Precursors and propeptides of neurotrophic factors as modulators of the biological activity of mature forms

Problems of the maturation of neurotrophic factors, the role of their precursors (proneurotrophins), and the contribution of elements that are removed in the course of maturation (propeptides) to the biological functions of these growth factors, are reviewed.     

Role of noradrenaline of the dorsal hippocampus in the mechanism of self-stimulation reaction in rats

In has been established that intrahippocampal bilateral injection of NA did not influence common frequency of lateral hypothalamic self stimulation. After the destruction of hippocampal NA - terminals of 6-OHDA increased the frequency of self stimulation and rearing. It is suggested that NA hippocampus inhibit the recall trace of the memory of sensory reinforcement stimuli in the course of stimulation "reward".     

Gadolinium complexes of linear and liquid-crystalline DNA

Binding of Gd³⁺ ions to linear dsDNA in water-salt solution and cholesteric liquid-crystalline dispersion (CLCD) drastically changes the optical and X-ray scattering characteristics of the samples. Depending on the complexing conditions, Gd³⁺ can bind to nucleobases and to phosphates, which differentially affects the properties of CLCD formed of such complexes. DNA packing in such dispersions changes with increasing Gd³⁺ occupancy, which is reflected in the decline of the Bragg reflection maximum in SAXS. The unique properties of this material open the way to its practical use.     

Observations of terrestrial locomotion in wild Polypterus senegalus from Lake Albert,Uganda

Polypterids, the most basal actinopterygians, are a group of fish long-considered living fossils and holding a key position for understanding fish and tetrapod evolution. Knowledge of the natural history of Polypterus is limited, their having been studied in little detail since the early 1900s. The locomotory habits of wild Polypterus senegalus from Lake Albert, Uganda, were investigated in 2014. High-speed videography demonstrated the capability of large Polypterus to move overland successfully. Contrary to previous evidence, field observations found that terrestrial locomotion in Polypterus is not inherently restricted by body size. Evidence that Polypterus exhibit this behaviour as part of their natural life history can be found in the existence of environmental challenges and the presence of adaptations for amphibious life.     

Oligomeric organization of recombinant human neurotrophins expressed in <Emphasis Type="Italic">Escherichia coli</Emphasis> cells

Genes of human neurotrophins NGF, BDNF, NT-3 were cloned, and the corresponding proteins and their fragments were expressed in Escherichia coli BL-21 (DE3λ) cells. Their intracellular localization was determined. The conditions for isolation and purification of the target recombinant proteins and for folding of BDNF and NT-3 precursors were selected. The recombinant proprecursors of human neurotrophines have been shown to possess complex oligomeric structure.     

Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli

The genes for the large and small subunits of anthranilate synthase (trpE and trpG, respectively) have been cloned from Pseudomonas aeruginosa PAC174 into E. coli by R-prime formation with the broad-host- range plasmid R68.44. Sequential subcloning into plasmid vectors reduced the active Pseudomonas DNA fragment to a length of 3.1 kb. We obtained evidence that this region contains the promoter for its own expression and retains a vestigial regulatory response to tryptophan scarcity or excess.      

Cloning, sequencing, expression, and characterization of protealysin, a novel neutral proteinase from Serratia proteamaculans representing a new group of thermolysin-like proteases with short N-terminal region of precursor

The gene of Serratia proteamaculans proteinase, protealysin, was cloned, sequenced, and expressed in Escherichia coli. The gene encoded a precursor of 341 amino acids (AAs) with a significant homology to thermolysin-like proteinases (TLPs). The molecular weight of the purified mature active recombinant protein was 32 kDa, the N-terminal amino acid sequence was AKTSTGGEVI. The optimum pH for azocasein hydrolysis by protealysin was seven and it was completely inhibited by o-phenanthroline. The enzyme hydrolyzed 3-(2-furyl)acryloyl-glycyl-L-leucine amide, the standard substrate for TLPs, with k(cat)/K(m) ratio of (2.52 +/- 0.02) x 10(2) M(-1) s(-1). Protealysin maturation removes 50 AA from the N-terminus of the precursor. The removed region had no similarity with the preprosequence of thermolysin (232 AA) but was homologous to some other TLPs. These proteins shared a conserved 7-AA motif near the initial methionine. Such motif was also found in some nonproteolytic putative proteins; two of them were eukaryotic.