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K A Kaluniants

Publications and source records attributed to K A Kaluniants.

8 recordsLinked to original sources
PubMed1980

[Isolation and characterization of the lytic enzyme from Bacillus subtilis 797].

The isolation procedure and some properties of the lytic enzyme produced by Bacillus subtilis 797 and capable of hydrolyzing the E. coli K-12 cells are described. Using hydrophobic chromatography on DNP-hexamethylene diamine Sepharose 4B and ion-exchange chromatography on DEAE-cellulose, a highly purified enzyme preparation with mol. weight of 28000, pI 8.2 has been obtained. The amino acid composition of the enzyme has been determined: Asp--37, Thr--17, Ser--34, Glu--15, Pro--14, Gly--17, Ala--36, Val--28, Met--4, Ile--11, Leu--17, Tyr--9, Phe--4, Lys--18, His--5, Arg--4. The enzyme is inhibited by a specific inhibitor of serine proteinases--benzylsulfonylfluoride, and is insensitive to EDTA and iodoacetic acid. The lytic enzyme has a proteolytic activity and splits the peptide substrate of bacterial serine proteinases--p-nitroanilide benzyloxycarbonyl-L-analyl-L-alanyl-L-leucine; the maxima for both activities lie within the pH range of 7.8-8.5. The lytic protease has the highest stability at pH 6-10. In some of its properties the enzyme is similar to serine proteinase from Bac. subtilis, i. e. subtilisins.

Amino Acids↗
PubMedDate not supplied

[Regularities in the synthesis of neutral protease from Bacillus subtilis].

Experiments were carried out to study the formation of extracellular protease by the suspension from Bacillus subtilis str. 103 washed cells selected at the growth stages characterized by the highest rate of the enzyme synthesis (after 12 and 35 hours). In relation to the protein and RNA synthesis as measured by 14C-valine and 14C-uracyl the cells of that age showed a high metabolic activity. The enzyme synthesis by the cells of the log-phase was inhibited completely with chloramphenicol and by the cells of the stationary phase--almost completely. The experiments demonstrated the protease synthesis insensitive to riphampycin for a long time. This may be indicative of a certain pool of long-lived mRNA responsible for the biosynthesis.

Bacillus subtilis↗
PubMedDate not supplied

[Enzyme complex celloconingine P10x].

The composition and properties of the enzyme preparation celloconingine P10x were studied. The preparation contained a number of citolytic enzymes and showed proteolytic and amylolytic activities. Optimal conditions for the enzyme action were found to be: for total citolytic and hemicellulase activities pH 5.2-6.2 and 45-55 degrees, for endo-beta-glucanase activity pH 4.2-5.2 and 58-62 degrees, for proteolytic activity pH 4.0-4.8 and 64-68 degrees, and for amylolytic activity pH 3.6-4.2 and 60-66 degrees C.

Glycoside Hydrolases↗
PubMedDate not supplied

[Composition of the regulators of bacterial autolysis].

This work was aimed at studying the composition of agents regulating bacterial autolysis and isolated from the lysate of Bacillus subtilis 402, B. subtilis R2 and Micrococcus lysodeikticus biomass by extraction with 5% TCA followed by precipitation from the extract with 5 volumes of isopropanol. Fractions activating bacterial autolysis and fractions inhibiting it were found in all of the preparations after separation on Acrylex P-60. Fractions with a molecular mass below 12,600 D activated the autolysis whereas fractions with a molecular mass above 18,400 D inhibited it. The activity of fractions inhibiting the autolysis decreased while that of fractions activating the autolysis increased in the regulating agents isolated from B. subtilis cultures with the aging of the latter. The capability of the fractions to activate the autolysis correlated with the content of amino groups and phosphate in them whereas the capacity to inhibit the autolysis correlated with the content of reducing sugars in the fractions. The preparation of the fraction which activated the autolysis from B. subtilis R2 contained 18 amino acids with the predominance of alanine, glutamic acid, lysine and phenylalanine. Apparently, the regulating properties of the preparations are created with the aid of teichoic acids as well as peptidoglycan and protein fragments associated with the acids.

Bacillus subtilis↗
PubMedDate not supplied

[Effect of sources of carbon, nitrogen, and phosphorus on the synthesis of proteases from Bacillus subtilis cultures].

The paper gives data on the influence of different sources of carbon, nitrogen and phosphorus on the accumulation of biomass and synthesis of neutral protease by Bacillus subtilis str. 103. The highest proteolytic activity was obtained on the medium containing maltose or hydrolyzed starch as a carbon source, monopotassium phosphate as a phosphorus source, and ammonium sulphate as a nitrogen source. The enzyme activity increased upon an addition of albumin, peptone or casein. A study of the amino acid effect showed that methionine, isoleucine and valine stimulated the protease synthesis to the greatest extent.

Amino Acids↗