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S V Bykovskaia O V Sysoev Ia I Bur'ianov 《Prikladnaia biokhimiia i mikrobiologiia》1988,24(2):280-283
A technique for quantification of S-adenosylmethionine in microbial cell-free extracts is proposed that involves dilution of S-adenosyl-L-(methyl-3H)methionine with non-labelled S-adenosylmethionine followed by DNA-cytosine-methyltransferase reaction. The content of S-adenosylmethionine and the activity of S-adenosylmethionine synthetase in yeasts and E. coli MRE-600 are in good agreement with the results obtained with labelled L-methionine and consistent with literature data. The sensitivity of the technique is about 0.1 nmol/0.1 ml of the reaction mixture (10(-6) M). The error was about 5% in every series of experiments. However, the combined use of different DNA-methyltransferase preparations resulted in a higher experimental error (up to 15%), which should be taken into consideration. 相似文献
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Milan Chytrý Jiří Danihelka Michal Horsák Martin Kočí Svatava Kubešová Zdeňka Lososová Zdenka Otýpková Lubomír Tichý Vasiliy B. Martynenko El’vira Z. Baisheva 《Journal of Biogeography》2010,37(4):767-780
Aim The diversity changes that occurred in Central European forests during the early Holocene can be better understood using ecological knowledge of modern analogues of these forests, which occur in far Eastern Europe. Here we compare the diversity of vascular plants, bryophytes and snails among different forest types of the Southern Urals to provide insights into the palaeoecology of the vanished Central European forests. Location Southern Ural Mountains, Bashkortostan, Russia. Methods We recorded all species of vascular plants, ground-dwelling bryophytes and land snails, and measured biotic and abiotic variables, in 100-m2 plots located in four forest types dominated by different trees: Pinus sylvestris–Larix sibirica, Betula pendula–Populus tremula, Quercus robur and Acer platanoides–Tilia cordata–Ulmus glabra. These types correspond to the chronosequence of forest communities that occurred in Central Europe in the early Holocene. Results The species richness of herb-layer plants was most affected by the canopy-transmitted light. The former three forest types had open canopy and were rich in species, whereas the Acer–Tilia–Ulmus forests were darker and poor in species. The species richness of ground-dwelling bryophytes decreased from coniferous to broad-leaved deciduous forests. In contrast, the highest species richness of snails was in the Acer–Tilia–Ulmus forests owing to the higher calcium content in the litter of these trees. Main conclusions Based on the modern analogue of the Southern Ural forests, we propose the hypothesis that the late-glacial open-canopy pine and larch forests of Central European lowlands were rich in light-demanding species of vascular plants, many of which were also typical of tall-grass steppes or mesic grasslands. They also contained several species of ground-dwelling bryophytes. The spread of birch, aspen and oak in the early Holocene reduced the local species richness of ground-dwelling bryophytes but not of vascular plants. The subsequent spread of elm, lime, maple and ash caused canopy closure, a retreat of the light-demanding herbs and a decline in the local species richness of vascular plants. Besides the increased shading by these tree species, their litter enriched soils in calcium, and enhanced decomposition and nutrient cycling. This supported an increase in the species richness of land snails. 相似文献
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Microdialysis technique has been developed to study secretory function of the adrenal gland in anesthesized rats. Concentration of adrenaline and noradrenaline in sequential 20 min microdialysis samples was measured by HPLC with electrochemical detection. The suitability of method was tested by local and central stimulation of catecholamine secretion. In the first case 100 mmol of KCl or 1 mmol of carbachol were added to perfusion medium, in the second one hypovolemic hypotension was applied. All the stimuli used increased catecholamine levels in the adrenal gland dialysates. Institute of Experimental Cardiology of the All-Union. 相似文献
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Lebedeva Marina V. Nikonova Ekaterina Y. Terentiev Alexey A. Taranov Vasiliy V. Babakov Alexey V. Nikonov Oleg S. 《Biochemistry. Biokhimii?a》2021,86(9):1128-1138
Biochemistry (Moscow) - Potato virus Y (PVY) is one of the most common and harmful plant viruses. Translation of viral RNA starts with the interaction between the plant cap-binding translation... 相似文献
107.
Nikolai Zlobin Konstantin Evlakov Yakov Alekseev Konstantin Blagodatskikh Aleksei Babakov Vasiliy Taranov 《Biochemistry and Biophysics Reports》2016
Plant cold shock domain proteins (CSDP) participate in maintenance of plant stress tolerance and in regulating their development. In the present paper we show that two out of three extremophyte plant Eutrema salsugineum proteins EsCSDP1-3, namely EsCSDP1 and EsCSDP3, possess high DNA-melting activity. DNA-melting activity of proteins was evaluated using molecular beacon assay in two ways: by measuring Tm parameter (the temperature at which half of the DNA beacon molecules is fully melted) and the beacon fluorescence at 4 °C. As the ratio protein/beacon was increased, a decrease in Tm was observed. Besides DNA-melting activity of full proteins, activity was measured for three isolated cold shock domains EsCSD1-3, C-terminal domain of EsCSDP1 (EsZnF1), as well as a mixture of EsCSD1 and EsZnF1. The Tm reduction efficiency of proteins formed the following sequence: EsCSDP3≈EsCSDP1>(EsCSD1+EsZnF1)>EsZnF1>EsCSDP2. Only full proteins EsCSDP3 and EsCSDP1 demonstrated DNA-melting activity at 4 °C. The presented experimental data indicate that i: interaction of EsCSDP1-3 with beacon single-stranded region is obligatory for efficient melting; ii: cold shock domain and C-terminal domain with zinc finger motifs should be present in one protein molecule to have high melting activity. 相似文献