Indicators of chemiluminescent and bioluminescent tests of biological liquids in the assessment of physical health.

The study includes anthropometry of 172 young male, obtained data on the length and body mass, measured the transverse diameters of the shoulders and pelvis, various body types was identified by the J.M. Tanner sexual dimorphism index (andromorphic, mesomorphic, gynecomorphic). The chemiluminescent and bioluminescent study of saliva and blood was conducted in the examined young male. We studied the indicators of the antioxidant defense system under the influence of stress. The antioxidant status of saliva was determined using the H2O2-luminol-dependent chemiluminescence method. Data on the activity of NAD (P) -dependent dehydrogenases in blood lymphocytes was obtained from a bioluminescent method of research. Young male of andromorphic body type had large overall and transverse body sizes. Indicators of antioxidant protection of saliva and blood in men of adolescence, the body type of the sexual dimorphism index J.M. Tanner was different. The persons of the andromorphic body type differed in terms of chemiluminescence in comparison with the young male of gynecomorphic body type. The results of bioluminescent blood tests suggest a violation of the catabolic and anabolic processes of carbohydrate and fat metabolism in young men of mesomorphic and gynecomorphic body types. Indicators of the system of antioxidant protection of saliva and blood reflect the sexual characteristics of the body of young male and can be used as additional criteria for diagnosing sex inversion and assessing the risk of developing socially attributed diseases.

Viscous Media Slow Down the Decay of the Key Intermediate in Bacterial Bioluminescent Reaction.

The effects of medium viscosity on the decay rate of the 4a-hydroperoxyflavin intermediate of the bioluminescent reaction was investigated. It was found that at low concentrations of glycerol or sucrose (viscosity 1.1-1.3 cP) the decay rate rises, whereas a further increase in viscosity to 6.2 cP leads to a decrease in the decay rate following a power function with an exponent of 0.82-0.84. Using molecular dynamics methods, it was shown that the presence of glycerol and sucrose molecules causes a change in the mobility of the amino acid residues in the active center of luciferase, particularly those responsible for binding of flavin. The results obtained are indicative of two opposite effects of viscous media with glycerol and sucrose: (1) destabilization of 4a-hydroperoxyflavin due to a change in the structural and dynamic properties of the protein and (2) stabilization of this intermediate by the decrease in the diffusion rate of its decay products.

Gelatin and Starch: What Better Stabilizes the Enzyme Activity?

The regularities of the functioning of a number of enzymes in a viscous environment created by natural polymers, starch and gelatin are examined. Based on the analysis of kinetic curves of thermal inactivation, mechanisms of thermal inactivation of enzymes in a viscous microenvironment are proposed. Using the example of butyrylcholinesterase, NAD(P)H:FMN oxidoreductase, and coupled system of the luminous bacteria (NAD(P)H:FMN oxidoreductase + luciferase), the conditions, under which starch and gelatin have a stabilizing effect on enzyme activity during storage and exposure to various physical and chemical environmental factors, were found. A significant increase in the stabilizing effect is achieved by eliminating water during drying the enzyme preparations immobilized in starch and gelatin polymer gels.

NAD(P)H:FMN­Oxidoreductase Functioning Under Macromolecular Crowding: In Vitro Modeling.

The functioning of NAD(P)H:FMN­oxidoreductase (Red) from Vibrio fischeri under conditions of macromolecular crowding (MMC) simulated in vitro by adding biopolymers (starch and gelatin) was studied. The dissociation rate constants and the activation energies of dissociation of Red to the subunits were calculated, and the process of denaturation of Red was analyzed. It is shown that the functioning of Red both under conditions of MMC and in diluted solutions is the same. This result refutes the common belief that the native conformation of enzymes in vivo is stabilized due to MMC as compared to the in vitro conditions.

Principles for Construction of Bioluminescent Enzyme Biotests for Analysis of Complex Media.

In this study, we formulated the principles of designing bioluminescent enzyme tests for assessing the quality of complex media, which consist in providing the maximum sensitivity to potentially toxic chemicals at a minimal impact of uncontaminated complex media. The developed principles served as a basis for designing a new bioluminescent method for an integrated rapid assessment of chemical safety of fruits and vegetables, which is based on using the luminous bacteria enzymes (NAD(P)H:FMN oxidoreductase and luciferase) as a test system.

Set of Enzymatic Bioassays for Assessment of Soil Contamination.

A concept of the comprehensive assessment of soil contamination is proposed. According to it, the conclusion regarding the presence of toxic substances in the analyzed sample is based on the inhibition of enzymatic reactions responsible for various functions of a living organism, such as luminescence, respiration, etc. These functions are taken as test functions in classical bioassays with the use of living objects (luminous bacteria, daphnia, algae, and others). The regularities of the impact of different classes of toxicants on the activity of particular enzymes or coupled oligo-enzyme chains have been established. These enzyme reactions are selected as potential test objects: markers of contamination. Three enzyme systems with the maximal sensitivity to different classes of toxicants have been chosen for the set of enzymatic bioassays: butyrylcholinesterase, NAD(P)H:FMN-oxidoreductase + luciferase, and lactate dehydrogenase + NAD(P)H:FMN-oxidoreductase + luciferase. The possibility to use enzymes instead of living organisms in the bioassay of natural complex systems has been shown.

Stabilization of Butyrylcholinesterase by the Entrapment into the Natural Polymer-Based Gels.

A new method for obtaining stable butyrylcholinesterase (BuChE) samples based on the enzyme immobilization in starch and gelatin gels followed by drying is proposed. Coimmobilization of BuChE with the thiol group indicator 5,5'-dithiobis(2-nitrobenzoic) acid did not reduce the activity of BuChE, which allowed us to simplify the procedure and reduce the time of analysis of organophosphorus pesticides. The resulting immobilized samples retained activity for at least 300 days. BuChE samples based on the starch gel showed a greater sensitivity in the determination of pesticides as compared to the samples based on the gelatin gel.

Bioluminescent assay for toxicological assessment of nanomaterials.

A new method for assessing biotoxicity of nanomaterials, based on the use of soluble bioluminescent coupled enzyme system NAD(P)⋅H:FMN oxidoreductase and luciferase, is proposed. The results of this study indicate a significant adverse biological effect exerted by nanoparticles at the molecular level. It was found that the most toxic nanoparticles the nanoparticles are based on copper and copper oxide, as well as single-walled carbon nanotubes and multi-walled carbon nanofibers, which are referred to hazard class II.

Bioluminescent enzymatic rapid assay of water integral toxicity.

A bioluminescent rapid method was developed to estimate the integral toxicity of natural and wastewater. This method is based on registering the effect of the polluted water sample on the parameters of the bioluminescent reaction catalyzed by the multi-component reagent containing NADH:FMN oxidoreductase, luciferase, and their substrates co-immobilized in a starch carrier. Several ways to increase the method's sensitivity to toxic substances were suggested; conditions were selected to make it possible to determine, with maximum efficiency, the content of toxic substances corresponding to a certain maximum permissible concentration. The sensitivity of soluble and immobilized coupled enzymatic systems to a series of organic pollutants (phenols, quinones, and salts of heavy metals) was compared. It was shown that the reagent is the most sensitive to the effect of phenols and quinones. The method was tested during analysis of the wastewater from a pulp and paper plant and can be used for biotesting in both laboratory and field conditions.

Comparative study of immobilized and soluble NADH:FMN-oxidoreductase-luciferase coupled enzyme system.

The properties of a coupled enzyme system (NAD(P)H:FMN-oxidoreductase and luciferase) from luminous bacteria were studied. The enzymes and their substrates were immobilized in polymer gels of different types: starch (polysaccharide) and gelatin (polypeptide). Maximum activity yield (100%) was achieved with the enzymes immobilized in starch gel. An increase in K(m) (app) was observed in both immobilized systems as compared with the soluble coupled enzyme system. Immobilization in starch and gelatin gels increased the resistance of the NAD(P)H:FMN-oxidoreductase and luciferase coupled enzyme system to the effects of external physical and chemical factors. The optimum pH range expanded both to the acidic and alkaline regions. The resistance to concentrated salt solutions and high temperature also increased. The coupled enzyme system immobilized in starch gel (with activation energy 30 kJ/mol) was characterized by the best thermostability. The immobilized coupled enzyme system can be used to produce a stable and highly active reagent for bioluminescent analysis.

A bioluminescent signal system: detection of chemical toxicants in water.

Prototype technologies of a bioluminescent signal system (BSS) based on the luminous bacterium Photobacterium phosphoreum and three enzymatic bioluminescence systems have been proposed for detecting and signalling the presence of toxicants in water systems. A number of pesticides, mostly known as poisonous substances, similar in their structures and physicochemical properties, have been taken as model compounds of chemical agents. The effect of toxicants (organophosphates, derivatives of dithiocarbamide acid, and pyrethroid preparations) on the bioluminescence of the four systems has been analysed. EC(50) and EC(80) have been determined and compared to the maximum permissible concentration for each of the analysed substances. The triple-enzyme systems with ADH and trypsin have been shown to be more sensitive to organophosphorous compounds (0.13-11 mg/L), while the triple-enzyme system with trypsin is highly sensitive to lipotropic poison, a derivative of dithiocarbamine acid (0.03 mg/L). Sensitivities of the triple-enzyme systems to pyrethroid preparations are similar to those of luminous bacteria (0.9-5 mg/L). The results can be used to construct an alarm-test bioluminescence system for detecting chemical toxicants, based on intact bacteria or enzyme systems.

Redox compounds influence on the NAD(P)H:FMN-oxidoreductase-luciferase bioluminescent system.

A review of the mechanisms of the exogenous redox compounds influence on the bacterial coupled enzyme system: NAD(P)H:FMN-oxidoreductase-luciferase has been done. A series of quinones has been used as model organic oxidants. The three mechanisms of the quinones' effects on bioluminescence were suggested: (1) inhibition of the NADH-dependent redox reactions; (2) interactions between the compounds and the enzymes of the coupled enzyme system; and (3) intermolecular energy migration. The correlation between the kinetic parameters of bioluminescence and the standard redox potential of the quinones proved that the inhibition of redox reactions was the key mechanism by which the quinones decrease the light emission intensity. The changes in the fluorescence anisotropy decay of the endogenous flavin of the enzyme preparations showed the direct interaction between quinones and enzymes. It has been demonstrated that the intermolecular energy migration mechanism played a minor role in the effect of quinones on the bioluminescence. A comparative analysis of the effect of quinones, phenols and inorganic redox compounds on bioluminescent coupled enzyme systems has been carried out.

Oxidative stress monitoring in biological samples by bioluminescent method.

The integral bioluminescent biotest with lyophilized fluorescent bacteria was used for monitoring of LPO processes in tissue extracts and serum of rats exposed to stress. A relationship between the content of MDA (LPO indicator) and fluorescence of bacteria was observed in all biological samples.

Effect of quinones and phenols on the triple-enzyme bioluminescent system with protease.

The study addressed the effects of redox-active compounds on trypsin activity. Series of organic oxidizers (quinones) and reducers (phenols) were chosen as model redox-active compounds. Trypsin activity was quantified by bioluminescent technique. Interactions of these compounds with trypsin were studied by fluorescent and light absorption methods. Luminescence intensity decay constants in the reduced nicotinamidadeninedinucleotide (NADH): flavinmononucleotide (FMN)-oxidoreductase (R)-luciferase (L)-trypsin (T) (R + L + T) triple-enzyme system were calculated and compared in the presence of different concentrations of quinones and phenols. The triple-enzyme system was shown to be sensitive to quinones and not sensitive to phenols. It has been found that the effects produced by quinones on the coupled enzyme system (R + L) and on the trypsin molecule (T) are not related. The conclusions were extrapolated to the properties of other proteases and antiproteases.

Bioluminescent analysis of intensity of pathological oxidative processes in cells of perfused rat liver after hyperthermia.

We studied the possibility of evaluation of the intensity of pathological oxidative processes in rat liver using an integral bioluminescent test with controlled perfusion of the isolated organ. The test revealed a significant correlation between the level of TBA-reactive products and bioluminescence intensity.

Estimation of energy of the upper electron-excited states of the bacterial bioluminescent emitter.

The hypothesis of activity of the upper electron-excited states of the bacterial bioluminescent emitter was verified using dye molecules as foreign energy acceptors. Six compounds were selected having fluorescent state energies ranging from 25,700 to 32,000 cm(-1) (anthracene, pyrene, 1.4-bis(5-phenyloxasol-2-yl)benzene (POPOP), p-bis(o-methylstyryl)benzene (MSB), 2-methoxy-naphtalene, p-terphenyl), exceeding that of the bioluminescent emitter (22,000 cm(-1)). Their absorption spectra do not overlap with the bioluminescence spectrum; the trivial light absorption and the intermolecular resonance S-S energy transfer were excluded. Bacterial bioluminescent spectra of the coupled enzyme system NADH:FMN-oxidoreductase-luciferase in the presence of MSB were presented as an example. The weak sensitized fluorescence of MSB was registered. The results obtained have confirmed the activity of the energetic precursor in the bacterial bioluminescence. Its energy can be located in the interval of 26,000-27,000 cm(-1).

Bioluminescence assays: effects of quinones and phenols.

The influence of a series of quinones and phenols on bacteria bioluminescence systems was investigated. Three bioluminescence systems used in ecological monitoring were compared: (1) water-soluble; (2) immobilized in starch gel coupled enzyme systems: NADH:FMN-oxidoreductase-luciferase; (3) luminescent bacteria. Bioluminescence inhibition constants of quinones and phenols and bioluminescence induction periods were compared. These kinetic parameters are proportional to quinone concentrations and depend on the quinone redox potential. Different effects of the substances are related to structure and properties of the bioluminescence systems. The set of bioluminescence assays for quinones and phenols monitoring should include two bioluminescence systems: 1 (or 2) and 3.

The use of bioluminescent biotests for study of natural and laboratory aquatic ecosystems.

A set of bioluminescent tests was developed to monitor water quality in natural and laboratory ecosystems. It consisted of four bioluminescent systems: luminous bacteria, coupled enzyme system NADH:FMN-oxidoreductase-luciferase and triplet enzyme systems with alcohol dehydrogenase and trypsin. The set of biotests was applied for a small forest pond (Siberia, Russia), laboratory microecosystems polluted with benzoquinone and a batch culture of blue-green algae. Thereby effects of natural water compared to those of models of heavy pollution and "bloom" of blue-greens on the bioluminescent tests were revealed. The set of biotests was not affected by a natural seasonal variability of water quality in the unpolluted pond, but responded to the heavy pollution and the "bloom" of blue-greens. The set of biotests could be recommended as the alarm test to control the acute toxicity of natural water bodies.

Bioluminescent water quality monitoring of salt lake Shira.

The coupled bioluminescent enzyme system luciferase-NADH:FMN-oxidoreductase was used as a biotest in ecological monitoring of the health resort salt lake Shira (South Siberia, Russia). The technique was adapted to saltwater conditions. Bioluminescence kinetic parameters sensitive to pollutants were determined. Conditions for the use of bacterial bioluminescence biotests in salty environmental media were established.