[Efficiency of Escherichia coli and Bacillus subtilis Expression Systems for Production of Binase Mutants].

Bacillus pumilus ribonuclease (binase) exhibits cytotoxic and oncolytic properties, while causing genotoxic effects at high concentrations. Mutants that have reduced catalytic activity and preserve the antitumor properties of the native enzyme could exert lower toxic side effects. Mutant binase forms with the Lys26Ala and His101Glu single substitutions were obtained by site-directed mutagenesis.

[Ribonucleolytic activity of mycoplasmas].

Mycoplasmas are incapable of de novo synthesis of nucleotides and must therefore secrete nucleases in order to replenish the pool of nucleic acid precursors. The nucleolytic activity of mycoplasmas is an important factor in their pathogenicity. Bacterial ribonucleases (RNases) may produce a broad spectrum of biological effects, including antiviral and antitumor activity.

[ResD-ResE two-component system positively regulates gene expression of bacilli guanyl-specific ribonucleases].

The role of the ResD-ResE two-component signal transduction system in regulation of the bacilli guanyl-specific ribonucleases genes expression was studied. The proteins with the homology to the Bacillus subtilis ResD and ResE regulatory proteins were found in all sequenced genomes of the Bacillus. Using the B.

[The effect of Spo0A and AbrB proteins on expression of the genes of guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis recombinant strains].

Guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus are actively secreted under phosphate starvation by recombinant strains of Bacillus subtilis with native regulatory systems and by strains defective in some proteins of the Spo0A phosphorylation pathway. The level of expression of ribonuclease genes has been shown to increase approximately sixfold in recombinant strains with mutation in the spo0A gene and threefold in the spo0A/abrB mutants, as compared with native strains. These results demonstrate that the Spo0A protein regulates the production of ribonucleases and thus acts as a repressor, while the AbrB protein is an activator of expression of the genes encoding ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis cells.

[The role of the promoter structure in the efficiency of the expression of guanylspecific ribonucleases from Bacillus intermedius and Bacillus pumilus].

Guanylspecific ribonucleases from B. intermedius (binase) and B.pumilus (RNase Bpu) are structural and functional homologues, and their biosynthesis is subjected to the same laws.

[The role of the promoter and leader sequences of extracellular ribonuclease from Bacillus amyloliquefaciens in regulation of enzyme biosynthesis].

It is shown that in the medium rich with inorganic phosphate there is a stimulation of biosynthesis of ribonuclease from B. amyloliquefaciens (barnase) by actinomycin D, while biosynthesis of ribonucleases from B. intermedius (binase) and B.

[Regulation of extracellular phosphohydrolase biosynthesis in bacilli].

Under phosphate-deficient conditions, B. intermedius, B. pumilus, and B.

[Expression of genes for guanyl-specific ribonucleases in Bacillus intermedius and Bacillus pumilus is regulated by the PhoP-PhoR two-component signal transduction system of PHO regulon of Bacillus subtilis].

Promoters of the genes of guanyl-specific ribonucleases of Bacillus intermedius (binase) and Bacillus pumilus (RNase Bp) were found to contain sequences homologous to those recognizable by the regulatory protein PhoP in the promoters of the PHO regulon of B. subtilis, as well as regions partially homologous to the binding sites of another regulatory protein, PhoB, in the promoters of the PHO regulon of Escherichia coli. The role of the two-component regulatory systems PhoP-PhoR and PhoB-PhoR in the regulation of expression of the genes of binase and RNase Bp in recombinant strains of B.

Expression of the genes for guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus is regulated by the two component signal transduction system PhoP-PhoR in B. subtilis.

Promoters of the genes for guanyl-specific ribonucleases, secreted by B. intermedius (binase) and B. pumilus (Rnase Bp) in phosphate deficient conditions, contain regions similar to appropriate consensus sequences in promoters of the PHO regulated genes of B.

[Expression of secreted guanyl-specific ribonuclease genes from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis cells].

Plasmids with whole genes for ribonucleases from B. intermedius (binase) and B. pumilis (RNase Bp) assembled with the whole gene of barstar, a specific intracellular inhibitor, are constructed.

[Biosynthesis of extracellular guanyl-specific ribonuclease from Bacillus circulans].

Biosynthesis of extracellular alkaline guanyl-specific RNase by Bacillus circulans (RNase Bci) was studied. Synthesis of the enzyme by the culture started in the late exponential phase and was inhibited by inorganic phosphate and glucose, in contrast to the biosynthesis of its structural and functional homologue, RNase Ba (barnase) of B. amyloliquefaciens.

Effects of medium viscosity on kinetics of the enzymatic reaction catalyzed by bacterial RNase.

Effects of medium viscosity on kinetic parameters of poly(U) hydrolysis catalyzed by RNase from Bac. intermedius 7P (binase) were studied in solutions of sucrose (4-50 wt. %) and glycerol (35-62 wt.

[Antibiotic-resistant mutants of Bacillus intermedius--producers of a number of enzymes].

New antibiotic-resistant strains Bacillus intermedius--producers of phosphohydrolase and protease have been obtained and characterized. Strain S 19 is the more active producer of extracellular enzymes. Autotrophic mutants obtained on its basis possess reduced activity of phosphohydrolase.

[The isolation of highly purified bacillary ribonucleases from recombinant strains of Escherichia coli].

Active and inactive highly purified extracellular alkaline ribonucleases (barnase) from recombinant Escherichia coli have been prepared according to the industrial technology of Bacillus intermedius ribonuclease purification. Electrophoretic parameters and ultraviolet spectra characterize these preparations as homogeneous proteins. Immunochemical test system of identification of inactive RNAse for its purification has been worked out.

[The cloning and expression of the RNAse structural gene of Bacillus intermedius].

The structure gene of extracellular alkaline ribonuclease Bacillus intermedius (binase) has been cloned in E. coli cells in composition of pMT 316 plasmid carrying the inhibitor gene (barstar of barnase--binase structure homologue. The possibility to use such vector has been proved during the barstar action on binase catalytic activity.

[Immunological reactivity to the products of normal microflora. IV. Antibodies to common species-specific pneumococcal antigens in the human spectrum of antibacterial antibodies].

Normal human serum antibodies to the protein complex more than 20 common (species-specific) STr. Pneumoniae antigens have been studied. In commercial lots of gamma globulin, manufactured during the last 8 years, antibodies to 9 pneumococcal antigens have been detected.

[Immunological reactivity to the products of normal microflora. III. Characteristics of antibodies to the common antigens of enterobacteria, enterococci and bifidobacteria].

The content and type of antibodies to the common antigens of enterobacteria, enterococci and bifidobacteria were studied in serum specimens obtained from 220 donors. Antibody titers to enterobacteria were almost twice as high as those to enterococci and 8 times higher than those in bifidobacteria. The final titer of the reaction with enterobacterial antigens in 90% of the donors was determined by IgG (7S); in respect of enterococci and bifidobacteria IgM played the leading role in 56% and 74% of the cases, respectively.

[Enterobacterial taxonomy: Erwinia carotovora and Yersinia enterocolitica].

The immunotyping of the intracellular protein complex in enterobacteria has allowed to reveal that the intracellular proteins of E. carotovora and Y. enterocolitica possess an antigenic profile characteristics of bacteria belonging to the family Enterobacteriaceae.

[Characteristics of the soluble antigens of bifidobacteria].

The immunological study of aqueous buffer extracts obtained from 45 strains of bifidobacteria belonging to the species B. bifidum, B. longum, B.

[Experience in studying protein A in staphylococcal cultures].

Methods of quantitative and qualitative determination of protein A in staphylococcus cultures were studied comparatively. The maximal number of strains positive by protein A were revealed by means of indirect hemagglutination test with cell extracts. Quantitative and qualitative characteristics by protein A can be used in studying the problems of strain and clone heterogeneity of S.