[Analysis of the Ca2+ response of mycelial fungi to external effects by the recombinant aequorin method]. / Analiz Ca2+-otveta mitselial'nykh gribov na vneshnie vozdeistviia s ispol'zovaniem rekombinantnogo ékvorina.

Using the mutant strain Aspergillus awamori 66A producing a recombinant Ca2+-dependent photosensitive protein aequorin, the dynamics of Ca2+ was studied for the first time in the cytosol of the micromycetes exposed to stressful factors, such as an increase in extracellular Ca2+ to 50 mM, hypoosmotic shock, and mechanical shock. Cell response to stress proved to involve an increase in the Ca2+ concentration in the cytosol, which was determined from the amplitude of aequorin luminescence and the time of the amplitude enhancement and relaxation. The level of Ca2+ response depended on the physiological stimulus. Inhibitory analysis with various agents that block Ca2+ channels and with agonists that specifically enhance the activity of the channels suggested that (1) the level of Ca2+ in the cytosol of micromycetes increases in response to stress because of the ion influx from both the growth medium and intracellular reservoirs and (2) the potential-dependent transport systems play the major role in the Ca2+ influx into the cytosol of the micromycete cells.

[Effect of a chemical analogue of autoinducers of microbial anabiosis on the Ca2+ response of mycelial fungi]. / Vliianie khimicheskogo analoga mikrobnykh autoinduktorov anabioza na Ca2+-otvet mitselial'nykh gribov.

The microbial alkylhydroxybenzenes (AHB), autoinducers of anabiosis, or d1 factors, participate in stress response of mycelial fungi, as determined from changes in intracellular Ca2+ concentration. By using the genetically modified strain Aspergillus awamori 66A, which produces a recombinant Ca2+-dependent protein aequorin, the dynamics of Ca2+ was studied in the cytosol of cells exposed to mechanical shock in the presence of the protective doses (0.001-0.01% w/vol) of a chemical AHB analogue, 4-n-hexylresorcinol. Like under stressful conditions, Ca2+ concentration increases in the cell cytosol in response to enhanced AHB level in a growing fungal culture; thus, AHB is perceived by cells as a stress signal. The level of cell response, which was determined from the amplitude of luminescence dependent on the Ca2+ concentration in cytosol was related to the physiological age of the cells and AHB concentration. Micromycete preincubation with AHB was found to protect cells from subsequent stress; this was reflected in the Ca2+ response. The protective AHB effect was manifested as (1) a significant decrease in the amplitude of luminescence and, thus, in Ca2+ accumulation in the cytosol during subsequent mechanical stress (as compared to the control--mechanical stress only); (2) development of the secondary Ca2+ response, which was not observed in the control; (3) a high level of Ca2+ retained in the cytosol for a long time in the presence of AHB (as compared to the control without preincubation with AHB). The mechanisms underlying the AHB effect on the Ca2+ transport systems are discussed.

[Effect of the RNAase from Bacillus intermedius on growth and physiological characteristics of Escherichia coli]. / Issledavanie vliianiia RNKazy Bacillus intermedius na rost i fiziologicheskuiu kharakteristiku Esherichia coli.

The effect of the RNase from Bacillus intermedius on the growth of Escherichia coli was investigated. RNase added to growth medium enhanced the synthesis of DNA, RNA, and protein and stimulated cell division; the degree of stimulation depended on the enzyme concentration. A necessary condition for stimulation was the adsorption of the enzyme on the cell surface and its interaction with the cytoplasmic membrane, as demonstrated immunocytochemically. The adsorption of the enzyme was accompanied by a 43% decrease in the surface charge density. Other effects of RNase involved a 25% increase in the growth rate, a 38% biomass gain, and generation time shortening by 10 min. The stimulation of bacterial growth correlated with the stimulation of cellular respiration rate.

[The stimulating action of exogenous RNase on eubiotic strains of Lactobacillus, Bifidobacterium and Escherichia coli]. / Stimuliruiushchee deistvie ékzogennoi RNKazy na éubioticheskie shtammy laktobatsill, bifidobakterii i Escherichia coli.

The influence of Bacillus intermedius RNAase on the multiplication on B.B.bifidum, L.fermentum and E. coli was studied. The study revealed that the stimulating action depended on the dose of the enzyme, the microbial species and the growth phase of the inoculate. RNAase, added to the nutrient medium, was shown to induce the acceleration of the synthesis of DNA, RNA, protein, as well as mitosis. At the same time the stimulating action of RNAase was accompanied not only by the reduction of the duration of the lag phase, but in some cases even by an increase in the specific growth rate.

[An immunocytochemical study of bacterial ribonuclease penetration into Candida utilis yeast cells and the effect of the enzyme on yeast multiplication]. / Immunotsitokhimicheskoe issledovanie proniknoveniia bakterial'noi ribonukleazy v kletki drozhzhei Candida utilis i vliianie fermenta na razmnozhenie drozhzhei.

Permeability of Candida utilis cells for exogenic Bacillus intermedius RNase was studied cytochemically. The enzyme was shown to penetrate through the outer membrane of C. utilis after a 20 min incubation with cells being in exponential phase, and to be connected with the yeast cytoplasmic membrane.

[The effect of Bacillus intermedius RNAase on the growth and development of Bacillus mucilaginosus]. / Vliianie RNKazy Bacillus intermedius na rost i razvitie Bacillus mucilaginosus.

The effect of Bacillus intermedius RNAase on vegetative cells and spores of siliceons bacteria Bacillus mucilaginosus was investigated. It is shown that the enzyme stimulates the growth of vegetative cells of B. mucilaginosus at a concentration of 10 mkg/ml and promotes germination of spores at a 1000-fold lesser concentration (0.1 mkg/ml). The spores at stages of activation and initiation appear to be most susceptible to the enzyme action. The effect of RNAase on B. mucilaginosus multiplication correlates with intensification of bacterial leaching of bauxites.

[Penetration of pancreatic DNase into Candida tropicalis cells]. / Proniknovenie pankreaticheskoi DNKazy v kletki Candida tropicalis.

Permeability of Candida tropicalis cells for exogenic DNAse was studied by a cytochemical method. The enzyme were shown to penetrate yeast outer membrane and cell wall after a 20 minute incubation period when incubated together with cells at the beginning of the stationary phase.

[The effect of Bacillus intermedius RNAse on the multiplication of Candida tropicalis yeasts]. / Vliianie RNKazy Bacillus intermedius na razmnozhenie drozhzhei Candida tropicalis.

The effect of Bacillus intermedius RNAse on the reproduction of Candida tropicalis and synthesis of the main biopolymers in the yeast cells. It has been found that stimulating action of the enzyme appears at the concentration of 10(-5)-10(-6) mg/ml and does not depend on the physiological state of the sowing culture. The connection between the increase of the ionic penetration and stimulation of the RNA and proteins synthesis in the yeast cells subjected to the RNAse action is shown. The mechanism of chromatine-associated RNA-polymerase activation is suggested to include the alteration of the ionic penetration of cells under the RNAse action.

[Photosensitized formation of singlet oxygen in water solutions of covalent porphyrin-antibody conjugates]. / Fotosensibilizirovannoe obrazovanie singletnogo kisloroda v vodnykh rastvorakh kovalenthykh kon''iugatov porfirinov s antitelami.

The effective photogeneration of singlet molecular oxygen (1O2) by porphyrins (coproporphyrin I; 2,4-bi (alpha-methoxyethyl) deuteroporphyrin IX and cyclopanten-coproporphyrin I) conjugated with antibodies (mouse monoclonal IgG and IgM and human gamma-globulin) have been observed with the direct luminescence method of 1O2 detection. Absolute quantum yields of 1O2 formation by the conjugates have been determined. The data suggest that porphyrin-antibody conjugates are promising for the use as drugs in photodynamic tumor treatment.

[Photogeneration of singlet molecular oxygen by the components of hematoporphyrin IX derivative]. / Fotogeneratsiia singletnogo molekuliarnogo kisloroda komponentami proizvodnogo gematoporfirina IX.

The photosensitized luminescence of singlet molecular oxygen has been studied in aqueous and alcoholic solutions of hematoporphyrin IX (HP) and di- and oligomeric components of "hematoporphyrin derivative" (photofrin II) which is known to be used as a drug in photodynamic tumor therapy. The quantum yields of 1O2 generation (gamma delta) by these compounds have been determined. It was found that the highest gamma delta values are characteristic of alcoholic and micellar detergent aqueous solutions. In detergent-free aqueous solutions containing mainly associated porphyrin molecules, gamma delta is much lower (5-30%), polymeric photofrin components being considerably less active than HP. Both localization of porphyrins in hydrophobic loci and high photosensitizing activity in lipid phase are supposed to play the key role in tumor photodestruction.

[Stimulating effect of pancreatic DNase on Bacillus subtilis growth as a function of the physiologic properties of the inoculation culture]. / Stimuliruiushchee deistvie pankreaticheskoi DNKazy na razmnozhenie Bacillus subtilis v zavisimosti ot fiziologicheskikh osobennostei posevnoi kul'tury.

The stimulating effect of pancreatic DNAse on Bacillus subtilis growth was studied in relation to the content of "slowly growing" cells in the inoculation culture in the phase of decelerated growth. Three cell fractions of B. subtilis were obtained using the stepwise separation of the population in terms of buoyant density in the phase of decelerated growth. In contrast to fractions II and III, fraction I contained cells with decelerated growth, competent, permeable to exogenous DNAase I, and sensitive to the action of this enzyme. The faster growth of bacterial cells in fraction I was shown to be associated with the shorter lag period of these cells having a longer generation time.

[Permeability of Escherichia coli K-12 cells to exogenous nucleodepolymerases]. / Pronitsaemost' kletok Escherichia coli K-12 dlia ékzogennykh nukleodepolimeraz.

The permeability of Escherichia coli cells for exogenous nucleodepolymerases has been studied by an immunoenzyme method. The enzyme ability to penetrate through the bacterial outer membrane and cell wall after 20 min of incubation with culture cells of delayed growth phase has been found.

[Effect of exogenous DNAses on various stages of DNA replication in microorganisms]. / Vliianie ékzogennykh DNKaz na otdel'nye étapy replikatsii DNK v kletkakh mikroorganizmov.

Effect of DNAase 1 on DNA synthesis and cell division was studied in microorganisms deficient in some stages of DNA replication initiation. The DNA synthesis induced by exogenous DNAase was found to be a replicative origin since it was registered from the "origin" of chromosomal replication under the conditions of initiation of proteins functioning. Stimulation of DNA synthesis in bacterial cells having mutations in DNA B and DNA G genes by DNAase 1 indicates that exogenous DNAases participate in replicative fork during the DNA synthesis.

[Quenching of singlet molecular oxygen by screening pigments-- melanins and ommochromes]. / Tushenie singletnogo molekuliarnogo kisloroda ékraniruiushchimi pigmentami--melaninami i ommokhromami.

Synthetic DOPA-melanin and natural screening pigments--sepiomelanin and ommochromes are shown to quench the luminescence of singlet molecular oxygen (1O2) in aqueous (D2O, pD = 7.5-8.1) solutions. The rate constants of 1O2 quenching are found to be equal to (1.2 +/- 0.6) 10(8) M-1 s-1 for monomeric units in DOPA-melanin and to (3 +/- 1) 10(6) M-1 s-1 for ommochromes. The data suggest that screening is not the only function of melanins, which may play a role of inhibitors of photodynamic damage in living tissues.

[Photosensitized generation of singlet molecular oxygen by endogenous substances of the eye lens]. / Fotosensibilizirovannaia generatsiia singletnogo molekuliarnogo kisloroda éndogennymi veshchestvami khrustalika glaza.

It is shown that kinurenine derivatives, harmane (beta-carboline) and tetracycline hydrochloride known as photosensitizers of cataractogenesis in lens produce luminescence of singlet molecular oxygen (1O2) under photoexcitation in air saturated aqueous (D2O) solution. The quantum yields of the 1O2 generation by these substances are determined. The data obtained by this direct 1O2 determination technique suggest that 1O2 might take part in cataractogenesis.

[Effect of pancreatic DNAse on Bacillus subtilis multiplication depending on the physiological state of the culture]. / Vliianie pankreaticheskoi DNKazy na razmnozhenie Bacillus subtilis v zavisimosti ot fiziologicheskogo sostoianiia kul'tury.

The effect of pancreatic DNAase on the growth of Bacillus subtilis, the synthesis of DNA, RNA and protein in the cells was studied as a function of their physiological state. The cells were found to be sensitive to the action of DNAase at the end of the linear growth phase, which coincided with their transition into the competence state and with their ability to adsorb the enzyme on the cell surface.