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51.
C. George Priya Doss B. Rajith R. Rajasekaran Jain Srajan N. Nagasundaram C. Debajyoti 《Cell biochemistry and biophysics》2013,67(3):1307-1318
Polymorphisms in the human prion proteins lead to amino acid substitutions by the conversion of PrPC to PrPSc and amyloid formation, resulting in prion diseases such as familial Creutzfeldt–Jakob disease, Gerstmann–Straussler–Scheinker disease and fatal familial insomnia. Cation–π interaction is a non-covalent binding force that plays a significant role in protein stability. Here, we employ a novel approach by combining various in silico tools along with molecular dynamics simulation to provide structural and functional insight into the effect of mutation on the stability and activity of mutant prion proteins. We have investigated impressions of prevalent mutations including 1E1S, 1E1P, 1E1U, 1E1P, 1FKC and 2K1D on the human prion proteins and compared them with wild type. Structural analyses of the models were performed with the aid of molecular dynamics simulation methods. According to our results, frequently occurred mutations were observed in conserved sequences of human prion proteins and the most fluctuation values appear in the 2K1D mutant model at around helix 4 with residues ranging from 190 to 194. Our observations in this study could help to further understand the structural stability of prion proteins. 相似文献
52.
T. Vijaya Lakshmi Y. Varalaxmi S. K. Yadav M. Maheswari 《Russian Journal of Plant Physiology》2017,64(6):889-898
Antioxidative enzyme activities and their isozyme patterns under water-deficit, salinity, high and low temperature stresses were studied in the seedlings of Pennisetum glaucum (L.) R.Br. It was observed that under water-deficit stress glutathione reductase (GR) was the key enzyme while in case of high temperature stress, GR along with catalase played a major role. Superoxide dismutase was found to be the main enzyme under low temperature stress. Co-ordinated higher expression of all the antioxidative enzymes was observed under salt stress. This study revealed the operation of different enzymatic antioxidative mechanisms under various abiotic stresses that will aid in understanding the metabolic basis of stress tolerance in pearl millet. 相似文献
53.
High-frequency stable transformation of cotton (Gossypium hirsutum L.) by particle bombardment of embryogenic cell suspension cultures 总被引:6,自引:0,他引:6
K. Rajasekaran R. L. Hudspeth J. W. Cary D. M. Anderson T. E. Cleveland 《Plant cell reports》2000,19(6):539-545
Stable transformation of cotton (Gossypium hirsutum L.) at a high frequency has been obtained by particle bombardment of embryogenic cell suspension cultures. Transient and
stable expression of the β-glucuronidase (GUS) gene was monitored in cell suspension cultures. Transient expression, measured 48 h after bombardment,
was abundant, and stable expression was observed in over 4% of the transiently expressing cells. The high efficiency of stable
expression is due to the multiple bombardment of rapidly dividing cell suspension cultures and the selection for transformed
cells by gradually increasing the concentrations of the antibiotic Geneticin (G418). Southern analysis indicated a minimum
transgene copy number of one to four in randomly selected plants. Fertile plants were obtained from transformed cell cultures
less than 3 months old. However, transgenic and control plants from cell cultures older than 6 months produced plants with
abnormal morphology and a high degree of sterility.
Received: 20 January 1999 / Revision received: 1 October 1999 / Accepted: 11 October 1999 相似文献
54.
Jin YP Singh RP Du ZY Rajasekaran AK Rozengurt E Reed EF 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(11):5415-5423
The development of chronic rejection is the major limitation to long-term allograft survival. HLA class I Ags have been implicated to play a role in this process because ligation of class I molecules by anti-HLA Abs stimulates smooth muscle cell and endothelial cell proliferation. In this study, we show that ligation of HLA class I molecules on the surface of human aortic endothelial cells stimulates phosphorylation of Src, focal adhesion kinase, and paxillin. Signaling through class I stimulated Src phosphorylation and mediated fibroblast growth factor receptor (FGFR) translocation to the nucleus. In contrast, Src kinase activity was not involved in class I-mediated transfer of FGFR from cytoplasmic stores to the cell surface. Inhibition of Src protein kinase activity blocked HLA class I-stimulated tyrosine phosphorylation of paxillin and focal adhesion kinase. Furthermore, HLA class I-mediated phosphorylation of the focal adhesion proteins and FGFR expression was inhibited by cytochalasin D and latrunculin A, suggesting a role for the actin cytoskeleton in the signaling process. These findings indicate that anti-HLA Abs have the capacity to transduce activation signals in endothelial cells that may promote the development of chronic rejection. 相似文献
55.
Moore J. Rajasekaran K. Cary J. W. Chlan C. 《International journal of peptide research and therapeutics》2019,25(3):1135-1145
International Journal of Peptide Research and Therapeutics - The synthetic, linear peptide, D4E1, demonstrates antimicrobial activity against a broad spectrum of organisms including the toxigenic... 相似文献
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57.
Enhancement of the anti‐inflammatory activity of temporin‐1Tl‐derived antimicrobial peptides by tryptophan,arginine and lysine substitutions 下载免费PDF全文
Ganesan Rajasekaran Radhakrishnan Kamalakannan Song Yub Shin 《Journal of peptide science》2015,21(10):779-785
Temporin‐1Tl (TL) is a 13‐residue frog antimicrobial peptide (AMP) exhibiting potent antimicrobial and anti‐inflammatory activity. To develop novel AMP with improved anti‐inflammatory activity and antimicrobial selectivity, we designed and synthesized a series of TL analogs by substituting Trp, Arg and Lys at selected positions. Except for Escherichia coli and Staphylococcus epidermidis, all TL analogs exhibited retained or increased antimicrobial activity against seven bacterial strains including three methicillin‐resistant Staphylococcus aureus strains compared with TL. TL‐1 and TL‐4 showed a little increase in antimicrobial selectivity, while TL‐2 and TL‐3 displayed slightly decreased antimicrobial selectivity because of their about twofold increased hemolytic activity. All TL analogs demonstrated greatly increased anti‐inflammatory activity, evident by their higher inhibition of the production tumor necrosis factor‐α (TNF‐α) and nitric oxide and the mRNA expression of inducible nitric oxide synthase and TNF‐α in lipopolysaccharide (LPS)‐stimulated RAW264.7 macrophage cells, compared with TL. Taken together, the peptide anti‐inflammatory activity is as follows: TL‐2 ≈ TL‐3 ≈ TL‐4 > TL‐1 > TL. In addition, LPS binding ability of the peptides corresponded with their anti‐inflammatory activity. These results apparently suggest that the anti‐inflammatory activity of TL analogs is associated with the direct binding ability between these peptides and LPS. Collectively, our designed TL analogs possess improved anti‐inflammatory activity and retain antimicrobial activity without a significant increase in hemolysis. Therefore, it is evident that our TL analogs constitute promising candidates for the development of peptide therapeutics for gram‐negative bacterial infection. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
58.
Arumugam Thiagarajan Rajasekaran Lada Steeve Pepin Charles Forney Yves Desjardins Martine Dorais 《Trees - Structure and Function》2012,26(5):1545-1553
To fulfill the US Thanksgiving and Christmas tree markets, balsam fir (Abies balsamea (L.) Mill.) is generally harvested before the cold season, anecdotally leading to premature needle senescence. Accordingly, we tested the hypothesis that LT exposure before harvest induces specific hormonal changes and delays postharvest senescence and/or abscission in balsam fir. Two hundred and six seedlings exposed to two temperature treatments for 48?h, LT at 5?°C and controls at 22?°C were severed off roots and monitored for their postharvest needle senescence. Root and shoot (needles and buds) tissues were examined for major endogenous hormone metabolites. LT increased shoot ABA (2,007?ng?g?1 DW) by 2.5× and decreased GA44 (9.84?ng?g?1 DW) by 3.5× over those in roots. LT did not alter cytokinins, auxins or any root hormonal concentration. With auxins, only IAA, IAA-Asp, IAA-Leu and IAA-Glu were detected and the concentrations of IAA and IAA-Asp in shoots were lower than those found in roots. Among cytokinins, shoot c-ZR (58.95?ng?g?1 DW) and t-ZR (4.17?ng?g?1 DW) were 3× higher than those in roots. Apart from GA44, GA9 (136.76?ng?g?1 DW) was abundant in shoots. The PBL and PNL were 46 and 1.2?%, irrespective of treatments. LT seedlings held needles 11?days longer than the controls (122?days). In balsam fir, short-term LT exposure augmented ABA and decreased GA44 levels in shoots and delayed postharvest needle senescence. 相似文献
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60.
Tannic acid attenuates TGF‐β1‐induced epithelial‐to‐mesenchymal transition by effectively intervening TGF‐β signaling in lung epithelial cells 下载免费PDF全文