[Induction-resonance energy transfer between the terbium-binding peptide and the red fluorescent proteins Dsred2 and TagRFP].

Two novel FRET-pairs: Tb3+ -binding peptide-DsRed2 and Tb3+ -binding peptide-TagRFP have been produced based on the terbium-binding peptide and the red fluorescent proteins DsRed2 and TagRFP. Two induction-resonance energy transfer processes in both FRET-pairs have been registered, from tryptophan of the terbium-binding peptide to Tb3+ and from sensitized Tb3+ to the acceptor, the chromophore, DsRed2 or TagRFP. The lifetimes of terbium in the presence and absence of the acceptor have been determined. It has been shown that the lifetime of Tb3+ in the presence of 150 mM NaCl decreases in both FRET-pairs. The efficiency of fluorescent resonance transfer from Tb3+ to the acceptor proteins is 28 and 35% for Tb3+ -binding peptide-DsRed2 and Tb3+ -binding peptide-TagRFP, respectively.

[Genetically encoded FRET-pair on the basis of terbium-binding peptide and red fluorescent protein].

The genetically encoded FRET-pair was developed on the basis of terbium-binding peptide and red fluorescent protein DsRed2. To study fluorescence resonance energy transfer within FRET-pair, the gene-engineered construction was obtained, where sequences of terbium-binding peptide and red fluorescent protein DsRed2 were fused in single reading frame. The expression of this construction in strain E. coli BL21 (DE3) was studied and conditions of synthesis, isolation and purification of recombinant protein were optimized. The hydrodynamic radius of hybrid protein was determined by the method of dynamic light scattering. Energy transfer between sensitized terbium and red fluorescent protein was confirmed by the methods of phosporescent spectroscopy. The obtained FRET-pair can be used both for studies in vitro and as a reporter in living cells.

[Signaling function of phagocytic NADPH oxidase: activation of MAP kinase cascades in phagocytosis].

Until recently, the production of reactive oxygen species by NADPH oxidase has been considered only in the context of the oxidative damage to pathogens inside the phagosome. However, homologues of phagocytic NADPH oxidase have been found in almost all cell types, where they produce hydrogen peroxide and thereby regulate the initial intracellular stages of MAP kinase cascades. In the present work, the activation of two MAP kinase cascades, p38 and Erk1/2, during phagocytosis has been studied. It was found that phagocytosis activates both cascades. The activation of Erkl/2 is dependent, and the activation of p38 is not dependent, on the activity of NADPH oxidase. Thus, it can be stated that the activation of MAP kinases in phagocytes during phagocytosis occurs by a mechanism similar to that operating in nonphagocytizing cells, indicating the universality of the function of NADPH oxidases in different cell types.

[Catechol siderophore, produced by thermoresistent strain of Bacillus licheniformis VK21]. / Katekhol'nyi siderofor, produtsiruemyi termorezistentnym shtammom Bacillus licheniformis VK21.

Thermophilic and thermoresistant strains of bacilli were screened on a medium containing Chrome Azurol S for producers of siderophores. It was found that the Bacillus licheniformis VK21 strain dramatically increases secretion of the metabolite, a chelator of Fe3+, in response to addition of manganese(II) salts. The growth of the producer on a minimum medium containing MnSO4 under the conditions of iron deficiency is accompanied by the accumulation of a catechol product, the content of which reaches a maximum at the beginning of the stationary growth phase of culture. In the presence of FeCl3, the amount of the catechol product in the medium considerably decreases. The siderophore, called SVK21, was isolated from the cultural medium and purified by reversed phase HPLC, and its siderophore function was confirmed by the test for the restoration of growth of producer cells in a medium containing EDTA. The UV spectrum of the siderophore has absorption maxima at 248 and 315 nm. According to amino acid analysis and NMR spectrometry, the metabolite SVK21 is 2,3-dihydroxybenzoyl-glycyl-threonine. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2003, vol. 29, no. 6; see also http://www.maik.ru.

[The dependence of stability of the green fluorescent protein-obelin hybrids on the nature of their constituent modules and the structure of the amino acid linker]. / Zavisimost' stabil'nosti gibridov zelenogo fluorestsentnogo belka s obelinom ot prirody sostavliaiushchikh ikh modulei i struktury aminokislotnogo linkera.

Recombinant plasmids containing genes for the green fluorescent protein (GFP) from Aequorea victoria and the photoprotein obelin from Obelia longissima linked in-frame by inserts differing in nucleotide sequences were constructed. The expression of the chimeric genes in Escherichia coli cells resulted in synthesis of the GFP-obelin hybrid proteins. These proteins were purified to homogeneity and subjected to limited trypsinolysis. It was shown that the resistance of GFP-obelin hybrid proteins to trypsin depends on the nature of their constituent modules and the amino acid sequences of linkers between the modules. The kinetics of accumulation of full-length hybrid proteins during the growth of bacterial cells does not depend on the structure of the peptide linkers. Most of the full-length product accumulates in cells in the form of inclusion bodies resistant to endogenous proteases. The soluble fraction of the protein undergoes considerable proteolysis regardless of the linker structure.

Green fluorescent protein purification by organic extraction.

Green fluorescent protein (GFP) is widely used as an excellent reporter molecule in biochemistry and cell biology. Some biochemical and immunological assays require high-purity GFP. However, the majority of current procedures for GFP purification include multiple time-consuming chromatography steps with a low yield of the desired product or require tag-containing proteins. An alternative method is described for the GFP purification without affinity extensions using organic extraction yielding a highly homogeneous protein indistinguishable in spectroscopic properties from that purified by previous methods.

Effect of the ATP level on the overall protein biosynthesis rate in a wheat germ cell-free system.

A sensitive assay which examines the effects of ATP level on the overall activity of a cell-free translation system in a protein synthesis is described. The translational activity of cell-free system was measured in terms of a rate of protein synthesis directed by the 'test' template. The test template encodes a photoluminescent protein, obelin accumulation was determined from the kinetic curves of obelin. The rate of obelin mRNA translation. Time-dependent nucleotide level measurements were conducted throughout the translation processes. It has been shown that the rate of translation decreases exponentially with the decrease of the ATP level. This fall in the overall translation rate is due in part to the mRNA becoming inactive in the translation process. This is not caused by degradation, this mRNA can be restored for translation in a fresh cell-free system by phenol treatment. The reported results provide evidence that the level of ATP unambiguously determines the translational activity of the system.

[Primary structure of the elongation factor G from Escherichia coli. VI. Structure of peptides of cyanogen bromide cleavage of the G-factor molecule]. / Pervichnaia struktura faktora élongatsii G iz Escherichia coli. VI. Struktura peptidov bromtsianovogo rasshchepleniia molekuly G-faktora.

Peptides obtained as a result of cyanogen bromide cleavage of the G-factor have been studied. All 12 peptides embracing the whole structure of fragment T4 have been isolated. For their amino acid sequence determination, cyanogen bromide peptides have been further cleaved with trypsin, chymotrypsin, thermolysin, staphylococcal glutamic protease and BNPS-skatole. The complete primary structure of 9 from 12 cyanogen bromide peptides has been determined.

[Primary structure of the elongation factor G from Escherichia coli. V. Amino acid sequence of the C-terminal domain]. / Pervichnaia struktura faktora élongatsii G iz Escherichia coli. V. Aminokislotnaia posledovatel'nost' C-kontsevogo domena.

The amino acid sequence of the C-terminal domain of the elongation factor G (EF-G) has been studied. The polypeptide chain of the domain consists of 228 amino acid residues, and contains no tryptophan or cysteine residues. To determine its structure, the peptides obtained as a result of the fragment digestion by staphylococcal glutamic protease, cyanogen bromide cleavage, and tryptic hydrolysis of the fragment modified by maleic anhydride have been analyzed, as well as peptides obtained after hydrolyses of cyanogen bromide fragments with chymotrypsin, thermolysin and trypsin.

[Primary structure of the elongation factor G from Escherichia coli. VII. Study of peptides generated during hydrolysis of the T4 fragment by glutamic proteinase from Staphylococcus aureus]. / Pervichnaia struktura faktora élongatsii G iz Escherichia coli. VII. Issledovanie peptidov, poluchennykh pri gidrolize fragmenta T4 glutaminovoi proteinazoi Staphylococcus aureus.

For fragment T4, obtained on limited trypsinolysis of the G-factor, the amino acid sequence embracing 76% of its structure has been determined by analysis of peptides resulting from the fragment T4 cleavage with staphylococcal glutamic protease. These data permitted to assemble into one polypeptide chain 7 out of 12 earlier characterized cyanogen bromide peptides contained in the fragment T4.

[Primary structure of the elongation factor G from Escherichia coli. VIII. Structure of tryptic peptides comprising the T4 fragment of limited trypsinolysis of the G-factor]. / Pervichnaia struktura faktora élongatsii G iz Escherichia coli. VIII. Issledovanie struktury peptidov tripticheskogo gidroliza, vkhodiashchikh v sostav fragmenta T4 ogranichennogo tripsinolizata G-faktora.

Products of tryptic hydrolysis of the maleic anhydride modified fragment Th3 from limited thermolytic hydrolysis of the G-factor have been studied. Some short peptides which result from the trypsin action on the native G-factor molecule and belong to the fragment T4 obtained on limited trypsinolysis of the G-factor have been separated and their structure has been studied. As a result amino acid sequence has been determined by tryptic peptides containing 322 amino acid residues of the fragment T4 which makes up about 94% of its polypeptide chain.

[Primary structure of the elongation factor G from Escherichia coli. IX. Structure of peptides generated by cyanogen bromide cleavage of the G-factor isolated on thiol-activated sepharose and of the products of the G-factor cleavage at Asp-Pro bonds. Complete primary structure]. / Pervichnaia struktura faktora élongatsii G iz Escherichia coli. IX. Issledovanie struktury peptidov bromtsianovogo rasshchepleniia G faktora, vydelennykh na tiol-aktivirovannoi sefaroze, i produktov rasshepleniia G-faktora po sviaziam Asp-Pro. Polnaia pervichnaia struktura.

The amino acid sequence of cysteine- and cystine-containing peptides resulting from cleavage of the G-factor by cyanogen bromide has been determined. For structure analysis cyanogen bromide peptides were further degradated using trypsin, chymotrypsin, thermolysin, staphylococcal glutamic protease, or limited acid hydrolysis. The products of the G-factor cleavage at Asp-Pro bonds were also studied. The obtained data together with those published earlier permitted to establish the complete primary structure of the elongation factor G. The polypeptide chain consists of 701 amino acid residues and has molecular mass of 77321,46.

[Primary structure of calmodulin from the human brain]. / Pervichnaia struktura kal'modulina iz mozga cheloveka.

The primary structure of calmodulin from human brain has been determined. As compared to calmodulin from bovine brain, it shows three substitutions of the amide----acid type at positions 24, 60, 129, and two acid----amide changes at positions 104 and 135.