Effect of the lantibiotic warnerin on lipid bilayer membranes

The effect of the lantibiotic warnerin on the ionic permeability of artificial membranes was studied. Membranes were composed of different lipid fractions, including lipids isolated from warnerin-sensitive cells of Staphylococcus epidermidis. Warnerin was shown to selectively interact with artificial membranes of different lipid composition, which in some cases led to formation of ion channels. Computer modeling of warnerin spatial structure supported the probable membranotropic activity of the peptide.     

Isolation and purification of bovine and porcine cerebral cathepsin D]

Cathepsin D was isolated from the grey matter of bovine and porcine large cerebral hemispheres and purified by affinity chromatography on haemoglobin--Sepharose. The isolation and purification of the enzyme also included: acidic extraction, precipitation by ammonium sulfate, dialysis, affinity chromatography, concentration and gel-chromatography on Sephadex G-100. The degree of purification of bovine cerebral enzyme was 3280. The Km value for the enzyme was 2,06 . 10(-5) M. The purified enzyme from bovine brain showed three major and two minor adjacent bands, possessing the cathepsin D activities. The purified enzyme from porcine brain showed only one protein band.     

Comparative analysis of spatial organization of myoglobins. II. Secondary structure]

An analysis of probability of distribution curves of alpha-helical sites and bends of polypeptide chains of myoglobins in half-water mammals (beaver, nutria, muskrat, otter) carried out in comparison with those of myoglobins of the horse and Sperm whale (X-ray diffraction analysis has revealed their tertiary structure) has revealed a coincidence of the secondary structure sites end bends of the chain in the studied respiratory hemoproteins of muscles. Despite a considerable number of amino acid substitutions the profiles of alpha-helicity and B-bends of the compared proteins are practically identical. This indicates to the "resistance" of the probability curves to amino acid substitutions and to retention of the tertiary structure of myoglobins in evolutionary remote species of the animals.     

Comparative analysis of the spatial organization of myoglobins. I. Hydrophobicity profiles]

Hydrophobicity profiles of myoglobins in the animal species far remote in the evolutionary series are considerably similar. A complete coincidence as to the arrangement of hydrophobic zones along the polypeptide chain in myoglobins of the compared species (from a man to mollusc) is revealed at the beginning of alpha-helix of B-segment and in the area corresponding to a cluster which embodies a heme- bound water molecule, distal histidine E7 being directed to this cluster. The mollusc myoglobin with two absent (as compared to myoglobins of other species) hydrophobic sites differs in the profile of hydrophobicity most of all. It is supposed that hydrophobic nuclei forming the heme circumference create a globule "skeleton" thus pre-setting general spatial structure of the myoglobin molecule, which is very significant for its functional activity.     

Suppression of development of vancomycin-resistant <Emphasis Type="Italic">Staphylococcus epidermidis</Emphasis> by low-molecular-weight cationic peptides of the lantibiotic family

Low-molecular-weight cationic peptides warnerin and hominin activate the autolytic systems and cause cell death of Staphylococcus epidermidis 33 GISK, as well as its vancomycin-resistant variant. Minimal bactericidal concentrations of warnerin for both strains studied were determined. Efficiency of antibacterial action of the peptide was found to depend directly on its concentration. Comparative investigation of adhesive properties and biofilm-forming ability of two strains was carried out. The cationic peptide warnerin was found to suppress biofilm formation by both vancomycin-sensitive and resistant strains of S. epidermidis 33 GISK and to have a pronounced destructuring effect on formed biofilms.     

Possibility of Using Phenol- and 2,4-Dichlorophenol-Degrading Strain, <Emphasis Type="Italic">Rhodococcus erythropolis</Emphasis> 17S,for Treatment of Industrial Wastewater

A new phenol- and 2,4-dichlorophenol (2,4-DCP)-degrading strain Rhodococcus erythropolis 17S isolated from the soil contaminated with phenol and its derivatives for a long time was characterized. The strain was identified based on phenotypic, physiological, and biochemical features as well as on the results of 16S rRNA gene sequencing. The growth of R. erythropolis 17S in batch culture using phenol and 2,4-DCP as sources of carbon and energy has been studied. The concentration of phenol and 2,4-DCP in culture medium decreased by 55% (on the fourth day) and 47% (on the 22nd day) in comparison to the control, respectively. It is concluded that R. erythropolis 17S can be used for phenol removal from industrial wastewaters of petrochemical and tanning extract production plants.     

Nitrite reductase activity of deoxyhemoglobin in diabetes and its correction by nicotinamide

The increase of deoxyhemoglobin nitrite-reductase activity was established at streptozotocin-induced diabetes in rats. The deoxyhemoglobin nitrosilation in the streptozotocin-induced diabetic rats was shown to increase the optical density in the aromatic acid region and cause additional absorption peak at 334 nm. The two-week injection of nicotinamide causes reduction in the nitrite reductase activity of the deoxyhemoglobin and the absorption peak at 334 nm disappearance.     

Identification and characterization of a plasmid in strain Aeronomas hydrophila IBRB-36 4CPA carrying genes for catabolism of chlorophenoxyacetic acids

Results of studying plasmid pAH36 in strain Aeronomas hydrophila IBRB-36 4CPA are presented. Plasmid pAH36 possesses BamHI, PstI, and HindIII restriction sites and is 5.4 kb in size. The plasmid was shown to contain genes for catabolism of chlor-substituted phenoxyacetic acids.     

Lysozyme of the mollusk Unio pictorum and the sensitivity of alkanotrophic rhodococci to its effect

A preparation of lysozyme from a freshwater bivalve, Unio pictorum, has been isolated by sorption to chitin, and its physicochemical properties have been studied. An assessment of the sensitivity of 48 strains of rhodococci, belonging to the species Rhodococcus rubber, R. luteus, and R. erythropolis (Specialized Collection of Alkanotrophic Microorganisms of the Institute of Ecology and Genetics of Microorganisms, Ural Division of the Russian Academy of Sciences), which were isolated from diverse natural waters, to lysozyme of the mollusk Unio pictorum demonstrated that the three species differ in their sensitivity to its effects. The high resistance of rhodococci to lysozyme is indicative of their considerable permanence in hydrobiocenoses (and, therefore, ability to maintain self-purification of microbiocenoses from hydrocarbons).