Microbore column exclusion chromatographic method for studying protein association and its relation with enzymatic activity

The principles of treating chromatographic data are considered to allow the determination of number of components, equilibrium and kinetic association constants of proteins by means of micro-column exclusion chromatography. The method is developed to study protein association in cases complicated by adsorption. The potentialities of the chromatographic method have been examined for the study of the mechanism of enzyme catalytic action.     

The proline biosynthesis gene proA from the thermophilic bacterium Thermus ruber: its cloning, sequencing and heterologous expression]

The proA proline biosynthesis gene of thermophilic bacterium Thermus ruber was cloned and sequenced, and several properties of the encoded enzyme, gamma-glutamylphosphate reductase (GPR) were studied. The proA open reading frame (ORF) was of 1286 bp. Nucleotide sequence analysis revealed the ATG initiation codon in position 36 and the TTA termination codon in position 1304. A deduced protein product of the gene was shown to be of 44,919 Da in molecular weight. The GC content was 66%, as is characteristic of various bacteria of the genus Thermus. An amino acid sequence encoded by the cloned gene showed the highest homology (up to 64%) with GPR of T. thermophilus. The maximum activity of GPR (8.2 x 10(-2) units/ml) was observed at 55 degrees C. A weak enzymatic activity was also detected at 70 degrees C. The enzyme can be used in biotechnological studies.     

Effect of ionizing radiation on the chemoreceptive properties of snail giant neurons. Correction by ATP and concanavalin A

Ionizing radiation was shown to reduce the membrane response to acetylcholine and gamma-aminobutyric acid and to modify the sensitivity of acetylcholine reactions to ouabain. The possibility was demonstrated of the postirradiation pharmacological correction of the neuronal membrane chemosensitivity by increasing the intracellular concentration of ATP and by the external application of concanavalin A. Possible mechanisms of action of ionizing radiation on the chemoreceptive properties of the neuronal membrane are discussed.     

Multiyear and seasonal hepatitis A morbidity in different population age groups in certain areas

At the areas with high activity of hepatitis A (HA) epidemic process the duration of epidemic cycles was shown to differ, the intervals between the peaks of morbidity increasing in older age groups. The beginning of seasonal rises exceeding the average annual HA morbidity level in different age groups was found to depend on the activity of the epidemic process. At the areas with the highest activity of the epidemic process children aged 1-2 years were the first to be affected by the seasonal rise of HA. Stable direct correlation between HA morbidity levels at the beginning of seasonal rises and some markers indicative of unfavorable sanitary conditions (the size of the fly population, the purity of water samples deviating from the requirement of the Government Standard) during the preceding year was demonstrated.