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251.
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Gerard A. O'Donovan Sara Herlick Debrah E. Beck Probir K. Dutta 《Archives of microbiology》1989,153(1):19-25
Intracellular nucleotides of Salmonella typhimurium were separated and quantified by high performance liquid chromatography (HPLC). Wild type and specially constructed strains of S. typhimurium, in which uridine and cytidine nucleotides could be manipulated independently, were used in this study. By varying growth conditions it was possible to create different concentrations of uridine and cytidine nucleotides in the cell. The specific activity of ATCase was determined for each condition. Generally, a direct correlation was found: at high nucleotide (UTP) concentrations, maximal repression of ATCase was usually seen; at low nucleotide (UTP) concentrations ATCase was derepressed. However, it was the ratio of the concentrations of UTP-to-CTP rather than either the concentration of UTP or CTP alone that best determined the extent of ATCase expression. This applied to all conditions in the present work as well as to all conditions in work hitherto reported by others. The ratio of UTP/CTP is proposed as a key regulatory parameter for pyr enzyme expression.Dedicated to Professor John Ingraham in appreciation for his guidance during my graduate work and in admiration for his confidence and eternal optimism 相似文献
253.
Kshatresh Dutta Dubey Amit Kumar ChaubeyRajendra Prasad Ojha 《Biochimica et Biophysica Acta - Proteins and Proteomics》2013,1834(1):53-64
Change in pH plays a crucial role in the stability and function of the dengue envelope (DENV) protein during conformational transition from dimeric (pre-fusion state) to trimeric form (post-fusion state). In the present study we have performed various molecular dynamics (MD) simulations of the trimeric DENV protein at different pH and ionic concentrations. We have used total binding energy to justify the stability of the complex using the MMPBSA method. We found a remarkable increase in the stability of the complex at neutral pH (pH ~ 7) due to the increment of sodium ions. However, at very low pH (pH ~ 4), the total energy of the complex becomes high enough to destabilize the complex. At a specific pH, almost at a range of 6, the stability of the complex is significantly better than the stability of the trimer at neutral pH, which connotes that the trimer is most stable at this pH (pH ~ 6). 相似文献
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Vivek Vikram Singh Dipanjan Dutta Mairaj Ahmed Ansari Sujoy Dutta Bala Chandran 《Journal of virology》2014,88(5):2821-2834
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Jayati Das Gupta Trishna Sengupta Chhabi Dutta Kathakali De S. De D. Sengupta 《Journal of biosciences》1985,9(3-4):159-163
The ontogeny of hexokinase, phosphofructokinase, phosphoglucoisornerase, aldolase, pyruvate kinase and lactate dehydrogenase
activities which are associated with glycolysis, an important energy yielding process, has been studied in human fetal heart
for periods ranging from 13 weeks to above 33 weeks of gestation. Hexokinase, phosphoglucoisomerase and pyruvate kinase activities
show similar developmental profiles exhibiting maximum activity at 25–28 weeks ofgestation. Phosphofructokinase activity,
on the other hand, shows a minimum at this period and exhibits a peak value at early stages (13–16 weeks of gestation). Though
considerable activity for aldolase is observed at an early period, it declines thereafter, but again increases in the later
period. The probable role and correlations of these glycolytic enzymes with energy demand and general functional development
in human fetal heart in ontogeny are evaluated. 相似文献
260.
Rabies fixed virus (CVS) was passaged 10 times in mice by intramuscular (im) route followed by experimental inoculation of the titrated virus in 4 groups of mice with the dose of 0.1 ml of 1000 mouse (LD50 0.03 ml) using intracerebral (ic), intravenous (iv), intramuscular (im), intraocular (io), and intranasal (in) routes respectively. No marked variation in clinical signs due to variation of routes could be detected. Involvement of brain with io route could be detected even in preclinical stage. Although the virus could be detected in the postclinical stage in all the tissues under study (brain, skin, salivary gland and corneal impression), with io and ic routes spread of the virus was observed in comparatively higher concentrations. 相似文献