[A model of the quinone-binding site of photosystem I: investigation of charge transfer complexes of phylloquinone and its derivatives with tryptophan]. / Model' khinonsviazyvaiushchego saita fotosistemy I: issledovanie kompleksov perenosa zariada fillokhinona i ego proizvodnykh s triptofanom.

Phylloquinone (vitamin K1; 2-methyl-3-phytyl-1,4-naphthoquinone), the secondary electron acceptor A1 in photosystem I of plants, algae, and cyanobacteria, mediates the electron transfer between A0 (a monomeric chlorophyll a) and the iron-sulfur cluster Fx. In order to investigate the interaction of vitamin K1 with the A1-binding site, their models on the non-covalent complexes were obtained and studied. The fluorescent properties of vitamin K1, its derivatives, and their complexes with Trp showed a possible role of amino acid components in the formation of a stable energy state, which provides the energy redistribution between oxidized and reduced forms of vitamin K1. The formation of the charge-transfer complex and the influence of the ratio of the components on fluorescence derived from the tryptophan-vitamin K1, tryptophan-dihydrovitamin K1 , tryptophan-quinhydrone K1, and tryptophan-naphthochromanol complexes are described. The data obtained allow us to suggest that naphthochromanol is involved in the energy transfer reaction in PS I as an intermediate form of the secondary electron acceptor.

[Fucolectins in diagnostic and neoplasm investigation]. / Primenenie fukozospetsifichnykh lektinov v diagnostike i izychenii novoobrazovanii.

Problems of practical application of fucose-binding lectins as selective histochemical markers and their diagnostical and prognostical value under different pathological states are considered. Special attention is paid to carbohydrate specificity of the most investigated and perspective fucolectins which are already applied in investigation of regularity of cell's functioning and differentiation. It is shown that fucose-specific lectins are useful diagnostic reagents in pathomorphological and clinical investigations.

[Studies of oligosaccharide specificity of perch roe fucolectin, using gold labeled neoglycoproteins]. / Izuchenie oligosakharidnoi spetsifichnosti fukolektina ikry okunia s ispol'zovaniem kompleksov neoglikoprotein-kolloidnoe zoloto.

The specificity of perch (Perca fluviatilis) roe fucolectin was studied using the protein dot blot technique, followed by detection with colloidal gold-labeled neoglycoproteins bearing human milk polysaccharides. The strongest binding was noted with the H type 1 pentasaccharide lacto-N-fucopentaose (LNFP I, Fuc alpha 1-2 Gal beta 1-3 GlcNAc beta 1-3 Gal beta 1-4Glc); the interaction with the H type 6 trisaccharide 2'-fucosyllactose (2-FL, Fuc alpha 1-2 Gal beta 1-4 Glc) was weaker. Binding of the perch lectin to the Lewis antigens (associated with tumors and embryonic tissues) was also studied. It was found that the lectin weakly interacted with the hexasaccharide lacto-N-difucohexaose I, Fuc alpha 1-2 Gal beta 1-3[Fuc alpha 1-4]GlcNac beta 1-3 Gal beta 1-4 Glc), but not with Lea, Lec, Lex antigens. Thus, perch roe lectin exhibited pronounced differences in carbohydrate specificity from other fucolectins--a feature that may be used in structural studies and isolation of fucose-containing glycoconjugates.

[Antiviral and anti-stress activity of the gamma-L-glutamyl-histamine and its derivatives]. / Protivovirusnaia i antistressornaia aktivnost' gamma-L-glutamilgistamina i ego analogov.

Effect of gamma-L-glutamylhistamine gamma-L-Glu-HA and some of its derivatives on the state of nonspecific resistance and antiviral activity was studied using experimental models of influenza virus and herpes simplex virus infections. Activities of natural killer (NK) cells and interferon (IFN) system were measured. The model of physical-emotional stress in mice was used. It was shown that the gamma-L-Glu-HA derivative II can prevent totally or substantially a decrease in the NK activity. This agent also prevents inhibition of synthesis of alpha- and gamma-IFN during the post-stress period. The gamma-L-Glu-HA derivatives II, III, and VII increased the mice resistance to influenza virus type A/Aichi at low infection dose (10LD50). The derivative II showed its protective effect even at high dose of pathogen (100LD50). However, this gamma-L-Glu-HA derivative was virtually ineffective under harsh experimental conditions. Thus, a number of gamma-L-Glu-HA derivatives tested in this work demonstrated immunomodulation activity. These agents were able to normalize parameters of nonspecific immunity. They exerted a pronounced antiviral effect against influenza virus but were virtually ineffective against encephalitis in mice caused by herpes simplex virus, type 1. Of all tested agents, gamma-L-Glu-HA derivative II was found to be the most promising.

[Hepatoprotective effects of gamma-L-glutamylhistamine]. / Gepatoprotektornaia aktivnost' gamma-L-glutamilgistamina.

The influence of gamma-GluHA and glutarylhistamine on the lipid peroxidation, cholesterol, phospholipid and liver aminotransferase activity was investigated using carbon tetrachloride-induced model of subacute liver damage. Pretreatment of rats with gamma-GluHA and glutarylhistamine prevented liver necrosis and normalized activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in blood plasma, lipid peroxidation in the liver and plasma, lipid profiles and cholesterol content in the liver and plasma.

[Synthesis of triads based on deuteroporphyrin IX, naphthoquinone, and aromatic amino acids]. / Sintez triad na osnove deiteroporfirina IX, naftokhinona i aromaticheskikh aminokislot.

Two triad systems were synthesized from deuteroporphyrin IX by tethering 1,4-naphthoquinone derivatives and aromatic amino acids to its propionic groups using the method of mixed anhydrides. Physicochemical characteristics of the triads were studied, and the pi-electron systems of their chromophores were shown to interact. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 4; see also http://www.maik.ru.

Effects of reduced and oxidized glutathione on sphingomyelinase activity and contents of sphingomyelin and lipid peroxidation products in murine liver.

Like the phosphatidyl inositol cycle, the sphingomyelin cycle produces a series of the secondary messengers transmitting extracellular signals from the cytoplasmic membrane into the nucleus. Sphingomyelin, ceramide, sphingosine, sphingomyelinase, and ceramidase are the main components of the sphingomyelin cycle. In spite of numerous data on the functional properties of sphingomyelin cycle products, the activation mechanism for the key enzyme of the sphingomyelin cycle, sphingomyelinase (SMase), is not well understood. We have discovered effects of both reduced (GSH) and oxidized (GSSG) glutathione on the activity of neutral SMase in animals. GSH administration (18 mg per mouse) inhibits this enzymatic activity in liver for 2 h and increases the sphingomyelin level exactly as occurs in cell culture. The levels of diene conjugates and ketodienes decrease simultaneously during the experiment, thus indicating the ability of GSH to suppress oxidative processes in the cell. GSSG administration (18 mg per mouse) has no effect on the SMase activity during the first 15 min, but increases it twofold after 1 h. A short-term decrease in this activity after 30 min may depend on the conversion of excess GSSG into its reduced form by glutathione reductase. Unlike GSH, GSSG has no effect on the level of ketodienes after 1 h, but it induces the accumulation of diene conjugates. A strong correlation exists between the changes in SMase activity and in the level of oxidation products caused by either GSH or GSSG. These data indicate a relationship between SMase activity and the level of peroxidation products and possibly a relation between two signaling systems: the sphingomyelin cycle and the oxidative system.

[The effect of gamma-L-glutamylhistamine analogues on the severity of experimental anaphylactic reaction, hormonal status and liver cytochrome P450 system]. / Vliianie analogov gamma-L-glutamilgistamina na izmenenie tiazhesti proiavlenii éksperimental'noi anafilakticheskoi reaktsii, gormonal'nogo statusa i sistemy tsitokhroma P450 pecheni.

The influence of gamma-L-glutamylhistamine analogues on the hexenal-induced sleeping, glucocorticoid hormone content in blood plasma and severity of experimental anaphylactic reaction was studied. It was observed that gamma-L-glutamylhistamine analogues caused decrease in the sleeping time and severity of experimental anaphylactic reaction, the elevation of glucocorticoids content in blood plasma. The present results indicate that substances have the wide spectrum of biological activity which depends on the length of the N-acyl radical.

[Effect of vitamin E and its functional analogs with different molecular structures on growth and lipids content of Pythium debaryanum]. / Effekt vitamina E i ego funktsional'nykh analogov razlichnoi molekuliarnoi struktury na rost i lipidnye kharakteristiki Pythium debaryanum.

The effect of exogenously added vitamin E and its synthetic analogues (the hydrophilic form of vitamin E and chromans C13 and C1) on the growth, lipogenic activity, and the fatty acid composition of the eicosapolyenoic acid-synthesizing oomycete Pythium debaryanum was studied. The effect was found to depend on the molecular structure of particular compounds. For instance, vitamin E and chroman C13 stimulated fungal growth, whereas chroman C1 inhibited it. The hydrophilic form of vitamin E enhanced the lipogenic activity of the oomycete. The studied compounds, which possess antioxidant activity, did not exert any noticeable effect on the level and the degree of the unsaturation of fungal lipids.

[Synthesis and antioxidant activity of azole derivatives of hemin]. / Sintez i antioksidantnaia aktivnost' azol'nykh proizvodnykh gemina.

New derivatives of proto- and deuterohemin IX containing tri- and tetrazole rings were synthesized and characterized. A pronounced antioxidant activity was found for these compounds in the Fe(II)/ascorbate-dependent system of lipid peroxidation in murine liver homogenates.

Photophysical properties of carborane-containing derivatives of 5,10,15,20-tetra(p-aminophenyl)porphyrin.

Absorption, fluorescence emission, fluorescence excitation spectra and fluorescence decay kinetics of carborane derivatives of 5,10,15,20-tetra(p-aminophenyl)porphyrin have been investigated. Carborane derivatives are prepared by acylation of the amino groups of 5,10,15,20-tetra(p-aminophenyl)porphyrin by 9-carboranyl acetyl chloride. From the analysis of the absorption and fluorescence spectra, it is concluded that covalent linking of carborane molecules to the tetraphenylporphyrin molecule significantly changes the self-conjugated pi-system of the porphyrin macrocycle: positions of maxima of absorption and fluorescence spectra shift to the red region by 3-8 nm; the halfwidths of these bands are broadened by 2.5-5.0 nm; the relative intensity of the bands I-IV also changes. The fluorescence decay kinetics of the carborane derivatives are biexponential. According to the experimental data and model simulation, it is concluded that the intramolecular electron transfer proceeds from the porphyrin excited part of the molecule to carboranyls with a rate constant of 415 ps(-1) and efficiency of 0.16-0.8. Recombination of separated charges occurs within 1.4 ns.

[Methods of searching for antigenic determinants for proteins with known primary structure]. / Metody poiska antigennykh determinant dlia belkov s izvestnoi pervichnoi strukturoi.

Theoretical and experimental methods for locating antigenic determinants of proteins with known amino acid sequences are discussed. These methods are systematized on the basis of the theoretical approaches applied, and the efficiency of various predictive methods is compared. Some examples of experimental epitope determination for a number of proteins are given.

[the synthesis of diporphyrin systems on the basis of tetraphenylporphyrin derivatives bridged with peptide spacers]. / Sintez diporfirinovykh sistem na osnove proizvodnykh tetrafenilporfinina, soedinennykh peptidnymi speiserami.

Diporphyrin systems based on tetraphenylporphyrin derivatives bridged with dipeptide or tripeptide spacers containing Gly and Phe residues were synthesized, and their physicochemical properties were studied.

[Synthesis of arginine-containing peptides and their conjugates with protohemin IX and tetraphenylporphyrin]. / Sintez argininsoderzhashchikh peptidov i ikh kon''iugatov s protogeminom IX i tetrafenilporfirinom.

Arg-containing peptides and their conjugates with protohemin IX were synthesized by the solid phase method using Merrifield resin. The conjugates of Arg-containing peptides with tetraphenylporphyrin were obtained by using phosphorus trichloride as an activating agent.

[The effect of gamma-L-glutamyl histamine on the severity of experimental anaphylactic reaction, hormonal status and liver cytochrome p-450]. / Vliianie gamma-L-glutamilgistamina na izmenenie tiazhesti proiavlenii éksperimental;noi anafilakticheskoi reaktsii, gormonal'nogo statusa i sistemy tsitokhroma p-450 pecheni.

gamma-L-Glutamyl-histamine (gamma-GluHA) was synthesized at Department of the chemistry and technology of fine organic compounds M. V. Lomonosov Moscow state academy of fine chemical technology. It was investigated the influence of gamma-L-glutamyl-histamine on the severity of experimental anaphylactic reaction, hormonal content in blood plasma and liver cytochrome P-450. The induction of liver cytochrome P-450, the elevation of hormonal content (thyroxine and glucocorticoids) in blood plasma and decrease of the severity of experimental anaphylactic reaction are observed.

[Synthesis and biological properties of artificial antigens based on 280-289 fragment of beta2-gpI]. / Sintez i biologicheskie svoistva iskusstvennykh antigenov na osnove peptida, sootvetstvuiushchego posledovatel'nosti 280-289 belka beta2-gpI.

A series of artificial antigens were synthesized on the basis of the FC(Acm)KNKEKKC(Acm)S peptide from the beta 2-glycoprotein I sequence: lipophilic analogues, the peptide-BSA conjugate, and multiple antigen peptide (MAP) containing eight copies of the peptide on an oligolysyl core. The solid phase method for acylation of the peptide with fatty acids and the HPLC analysis of the acylpeptides were described. Antigenic properties of the resulting compounds were evaluated by CL-ELISA.

Vitamin E as a universal antioxidant and stabilizer of biological membranes.

The known literature data concerning the mechanisms of molecular action of vitamin E in biological membrane systems are reviewed. The role of vitamin E, possessing a broad range of biological activities, as a universal stabilizer of biological membranes in normal oxygen metabolism and peroxidation, and also in disorders of normal metabolism resulting in pathological alterations, has been discussed. The participation of vitamin E in redox reactions taking place in lipid media, its interaction with singlet oxygen, free fatty acids and enzyme systems are considered. Physiological effects of vitamin E and its ability to prevent numerous pathologies are also considered. Vitamin E was concluded to be a universal participant of antioxidant defence reactions in biological membranes, since it acts at all stages of membrane oxidative damage.