Effect of Conditioned Medium and Bone Marrow Stem Cell Lysate on the Course of Acetaminophen-Induced Liver Failure.

A composition containing culture medium conditioned by mesenchymal stem cells and mesenchymal stem cell lysate improves biochemical parameters, reduces inflammation, and stimulates regenerative processes in the liver.

The antifungal effect of cellobiose lipid on the cells of Saccharomyces cerevisiae depends on carbon source.

The cellobiose lipid of Cryptococcus humicola, 16-(tetra-O-acetyl-β-cellobiosyloxy)-2-hydroxyhexadecanoic acid, is a natural fungicide. Sensitivity of the cells of Saccharomyces cerevisiae to the fungicide depends on a carbon source. Cellobiose lipid concentrations inducing the leakage of potassium ions and ATP were similar for the cells grown in the medium with glucose and ethanol.

Inorganic polyphosphates in mitochondria.

Current data concerning the crucial role of inorganic polyphosphates (polyP) in mitochondrial functions and dysfunctions in yeast and animal cells are reviewed. Biopolymers with short chain length (approximately 15 phosphate residues) were found in the mitochondria of Saccharomyces cerevisiae. They comprised 7-10% of the total polyP content of the cell.

[The concentration dynamics of inorganic polyphosphates during the cephalosporin C synthesis by Acremonium chrysogenum].

The contents of five fractions of energy-rich inorganic polyphosphates (polyPs), ATP, and H(+)-ATPase activity in the plasma membrane were determined in a low-activity cephalosporin C (cephC) producer Acremonium chrysogenum ATCC 11550 and selected highly efficient producer strain 26/8 grown on glucose or a synthetic medium providing for active synthesis of this antibiotic. It was shown that strain 26/8 on the synthetic medium produced 26-fold higher amount of cephC as compared with strain ATCC 11550. This was accompanied by a drastic decrease in the cell contents of ATP and the high-molecular-weight fractions polyP2, polyP3, and polyPS with a concurrent increase in the low-molecular-weight fraction polyP1.

[Metabolism characteristics of Chelativorans oligotrophicus by two-phase growth on the mixture of EDTA and glucose].

The obligate destructor of ethylene diamine tetraacetate--a culture of Chelativorans oligotrophicus LPM-4--did not grow on a medium with glucose, but it was good to use it under cultivation on a mixture with EDTA after considerable decrease of the EDTA concentration in the medium (two-phase growth). Strong inhibition of hexokinase and glucose 6-phosphate dehydrogenase in cell exracts 4 mM EDTA was revealed. Using EDTA, cells accumulated polyphosphates whose rate decreased during glucose utilization phase.

Efflux of potassium ions from cells and spheroplasts of Saccharomyces cerevisiae yeast treated with silver and copper ions.

Silver ions induce the efflux of potassium from cells of the yeast Saccharomyces cerevisiae but have no such effect on spheroplasts. Copper ions and the natural fungicide 2-O-3-hydroxyhexanoyl-beta-D-glucopyranosyl-(1-->4)-(6-O-acetyl-beta-D-glucopyranosyl-(1-->16)-2,15,16-trihydroxyhexadecanoic acid) induce the efflux of potassium ions from both cells and spheroplasts of S. cerevisiae.

[Study of the content of inorganic polyphosphates in Saccharomyces cerevisiae grown on different carbon sources with different O2 concentrations in the medium].

The content of different fractions of inorganic polyphosphates (polyP) was studied in Saccharomyces cerevisiae VKM Y-1173 growing on a complete medium with glucose under hypoxia and active aeration as well as on ethanol. The highest growth rate was observed for aerobic fermentation, while the yield of biomass was maximal for cultivation on ethanol. In the mid-log growth phase, the amount of polyP was maximal in the cells grown on glucose under hypoxia and minimal on ethanol.

[Effects of cellobiose lipid B on Saccharomyces cerevisiae cells: K+ leakage and inhibition of polyphosphate accumulation].

Cellobiose lipid B, a natural fungicide produced by the yeast Pseudozyma fusiformata, induces the leakage of K+ and ATP from cells of Saccharomyces cerevisiae. The presence of glucose decreases the effective concentration of cellobiose lipid B. The concentration of cellobiose lipid B was selected that results in a high rate of K+ leakage and a five- to sevenfold decrease in the intracellular ATP content, while the accumulation of acid-soluble polyphosphates decreased only by half.

Effect of a carbon source on polyphosphate accumulation in Saccharomyces cerevisiae.

The cells of Saccharomyces cerevisiae accumulate inorganic polyphosphate (polyP) when reinoculated on a phosphate-containing medium after phosphorus starvation. Total polyP accumulation was similar at cultivation on both glucose and ethanol. Five separate fractions of polyP: acid-soluble fraction polyP1, salt-soluble fraction polyP2, weakly alkali-soluble fraction polyP3, alkali-soluble fraction polyP4, and polyP5, have been obtained from the cells grown on glucose and ethanol under phosphate overplus.

[The effect of inactivation of the exo- and endopolyphosphatase genes PPX1 and PPN1 on the level of different polyphosphates in the yeast Saccharomyces cerevisiae].

The inactivation of the PPX1 and PPN1 genes, which encode the major enzymes of polyphosphate degradation (exopolyphosphatase and endopolyphosphatase, respectively), was found to exert different effects on the content of different polyphosphates in the yeast Saccharomyces cerevisiae. The content of relatively low-molecular-weight acid-soluble polyphosphates in mutant yeast strains is inversely proportional to the exopolyphosphatase activity of the cytosol. At the same time, the mutation of these genes exerts no effect on salt-soluble polyphosphates.

Accumulation of polyphosphates and expression of high molecular weight exopolyphosphatase in the yeast Saccharomyces cerevisiae.

The effect of cultivation time and concentration of inorganic phosphate (P(i)) in the culture medium on the accumulation of polyphosphates (polyP) and the activity of two cytosolic exopolyphosphatases of the yeast Saccharomyces cerevisiae was studied: an exopolyphosphatase of 40 kD encoded by PPX1 and a high molecular weight exopolyphosphatase encoded by another gene. Depletion of polyP in the cells on P(i) starvation is a signal factor for the accumulation of polyP after the subsequent addition of 5-20 mM P(i) and glucose to the cells or spheroplasts. A high activity of both exopolyphosphatases does not prevent the accumulation of polyP.

New aspects of inorganic polyphosphate metabolism and function.

The review analyzes the results of recent studies on the biochemistry of high-molecular inorganic poly-phosphates (PolyPs). The data obtained lead to the following main conclusions. PolyPs are polyfunctional compounds.

Effect of inhibitors on polyphosphate metabolism in the yeast Saccharomyces cerevisiae under hypercompensation conditions.

After re-inoculation of the yeast Saccharomyces cerevisiae from phosphate-deficient to complete medium, the total content of polyphosphates increased tenfold during 2 h (hypercompensation), but the content of certain fractions increased differently. The content of acid-soluble polyphosphate increased to the maximal extent. The ratio of the activities of two exopolyphosphatases also changed in the cytosol.

The content and chain length of polyphosphates from vacuoles of Saccharomyces cerevisiae VKM Y-1173.

The content of inorganic polyphosphates (polyP) in vacuoles of the yeast Saccharomyces cerevisiae is approximately 15% of the total cellular polyP. Over 80% of the vacuole polyP are in an acid-soluble fraction. It was first established by (31)P-NMR spectroscopy that a polymeric degree (n) of two subfractions obtained by precipitation with Ba(2+) in succession at pH 4.

Dependence of inorganic polyphosphate chain length on the orthophosphate content in the culture medium of the yeast Saccharomyces cerevisiae.

The content of inorganic linear polyphosphate (polyP) and the polymeric degree (n) of these compounds were determined in the process of growth of the yeast Saccharomyces cerevisiae VKM Y-1173 in a medium, which contained varying Pi amount with the constant level of all the necessary components. For this purpose, a combination of chemical methods of polyP extraction and 31P-NMR spectroscopy studies of their chain length were used. After 7 h of phosphate starvation, the yeast was shown to use almost completely the phosphate reserve in the form of polyP localized in various cell compartments to support their vitality.

The development of A. N. Belozersky's ideas in polyphosphate biochemistry.

This review covers some trends and approaches to the study of inorganic polyphosphates that originated from the fruitful ideas and pioneering works of A. N. Belozersky.

[Effect of conditions od Trichosporon pullulans culturing on the synthesis of immunomodulating glycoprotein].

An extracellular glycoprotein (GP) exhibiting immunomodulating activity produced by the yeast Trichosporon pullulans grown in a defined ethanol-containing medium differed substantially in its composition from that of the yeast cell walls: therefore, it cannot be considered a structural component of the cell walls. In batch culture, the greatest GP production (40 mg/l) occurred in the exponential phase of the yeast growth. Under continuous cultivation, in both chemostat and pH-auxostat regimes, the specific rate of GP synthesis (qGP) increased with the increasing specific growth rate (mu) and reached 1.

[Hypochromic effect of signal attenuation in 31P-NMR spectra of linear polyphosphates].

Chemical shifts in 31P-NMR spectra of linear polyphosphates were studied. In each polyphosphate species tested, the sum of signal intensities of the internal (core) phosphate groups was proportional to the concentration of each polyphosphate, but the contribution of such groups to the total intensity of the signal decreased with increasing the length of the polyphosphate chain. An equation for estimating the polyphosphate chain length in biological objects taking into account a decrease in the 31P-NMR spectral intensity is proposed.

[Change in inorganic polyphosphate chain length depending on the stage of Saccharomyces cerevisiae growth].

The dynamics of the content and the degree of polymerization of polyphosphates (PPs) during the growth of Saccharomyces cerevisiae VKM Y-1176 was studied by chemical methods and P NMR spectroscopy. The overall PP content of Saccharomyces cerevisiae cells growing in orthophosphate-sufficient medium was found to increase until glucose was exhausted in the medium. In the early logarithimic phase, the degree of polymerization of PPs (high-polymeric PPs in particular) fell drastically.

[Properties of polyphosphate phosphohydrolase of the "leaky" mutant Neurospora crassa with respect to the specific enzyme].

Some properties of polyphosphate phosphohydrolase from N. crassa strain ad-6.28610a and from its mutant with a decreased polyphosphate phosphohydrolase activity were compared.

[Inhibiting effect of concanavalin A on certain biosynthetic processes in spheroplasts of the yeast Saccharomyces cerevisiae].

The effect of concanavalin A on biosynthesis of nucleic acids, proteins, structural polysaccharides and glycoproteins of the yeast cell membrane and of enzymes having different localization in the cell as well as on other processes occurring in spheroplasts of the yeasts Saccharomyces cerevisiae IBPhM-350 and CCY 21-4-13 were studied. In both yeast strains lectin strongly inhibited total protein synthesis and produced a weaker inhibiting effect on DNA and RNA synthesis. This was accompanied by a decrease of the activity of the majority of already known enzymes (acid phosphatase, invertase, alpha-glucosidase, polyphosphatase, pyrophosphatase, ATPase) and glucose consumption.