Showing papers in "Ukraïns'kyĭ biokhimichnyĭ zhurnal in 2007"

[Purification of lectin from fruiting bodies of Lactarius rufus (Scop.: Fr.)Fr. and its carbohydrate specificity].

Abstract: A lectin from fruiting bodies of Lactarius rufus (Scop.: Fr.)Fr. has been purified by affinity chromatography on copolymer of polyvinyl alcohol with a blood group B specific substance. The lectin gives a single band at disk-electrophoresis in acidic (pH 4.3) and alkaline (pH 8.6) buffer systems. Under electrophoresis in 10-20% SDS-PAGE, the lectin consists of identical subunits with molecular weight 17 +/- 1 kDa. Molecular weight of the lectin is 98 kDa according to gel-chromatography on Tojopearl HW-55. It is supposed that the lectin contains six subunits. The lectin is quite enough stable in pH 4.0-10.0, its activity does not depend upon bivalent metal ions. When heating the lectin solution to 65 degrees C it lost more than 85% of its activity. The lectin agglutinates human etrythrocytes without any marked group specificity, it agglutinates 2-4 times worse rabbit erythrocytes, very weakly crucian erythrocytes and does not agglutinate sheep erythrocytes. Mono- and disaccharides are not inhibitors of the lectin activity, while alpha-phenyl-N-acethyl-D-glucosaminopyranosid (0.08 mM) and 4-nitrophenyl-beta-D-glucosamin are the best inhibitors of its activity. Among glycoproteins the best inhibitors of the lectin activity are: group-specific substances from human blood erythrocytes, asialosubmaxillary bovine mucin, human and bovine thyroglobulin and more weak inhibitors are fetuin, transferrin and human Ig G.

Lipid peroxidation and antioxidant defence enzyme activity in multiple sclerosis

Abstract: Changes of state of lipid peroxidation and activity of antioxidant defence enzymes katalase, superoxide dismutase, glutathione peroxidase and glutathione reductase - in the brain and liver tissue of guinea-pig in conditions of different stages of experimental autoimmune encephalomyelitis (EAE; 11th, 21st, 27th day after inoculation) and in blood of multiple sclerosis (MS) patients with different types, degrees of severity and length of disease and blood level of reduced glutathione have been investigated. We have found, that the development of oxidative stress in animal organism during the disease development is progressive and intensive lipid peroxide oxidation without compensation by antioxidant mechanisms have been shown in the late period (27th day) of the experiment. In MS conditions this state was accompanied with high activity of demyelination process, severe degree of neuronal injury and length of disease above 5 years. In addition reduced glutathione level was increased in many patient groups: remitting type, light (II) degree of severity and among the patients with strongly disturbed neurological functions and long course of the disease. The obtained data allow us to suppose that the development of oxidative stress under demyelination conditions is a result of strong metabolic disorders and decrease of antioxidant defence in the patients during the disease development. The necessity of individual approaches for antioxidant therapy of patients with MS is discussed.

Effect of o,p'-DDD and Li+ on apoptotic DNA fragmentation in conventionally normal and tumour tissues of human adrenal cortex.

Abstract: The actions of 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloroethane (o,p'-DDD), potassium and lithium ions upon apoptotic processes in conventionally normal and tumour tissues of human adrenal cortex were studied. There was no effect of K+ on the apoptosis in tumour tissue. o,p'-DDD--the specific drug for conservative therapy of adrenocortical cancer--enhanced the apoptotic DNA fragmentation in all tested tissues. The conclusion was made that apoptosis may be involved in curative effect of o,p'-DDD in adrenal cortex. Lithium ions, which are used in clinic as antidepressant, inhibited the apoptosis in conventionally normal tissue and in most tumours. On the other hand, lithium enhanced the DNA fragmentation in the postoperative tissue of patients with Cushing disease. The possible mechanisms mediating lithium effects on the adrenal cortex are discussed.

[Aflatoxin-selective molecularly-imprinted polymer membranes based on acrylate-polyurethane semi-interpenetrating polymer networks].

Abstract: Synthetic analogs of biological receptors able to group-selective recognition of aflatoxins were obtained using the combination of the technique of molecular imprinting with the method of computer modeling. The synthetic receptors were obtained in a form of thin and porous membranes based on semi-interpenetrating polymer networks. The selection of functional monomers able to noncovalent interactions with aflatoxins B1, B2, and G2 was based on the data of computer modeling. Allylamine, diethylaminoethylmethacrylate, and N,N'-methylenebisacrylamide, providing high binding energies with aflatoxins B1, B2, and G2 were selected as functional monomers for the formation of aflatoxin B1-imprinted polymer membranes. It was shown that aflatoxin-B1-imprinted polymeric membranes synthesized using N,N'-methylenebisacrylamide as a functional monomer were characterized with good physico-mechanical properties as well as good adsorbtion capability towards aflatoxin B1. Neglidgible levels of aflatoxin B1 adsorbtion on the surface of blank membranes were observed. High adsorbtion capability of the MIP membranes towards mycotoxins affiliated to the group of aflatoxins was demonstrated, while negligible adsorbtion of ochratoxin A was observed. Therefore, synthetic analogs of biological receptors able to group-selective recognition of aflatoxins in the range 1-1000 ppb were developed.

[The N-stearoylethanolamine effect on the NO-synthase way of nitrogen oxide formation and phospholipid composition of erythrocyte membranes in rats with streptozotocine diabetes].

Abstract: The influence of N-stearoylethanolamine (NSE) on the NO-synthase way of NO generation and phospholipids composition of erythrocyte membranes of rats with streptozotocine-induced diabetes has been studied. It has been shown that the activation of iNOS activity, cNOS activity inhibition and increase of the stable NO metabolites content takes place in the red blood cells (RBC) of diabetic rats. The alterations were also found in the RBC membrane phospholipid content: a decrease of phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, sphingomieline content and increase of phosphatidylethanolamine, phosphatidylcholine lysoforms level. The NSE suspension administration (50 mg/kg of body weight) to diabetic rats (3 months after the diabetes induction) resulted in iNOS activity inhibition, recovering of cNOS activity and normalization of NO stable metabolites level in RBC. The decrease of phospholipids lysoform levels, normalization of phosphatidylethanolamine, phosphatidylcholine content and increase of phosphatidylinositol level were found after NSE action.

[Lectins from Sambucus nigra L inflorescences: isolation and investigation of biological activity using procaryotic test-systems].

Abstract: Isolation of lectins from extracts of the Sambucus nigra inflorescences and of pollen material have been performed using isoelectric focusing without carrier ampholytes (autofocusing). Fractions active in agglutination tests with different carbohydrate specificity were subjected to SDS-PAGE. The major lectin found in whole inflores-cences was GalNAc specific and is proposed to be a heterotetramer with subunits of about 30 and 33 kDa. It was called SNAflu-I. At least two other lectins were present in the pollen material and supposed to consist of identical subunits. Major positively charged lectin was Glc/Man specific with subunit of 26 kDa and called SNApol-I. Other pollen component (SNApol-II) was Gal specific with subunit of about 20 kDa. In order to elucidate cell targets sensitive for the S. nigra lectin's activity the combined effects of the lectins and transcriptional of phenazine origin on B. subtilis cells growth have been studied. Only SNApol-I demonstrated the antagonistic activity against these inhibitors in vivo. This lectin but not the SNAflu-I can also inhibit transcription in vitro. It is supposed that lectins from the same source may act in different directions on cell metabolism. Particularly one of the common targets may be the DNA-dependent synthesis of RNA.

Isolation of surface antigen of hepatites B virus

Abstract: The scheme of immunoaffinity isolation of surface antigen of hepatitis B virus is developed. Selection of monoclonal antibodies was carried out and conditions for synthesis of immunoaffinity matrix were optimized; specificity of binding of HBs-antigen with a sorbent is improved; conditions of washing of columns and elution of HBs-antigen are chosen. The yield of purified HBs-antigen obtained according to the developed scheme exceeded 90% and it allows to use such HBsAg for immunization of animals and application in immunoanalysis.

[Effect of N-stearoylethanolamine on the lipid peroxidation process and lipid composition of the rat liver in acute morphine intoxication].

Abstract: The effect of N-stearoylethanolamine (NSE) on the lipid peroxidation process, antioxidant enzymes activity, phospholipid and fatty acid content in the rat liver tissues under acute morphine administration was studied. It was shown that morphine administration (30 mg/kg of body weight) caused an increase of the amount of thiobarbituric acid reactive substances (TBARS), alteration of antioxidant enzymes activity, decrease the protein level, quantity of total lipids and phospholipids, phosphatidylcholine, cholesterol esters; altered the content of some individual fatty acids. NSE administration (50 mg/kg of body weight) promoted normalization of the antioxidant enzymes activity and prevented the TBARS accumulation and decreased the total lipid and phospholipid quantity, increased the content of free and total cholesterol, corrected the level of free and individual fatty acids. It was assumed that NSE possessed antioxidative, membranoprotective and adaptive properties.

[Development of recombinant scFv-antibodies against diphtheria toxin using phage display system].

Abstract: Phage display technology is an effective approach to the development of the next generation of immunodiagnostic reagents. Naive murine phage display a library of single-chain variable antibodies (scFv) was used to isolate scFv recognizing the diphtheria toxin, an important diagnostic antigen of diphtheria. The diphtheria toxin B subunit-binding clone with affinity constant of 1.13 x 10(7) M(-1) was selected. scFv preserved activity on storage in the course of 8 months.

[Characteristic metabolic disturbances in the rat tissues caused by long-term use of alcohol].

Abstract: In the researches carried out on rats with models of chronic alcoholism and alcohol abstinence the most vulnerable to chronic action of alcohol biochemical parameters are revealed: a level of reduced glutathione (it was estimated by the content of free SH-groups in tissues), the content of thiamine diphosphate and thiaminekinase activity in a brain, the content of folic acid in the blood, the content of ubiquinone in the cardiac muscle, RNA/DNA relation in the liver The data obtained demonstrate first of all the negative influence of alcohol on metabolism of sulfur-containing substances and processes of transmethylation The results of our investigation have also shown that the part of metabolic changes caused by long-term usage of alcohol, can be caused by direct influence of ethanol or its metabolites on those or other enzymatic proteins or receptors, and their functions can quickly be normalized after the abolition of alcohol (NAD+ contents, alpha-ketoglutarate dehydrogenase activity and some others) More stable changes in other parts of metabolism, that were specified earlier, may be also a result of long-term alcohol consumption

[Methyl-beta-cyclodextrin influences glutamate transport in the rat brain nerve terminals by depletion of membrane cholesterol].

Abstract: Role of membrane cholesterol in direct and reversed function of Na+ -dependent glutamate transporters and exocytosis was investigated. The depletion of membrane cholesterol by methyl-beta-cyclodextrin (MebetaCD) resulted in a dose-dependent significant reduction of the L-[14C]glutamate uptake by synaptosomes. Treatment of synaptosomes with 15 mM MebetaCD caused a decrease in the velocity of L-[14C]glutamate uptake by 49 +/- 4% (P < or = 0.05). The depolarization stimulated Ca2+ -dependent glutamate release that occurred via reverse functioning of glutamate transporters decreased insignificantly for 1 min from 8.0 +/- 0.4% to 6.7 +/- 0.4% of total accumulated synaptosomal label after MebetaCD treatment. The depletion of membrane cholesterol resulted in a reduction of the depolarization evoked exocytotic release from 8.0 +/- 1.0% to 4.2 +/- 1.0% of total synaptosomal label. Thus, cholesterol depletion was found to decrease significantly the Na+ -dependent uptake and exocytotic release of glutamate.

[Influence of omeprasole and lansoprasole on Na+, K+ -ATPase and Mg2+ -ATPase activity of the plasmatic membrane of myometrium smooth muscle cells]

Abstract: The paper deals with the influence of the proton pump inhibitors - omeprasole and lansoprasole on the enzymatic activity of the ouabain-sensitive Na+, K+ -ATPase and the ouabain-resistant Mg2+ - ATPase in the suspension of the myometrium cell plasmatic membranes treated with 0.1% digitonin solution. It was found, that omeprasole and lansoprasole inhibited Na+, K+ -ATPase in the range from 10 to 100 microM. The maximal effect was observed at a concentration of 100 microM with the percentage of inhibition of 81 and 86% at an average as compared with the control for omeprasole and lansoprasole, respectively. The magnitudes of the inhibition coefficient I(0.5) for omeprasole and lansoprasole were 35.60 +/- 0.81 and 29.40 +/- 1.79 microM respectively. Meanwhile cooperative effects on the Na+, K+ - ATPase activity were not found, as the Hill coefficient n(H) for omeprasole was 1.00 +/- 0.08, while for lansoprasole it was 1.20 +/- 0.03. These substances had also insignificant influence on Mg2+ -ATPase: the enzymatic activity was decreased to 84 and 82% as compared with the control with omeprasole and lansoprasole, respectively, in concentration of 100 microM for each inhibitor. The inhibition of Na+, K+ -ATPase activity can evidence for the possible side effects of omeprasole and lansoprasole when they are used for treatment of acid-dependent diseases of the stomach. In addition, obtained experimental data can be useful for further research of the membrane mechanisms of omeprasole and lansoprasole action on cationic exchange in the smooth muscle cells.

Thermal biosensor for detecting nonylphenol in the environment.

Abstract: The main goal of the research was the development of thermal immune biosensor for highly sensitive and specific determination of nonylphenol (NPh), based on measuring the heat released as a result of the interaction between hapten and specific antibodies. As it was shown previously, in case of SPR based immune biosensor a number of algorithms of analysis was realized, including "competitive" (with the sensitivity on the level of about 7-10 ng/ml), "direct" (10 ng/ml) ways, and the so called algorithm "to saturation" (about 2-5 ng/ml). The time of analysis by immune SPR biosensor is about 10 min (on the previously prepared transducer surface, including immobilization of sensitive structures). The developed thermal biosensor provides direct detection of NPh with the sensitivity of about 1 microg/ml and the overall time of analysis of about 20-30 min. In spite of a lower sensitivity of the thermal biosensor, it is less sensitive to admixtures in real samples and simpler in use than the biosensor based on SPR and, consequently, the thermal biosensor is more applicable in the field conditions.

Investigation of mechanisms of synaptic vesicles fusion with acceptor membranes in the model of exocytosis

Abstract: Fusion of synaptic vesicles with various target membranes was investigated on the cell-free model system that reflects the final step of exocytosis. Plasma membranes, synaptic vesicles and liposomes were used as acceptor membranes. The process of membrane fusion was triggered by Ca2+. We have demonstrated that synaptic vesicles are prone to fuse with liposomes in buffer solution. This process was strongly dependent on ionic force of medium and phospholipid composition of liposomes. Cytosolic proteins of synaptosomes inhibited the fusion of synaptic vesicles with liposomes, while these were required for the fusion of synaptic vesicles with native membrane structures. Trypsinolysis of acceptor membranes markedly inhibited the fusion response. It means protein components of target membrane are necessary for realization of the final step of exocytosis.

[Effect of endogenous lectins on HCO(3)-ATPase activity of the brain glia cells].

Abstract: The influence of galactose--(GL-GAL) and inositol-specific (GL-I) lectins from the glial cells of the chicken brain fraction on the HCO3- -ATPase activity was studied. It was established that enzyme activity changes depended on the concentration of lectins. It must be said that the presence of these lectins also changes the pH optimum of enzyme activity. Calcium ions have an inhibitory effect on the HCO3- -ATPase activity. This effect sharply decreases as a result of the presence of GL-GAL and GL-I. The modulator influence of lectin on the HCO3- -ATPase activity is determined by changing the enzyme affinity for Ca2+ ions.

[Induction of synthesis and activation of Penicillium commune alpha-L-rhamnosidase].

Abstract: For the first time the influence of a number of synthetic porfirin and fluoren derivatives, coordinative germanium substances and surfactants on the biosynthesis and activity of Penicillium commune 266 alpha-L-rhamnosidase has been studied. It is shown that some of porfirin derivatives and coordinative germanium substances may be used as inducers of biosynthesis (143-430%) and also as stimulators of alpha-L-rhamnosidase activity (15-44%). It is more expedient to use biscitratgermanium acid in a complex with asparaginic acid (430%) or threonine (370%) as inducers of biosynthesis of enzyme. At the same time the use of porfirin derivatives, in particular meso-tetra(N-methyl-6-chinoline)porfirin tosilate or its manganese complex, is more efficient as stimulators (40%) of alpha-L-rhamnosidase activity. The utilization of such surfactants as tregaloso-, peptido- and rhamnolipids is not expedient. These compounds either do not influence or inhibit biosynthesis and activity of P. commune alpha-L-rhamnosidase. Only in concentration of 0.01% rhamnolipid increased the activity of enzyme by 7.5%.

Diversity of DIS, SD and psi hairpins in HIV-1 isolates of group M: in silico study.

Abstract: The primary sequence and secondary structure of the region encompassing DIS, SD and psi hairpins in HIV-1 genomic RNAs have been analyzed for 731 group M isolates from NCBI database. The secondary structures have been predicted by the m fold program (M. Zuker). Though the primary sequence of the region studied was found to be highly heterogeneous, this region is folded into DIS, SD and psi hairpins (DIS-, SD- and psi-like hairpins) in 96% of the isolates studied. The phylogenetic analysis showed that the most frequent variants of DIS hairpin (DIS(Lai), DIS(Mal) and DIS(C)) tolerate certain base changes. Particularly, base changes at stem position 23 occur 5 and 33 times more frequently in DIS(Lai) than in DIS(Mal) and DIS(C), respectively, while A insertion at the 5'end of apical loop is tolerated in DIS(Mal) and DIS(C) but not in DIS(Lai). We have revealed that the bottom base pair substitution G-C --> A-U in SD hairpin is highly specific for subtype D isolates. All variants of DIS, SD and psi hairpins found in our database are discussed, systematized and presented in schemes of hypothetical transitions between variants via a single base change. Most variants of DIS and psi hairpins were found to adopt several conformations.

[Modifying effect of low-molecular metabolities on the state of extracellular matrix of connective tissue of animals].

Abstract: On the basis of complex approach to bone and haematopoetic tissue interaction the authors studied the influence of low weight metabolites on stromal fibroblasts and components of extacellular matrix of bone and skin (collagen and glycosaminoglycans). Specificity of different metabolites action on physico-chemical abilities of type I collagen, amino acid composition changes, surface charge, ratio of alpha- and beta-compounds, BrCN-fragments of alpha-1 component cross-links was shown. The dose dependence of formiate effect on processes of proteins glycosilation, cross-linking in bone and cartilage connective tissue and serum glycoproteins was established. The results obtained showed sensitivity of the bone tissue exstacellular matrix to influence of low-weight metabolites action at the level of post-synthetic modification of its components, their intermolecular interaction and process of osteogenesis.

[Comparative study of calixarene effect on Mg2+ -dependent ATP-hydrolase enzymatic systems from smooth muscle cells of the uterus].

Abstract: Investigation the influence of calyx[4]arenes C-90, C-91, C-97 and C-99 (codes are indicated) on the enzymatic activity of four functionally different Mg2+ -dependent ATPases from smooth muscle of the uterus: actomyosin ATPase, transporting Ca2+, Mg2+ -ATPase, ouabain-sensible Na+, K+ -ATPase and basal Mg2+ -ATPase. It was shown that calixarenes C-90 and C-91 in concentration 100 microM act multidirectionally on the functionally different Mg2+ -dependent ATP-hydrolase enzymatic systems. These compounds activate effectively the actomyosin ATPase (Ka = 52 +/- 11 microM [Ukrainian character: see text] 8 +/- 2 microM, accordingly), at the same time calixarene C-90 inhibited effectively activity of transporting Ca2+, Mg2+ -ATPase of plasmatic membranes (I(0,5) = 34.6 +/- 6.4 microM), but influence on membrane-bound Na+, K+ -ATPase and basal Mg2+ -ATPase. Calixarene C-91 reduce effectively basal Mg2+ -ATPase activity, insignificantly activating Na+, K+ -ATPase but has no influence on transporting Ca2+, Mg2+ -ATPase activity of plasmatic membranes. Calixarenes C-97 and C-99 (100 microM), which have similar structure, have monodirectional influence on activity of three functionally different Mg2+-dependent ATPases of the myometrium: actomyosin ATPase and two ATPases, that related to the ATP-hydrolases of P-type--Ca2+, Mg2+ -ATPase and Na+, K+ -ATPase of plasmatic membranes. Basal Mg2+ -ATPase is resistant to the action of these two connections. Results of comparative experiments that were obtained by catalytic titration of calixarenes C-97 and C-99 by actomyosin ATPase (I(0,5) = 88 +/- 9 and 86 +/- 8 microM accordingly) and Na+, K+ -ATPase from plasmatic membranes (I(0,5) = 33 +/- 4 and 98 +/- 8 nM accordingly) indicate to the considerably more sensitiveness of Na+, K+ -ATP-ase to these calixarenes than ATPase of contractile proteins. Thus, it is shown that calixarenes have influence on activity of a number of important enzymes, involved in functioning of the smooth muscle of the uterus and related to energy-supplies of the process of the muscle contracting and support of intracellular ionic homeostasis. The obtained results can be useful in further researches, directed at the use of calixarenes as pharmaceutical substance, able to normalize the contractile function of the uterus at some pregnancy pathologies in women's.

Possibility of enzymatic lactate disintegration followed by formate production

Abstract: A possibility of lactate reverse desintegration to formate and acetaldehyde by lactate-synthase was established by the methods of enzymatic analysis, isotope indication, thin layer chromatography.

Age peculiarities in changes of free radical oxidation processes in the brain of rats with hypothyroidism

Abstract: The objective of the present experiment was to study age peculiarities of free radical protein oxidation and lipid peroxidation in brain of 1.5-month-old and 12-month-old rats with drug-induced hypothyroidism. It has been shown that hypothyroidism in both 1.5-month and 12-month old rat is accompanied by the oxidative stress in the brain. It manifests by an increase of content of lipid peroxidation products and protein carbonyls in mitochondrial and microsomal fractions. Hypothyroidism decreases the prooxidant effect of exercises on the brain mitochondria.

[The effects of n-stearoylethanolamine on the NO-synthase pathway of NO generation in the aorta and heart of streptozotocin-induced diabetic rats].

Abstract: The aim of the presented experiments was to study the influence of suturated NAE--N-stearoylethanolamine (NSE) on the NO synthesis by NO-synthases in aorta and heart tissues of rats with developmental (12-week) streptozotocin-induced (50 mg/kg of body weight) diabetes. Also we evaluated the state of endothelium-dependent relax reactions of aorta smooth muscles. It was shown that the development of diabetes is accompanied with disbalance of NO-synthesis wich consist in inducible NOS (iNOS) activation and inhibition of constitutive NOS (cNOS) and arginase activities. The aorta smooth muscle endothelium-dependent relax reactions were decreased in diabetic rats. The NSE administration to rats with development streptozotocin-induced diabetes resulted in inhibition of iNOS activity and elevation of cNOS and arginase activities in these tissues. Normalization of NO-synthesis under NSE action was accompanied with restoration of aorta smooth muscle endothelium-dependent relax reactions in diabetic rats.

Secretory IgAs from human milk with affinity to mammalian DNA are capable of hydrolyzing ribosomal RNA.

Abstract: It was found that milk of clinical healthy women contains sIgA possessing high affinity for the mammalian thymus DNA and DNA-hydrolyzing activity (sIgA-abzymes). Here we present data that such sIgA-abzymes, purified by sequential chromatography on DEAE-fractogel, heparin-sepharose, DNA-cellulose and followed by gel-filtration, are also able to hydrolyse total RNA from E. coli better than plasmid DNA. Besides, such sIgA-abzymes effectively cleaved 18S and 28S ribosomal RNA isolated from human A549 cells. It is noteworthy that the nuclease activity of sIgA-abzymes was significantly inhibited by ATP, while dATP had no effect on it. A potential role of the ribonuclease activity of sIgA-abzymes present in human milk is discussed.

Furin and its biological role

Abstract: The survey deals with structure, properties and biological role of furin, the calcium-dependent serine endoprotease, which is expressed in all tissues and cell lines examined. It is the best-characterized representative of the mammalian subtilisin-like family of proprotein convertases, which is capable to cleave precursors of a wide variety of proteins, including hormones, growth factors, serum proteins, proteases of the blood-clotting system, matrix metalloproteinases, receptors, viral envelope glycoproteins, and bacterial exotoxins, and so on. The enzyme plays the essential role in embryogenesis, homeostasis; it is also involved in tumor metastasis, activation and virulence of many bacterial and viral pathogens and in neurodegenerative processes associated with Alzheimer's disease. Furin is a very specific enzyme: it recognizes the cleavage-site sequence Arg-Xaa-Lys/Arg-Arg and catalyzes the hydrolysis of the precursors, containing a pair of basic amino acids Arg-Arg or Lys-Arg. The enzyme is a multidomain protein which is initially synthesized as 100 kDa glycosylated profurin consisting of 794 amino acid residues (for human furin) and including a N-terminal signal peptide, propeptide, catalytic domain, possessing approximately 30% homology to subtilisin, a well-conserved P-domain, Cys-rich domain, transmembrane domain and cytoplasmic domain. The active site cleft of furin differs considerably from that of subtilisin with respect to the depth, shape and molecule charge. In furin it is a canyon-like groove with clusters of negatively charged residues along it. Furin inhibitors are rather promising therapeutic agents for treating furin-mediated diseases and bacterial infections. Most furin inhibitors belong to proteins or peptides. The protein-based inhibitors include both naturally occurring and bioengineered variants of protease inhibitors. The peptide-based inhibitors are represented by polyarginines, peptidyl chloromethyl ketones, aminomethyl ketones or ketomethylene pseudopeptides, isostere-containing cyclic peptides, short peptides derived from the prosegments of furin or al-PDX-related peptides. The nonpeptide inhibitors are natural products of the andrographolide family, certain metal complexes of pyridine derivatives and small molecules derived from 2.5-dideoxystreptamine. The furin inhibitors may be used not only as valuable tools for studying furin action, but also as therapeutic agents for furin-dependent diseases.

Dose effect of cyanidin interaction with lead ions in roots of maize seedlings

Abstract: The dose effect of cyanidin interaction with lead ions in maize seedling roots was established using reflectance spectroscopy and colorimetry. It was demonstrated basing on the regression analysis that changes of spectral parameters were related to enhanced complex formation when the metal concentration increases.

Some aspects of glutathione S-transferase P1-1 gene transcription regulation in human placenta

Abstract: Glutathione S-transferase P1-1 is the main phase II xenobiotic metabolism enzyme in human placenta. Low level of its gene expression and corresponding ineffective protection of fetus from toxic compounds is associated with pregnancy disorders such as preeclampsia and abnormalities of fetus development. It was previously reported that environmental radioactive contamination caused down-regulation of GSTP1 transcription in human placenta, but mechanisms responsible for such changes were unclear. In the present study we have found that observed changes in transcription of this gene are not caused by promoter methylation because GSTP1 promoter was not methylated in any of analyzed 91 placental samples. Regulation of GSTP1 by methylation or transcription factors was not previously studied in human placenta. Using "Gene Expression Atlas" online software the placental expression profile of transcription factors known to interact with GSTP1 promoter in other cell types, was identified. According to computer analysis the genes coding for GATA2, GATA3, Fos-B, Nrf3 and MafK transcription factors are highly expressed in human placenta, while genes coding for c-Fos, Juns, Mafs, ERbeta, RARalpha and NF-kappaB factors have moderate level of expression. Competitive EMSA provided the evidence that ARE and NF-kappaB-like sites specifically interacted with placental nuclear proteins. Among these proteins transcription factors AP-1 and NF-kappaB were identified using corresponding consensus oligonucleotides as competitors in EMSA.

[Oxidative modification and change of intramolecular hydrophobicity of hemoglobin A during incubation of human erythrocytes in Fenton's medium].

Abstract: It has been established by method of fluorescentive spectroscopy with using of zond FNA (N-phenilnaftilamine) that under incubation of human erythrocytes in Fenton's system (under intensive generation of oxygen active forms) the hydrophobicity of major hemoglobin fraction is lowered. The changes in the state of hemoglobin A intramolecular structure are correlated with formation of oxidative modification products. It has been shown that aldehydes and ketones of neutral character, which may be oxidative modification products of hydrophobic aminoacid residues, have the highest coefficient of correlation (r =-0.95).

[Calixarene C-91 stimulates Ca2+ accumulation in the myometrium mitochondria].

Abstract: Calixarenes, owing to the ability to form supramolecular complexes with biologically important molecules and ions, can influence a course of biochemical processes and, accordingly, be considered as perspective molecular platforms for creation of physiologically active compounds. The work purpose is to study calixarene C-91 influence on systems of active Ca ions transport which are localized in subcellular membrane structures (mitochondria, sarcoplasmic reticulum, plasma membrane) of myometrial cells. It has been shown, that calixarene C-91 addition to incubation medium led to an increase in Ca2+ accumulation level in mitochondria. The maximal stimulating effect was 173% and it was observed at 100 microM concentration. It is suggested, that calixarene C-91 can enter mitochondria with the subsequent precipitation of Ca ions in a matrix therefore calcium capacity increases, and as a consequence, higher Ca2+ accumulation in these structures is observed. In a wide range of concentration (1-100 microM) calixarene C-91 did not influence a level of Ca2+ accumulation in sarcoplasmic reticulum of myometrial cells. Titration of solubilized Ca2+, Mg2+-ATPase by calixarene C-91 (0,1-100 microM) did not cause changes in its activity. Thus, calixarene C-91 increases Ca2+ accumulation level in mitochondria, but practically does not influence calcium pumps activity of a plasma membrane and sarcoplasmic reticulum of myometrial cells.

[Noncoenzyme function of vitamin PP and its biologically active derivatives: the current state of the problem].

Abstract: This review is devoted to the current state of investigations of vitamin PP and nicotinamide dinucleotides noncoenzyme functions. Particular attention has been focused on the role of these compounds in post-translation modification of proteins (mono- and poly-ADP-ribosylation), in regulation of gene activity, calcium homeostasis and Ca2+ signalling as well as in modulation of synaptic transmission. Biological significance of these processes in cell function was elicited. The role of deregulation of vitamin PP mediated signalling mechanisms involved in control over the cell function under conditions of different diseases was emphasized.

Some mechanisms of lymphoid cell differentiation

Abstract: Lymphoid cells differentiation is a well coordinated and highly integrated process, which is defined by the interaction of genes and cell signaling pathways of the maturing cell with the microenvironment factors. In the course of such interaction in the maturing cell, new ways of signal transduction appear, and on the basis of such new ways new gene networks are formed, which start to play rapidly, even during the course of the present or following cell specialization stage, the key role in the further cell fate.