Biomedical subjects
Publications and source records attributed to V I Tiulenev.
3-5 hours incubation of calf thymus nuclei at 37 degrees C leads to the proteolysis of histones H1, H3 and H2B; 1-10 mM NiCl2 and ZnSO4 inhibits the proteolysis of the histones H1, H3 and H2B.
Electric stimulation of paraventricular hypothalamic nucleus results in intensification of RNA synthesis in rat brain. Content of acid proteins and RNA in liver and brain chromatin of geese changes in the period of sexual activity controlled by hypothalamus. With long introduction of hydrocortisone content of non-histone proteins of chromatine and RNA as well as total content of RNA in rat liver cells increases. These and other facts confirm the supposition that the central nervous system has an influence on the function of organs and tissues by means of genetical apparatus of cells.
Optical absorption and fluorescence of histones F2a and F2b were studied. An increase in pH and ionic strength induced the structure change in these histones fractions. The hydrofobic sites are formed in protein molecules and this leads to an intensification of histone-histone interactions. The change in the histone tertiary structure is of importance for processes associated with regulation of gene activity in eukaryotic cells.
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The liver nuclear proteins of 3- and 6-month old rats were studied by the gel-electrophoresis technique after electrostimulation of hypothalamus. In this case new nuclear proteins with low molecular weight were found. The electrophoretic rate of these proteins is higher than that of histone H4. A decrease in the content of histone H2B in the nuclear liver of 6-month old rats was also found after electrostimulation of hypothalamus. The mechanism of this phenomenon is discussed.
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Explore the source record for details and available documents.
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The influence of histones, protamine, pronase E and albumin on the corticosterone amount in the blood of rats has been studied. It is shown that injection of 10 and 100 (or 500) mkg of histones per 100 g of body weight leads to a decrease of the corticosterone amount in the blood 24 and 5 h (respectively) later. Irrespective of the injection way (intra-abdominal or per os), a dose of 500 mkg of histones per 100 g of body weight decreases the corticosterone amount in blood by 96%, already 5 h later and, after 24 h the corticosterone amount is practically undetermined. In all cases regeneration of the corticosterone amount in blood is observed after 48 h, and besides, the regeneration extent is inversely proportional to the extent of the corticosterone amount decrease in the first hours of the histone injection. After digestion of 500 mkg of histones with 10 mkg of pronase E during 10 min at 37 degrees C and following injection of this mixture, the corticosterone amount in blood decreases but to much less extent than with injection of the same quantity of intact histones. After more intensive digestion (500 mkg of histones with 50 mkg of pronase E during 30 min at 37 degrees C), histones do not decrease the corticosterone amount in blood but they increase it 5 h after the injection, and then exert no influence on the corticosterone amount. The protamine injection does not influence the corticosterone amount in the first hours but increases it 48 h later. Injection of pronase E and albumin increases the corticosterone amount in blood.(ABSTRACT TRUNCATED AT 250 WORDS)
It has been shown that the administration of total histones (H1, H3, H2B, H2A, H4), the total histones without histones H4 (H1, H3, H2B, H2A), H1 histones at concentrations of 0.001 and 1 microgram per 100 g of body weight (low and high concentrations) to intact rats during 6 days leads to the decrease of T4 amount in the blood plasm. The total histones and histone H1 at low concentration decrease the T4 amount by the coefficients 5.2 and 5.8 respectively. The corresponding coefficients for high concentration are 2.6 and 1.2. There is no difference in the action of the total histones and H1 histone at low concentration. Low concentration of histones is more effective for the decrease of T4 amount than the high one or than the antithyroid agents mercasolyl and LiCl (3 mg and 2 mM per .100 g of body weight), which decrease the amount of T4 in intact rats by the coefficient 3.6 in 38 days. Administration of histones decreases the amount of T4 in the intact rats but, on the contrary, the 3-4 fold increase is observed in hypothyroid rats, so the amount of T4 is practically reverted to the level of intact rats. The mechanism of regulation of the amount of T4 by histones is discussed.
The investigation of fluorescence and light-scattering change of histone F2a, ribonuclease, tyrosine, N-acetyltirosinamide, methyl ether tyrosine by the concentration increasing of NaCl, MgCl2, Na2SO4 in the surrounding medium was carried out. In the case of used salts the changes of tertiary structure and histones aggregations depend on the anion type, which is presented in the environment. The tertiary structure of histones formed in the presence of salt is stabilized by weak (hydrophobic and hydrogenic) interactions.
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Data on physico-chemical properties and functional role of protein S-100 have been generalized. An analysis of literary data permits making a conclusion that the protein interaction with Ca2+ ions plays great part in its action mechanisms. Data are presented on the properties of the family of Ca-binding proteins similar to protein S-100 as to their structure. Peculiar attention is paid to the analysis of this protein function in the cellular nucleus, changing the degree of proteins phosphorylation and RNA synthesis.
Proteolysis of histones H1b and H1(0) is observed after the incubation of rat spleen nuclei at 37 degrees C during 1 hour. Adenosine triphosphate, inorganic pyrophosphate and nicotinamide adenine dinucleotide decrease the digestion of histone H1b. ATP, PP1 and NAD+, in the case of 3 hours incubation, do not affect proteolysis of H1 histones in rat spleen nuclei. The incubation of rat liver nuclei at 37 degrees C during 1 hour leads to a decrease of the amount of histone H1b and, to much more extent, H1a. In this case ATP, PP1 and NAD+ increase proteolysis of histone H1a but practically do not affect proteolysis of H1b. After 2-hours incubations histone H1a is completely digested but histone H1b is partially preserved: ATP in this case, as well as in spleen nuclei, decreases proteolysis of histone H1b. During the 3 hours incubation, when histones H H1a and H1b are completely digested, partial digestion of histone H3 being observed, ATP does not prevent from proteolysis of histone H1b. A protein appears between the H2A and H4 histones after heating at 37 degrees C in both spleen and liver rat nuclei. Neither ATP nor PP1 and NAD+ affect the amount of this protein. It is suggested that the location of histones H1a and H1b in different chromatin domains determines the digestion of these histones by ATP-dependent proteinases.
It has been demonstrated that total homogenates and subcellular fractions of the liver and kidneys of rats exhibit proteolytic activity which specifically digests histone at pH 8.5. The activity of histone hydrolase undergoes age changes in all the subcellular fractions of the liver and kidneys, except the nuclear fraction. Various histone fractions possess different sensitivity to the effect of histone hydrolase. The described enzyme from the liver and kidneys of rats is similar to the histone protease of other vertebrates, although in some respects its properties are somewhat different.