[The mechanism of formation of emitter by fluorescence of calcium-discharged obelin].

It is known that bioluminescence of obelin is triggered by Ca2+ the binding of which to the protein induces the decarboxylation of 2-hydroperoxycoelenterazine. The molecular mechanism of fluorescence of obelin, which determines the fluorescence of see hydroid Obelia Longissima, has been investigated with the use of quantum chemical calculations. According to quantum chemical calculations, the emitter of the reaction is the ion-pair state of phenolate-anion of coelenteramide. It has been shown that the fluorescence spectrum of this state depends on the position of the proton between the oxygen atoms of the phenol group of coelenteramide and the nitrogen atom of His22. The agreement of the calculated absorption and fluorescence spectra with the experimental spectrum shows the accuracy of the quantum chemical calculations and conclusions.

[Affine magnetic sorbents supported on coal ash microspheres for recombinant protein isolation].

The results of the development and utilization of an affine magnetic sorbent with Ni2+ ions immobilized on coal ash microspheres are reported. The applicability of the material in the isolation of Histag proteins is demonstrated by examples of the recombinant green fluorescent protein from Clytia gregarium and the Ca2+ regulated photoprotein obelin from Obelia longissima. The specific sorption capacity of the sorbent was 2-7 mg/cm3 for medium-size proteins (20-30 kDa). The particles are suitable for chromatography with the presence of chaotropic agents and EDTA. They are easy to manipulate as isolation of a target protein takes 30-35 min. On one hand, the elevated affinity of the sorbent to proteins rich in native histidines may result in a high degree of irreversible sorption; on the other hand, it allows isolation of such proteins without the introduction of artificial polyhistidine tracts.

[Volatile metabolites and external CO2 exchange of wheat cenoses under optimal conditions and thermal stress]. / Letuchie metabolity i vneshnii gazoobmen CO2 tsenozov pshenitsy pri optimal'nykh usloviiakh i temperaturnom stresse.

The effects of elevated temperature (35 and 45 degrees C) on photosynthesis, respiration, and both the qualitative and quantitative compositions of volatile emissions (VE) of wheat (Triticum aestuvum L. cultivar 232) cenoses at light intensities of 70, 150, or 240 W/m2 of photosynthetically available radiation (PAR) were studied. At a PAR of 240 W/m2, the thermal stabilities of photosynthesis and respiration increased at 35 degrees C and decreased at 45 degrees C. Elevated temperatures nonuniformly changed the rates and direction of VE syntheses. In this process, the highest increase in VE evolution was observed at 70 W/m2; the lowest, at 240 W/m2 and 35 degrees C. In addition, the concentrations and composition of VE during the repair period differed from the initial values.

[Perspectives of the use of bioluminescence methods in medicine]. / Perspektivy primeneniia bioliuminestsentnykh metodov v meditsine.

Major advances in the development and application of the bioluminescent analysis to detect certain biologically active substances are discussed. The main merit of the method lies in its high sensitivity and specificity along with its simplicity and rapid performance. The available methodologies allow for detection of substances of varying nature: Ca2+, ATP, FMN, NAD(P), long-chain aldehydes, ATP- and NAD(P)-dependent enzymes and their substrates, many xenobiotics and antibiotics, and mutagens. The bioluminescence methodologies may be widely applied in clinical laboratory diagnosis.

[Nucleotide sequence of genes for alpha- and beta-subunits of luciferase from Photobacterium leiognathi]. / Nukleotidnaia posledovatel'nost' genov alpha- i beta-sub''edinits liutsiferazy Photobacterium leiognathi.

Nucleotide sequence of the Photobacterium leiognathi DNA containing genes of alpha and beta subunits of luciferase has been determined. We also deduced amino acid sequence and molecular mass of luciferase and localized luciferase genes in the sequenced DNA fragment.

[Bioluminescent method of determining antiprotease activity]. / Bioliuminestsentnyi sposob opredeleniia aktivnosti antiproteaz.

A method for antiprotease activity measurement based on the use of luminous bacteria luciferase as protein substrate of proteases is suggested. Antiprotease is incubated with protease for 1 to 2 min at 30 degrees C and then it is added to the reaction mixture containing luciferase, NADH: FMN-oxidoreductase and their substrates--myristic aldehyde, FMN and NADH. Biofluorescence is measured in a temperature-controlled cuvette for 1 min. The total time of the measurement is 3 min. The method can be applied both in fine biochemical assays and in medical rapid diagnosis.

[Measurement of the intensity of erythropoiesis based on the RNA content of erythrocytes]. / Izmerenie intensivnosti éritropoéza po soderzhaniiu RNK v éritrotsitakh.

The relationship between RNA content in erythrocytes and the erythropoiesis rate was studied at varying exposures as a result of which a simple method for erythropoietic activity testing was proposed. It consists in the measurement of ribonucleic acid content in erythrocytes of mice with a decreased erythropoiesis after administration of the test sample. Erythropoietic activity is determined from the magnitude found. The method suggested is marked by simplicity and higher sensitivity and thus may be applied in clinical medicine and research.

[Obtaining purified erythropoietin from rabbit plasma]. / Poluchenie ochishchennogo éritropoetina iz plazmy krovi krolika.

A scheme of preparing partly purified erythropoietin from rabbit blood plasma is offered. The factor of purification is about 25000. Erythropoietin was purified by ion exchange chromatography on DE-32 cellulose, affinity chromatography on phytohemagglutinin-P and by gel filtration through Ultragel ACA-44. The specific activity of erythropoietin thus obtained was about 75-100 units per mg protein. The preparation may be used for exploring the regulation and differentiation of red blood cells and as an initial material for obtaining high-purified erythropoietin..

[Characteristics of the proteins of unicellular organisms as potential components of ecological life-support systems]. / Kharakteristika belkov nekotorykh odnokletochnykh organizmov kak potentsial'nykh komponentov ékologicheskikh sistem zhizneobespecheniia.

A comparative characterization of the biological value of proteins from green and blue-green algae, bacteria, and microbial coenosis of straw mineralizing active sludge is given with respect to the fractional composition of total protein, its amino acid composition, and affinity for proteolytic enzymes in vitro. The above microorganisms have an adequate amino acid composition, a high content of essential amino acids, and differ in their content of readily soluble proteins. The presence of protein complexes with other cellular components, for instance lipids and carbohydrates, seems to be responsible for a poor digestibility of these proteins.

[Effect of hypoxemia on the erythropoietic activity of organs during perfusion]. / Vliianie gipoksemii na éritropoéticheskuiu aktivnost' organov pri perfuzii.

Hypoxemia (45-minute) influence in vivo on erythropoietic activity of the kidney, liver, spleen, and sternum was studied by normoxemic perfusion of the isolated organs. The erythropoietic activity proved to increase after 6-hour perfusion of the liver; this confirmed the participation of this organ in the extrarenal secretion of the erythropoietic factor.

[Cell population mechanisms of inhibition of erythropoiesis in polycythemia]. / Populiatsionno-kletochnye mekhanizmy tormozheniia éritropoéza pri politsitemii.

The ciliary activity of Ctenophore bolinopsis is inhibited by decreasing concentration of Mg2+ and increasing concentration of Ca2+ in the medium. The same changes in Mg2+ and Ca2+ concentration trigger muscle contractions and bioluminescence. Co2+ arrests the cilia beating in the rectangular position. An increase in Mg2+ concentration or decrease in Ca2+ concentration switch off the nervous inhibitory mechanisms of ciliary activity, suppress muscle contractions and bioluminescence. Ni2+ produces a similar effect, but the ciliary heating is only slightly accelerated, by the contrast to the effect of increased Mg2+ concentration. A Cl-free medium Mn2+ and tetrodotoxin in commonly used concentrations are of no effect on the systems studied. Experiments involving changes in K+ concentrations and administration of tetraethylammonium suggest that the resting potential in the examined cells may be due to K+ as the most permeant ion, and that K+-channels in the cell membrane may be voltage--controlled. The proposal about "biionic" (Ca2+/Mg2+) bioelectric control of a number of intracellular reactions is discussed.