α-tubulin tail modifications regulate microtubule stability through selective effector recruitment,not changes in intrinsic polymer dynamics

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Ammonia release and binding processes and the activity of acid proteinase and glycolysis enzymes in the dynamics of experimental toxic adrenal encephalopathy

The content of ammonium, glutamine, glutamate, aspartate and GABA, glutamine synthetase activity, acid proteinase, hexonase, phosphohexoisomerase and dehydrogenase glucose-6-phosphate were studied in dog brain homogenates after individual injections of Bacillus coli endotoxin (10 micrograms/kg) and adrenaline (75 micrograms/kg) into veins and their combined injections into the carotid artery. Isolated injections of endotoxin and adrenaline were shown to cause transient metabolic compensatory changes. Combined injections caused stable progressing brain metabolic disorders. It is suggested that neurochemical changes influence endogenous development of toxic adrenal encephalopathy.     

Detection of nonsense and frameshift mutations in <Emphasis Type="Italic">BRCA1</Emphasis> gene using a new plasmid vector pPhoA-frame

The technique for detecting frameshift and nonsense mutations in the human BRCA1 gene has been suggested. The technique presumes the construction of recombinant plasmids where the tested DNA fragment is placed in frame with alkaline phosphatase gene of Escherichia coli (phoA). A special plasmid pPhoA-frame was constructed for this analysis, and the plasmid contained the DNA fragment that encodes alkaline phosphatase of E. coli. The synthetic DNA fragment with BglII, StuI, ApaI and SacII sites was inserted into the DNA fragment that encodes alkaline phosphatase of E. coli between Ala218 and Gly219 codons to facilitate the cloning of BRCA1 gene fragments. The occurrence of the frameshift or nonsense mutation in the tested DNA fragment can be detected after the transformation of E. coli by the recombinant plasmid that contains the tested fragment. E. coli colonies with newly constructed recombinant plasmids are plated out on the indicator agar. In the case of the frameshift or nonsense mutation, the colonies are not colored, and DNA fragments without these mutations result in the formation of blue colonies.     

Study on physicochemical properties of biocatalysts with thermostable lipase activity and final products of triglycerides’ interesterification

The physicochemical properties of multicomponent biocatalysts for triglycerides’ interesterification have been studied. They were prepared by entrapment of partially or completely destructed cells of a recombinant rE.coli/lip strain—the producer of a thermostable lipase from Thermomyces lanuginosus—inside silica xerogel. The functional role and optimum contents of components included such as whole cells or cells’ lysates, water, water-retaining agents, and nanostructured carbon forms (nanotubes, nanospheres) were investigated. The optimum composition of biocatalysts prepared on the basis of rE.coli/lip cells’ lysates, which possess enzymatic activity in water-free media, was selected. The half-inactivation time of the prepared biocatalysts in the process of interesterification of oil-fat blends in a flow packed-bed reactor was ～70 h at 70–75°C.     

The dynamics of the microorganism count of active sludge during the aerobic treatment of sewage

Dynamics of the active sludge microorganism quantity is studied under different cultivation regimes. It is shown that quantity of microorganisms in different physiological groups depends on the specific growth rate, micro, determined by the dilution rate and biomass recirculation level. The results may be used for selecting optimal regime of the sewage treatment system functioning.     

Exopolysaccharide Production and Peculiarities of C6-Metabolism in Acinetobacter sp. Grown on Carbohydrate Substrates

An Acinetobacter sp. strain grown on carbohydrate substrates (mono- and disaccharides, molasses, starch) was shown to synthesize exopolysaccharides (EPS). Glucose catabolism proved to proceed via the Embden–Meyerhof–Parnas and Entner–Doudoroff pathways. Pyruvate entered the tricarboxylic acid cycle due to pyruvate dehydrogenase activity. Pyruvate carboxylation by pyruvate carboxylase was the anaplerotic reaction providing for the synthesis of intermediates for the constructive metabolism of Acinetobacter sp. grown on C₆-substrates. The C₆-metabolism in Acinetobacter sp. was limited by coenzyme A. Irrespective of the carbohydrate growth substrate (glucose, ethanol), the activities of the key enzymes of both C₂- and C₆-metabolism was high, except for the isocitrate lyase activity in glucose-grown bacteria. Isocitrate lyase activity was induced by C₂-compounds (ethanol or acetate). After their addition to glucose-containing medium, both substrates were utilized simultaneously, and an increase was observed in the EPS synthesis, as well as in the EPS yield relative to biomass. The mechanisms responsible for enhancing the EPS synthesis in Acinetobacter sp. grown on a mixture of C₂- and C₆-substrates are discussed.