[Enzymatic synthesis of electroconductive biocomposites based on DNA and optically active polyaniline].

Electroconductive interpolymer polyaniline complexes are synthesized on the DNA matrix, using the method of oxidative polymerization of aniline with two different biocatalyzers: horseradish root peroxidase and micropiroxidase-11 biomimetic. The spectral characteristics and morphology of the acquired biocomposites have been studied. The stereospecificity of the acquired samples of interpolymer complexes is shown, depending on the biocatalyzers used.

[Synthesis of electroconductive polyaniline using immobilized laccase].

A new method for synthesis of the conductive complex between polyaniline (PANI) and poly(2-acrylamido-2-methyl-1-propanosulfonic acid) (PAMPS) was proposed; in this method, the immobilized laccase from the basidiomycete Trametes hirsuta is used as a biocatalyst for aniline oxidative polymerization. The conditions for laccase immobilization on CM cellulose by bifunctional Woodward's reagent were optimized. The catalytic properties of immobilized and native laccases were compared.

[Micellar laccase-catalyzed synthesis of electroconductive polyaniline].

A method of enzymatic synthesis of electroconductive polyaniline on the micelles of dodecylben-zenesulfonic acid sodium salt (DBSNa) is proposed. The high potential laccase from the basidiomycete Trametes hirsuta was used as a biocatalyst. The conditions for polyaniline synthesis were optimized (pH 4.

[Laccase-mediator systems and their applications: a review].

The mechanism of operation of laccase-mediator systems (LMSs) in xenobiotic degradation mediated by "true" redox mediators and laccase enhancing agents is considered. Structural formulae of most common laccase mediators and compounds that can be used as agents enhancing the enzyme operation are presented. Examples of LMS application in biotechnology are described.

[Oxygen can be replaced by artificial electron acceptors in reactions catalyzed by alcohol oxidase].

For the first time, spectrometric and electrochemical studies demonstrated the possibility of using artificial electron acceptors in reactions catalyzed by alcohol oxidase. We report kinetic parameters of homogenous catalytic oxidation of formaldehyde by organic redox compounds belonging to different structural classes (toluidine blue, methylene blue, 2,6-dichlorophenolindo-phenol, and p-benzoquinone) and replacing dioxygen in these reactions. p-Benzoquinone, having the highest redox potential, proved to be the most efficient artificial electron acceptor of all compounds studied.

[The dynamics of oxidase activity during cultivation of basidiomycetes from the genus Trametes Fr].

Twenty strains of the wood-degrading fungi from the genus Trametes Fr., capable of synthesizing laccases, were screened according to the changes in the oxidase activity in a submerged culture. The range of maximal efficiency of various species with respect to extracellular oxidase activity was determined.

[An electrochemical method for measuring metabolic activity and counting cells].

An express electrochemical method for determining the metabolic activity of live cells based on the possibility of an electron exchange between an electrode and elements of the biological electron transfer chain in the presence of a mediator is proposed. This method is useful for studying any live cells (animal, plant, and microbial), including anaerobic, dormant, and spore cells. The sample preparation and measurement itself does not take more than 30 min.

[Enzymatic synthesis of a conducting complex of polyaniline and poly(2-arcylamido-2-methyl-1-propanesulfonic ACID) using palm tree peroxidase and its properties].

An enzymatic method of producing a conducting polyelectrolyte complex of polyaniline (PANI) and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) was developed. Acidic stable peroxidase isolated from royal palm tree (Roystonea regia L.) leaves was used as a catalyst in the oxidative polymerization of aniline at pH 2.

[Phenyl pyrazolones--novel oxidoreductase redox-mediators for degradation of xenobiotics].

An approach was developed to screening organic compounds for putative activity of redox mediators of oxidoreductases, including laccases and peroxidases, applicable for xenobiotic degradation. The study was carried out with a homogenous laccase preparation from the basidiomycete Trametes hirsuta and horse-radish root peroxidase. Compounds belonging to 1-phenyl-3-methylpyrazolones were selected.

[Optimization of conditions for cultivation of the basidiomycete Coriolus hirsutus--producer of extracellular laccase].

The effects of various factors on the biosynthesis of extracellular laccase (EC 1.14.18.

[Study of kinetic parameters of glucose oxidase and alpha-chymotrypsin, immobilized in polymeric matrices, using a light-addressable sensor].

Light-addressable potentiometric sensors were prepared by immobilizing glucose oxidase or alpha-chymotrypsin on the surface of a pH-sensitive electrode. Two methods of immobilization were used: incorporation into a hydrophilic matrix of bovine serum albumin and incorporation into a hydrophobic matrix of modified polyethylenimine. The glucose oxidase and alpha-chymotrypsin preparations immobilized in the polyethylenimine matrix were characterized by the Michaelis constant values of 6.

[Selection of optimal conditions for synthesis of protein A-laccase conjugates and their use in different variants of immunoenzyme analysis].

A study to determine optimal molar ratios of Protein A to laccase for the synthesis of their conjugate by periodate method is presented. No loss of enzymatic or immunological activity of the conjugate developed was observed during 6 month. The conjugate could be effectively used in various techniques of enzyme immunoassay (competitive or sandwich techniques, dot immunoblotting) for immunoglobulin G.

[Immunoenzyme analysis based on laccase conjugates with fluorometric detection of the enzymatic reaction product].

The possibility of using homovanillic acid as a substrate of laccase (produced by the basidiomycete Coryolus hirsutus) has been demonstrated for the first time. The reaction was shown to result in the formation of a fluorescent product. Several kinetic parameters and optimal conditions were determined for this enzymatic reaction.

[Study of physiological functions of human ceruloplasmin. The effect of ceruloplasmin on immunocytes in a normal state and in pathology].

The immunomodulating effect of ceruloplasmin (CP) on the major components of the immunocompetent system of the organism--the natural resistance system and the specific immune response--has been established. CP can exert various influences on the level of expression of specific markers of T- and B-lymphocytes (as determined by various modifications of the rosette-forming test), on the phagocytic activity of neutrophils and monocytes as well as on the activity of "respiratory burst" enzymes. CP modulation was found to depend predominantly on the initial level of the immunological parameters to be determined, i.

[The effect of conditions of synthesis of immunolaccase conjugates on characteristics and composition of the compounds obtained].

Optimal conditions for preparing laccase conjugates by the periodate method have been selected. The effect of the initial molar ratio of IgG to laccase and pH of the medium on the composition of laccase conjugates was studied by the HPLC method. The maximum yield of the conjugates was observed, when laccase was oxidized with 0.

[Laccase from Coriolus hirsutus--a new marker enzyme for immunoenzyme analysis].

A new immunochemical reagent is proposed which contains laccase, isolated from the culture liquid of the basidial fungus Coriolus hirsutus, as a marker enzyme. The feasibility of immunolaccase conjugates for different variants of immunoassay, i.e.

[Regulation of aldose reductase activity. Mechanism of action of an activated form of the enzyme].

Activation of bovine eye lens aldose reductase during its incubation with NADPH and glucose was studied. The activated form of the enzyme was isolated, and the rate of glucose reduction measured within a broad range of substrate concentrations. Spectrophotometric titration and equilibrium gel-filtration were used to study the interaction of the enzyme active center with substrates.

[Aldose reductase: physiological role, properties and prospects for regulating activity].

Some properties of aldose reductase isolated from various sources and possible ways of regulation of the enzyme catalytic activity are reviewed. Mammalian aldose reductases are monomeric enzymes with M(r) of 30-40 kDa and a broad substrate specificity towards aldoses. The physiological role of this enzyme consists, apparently, in providing an additional pathway for utilization of glucose and removing toxic compounds carrying an aldehyde group from the cell.

[Regulation of aldose reductase activity. The influence of effectors on reverse isomerization of the enzyme].

The effects of ligands of active and inhibitory centers of homogeneous aldose reductase from cattle eye lens on glucose reduction were studied. Using spectrophotometric titration and equilibrium gel filtration, the interaction of the enzyme active center with substrates was investigated. It was shown that the reaction kinetics obeys a mechanism with a quasi-equilibrium non-ordered attachment of substrates and isomerization of enzyme complexes with nicotinamide dinucleotide phosphates in the course of the catalytic act.

[Immunoenzyme determination of the total level of ceruloplasmin in the serum from patients with hepatocerebral dystrophy].

An immunoenzymatic method for ceruloplasmin analysis (IEA) based on the use of horseradish peroxidase-labelled monospecific antibodies as markers has been developed. IEA can be used for direct measurements of ceruloplasmin in blood serum, as can be evidenced from the coincidence of calibration plots obtained after the use of potassium-phosphate buffer and ceruloplasmin-free sera. The procedure allows the determination of the total content of ceruloplasmin present in the blood sera of patients with hepatocerebral dystrophies both in the active and inactive forms.

[Interconnection between the structure and protective action of normal and pathological ceruloplasmin preparations in copper-induced erythrocyte lysis].

It was found that the differences in the protective effects of ceruloplasmin (CP) isolated from the blood of healthy donors and of the ceruloplasmin-like protein (pat-CP) isolated from the blood of patients with hepatovertebral dystrophy (HCD) during Ca(2+)-induced lysis of erythrocytes (RBC) result from significant changes in the carbohydrate fragment of pat-CP, the bulk of which (65%) is devoid of mannose and acetylglucosamine residues. According to the data from lentil-lectin Sepharose chromatography, only 4% of pat-CP molecules contain the [formula; see text] fragment necessary for the binding to ER receptors. The curves reflecting the Cu2+ accumulation in healthy donor ER and in pat-CP during the Cu(2+)-induced lysis were found to differ significantly.

[Protective effect of various forms of human ceruloplasmin in copper-induced erythrocyte lysis].

It is known that human ceruloplasmin (CP) is made up of several isoforms which differ by the structure of their carbohydrate fragment. One of these isoforms, CP1, which makes up to approximately 40% of the native CP molecule and which contains a carbohydrate fragment, [formula: see text] is specifically bound to human erythrocyte (ER) receptors. This isoform was isolated by using lectin affinity chromatography.

[Regulation of crystalline lens aldose reductase activity. Nonhyperbolic oxidation kinetics of NADPH by glucose].

A homogeneous aldose reductase was isolated from bovine eye lens tissue by using affinity chromatography on blue agarose. A kinetic analysis of the initial rates of NADPH oxidation at 0.5-100 mM glucose and at 1.

[Comparison of the protective effects on the erythrocytes of ceruloplasmin from the blood of healthy donors and patients with hepatocerebral dystrophy].

The binding of the ceruloplasmin (CP) from the healthy donor's blood and of ceruloplasmin--like protein (p-CP) isolated from the Wilson disease patient's blood with erythrocytes (RBC) of healthy donors and with RBC of Wilson's patients (p-RBC) was investigated. It was shown, that the CP number of binding sites both on the RBC and p-RBC was significantly lower than that for p-CP, but Kd value for p-CP binding of the both types of erythrocytes was approximately 10 times higher than Kd value for CP. The protective action of CP on copper stimulated hemolysis is almost 3 times higher than that of p-CP.