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71.
A temperature increase from 35° to 40–42°C enhances the rise of cytoplasmic serine proteinase (ISP1) activity in Bacillus megaterium incubated in a sporulation medium. A temperature shift from 27°C in the growth medium to 35°C in the sporulation medium has the same effect. Elevated temperature stimulates the increase of ISP1 level when applied immediately after the transfer of cells from the growth to the sporulation medium (at T0) or at T3, when sporulation becomes irreversible. The cytoplasmic PMSF-resistant activity or the proteolytic activity associated with the membrane fraction is stimulated only slightly or not at all. A temperature increase to 45–47°C suppresses the rise of proteolytic activities in all cell fractions. In addition to the elevation of the ISP1 activity by an upward temperature shift, the rise of this enzyme in nongrowing cells is also stimulated by osmotic stress. In growing populations, in contrast to the rise of the ISP1 activity caused by elevated temperature in nongrowing cells, this proteinase is induced by low temperatures (24–27°C). The ISP1 activity roughly correlates with the enzyme protein concentration determined by immunoblotting. 相似文献
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Summary The presence of 1% agar in the fixation and substrate solutions for the histochemical demonstration of thiamine pyrophosphatase (4.4 mM TPP; 3.6 mM Pb2+; 0.025 Tris-maleate buffer, pH 7.2) clearly facilitates the localization of the enzyme in Golgi apparatus in cold microtome sections prepared from unfixed specimens. 相似文献
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Marie Kselíková Tomáš Mařík Bedřich Bíbr Jaroslav Lener 《Biological trace element research》1980,2(1):57-64
This study describes the interaction of molybdenum with blood components. Molybdenum-99 was added to blood, and after four
washings, 3% of the total radioactivity was found in red cells. More specifically, the radioactivity was determined to be
associated with the cell membrane.
Molybdenum-99 in the +VI form did not interact with the human erythrocyte membrane; however, Mo(V) forms did interact. Of
five different compounds, the highes uptake was observed with a brown Mo(V)-ascorbate complex generated from Mo(VI) and ascorbic
acid in the molar ratio 1∶20. A membrane suspension of Mo-ascorbate-treated human erythrocytes was prepared and the solubilized
proteins were separated on a polyacrylamide gel in the presence of sodium dodecyl sulfate (SDS). Molybdenum-99 binding to
spectrin was demonstrated, as well as some minor interactions with membrane hemoglobin and bands 6 and 8. 相似文献
77.
M. Podojil M. Blumauerová V. Přikrylová Z. Vaněk G. F. Gauze T. S. Maksimova 《Folia microbiologica》1980,25(6):464-466
The strainStreptomyces griseoruber 4620 produces, besides the anthracycline antibiotics beromycins, some other anthracyclines of the rhodomycin type. Twelve
isolates exhibiting a higher antibiotic activity (up to 2.5×), as compared to the parent strain, were obtained after a spontaneous
selection. The following species were isolated from the hydrolysate of mycelial extract: β-rhodomycinone, β-isorhodomycinone,
α2-rhodomycinone and 10-deoxy-β-rhodomycinone, which has not yet been described. 相似文献
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Jiří Ponert 《Folia Geobotanica》1977,12(1):9-22
Studies of the Adjarian flora resulted in a detailed classification of the ergasiophygophytes, based mainly on the degree of their naturalization: (1) The ephemeroergasiophygophytes display unstable naturalization both in artificial and natural habitats, and disappear after only a few growing seasons. (2) The deuteroergasiophygophtes show stable naturalization in anthropogenic habitats. (3) The protoergasiophygophytes are distinguished by uncertain stability of naturalization in natural habitats, and, if firmly naturalized on a certain spot, they lack any tendency to further spreading. (4) The autergasiophygophytes tend to spread in natural habitats. (5) The aggressive ergasiophygophytes transform natural vegetation in new plant communities, and can become dominant species in these communities. New terms, viz. emphemeroxenophytes, protoneophytes, non-aggressive neophytes, slightly aggressive neophytes, and postneophytes with vegetative reproduction have also been introduced to express diverse features of the xenophytes. 相似文献