[Lipid-protein interactions and conformation of proteinaceous macromolecules].

Analysis of the data as to the mechanism of specific antibody transformation into polyreactive immunoglobulins (PRIG) shows that for this transformation it is necessary and sufficiently to deprive antibodies of lipids, which are in norm tightly bound to the antibodies. Removal of these lipids by any methods (by treatment of antibodies with chaotropic ions, low/high pH, reactive oxygen species and lipases) leads to the loose by antibodies of their specificity and acquiring the ability to react with various non-related antigens, i.e.

[Comparative study of the effect of aliphatic alcohols on energy-dependent accumulation of Ca2+ in intracellular membranes of smooth muscle cells].

The effects of ethanol and other aliphatic alcohols on energy-dependent Ca2+ transport in endoplasmic reticulum and mitochondria were studied in digitonin-treated myometrium cells. The Ca2+ uptake in mitochondria increased (on 15-20%) with increasing methanol, ethanol and propanol concentrations in medium, whereas further rise of concentration inhibited this process. Treatments of myometrial cells with short-chain alcohols caused an inhibition of calcium uptake in endoplasmic reticulum.

[A method for determining a rate constant for biexponential processes using data on dynamics of accumulating the end product of a reaction].

A new method the rate constant determination of some biexponential processes is suggested. The method is based on the asymptotic solution of transcendental irrational equations, described such processes. This method can be used when kinetics of the final product of reaction is known.

[Determination of the concentration of ligand-specific molecules, found in mixtures with ligand-nonspecific molecules].

A new method, which allows determination of the concentration of ligand-specific molecules in a mixture of these molecules with biochemically similar but ligand-unspecific molecules, is suggested. The method is based on a partial exhaustion of the mixture on a column with immobilized ligand and determination of the part of ligand-specific molecules presented in exhausted mixture. The concentration of monoclonal antibodies specific to bovine serum albumin in a commercial "Sigma" preparation and concentration of polyreactive immunoglobulins in a commercial "Sigma" preparation of bovine immunoglobulins were determined by suggested method.

[Effect of ethanol on the activity of the energy-dependent Ca2+-transporting system of myometrial cells].

In order of estimating some regularities of ethanol direct (effectory) effect to transmembrane calcium metabolism in the myometrium the action of this substance on the energy-dependent Ca(2+)-transporting systems of the uterine myocytes subcellular structures has been studied. The systems of Mg2+, ATP-dependent Ca2+ transport regarding their sensitivity to ethanol inhibitory effect were displayed as satisfying the following sequences: endoplasmic reticulum calcium pump > plasma membrane solubilized Ca2+, Mg2+, ATP-ase > mitochondrial Ca(2+)-accumulating system = plasma membrane calcium pump. Alongside with the latter, the oxytocin-insensitive component of Mg2+, ATP-dependent Ca2+ accumulation in the endoplasmic reticulum was defined to be less resistant to inhibitory effect of ethanol if compared with the oxytocin-sensitive one.

[A quantitative method for determining lectin activity on microplates].

A modification of a known quantitative solidphase microtiter plate lectin assay elaborated by Hatakeyama and coauthors developed with biotinylated lectins and ExtrAvidin--alkaline phosphatase conjugate was proposed. The modification was performed in order to use a broad spectra of lectin ligands, including glycopeptides, peptides, etc. The optimal concentrations of the reagents and time of the reagents incubation were selected.

[Isolation and characteristics of antistreptokinase antibodies from blood serum of myocardial infarct patients treated with streptokinase].

Antistreptokinase IgG (antiSK IgG) from blood of 8 patients with acute myocardial infarction that were treated by streptokinase (SK) has been investigated. AntiSK IgG contained 1.8% of total serum IgG.

[Characteristics of antioxidant properties of 20-hydroxyecdysone in low density lipoproteins by kinetic parameters of chemiluminescence].

20-Hydroxyecdysone is capable to terminate the lipid free-radical oxidation in low density lipoprotein in vitro as displayed by the kinetic chemiluminescence parameters. In concentrations interval from 2 x 10(-6) mol/l up to 8 x 10(-6) mol/l it statistically reliably reduces maximum of the first flash intensity of the low density lipoprotein Fe(2+)-initiated chemiluminescence. It testifies about Fe(2+)-initiated lipid peroxide process decomposition in low density lipoprotein slowing down by 20-hydroxyecdysone.

Iron uptake by the yeast Pichia guilliermondii. Flavinogenesis and reductive iron assimilation are co-regulated processes.

Pichia guilliermondii cells overproduce riboflavin (vitamin B2) in responce to iron deprivation. The increase in ferrireductase activity in iron-starved P. guilliermondii cells correlated with the increase in flavin excretion.

[A new type of electrochemical immunosensor based on ion-selective field effect transistors].

A new type of an electrochemical sensor based on the use of ion-selective field effect transistors (ISFETs) and conjugates of horse radish peroxidase with specific monoclonal antibodies was developed for the express determination of myoglobine in a solution. For this purpose a simple method of covalent immobilization of myoglobine on the surface of ISFET gate was worked out, an appropriate biochemical approach which allowed potentiometrical registration of the peroxidase activity was used, and an immune chemical analysis was accomplished in competitive way. It was shown that the sensitivity of the analysis with the help of the electrochemical immune sensor corresponds to the demands of medical practice to reveal early stages of myocardial infarction.

[Effector action of ethanol on the accumulation of Ca2+ in intracellular structures of uterine smooth muscle].

The work is devoted to the investigation of ethanol direct effect on the transmembrane Ca2+ metabolism in the intracellular structures of myometrium. In the experiments in vitro it has been shown that the Mg2+, ATP-dependent system for Ca2+ accumulation in endoplasmic reticulum is more sensitive then Ca(2+)-accumulating system in mitochondria. It has also been found that the oxytocin insensitive part of Mg2+, ATP-dependent Ca2+ accumulation of the endoplasmic reticulum is less resistant to ethanol inhibition than the oxytocin sensitive one.

Preparation of fibrin des-AA by thrombin.

The active thrombin is formed in the blood stream when the blood coagulation system is activated. It attacks fibrinogen, splits off two fibrinopeptides A and fibrinogen is transformed into des-AA fibrin which is able to polymerize spontaneously forming protofibrils. At high thrombin concentration the enzyme splits off two fibrinopeptides B and des-AA fibrin units are transformed into des-AABB fibrin.

[Characteristics of H2O2-initiated oxidation of blood serum lipids by kinetic parameters of chemiluminescence].

H2O2-initiated free radical oxidation of blood serum lipids was investigated by the chemiluminescence method. The first flash of the chemiluminescence was stimulated by H2O2 decomposition on the reaction, similar to Fenton reaction. The time of the chemiluminescence flash second maximum was correlated with the contents of antioxidants.

[Interaction of thiamine with rat brain synaptosomes].

Thiamine has been shown to be bound specifically by a synaptosomal plasmatic membrane and transported inside to the nervous ending. Apparent K[symbol: see text] and Km for processes of binding and transport have been determined as equal 2.34 +/- 0.

[Placenta--a source of biologically active substances].

In the review there are some data displaying the scientific and patent literature presenting placenta as a rich source of some biologically active substances (BAS): proteins, lipids, enzymes, glycolipids and glycolipoproteins, hormones. This information is capable to be used while developing the techniques of BAS producing from placenta in order of creating the organospecific complex preparations with medically-preventive properties.

[Prions and serpins: structural analogs and their consequences. I. Protease-transport hypothesis].

The structural analogy between prions pathogenic form and serine proteinase inhibitors (serpins) was laid into the basis of explaining the prion diseases main peculiarities--nucleic-acid-free transfer of infection, neurodegenerative processes, existence of the minimal infective dose, long-term latent period and some others. The assumption about pathogenic prions as the proteins supplying the extracellular proteinases transport into the intracellular space permits to bring the pathogenesis of prion diseases to the known and partially proved processes order regarding the case of prion diseases.

[New systems of coordinates in the study of ligand-receptor interaction].

Two new coordinate systems that allow to determine the parameters of ligand-receptor interaction are suggested. These coordinate systems principally differ from the well-known coordinates of Klotz and Scatchard. It was shown that suggested coordinates were simpler and more convenient then coordinates of Klotz and Scatchard and in some cases was more informative.

[Effect of vitamin D3 on free-radical oxidation of lipids in low density lipoproteins in vitamin D deficiency].

The lipid free radical oxidation in low density lipoproteins was investigated on D-deficiency model in vivo. The processes of lipid free radical oxidative activation in low density lipoproteins at D-deficiency occurred. The chemiluminescence kinetic parameters: the maximum intensity of the first flash and inclination angle tangent of an ascending branch of the second flash grew at D-deficiency in comparison with control group (p < 0.

[Plasminogen binding with decapeptide and polypeptide fragments of streptokinase].

The plasminogen binding with streptokinase decapeptides, modeling the primary structure of molecule, and chymotryptic fragments of streptokinase have been investigated. The immunoenzymatic assay has shown that plasminogen binds to all streptokinase fragments with the decreasing affinity in the set of fragments: 36 > 30 > 17 > 7 > 11 kDa. Location of the binding sites in streptokinase primary structure was performed using the immobilized decapeptides on plastic pins adopted to IEA.

[Features of plasminogen activation in a complex with antiplasminogen monoclonal antibody IV-1C].

Antiplasminogen monoclonal antibody IV-1c (IV-1c) with antigenic determinant in V709-G718 site of plasminogen (Pg) protease domain (Druzhina N.N. et al.

[Minimal amino acid sequence, recognized by anibodies to the peptide GPQPPQPPQP from the proline-rich region of pertactin].

Three antiserum samples obtained from rabbits immunized by the conjugate KLH-10P (keyhole limpet hemocyanine-decapeptide GPQPPQPPQP) were used to study antigenic structure of 10P. Antigenic properties of conjugates 6P (PGPQPP) and 4P (PQPP) with ovalbumine were studied by an indirect immunoassay (ELISA). Also 4P, 6P, PQP and QPP peptides were used for a competition assay.

[Lectins and recognition of protein ligands].

The general principles of protein-carbohydrate lectin interactions were discussed. Experimental evidences of the molecular mimicry between carbohydrate and protein lectin ligands were analyzed. The interdomain interactions in lectins as well as the interactions between ligands and lectin domains other than carbohydrate-binding domains were considered.

Determination the rate constants of some biexponential reactions.

Reactions that are described by biexponential functions are typical for many biological processes. The kinetics of these reactions is described by transcendental irrational equations interconnecting the reagent concentrations, time and rate constants. Meantime, their graphical representation in the semi-logarithmic coordinates can be decomposed into two straight lines that intercept at some angle.

[Immune sensor for determining myoglobin level].

For the first time, the photoluminescence of porous silicon was used to create an immune sensor capable of detection of low concentrations of myoglobin important for the diagnostics of heart failure diseases which in both model solutions and human serum, being. It is shown that the sensitivity of the sensor was 10 ng/ml, time of 1 measurement--15-30 min. Duration of the analysis can be even shorter if measurements are performed in the kinetic regime.

[Antioxidant effect of 20-hydroxyecdysone in a model system].

Changes in the level of lipid free-radical oxidation in mitochondrial fraction at the presence of 20-hydroxyecdysone in 1, 2, 4, 6, 8 microM concentration with the help of a chemiluminescence (ChL) method were investigated in vitro. Statistically authentic reduction of ChL kinetic parameters--I(s) and tg alpha, at 20-hydroxyecdysone presence in concentration of 2 microM was found. 20-hydroxyecdysone administration in concentration 4 microM and more leads to the statistically authentic change of all four ChL parameters.