[Relative hydrophobicity of mononucleotides and nucleosides determined by partition in aqueous two-phase polymeric system ficoll-dextran]. / Issledovanie otnositel'noi gidrofobnosti mononukleotidov i nukleozidov metodom raspredeleniia v vodnoi polimernoi dvukhfaznoi sisteme fikoll-dekstran.

The effect of ionic strength on the partition of several mononucleotides, deoxyribonucleosides and the corresponding bases in aqueous buffered (pH 7.4) ficoll--dextran biphasic system was examined. The relative hydrophobicity of the compounds at zero ionic strength was estimated in terms of an equivalent number of CH2 groups. It is found that the effect of the ionic strength on the relative hydrophobicity of the phosphate group is similar for all the mononucleotides examined but for the adenosine derivative.

[The effect of structure and conformation on the relative hydrophobicity of dinucleosidephosphates and their analogs]. / Vliianie stroeniia i konformatsii na otnositel'nuiu gidrofobnost' dinukleozidfosfatov i ikh analogov.

Partition of a number of dinucleosidephosphates, their (2'-5')-isomers and a series of their analogues, in which the ribose ring was replaced by acyclic hydroxyalkyl substituents, in an aqueous biphasic ficoll--dextran system has been studied. Effect of the ionic composition of the biphasic system on partitioning of the compounds was examined. The relative hydrophobicity of the compounds in the presence of 0.11 M phosphate buffer, pH 7.4, and in the presence of 0.15 M NaCl in 0.01 M buffer, pH 7.4, was estimated. The results obtained are considered in regard to the effect of structure and conformation of a molecule on its affinity for an aqueous environment.

[Effect of the molecular structure of natural anthracycline antibiotics on their relative hydrophobicity]. / Vliianie molekuliarnoi struktury prirodnykh antratsiklinovykh antibiotikov na ikh otnositel'nuiu gidrofobnost'.

Relative hydrophobicities of anthracycline antibiotics, adriamycin, rubomycin and carminomycin, have been measured by the two-phase distribution method. Two different biphasic systems were used for this purpose. Possible reasons of discrepancies between results obtained and other authors, data are discussed. It was established that the relative hydrophobicities of the compounds investigated contradict the theory of increment additivity. The results are compared with quantum-chemical calculations.

[Effect of sodium dodecyl sulfate on biological membranes]. / Deistvie dodetsilsul'fata natriia na biologicheskie membrany.

Effect of sodium dodecyl sulfate (SDS) on yeast cells resulting in the cellular proteins release from the cells was examined. The influence of pH, ionic strength, the agent concentration and the cells lipids content on the proteins extraction degree was studied. It is assumed that the proteins release is due to the plasma membrane solubilization under the surfactant treatment. It is established that the mechanism of the monimer--membrane interaction and that of the micelle--membrane interaction are likely to be different. It is shown that micelle-like surfactant--protein complexes can solubilize the membrane as well as the SDS micellies. It is found an increase of the ionic strength decreases the efficiency of the SDS action probably due to an increase of the micelle volume. It is assumed that the efficiency of the SDS action on the cell is limited particularly by the ratio of cell wall pere size to the size of micelles formed by the agent in the solution. It is shown also that removal of the largest portion of the lipids from the yeast cell favours an increase in the efficiency of the SDS extractive action at the agent concentrations larger than the critical micelle concentration value probably due to the corresponding decrease of the amount of the cellular components which must be solubilized by the surfactant micelles.

[Effect of yeast cell membrane components on the IR spectrum of the cell]. / Vliianie komponentov drozhzhevoi kletochnoi obolochki na IK-spectr kletki

IR-technique was used to study the effect of yeast cells treatment by water-alcohols mixtures on the quantitative relationship between the intensities of different bands in the spectra. The analysis of spectra made it possible to suggest that the reflection of the IR-irradiation from the cell is governed by the nucleoprotein layer of its envelope. It is shown that the treatment of yeast cell with ribonuclease raises the "IR-permeability" of the cell envelope.

[New approach to the interpretation of vibrational spectra of microbial cells]. / Novyi podkhod k interpretatsii kolebatel'nykh spektrov mikrobnoi kletki

IR-technique was applied to study baker's yeast cell and its envelope fragments. The quantitative evaluation of spectra was made using the polysaccharide band at 1070 cm-1 as the bench one. The comparison of the spectra of the whole cells and of the envelope fragments suggested that the spectrum of the yeast cell was governed by the composition of its envelope only. ATR-spectra of the whole cells and of envelope debris were obtained and the comparison of these with the "absorption" ones made it possible to conclude that the yeast cells vibration spectrum was for the most part the reflection spectrum governed by the composition of the cell envelope rather than the absorption one.

[Thermodynamic characteristics of aqueous solutions of plant glucomannans]. / Issledovanie termodinamicheskikh kharakteristik vodnykh rastvovov rastitel'nykh gliukomannanov.

The effect of plant beta-1,4-glucomannanes on the thermodynamic properties of their aqueous solutions was examined. In this context, the coefficients of distribution of the homologous series of marker compounds with a varying length of the side aliphatic chain in the biphase system: n-octanol-polysaccharide aqueous solution were determined, and the free energy required for the transfer of the methylene group from the buffer solution to the polysaccharide solution was calculated. The dependence of this parameter on the polysaccharide concentration was investigated. It is suggested that the factors responsible for the effect of glucomannanes on the properties of their aqueous solutions include the type and configuration of glycoside bonds, chemical nature of monomer components, and, although to a far smaller extent, the molecular mass.

[Effect of chemical modification of the surface of erythrocytes on their stability to the hemolytic action of sodium alkyl sulfates]. / Vliianie khimicheskoi modifikatsii poverkhnosti eritorotsitov na ikh ustoichivost' k liticheskomu deistviiu alkilsul'fatov natriia.

The hemolytic action of a homologous series of sodium alkyl sulfates (C8 to C15) on dog and human erythrocytes was measured. The influence of trypsin, pronase and neuraminidase treatments on the lytic resistance of human red cells was studied. A new approach evaluating the hemolytic activity of ionic surfactants is expressed as a ratio of a concentration providing 50% lysis to its CMC-value. The results obtained are examined for their bearing on the use of surfactants as a means to study the structure organization of biological membranes.

[Comparative study of the effect of ionic and non-ionic surface-active compounds on plasmic membrane of yeast protoplasts]. / Sravienie deistviia ionnykh i neionnykh poverkhonostno-aktivnykh veshchestv na plazmaticheskuiu mambrany drozhzhevykh protoplastov.

Lytic effect of some cationic surface-active compounds (SAC) on yeast protoplast plasmic membrane is studied. Comparative analysis of the lytic effect of anionic, cationic and non-ionic SAC is carried out, a correlation between key physico-chemical characteristics of the agents (critical concentration of micellization, hydrophyle-lipophyle balance) and their lytic activity is investigated. A proposition is made on the presence in all biphylic compounds of a hydrophyly gradient, which is due to the effect of hydrophylic group on lipophylic properties of hydrophobic part of the molecule, and possible role of this factor in thelytic effect of biphylic compounds on biological membranes is discussed.

[Infrared spectrum of yeast cell walls]. / Infrakrasnye spektry drozhzhevykh kletochnykh stenok.

Infrared spectra of whole cells and cell walls were studied with Schizosaccharomyces pombe, Endomyces magnusii. Rhodotorula rubra, and Candida lipolytica. Qualitative analysis of the spectra and comparison of the spectra recorded for the cells and for their walls led to a conclusion that, contrary to the common viewpoint, an ir spectrum of the whole cell of any yeast species was determined by the components contained in the cell rather wall than by all components of the cell.

[Relative hydrophobicity and other properties of lectins in aqueous binary phase polymeric systems]. / Izuchenie otnositel'noi gidrofobnosti i drugikh svoistv lektinov v vodnykh dvukhfaznykh polimernykh sistemakh.

The relative hydrophobicity of ten purified lectins preparations (SBA, LCA, PNA, PSA, STA, WGA, Con A, PHA-P, RCA-I and HPA) was determined using the aqueous two-phase polymeric system Ficoll 400-dextran 70 (13.53% - 11.59%, w/w in H2O, respectively). The linear correlation was found between the relative hydrophobicity of the lectin preparations and their hemagglutinating activity towards native rabbit erythrocytes (r2 = 0.925). Con A specific carbohydrate ligands added to the system decreased the relative hydrophobicity of lectin. Using cross partition, isoelectric points for the lectins were determined.

[Removal of surface-active substances from proteins by reversible immobilization on water-insoluble carrier]. / Osvobozhdenie belkov ot poverkhnostio-aktivnykh veshchestv metodom obratimoí immobilizatsii na nerastvorimom nostitele.

Techniques for removing of surface-active substances from cysteine and cystine-containing proteins preliminarily immobilized by thiol-disulfide exchange on water-insoluble carrier, followed by protein transfer into solution, as examplified in sodium dodecyl sulfate, cetyltrimethylammonium bromide and bovine serum albumin are described. This procedure may be used to remove any sort of material non-covalently bound to protein.