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I S Kulaev

Publications and source records attributed to I S Kulaev.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

[Fatty acid makeup of Escherichia coli cells with repressed and derepressed phosphohydrolase biosynthesis].

Fatty acid composition of the cells of Escherchia coli wild strains K-10, and K-12 and the mutants of the regulatory genes for alkaline phosphatase was studied in conditions of repression and derepression of biosynthesis of phosphohydrolases. Derepression of phosphohydrolases was not accompanied with specific changes in fatty acid composition of the cells. An increase in the content of cyclopropanic acid in conditions of phosphorus deficiency and a decrease in the level of unsaturated fatty acids are related to deceleration of growth of the cells in these conditions.

Enzyme Repression↗
PubMedDate not supplied

[The effect of bacteriolytic preparation lysoamidase on Staphylococcus aureus 209P cells].

The effect of the bacteriolytic preparation "Lysoamidase" on Staphylococcus aureus 299 P was studied. The maximum activity of the preparation was observed at pH 8.0 ionic strength 0.01-0.02 M and 50-60 degrees of the incubation medium. The electron microscopic examination revealed that "Lysoamidase" hydrolyzed the cell wall in one or several points with the following osmotic shock and extrusion of the cytoplasm. In an isotonic solution (1 M sucrose) "Lysoamidase" caused protoplast formation.

Hydrogen-Ion Concentration↗
PubMedDate not supplied

[Isolation of Staphylococcus aureus protoplasts using lysoamidase].

The effect of the bacteriolytic enzyme preparation, lysoamidase, on Staphylococcus aureus 209P cells was studied. The protoplast formation was examined by spectrophotometric, biochemical and electron microscopic methods. Optimal conditions for isolation of S. aureus protoplasts were chosen. The susceptibility of S. aureus cells to lysoamidase depended on the culture age: the maximum effect was observed in the logarithmic growth phase. The protoplast yield was 80% when 1 M sucrose was used as an osmotic stabilizer. Lysoamidase caused local disruptures of the staphylococcus cell walls, which resulted in the formation of osmotically fragile spheroplasts and the release of protoplasts into the medium. The protoplasts obtained could retain 85-90% of the respiration activity and were able of cell wall regeneration.

Hydrolysis↗
PubMedDate not supplied

[The nature of N-terminal signal sequence determines the type of intracellular distribution and effectiveness of export of human growth hormone in Saccharomyces cerevisiae].

Various N-terminal signal peptides (SP) were tested to investigate a human growth hormone (hGH) synthesis, processing and intracellular sorting in yeast. Maximal level of hGH was observed in the case when the mature hGH gene was placed under the control of PHO5 promoter. In this case about 90% of hGH was localized in the cytosol, but some portion was trustworthly detected in microsomes and periplasma in spite of the absence of SP. Addition of own or PHO5 SP resulted in lowering of the synthesis and a difficulty in the prehGH processing. In this case the immunoreactive products were localized mainly in periplasma and vacuoles and to a lesser degree in the cytosol. When hGH gene was placed under the control of the yeast MF alpha 1 promoter and alpha-factor preprosegment was used as SP more then a half (67%) of hGH processed correctly was exported in a medium, the rest was detected in vacuole (17%) and periplasma (8%).

Amino Acid Sequence↗
PubMedDate not supplied

[Isolation and properties of polyphosphatase of Neurospora crassa].

Polyphosphatase (polyphosphate-phosphohydrolase) has been isolated from mycelium of Neurospora crassa and purified to homogenous state. The enzyme is shown to be strictly specific to high molecular weight inorganic polyphosphates. Km for phosphate in polymeric form is 6.8-10(-4) M. The molecular weight of this enzyme is 50 000 +/- 3000. To display its activity polyphosphatase requires the presence of bivalent cations of some metals, Mg2+ ions being the best activator with Co2+, Mn2+ and Fe2+ ions-slightly less effective.

Cations, Divalent↗
PubMedDate not supplied

[Specificity of hydrolysis of S. aureus 209P cell walls by a lytic preparation of Pseudomonas lytica].

Specificity of Staphylococcus aureus 209P cell wall hydrolysis by a lytic preparation isolated from the culture liquid filtrate of Pseudomonas lytica VKM V-1454D was studied by the dansylation method. The lytic preparation was found to contain the lytic proteinase lysing the cells of Gram-positive microorganisms. The enzyme hydrolysed the cell walls of S. aureus 209P releasing N-terminal glycine and alanine in amounts of 0.73 and 0.34 mumoles per 1 mumole of lysine, respectively, which indicated the cleavage of the bonds in the pentaglycine bridge and, apparently, of the bond between N-acetylmuramic acid.

Amino Acids↗
PubMedDate not supplied

[Cell wall permeability and export of proteins into the culture broth of Saccharomyces cerevisiae].

The upper limit of Saccharomyces cerevisiae cell wall permeability is such that only molecules with a mass not greater than 2-3 kDa can pass across the cell wall. However, proteins with a much higher molecular mass are exported into the cultural broth when the organism is cultivated in a liquid medium with peptone. Under certain conditions, exogenous proteins interact with the cytoplasmic membrane. These as well as some other findings imply that the cell wall may have microplots with an anomalous permeability, via which the regulated exchange of macromolecules is realized between the intracellular and outer media.

Acid Phosphatase↗
PubMedDate not supplied

[Relationship between the content of some fractions of high molecular weight polyphosphates and total nucleic acids upon dehydration of the yeast Saccharomyces cerevisiae].

Essential redistribution of various polyphosphate fractions was shown during dehydration and subsequent reactivation of Saccharomyces cerevisiae 14. Dehydration no matter what method was used, was followed by an increase in the content of acid soluble polyphosphates (fraction Poly P1) and a decrease of that of salt soluble polyphosphates (fraction Poly P2). Reactivation of dehydrated yeast was, on the contrary, accompanied by a decrease in the PP 1 and an increase in the Poly P2 content. A direct correlation between the Poly P2 fraction and total nucleic acids was demonstrated under various conditions of dehydration and subsequent reactivation. An inverse correlation between the content of the Poly P2, fraction and nucleic acids, on the one hand, and that of the Poly P1 fraction, on the other, was observed. Study of activities of polyphosphatases, tripolyphosphatase, pyrophosphatase and ATPase in dehydrated yeast showed values similar to those in original cells.

DNA↗
PubMedDate not supplied

[Effect of mutation in phoB and phoM genes for the positive control of alkaline phosphatase biosynthesis on Escherichia coli envelope proteins].

The suppression of some envelope proteins, localized in both the periplasm and the outer and inner membranes was shown in phoB and phoM phoR mutants of E. coli. Among these proteins are the proteins of the phosphate regulon and also those not pertaining them. As a result of phoB and phoM phoR mutations, the cytoplasmic membrane was found to be lacking in minor protein of 28,000 Mr, which belongs to the phosphate regulon. Besides, the phoM phoR mutation leads to the loss of protein of 55,000 Mr of the outer membranes, whereas phoB mutation causes loss of protein 37 000 Mr, identified as outer membrane protein OmpT. A damage in the phoB mutant of the protein proteolytic modification, probably determining the suppression of the biosynthesis of E. coli envelope secreted proteins is suggested.

Alkaline Phosphatase↗