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401.
Alka Singh Niraj K. Nirala Sandip Das Alka Narula M. V. Rajam P. S. Srivastava 《Acta Physiologiae Plantarum》2011,33(6):2453-2459
Scopolamine is widely used for its anticholinergic properties. Because of higher physiological activity and less side effects
the world demand of scopolamine is estimated to be ten times greater than other anticholinergic agents, hyoscyamine and atropine.
Since natural production is limited, alternatives are required to boost the production. We report the introduction of mouse
odc gene of polyamine biosynthesis pathway which is also the primary pathway of tropane alkaloids in Datura innoxia. Polyamines, mainly putrescine, serve as the common metabolite for tropane alkaloids and nicotine. We have overexpressed
odc gene to modulate the metabolic flux downstream and eventually achieved higher accumulation of scopolamine in transgenic plants.
Among six independent transformed lines one line (O10) produced scopolamine (0.258 μg/g dry weight) almost six times higher
than that produced by control plants (0.042 μg/g DW). To our knowledge, this is the first report of odc overexpression in D. innoxia leading to higher scopolamine yield. 相似文献
402.
Factor VII activating protease (FSAP) is associated with cardiovascular diseases and liver fibrosis. To understand the regulation of its proteolytic activity we have characterized recombinant FSAP-mutants over-expressed in HEK-293 cells. The secreted FSAP-protein concentration correlated inversely with the enzymatic activity of the FSAP-mutants. Over-expression of enzymatically active FSAP decreased cell viability, whereas inactive variants were expressed and secreted in adequate amounts. The naturally occurring G534E-variant exhibited reduced proteolytic activity. The ΔEGF-3 mutant showed diminished binding to and activation by heparin. Hence, regulation of FSAP activity is dependent on its EGF-3 domain and over-expression of active variants induces cell death. 相似文献
403.
The paper first deals with the linear stability analysis of an activator-inhibitor reaction diffusion system to determine the nature of the bifurcation point of the system. The non-linear bifurcation analysis determining the steady state solution beyond the critical point enables us to determine characteristic features of the spatial inhomogeneous pattern formation arising out of the bifurcation of the state of the system. 相似文献
404.
405.
Chattopadhyay Sandip Khatun Shamima Maity Moulima Jana Suryashis Perveen Hasina Dash Moumita Dey Arindam Jana Lipi Rani Maity Pikash Pratim 《Probiotics and antimicrobial proteins》2019,11(1):30-42
Probiotics and Antimicrobial Proteins - Managing arsenic intoxication with conventional metal chelators is a global challenge. The present study demonstrated the therapeutic role of probiotics... 相似文献
406.
Sandip K. Basu 《Journal of biosciences》1984,6(4):535-542
The decade of the 70’s was remarkable for the insights that rapidly accumulated to provide us with an understanding of one
of the fundamental processes of animal cell metabolism, namely, how mammalian cells ingest a host of extracellular substances
to satisfy their various metabolic needs. It has long been appreciated that the surfaces of mammalian cells are in a continual
state of flux. Surface membranes often fold inward and pinch of in a vesicular form trapping some of the contents of the extracellular
material which are thus transported into the cell. This process is called endocytosis (reviewed in Silversteinet al., 1977). When extracellular fluids are taken up in this manner, the process is called fluid-phase endocytosis or pinocytosis.
When solids are ingested, the process is called phagocytosis. Although quantitatively important over the long run, these modes
of uptake are slow, non-specific and dependent on the concentration of the substance in the extracellular medium. In recent
years it has been recognized that animal cells have developed a specialized form of this vesicular transport system to selectively
retrieve and assimilate macromolecules from the extracellular milieu with high efficiency. This process is called receptor-mediated
endocytosis. In this review an attempt is made to collate and correlate the evidence establishing receptor-mediated endocytosis
as a dynamic process that routes cell surface receptors and ligands through multiple intracellular compartments to their ultimate
destination. 相似文献
407.
408.
The role of rat liver cytosolic lipoxygenase in the metabolism of benzidine was studied using linoleic acid as a cosubstrate. Under optimum assay conditions, cytosolic dioxygenase activity in the presence of 3.5 mM linoleic acid at pH 7.2 was 74.07 ± 1.43 nmoles/min/mg protein. Benzidine was oxidized at the rate of 3.18 ± 0.13 nmoles/min/mg cytosolic protein to benzidine diimine at pH 7.2 in the presence of 3.65 mM linoleic acid. Both dioxygenase and cooxidase reactions were inhibited by nordihydroguaiaretic acid in a concentration-dependent manner. Partially purified preparations of rat liver lipoxygenase, free of hemoglobin, exhibited a dioxygenase activity of 223.1 ± 65.9 nmoles/min/mg protein and cooxidase activity of 6.1 ± 0.5 nmoles/min/mg protein toward benzidine. These results suggest that hepatic lipoxygenase may play an important role in the metabolism of this hepatocarcinogen. 相似文献
409.
Interaction of water with a benzimidazole derivative: fluorescence and colorimetric recognition of trace level water involving intra‐molecular charge transfer process
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Sandip Nandi Sandip Mandal Jesus Sanmartin Matalobos Animesh Sahana Debasis Das 《Journal of molecular recognition : JMR》2016,29(1):5-9
Benzimidazole‐derived ICT‐based probe, DFPBEN is developed for trace level determination of water. In presence of water, the naked eye color of DFPBEN changes from red to yellow, while it turns to green from red under UV light. Upon addition of water, DFPBEN shows a ratiometric absorbance change in methanol. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
410.
The maximum force that a crawling cell can exert on a substrate is a quantity of interest in cell biomechanics. One way of quantifying this force is to allow the cell to crawl against a measurable and adjustable restraining force until the cell is no longer able to move in a direction opposite to the applied force. Fukui et al. (2000) reported on an experiment where amoeboid cells were imaged while they crawled against an artificial gravity field created by a centrifuge. An unexpected observation was that the net applied force on the amoeba did not seem to be the primary factor that limited its ability to climb. Instead, it appeared that the amoeba stalled when it was no longer able to support a pseudopodium against the applied gravity field. The high g-load bend the pseudopodium thereby preventing its attachment to the target point directly ahead of the cell. In this paper we further refine this idea by identifying the bending of the pseudopodium with the onset of elastic instability of a beam under its own weight. It is shown that the principal features of the experiment may be understood through this model and an estimate for the limiting g-load in reasonable accord with the experimental measurements is recovered. 相似文献