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1.
Vikas Yadav Patade Sujata Bhargava Penna Suprasanna 《Plant Cell, Tissue and Organ Culture》2012,108(2):279-286
In order to discriminate between the ionic and osmotic components of salt stress, sugarcane (Saccharum officinarum L. cv. Co 86032) calli were cultured on media containing NaCl or polyethylene glycol (PEG) 8000 that exerted the same osmotic
pressure (−0.7 MPa). PEG stress exposure for 15 days led to significant growth reduction and loss in water content than salt
stressed and control tissues. Osmotic adjustment (OA) was observed in callus tissues grown on salt, but was not evident in
callus grown on PEG. Oxidative damage to membranes, estimated in terms of accumulation of thiobarbituric acid reactive substances-TBARS
and electrolytic leakage was significantly higher in both the stressed calli than the control however, the extent of damage
was more in the PEG stressed calli. The stressed callus tissues showed inhibition of ascorbate peroxidase activity, while
catalase activity was increased. These results indicate sensitivity of cells to PEG-mediated stress than salt stress and differences
in their OA to these two stress conditions. The sensitivity to the osmotic stress indicate that expression of the stress tolerance
response requires the coordinated action of different tissues in a plant and hence was not expressed at the cellular level. 相似文献
2.
Rashi Verma Monika Yadav Rajabrata Bhuyan Shweta Aggarwal Arnab Nayek 《Journal of receptor and signal transduction research》2016,36(6):601-616
Computer-aided antibody engineering has been successful in the design of new biologics for disease diagnosis and therapeutic interventions. Interleukin-6 (IL-6), a well-recognized drug target for various autoimmune and inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, and psoriasis, was investigated in silico to design potential lead antibodies. Here, crystal structure of IL-6 along with monoclonal antibody olokizumab was explored to predict antigen–antibody (Ag???Ab)-interacting residues using DiscoTope, Paratome, and PyMOL. Tyr56, Tyr103 in heavy chain and Gly30, Ile31 in light chain of olokizumab were mutated with residues Ser, Thr, Tyr, Trp, and Phe. A set of 899 mutant macromolecules were designed, and binding affinity of these macromolecules to IL-6 was evaluated through Ag???Ab docking (ZDOCK, ClusPro, and Rosetta server), binding free-energy calculations using Molecular Mechanics/Poisson Boltzman Surface Area (MM/PBSA) method, and interaction energy estimation. In comparison to olokizumab, eight newly designed theoretical antibodies demonstrated better result in all assessments. Therefore, these newly designed macromolecules were proposed as potential lead antibodies to serve as a therapeutics option for IL-6-mediated diseases. 相似文献
3.
For estimation of growth, the efficiency of linked cross sectional scheme has been compared with pure longitudinal and cross sectional schemes. The relevant estimation theory has been developed and the expressions for the optimum estimators alongwith their variances have been derived. It has been observed that for estimation of growth, the linked cross-sectional scheme has been observed to be less efficient as compared to pure longitudinal scheme but more efficient than pure cross-sectional scheme. 相似文献
4.
R. R. Yadav 《Journal of biosciences》2009,34(5):699-707
Tree-ring analyses from semi-arid to arid regions in western Himalaya show immense potential for developing millennia long
climate records. Millennium and longer ring-width chronologies of Himalayan pencil juniper (Juniperus polycarpos), Himalayan pencil cedar (Cedrus deodara) and Chilgoza pine (Pinus gerardiana) have been developed from different sites in western Himalaya. Studies conducted so far on various conifer species indicate
strong precipitation signatures in ring-width measurement series. The paucity of weather records from stations close to tree-ring
sampling sites poses difficulty in calibrating tree-ring data against climate data especially precipitation for its strong
spatial variability in mountain regions. However, for the existence of strong coherence in temperature, even in data from
distant stations, more robust temperature reconstructions representing regional and hemispheric signatures have been developed.
Tree-ring records from the region indicate multi-century warm and cool anomalies consistent with the Medieval Warm Period
and Little Ice Age anomalies.
Significant relationships noted between mean premonsoon temperature over the western Himalaya and ENSO features endorse utility
of climate records from western Himalayan region in understanding long-term climate variability and attribution of anthropogenic
impact. 相似文献
5.
6.
Characterization of the promoter elements required for hepatic and intestinal transcription of the human apoB gene: definition of the DNA-binding site of a tissue-specific transcriptional factor. 总被引:8,自引:5,他引:3 下载免费PDF全文
D Kardassis M Hadzopoulou-Cladaras D P Ramji R Cortese V I Zannis C Cladaras 《Molecular and cellular biology》1990,10(6):2653-2659
7.
William J. Roesler Subbiah Pugazhenthi Ramji L. Khandelwal 《Molecular and cellular biochemistry》1990,92(2):99-106
Summary Knowledge of the metabolic changes that occur in insulin-resistant type 2 diabetes is relatively lacking compared to insulin-deficient type 1 diabetes. This paper summarizes the importance of the C57BL/KsJ-db/db mouse as a model of type 2 diabetes, and illustrates the effects that insulin-deficient and insulin-resistant states have on hepatic glycogen metabolism. A longitudinal study of db/db mice of ages 2–15 weeks revealed that significant changes in certain parameters of hepatic glycogen metabolism occur during this period. The liver glycogen levels were similar between diabetic and control mice. However, glycogen particles from db/db mice were on average smaller in mass and had shorter exterior and interior chain lengths. Total phosphorylase and phosphorylase a activities were elevated in the genetically diabetic mice. This was primarily due to an increase in the amount of enzymic protein apparently the result of a decreased rate of degradation. It was not possible to find a consistent alteration in glycogen synthase activity in the db/db mice. Glycogen synthase and phosphorylase from diabetic liver revealed some changes in kinetic properties in the form of a decrease in Vmax, and altered sensitivity to inhibitors like ATP. The altered glycogen structure in db/db mice may have contributed to changes in the activities and properties of glycogen synthase and phosphorylase. The exact role played by hormones (insulin and glucagon) in these changes is not clear but further studies should reveal their contributions. The db/db mouse provides a good model for type 2 diabetes and for fluctuating insulin and glucagon ratios. Its use should clarify the regulation of hepatic glycogen metabolism and other metabolic processes known to be controlled by these hormones. The other animal models of type 2 diabetes, ob/ob mouse and fatty Zucker (fa/fa) rat, show similar impairment of hepatic glycogen metabolism. The concentrations of glycogen metabolizing enzymes are high and in vitro studies indicate enhanced rate of glycogen synthesis and breakdown. However, streptozotocin-induced diabetic animals and BB rats which resemble insulin-deficient type 1 diabetes are characterized by decreased glycogen turnover as a result of reduction in the levels of glycogen metabolizing enzymes. 相似文献
8.
V. Johnson M. Singh V. S. Saini V. R. Sista N. K. Yadav 《World journal of microbiology & biotechnology》1992,8(4):382-384
Maximum lipid production (66% w/w dry wt) inRhodotorula glutinis IIP-30 utilizing glucose in a fed-batch fermentation under N-limiting conditions at 30°C, was at pH 4. At pH 3, 5 and 6, the lipid contents were 12%, 48% and 44%, respectively. There was only a small change in the fatty acid profile over the pH range examined, although the ergosterol content decreased by a third as the pH increased. 相似文献
9.
Genes encoding wild type acetolactate synthase (ALS) and a sulfonylurea herbicide-resistant form of the enzyme, isolated from Arabidopsis thaliana, were expressed in transgenic Nicotiana tabacum plants under the control of their native promoters or of the highly active cauliflower mosaic virus 35S promoter. Expression of the wild type coding region from the 35S promoter resulted in a small, threefold increase in sulfonylurea tolerance above the levels measured in tissue expressing the native wild type gene. A much larger, 300-fold increase in herbicide tolerance was conferred by the mutant gene encoding a herbicide-resistant ALS. An additional 10-fold increase in tolerance was attained by expressing this coding region from the 35S promoter. The increase in both wild type and mutant gene expression directed by the 35S promoter resulted in over 25-fold higher levels of ALS messenger RNA in some transformants as compared with those expressing the native genes. However, ALS specific activity increased at most twofold, indicating that the amount of functional enzyme and messenger RNA are not correlated. 相似文献
10.
A complete three-dimensional structure of the Klenow fragment of Escherichia coli DNA polymerase I (pol I) has been proposed on the basis of molecular modeling and molecular mechanics studies using available C alpha coordinates. The structure seems quite reliable because the overall surface of electrostatic potentials calculated for the molecularly modeled enzyme closely resembles that reported for the X-ray structure. The modeled structure is then used in developing a ternary complex of dTTP and (dA)25-(dT)14 poised in its active site. The orientation of both substrates in the ternary complex was primarily guided by the amino acid residues which had been known to interact with dNTP and DNA substrates from earlier studies. The proposed model (a) explains the geometrical and physicochemical relationship of the two substrates with the various critical amino acid residues involved in the binding process and (b) suggests possible roles for additional residues in the binding and/or polymerization reaction. Furthermore, the ternary complex appears to satisfy many biochemical and genetic data concerning catalytic requirements known to exist for the polymerization reaction. 相似文献