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101.
102.
Dharmu I Ramamurty N Kannan R Babu M 《In vitro cellular & developmental biology. Animal》2007,43(8-9):306-314
The hemolymph-derived achatininH (lectin) from Achatina fulica showed a marked cytotoxic effect on MCF7, a human mammary carcinoma cell line. IC50 values as measured by the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay for achatininH ranged from 6 to 10 μg/ml in the MCF7 cells. MCF7 cells showed significant morphological changes leading to cell death. The
above cell death was observed after 48 h of treatment with 8 μg/ml when compared to untreated cells. Alterations in the tumor
marker enzymes, as well as in antioxidant enzymes, were observed after achatininH treatment. The specificity and purity of the achatininH was confirmed by the Western blot assay. AchatininH binding to MCF7 cells was detected by anti-achatininH, and visualization of the achatininH binding sites on confluent MCF7 cells was confirmed by flourescein isothiocyanate conjugated secondary antibody. MCF7-treated
cells fluoresced, indicating the presence of achatininH binding sites. Fluorescence-activated cell sorting analysis of the cell cycle showed a significant increase in S-phase in
MCF7 cells after 48 h of achatininH treatment. The cells were arrested in G2/M phase of the cell cycle after 48 h with significant changes in cell viability. Cellular damage was confirmed by agarose
gel electrophoresis with the characteristic appearance of a DNA streak in treated MCF7 cells indicating the ongoing apoptosis.
An erratum to this article can be found at 相似文献
103.
104.
The catalytic domain of epidermal growth factor receptor (EGFR) is activated by dimerization, which requires allosteric coupling between distal dimerization and catalytic sites. Although crystal structures of EGFR kinases, solved in various conformational states, have provided important insights into EGFR activation by dimerization, the atomic details of how dimerization signals are dynamically coupled to catalytic regions of the kinase core are not fully understood. In this study, we have performed unrestrained and targeted molecular dynamics simulations on the active and inactive states of EGFR, followed by principal component analysis on the simulated trajectories, to identify correlated motions in the EGFR kinase domain upon dimerization. Our analysis reveals that the conformational changes associated with the catalytic functions of the kinase core are highly correlated with motions in the juxtamembrane (JM) and C-terminal tail, two flexible structural elements that play an active role in EGFR kinase activation and dimerization. In particular, the opening and closing of the ATP binding lobe relative to the substrate binding lobe is highly correlated with motions in the JM and C-terminal tail, suggesting that ATP and substrate binding can be coordinated with dimerization through conformational changes in the JM and C-terminal tail. Our study pinpoints key residues involved in this conformational coupling, and provides new insights into the role of the JM and C-terminal tail segments in EGFR kinase functions. 相似文献
105.
Design of potential drug-like candidates for cancer is of interest in recent years. We used 60 compounds which are known to have the potential to down regulate Nuclear Factor kappaB (NFκB) for this study. The compounds were assessed for Lipinski's RO5 and ADMET properties. Allixin, anethole, capsaicin, linearol and syringic acid satisfied both Lipinski's RO5 and ADMET properties. These compounds showed strong molecular interaction with receptor GPCR55 indicating they have ability to block GPCR55. Thus, their role in anticellular proliferation and induction of apoptosis is implied. 相似文献
106.
An extracellular nuclease from Bacillus firmus VKPACU-1 was multifunctional enzyme, this nuclease hydrolyzed poly U rapidly and more preferentially than the other homopolyribonucleotides. Hydrolysis of RNA this enzyme released mononucleotides in the order 5'UMP > 5'AMP > 5'GMP where as in hydrolysis of DNA the mononucleotides in the order of 5'dAMP > 5'dGMP > 5'dTMP and oligonucleotides. Uridylic linkages in RNA and adenylic linkages in DNA were preferentially cleaved by the nuclease. Nuclease produced oligonucleotides having only 3' hydroxyl and 5' phosphate termini. Present nuclease hydrolyzed RNA and DNA released oligonucleotides as major end products and mononucleotides, suggesting an endo mode of action. 相似文献
107.
108.
Thanukrishnan Kannan Duraikkannu Loganathan Yukti Bhatia Saroj Mishra Virendra S. Bisaria 《Biocatalysis and Biotransformation》2004,22(1):1-7
The stability of almond β-glucosidase in five different organic media was evaluated. After 1 hour of incubation at 30°C, the enzyme retained 95, 91, 81, 74 and 56% relative activity in aqueous solutions [30% (v/v)] of dioxane, DMSO, DMF, acetone and acetonitrile, respectively. Transglucosylation involving p-nitrophenyl β-D-glucopyranoside as donor and β-1-N-acetamido-D-glucopyranose, which is a glycosylasparagine mimic, as acceptor was explored under different reaction conditions using almond βglucosidase and cloned Pichia etchellsii β-glucosidase II. The yield of disaccharides obtained in both reactions turned out to be 3%. Both enzymes catalyzed the formation of (1→3)- as well as (1→6)- regioisomeric disaccharides, the former being the major product in cloned β-glucosidase II reaction while the latter predominated in the almond enzyme catalyzed reaction. Use of β-1-N-acetamido-D-mannopyranose and β-1-N-acetamido-2-acetamido-2-deoxy-D-glucopyranose as acceptors in almond β-glucosidase catalyzed reactions, however, did not afford any disaccharide products revealing the high acceptor specificity of this enzyme. 相似文献
109.
Paliakkara L. Jaison Vadakkedath M. Kannan Mandagini Geetha Padinjaradath S. Appukuttan 《Journal of biosciences》1993,18(2):187-193
Naturally occurring serum IgG against terminal α-galactoside epitopes (anti-Gal), present exclusively in man, apes and old
world monkeys, was used as probe for these epitopes in human brain. Human brain grey matter soluble glycoproteins enriched
inα galactosyl groups by affinity chromatography on jacalin-sepharose, specifically binds to human anti-Gal in immuno dot
blots. Anti-Gal recognized exclusively the terminal α galactoside epitope in human brain glycoproteins since binding was abolished
by the presence of 1-0-methyl α-D-galactopyranoside as well as by pretreatment of glycoproteins with coffee bean α-galactosidase.
Anti-Gal-peroxidase staining of jacalin-binding human brain glycoproteins in western immuno blots revealed mainly five anti-Gal-binding
polypeptides withM
r
(in kDa) of 94, 108, 180, 210 and 230 respectively. Since the presence of anti-Gal in higher animals accompanies suppression
of the corresponding epitope in most tissues, apparently to maintain immunological balance, possible implications of the above
observation for autoimmunity, tumor metastasis and infection are discussed. 相似文献
110.