Arthrobacter luteus and the mineral composition of the culture medium providing active synthesis of proteinase was optimized. The proteinase was isolated from the culture liquid of Arthrobacter luteus using preparative ion-exchange chromatography on a carboxyl cation exchange resin KMT. The enzyme was homogeneous according to gel chromatography on Sephadex G-200 and had a molecular weight of 24 kD. The fibrinolytic activity of the proteinase is comparable with that of trypsin.

[Effect of normal and specific immune sera on neuraminidase activity]. / Vliianie normal'nykh i spetsificheskikh immunnykh syvorotok na aktivnost' neiraminidazy.

We have got evidence that there is no antigenic relationship reflecting the structural similarity between neuraminidases synthesized by noncholera vibrios and Arthrobacter nicotianae. The cross-reactions between the enzymes and heterological antisera were not observed. Antibodies against the A. nicotianae neuraminidase inhibited the activity of the enzyme for a glycomacropeptide of milk whey and for components of the blood serum, and had no effect no the neuraminidase from noncholera vibrios. Antibodies against the neuraminidase of noncholera vibrios inhibited only the activity of the homologous enzyme. Upon gel-filtration on Sephadex G-200 the antibodies inhibiting the activity of the enzymes under study were found in the fraction of 7S-gamma-globulins.

[The use of a glycomacropeptide of kappa-casein as a substrate for neuraminidase]. / Ispol'zovanie glikomakropeptida kappa-kazeina v kachestve substrata neiraminidazy.

Glycomacropeptide from milk was studied; its molecular mass and amino acid composition were evaluated. When the glycomacropeptide was used as a substrate of neuraminidase, it exhibited many advantages as compared with ovomucin (high molecular substrate of the enzyme) due to increased content of sialic acids in the glycomacropeptide composition and to high solubility.

[Structure and sorption properties of regenerated hemosorbent SCN]. / Struktura i sorbtsionnye svoistva regenerirovannogo gemosorbenta SKN.

Stepwise desorption of protein components from the hemosorbent SCN after hemoperfusion was studied, and their molecular weights were determined. It was found that hard alkaline regeneration and oxidation with nitric acid do not affect the hemosorbent structure, composition and potentiometric characteristics. The regenerated hemosorbent can be successfully used for adsorbtion of extraneous low- and medium-molecular weight components to clarify microbiological liquids.

[Effect of FAF anionite swelling on its sorption properties]. / Vliianie nebukhaniia anionita FAF na ego sorbtsionnye svoistva.

Experiments were carried out to clarify the effect of swelling coefficients of various samples of the polycondensation anion exchange resin FAF in the C1 form on its sorption properties. The anion exchange resin was used to eliminate contaminating proteins and low molecular weight agents from the allantois fluid and liver cultured cells of pigs. Thermal treatment of the anion exchange resin increased the coefficient of its swelling, leaving the structure unchanged. The resin structure was controlled by electron microscopy and X-ray scattering of low angle. When the resin samples with the swelling coefficients of 3.5 and 4.0 were used, 30-40% of proteins, 50% of reducing agents and neutral carbohydrates and a small quantity of phosphorus were adsorbed.

[Isolation and purification of urokinase]. / Vydelenie i ochistka urokinazy.

An improved procedure is developed for isolation of urokinase from human urine by means of ion exchange on cyrboxyl cationite SMT at pH 4.7. with subsequent stepwice elution by phosphate buffer, rH7.0. Depigmentation of the urine was achieved by pretreatment with an anionite FAF. Chromatographically pure preparation of urokinase was obtained as shown by gel filtration through Sephadex G-100 and G-150.

[Sorption properties of carboxyl cation exchangers with a bacteriostatic effect]. / Sorbtsionnye svoistva karboksil'nykh kationitov, obladaiushchikh bakteriostaticheskim deistviem.

Sorption properties of new carboxyl cation exchangers containing components of salicylic acid (CST and CMTS) and benzoic acid (CBT and CMTB) were examined with respect to large organic ions. Such cation exchangers were shown to have greater permeability for high molecular weight proteins that sorbents of the Biocarb type. Bacteriostatic properties of the above cation exchangers were studied. With an increase in the content of the bactericidal component the bacteriostatic effect of the cation exchangers on Escherichia coli and Staphylococcus aureus enhanced. The cation exchangers CST and CMTS showed a greater bacteriostatic effect than those CBT and CMTB.