[Interrelation between structural state, physicochemical properties and lipid composition in microbial cells].

We performed complex investigations of antioxidant properties and the lipid composition of the five gram-negative bacteria depending on the cultivation season. Structural state, the lipid composition and physicochemical properties of lipids of the three gram-negative bacteria (Renobacter vacuolatum, Flectobacillus major WKM 869, Pseudomonas fluorescens) during their growth and mycelium of four species of the xylotrophic basidiomycetes (Panus tigrinus IBK-131, Fomes fomentarius M71, Laetiporus sulfureus M131, Piptoporus betulinus M60) during the lag phase were also studied. Changes in the composition of the lipid component in the studied bacteria led to considerable structural rearrangements in their membrane system during the growth of bacteria. It is shown that more hydrophilic regions of the lipid component are of paramount importance in maintaining the fluidity of the entire lipid bilayer in the basidiomycete mycelium. The scale and direction of the revealed interrelations between rotational correlation times of probes and the lipid composition depend both on localization of the probe in membrane and the composition and physicochemical properties of the microorganism lipids.

[Molecular characteristics of testosterone binding globulin and analysis of their regulation].

Molecular characteristics of testosterone binding globulin (TeBG) were investigated in microaliquots of human serum samples using 3H-5-alpha-dihydrotestosterone radioligand assays. Under experimental conditions used TeBG demonstrated high conformational plasticity and ability to adopt three conformational states (olygo-, di-, and monomer) with different functional activities. Using alipidspolyene complex from basidiomycete Laetiporus sulphureus we demonstrate a novel effective pharmacological correction of the TeBG characteristics.

A rapid method to quantify pro-oxidant activity in cultures of wood-decaying white-rot fungi.

A new, rapid method for evaluation of lipid peroxidation promoting (pro-oxidant) activity in cultures of wood-decaying fungi was developed. The method is based on measurement of the rate of oxygen consumption in the reaction of linoleic acid peroxidation initiated by fungal culture filtrates. The liquid cultures of the white-rot fungi Bjerkandera adusta and Phanerochaete chrysosporium grown on wheat straw-containing glucose-peptone-corn steep liquor medium possessed significant levels of the pro-oxidant activity. Other white-rot fungi producing manganese peroxidase (MnP) were also found to show the activity. MnP demonstrated a crucial role as the major pro-oxidant agent in the fungal cultures. The total pro-oxidant activity may be considered as net result of the peroxidation by MnP and the inhibition by antioxidant compounds present in the fungal culture fluids.

Peroxyl radicals are potential agents of lignin biodegradation.

Past work has shown that the extracellular manganese-dependent peroxidases (MnPs) of ligninolytic fungi degrade the principal non-phenolic structures of lignin when they peroxidize unsaturated fatty acids. This reaction is likely to be relevant to ligninolysis in sound wood, where enzymes cannot penetrate, only if it employs a small, diffusible lipid radical as the proximal oxidant of lignin. Here we show that a non-phenolic beta-O-4-linked lignin model dimer was oxidized to products indicative of hydrogen abstraction and electron transfer by three different peroxyl radical-generating systems: (a) MnP/Mn(II)/linoleic acid, (b) arachidonic acid in which peroxidation was initiated by a small amount of H(2)O(2)/Fe(II), and (c) the thermolysis in air of either 4,4'-azobis(4-cyanovaleric acid) or 2,2'-azobis(2-methylpropionamidine) dihydrochloride. Some quantitative differences in the product distributions were found, but these were attributable to the presence of electron-withdrawing substituents on the peroxyl radicals derived from azo precursors. Our results introduce a new hypothesis: that biogenic peroxyl radicals may be agents of lignin biodegradation.

[Evaluation of radioprotective properties of a lipocarotenoid extract from mycelium of basidiomycetes during external irradiation]. / Otsenka radiozashchitnykh svoistv lipokarotinoidnogo ékstrakta iz mitseliia bazodial'nogo griba v usloviiakh vneshnego oblucheniia.

Radioprotective properties of LPC extract from mycelium of Basidiomycetes fungus at doses 12.0; 3.0 and 1.0 Gy of external irradiation were investigated. The extract of LPC at 2.5 mkg/ml concentration promoted the survival of animals (to 40%) and increased the average life at the lethal dose. At 1.0 Gy dose the use of extract resulted in restoration of radiosensitive organs weights, the number of blood leucocytes and some indexes of lipid peroxidation in blood plasma. The extract has produced some effect on the amount of spermatogenic cells in the testis.

[Effects of fungal mycelium extracts on 137Cs accumulation in human embryo cells]. / Izuchenie vliianiia ékstraktov mitseliia gribov na nakoplenie 137Cs v kletkakh émbriona cheloveka.

The method is proposed for primary evaluation of the ability of drugs of various genesis to affect the accumulation of radionuclides in cells. Extracts of mycelium of wood-rotting Basidiomycetes were shown to prevent 137Cs accumulation in cultures of human embryo fibroblast.