Search results for "binding"
showing 10 items of 3896 documents
Amyloid-Beta Induces Different Expression Pattern of Tissue Transglutaminase and Its Isoforms on Olfactory Ensheathing Cells: Modulatory Effect of In…
2021
Abstract Alzhèimer Disease (AD) is characterized by protein aggregates in the brain, including amyloid-beta (Aβ), a substrate for tissue transglutaminase (TG2). We assessed the effect of full native peptide of Aβ (1–42), the fragments (25–35 and 35–25) on TG2 expression and its isoforms (Long and Short) on mouse Olfactory Ensheathing Cells (OECs). The levels of cytoskeletal proteins, Vimentin and Glial Fibrillary Acid Protein, were also studied. The effect of the pre-treatment with Indicaxanthin on cell viability, total Reactive Oxygen Species, superoxide anion and apoptotic pathway activation was assessed. Since Nestin is co-expressed in pluripotent stem cells with cyclin D1, their levels …
A Comparative Study on Nickel Binding to Hpn-like Polypeptides from Two Helicobacter pylori Strains
2021
Combined potentiometric titration and isothermal titration calorimetry (ITC) methods were used to study the interactions of nickel(II) ions with the N-terminal fragments and histidine-rich fragments of Hpn-like protein from two Helicobacter pylori strains (11637 and 26695). The ITC measurements were performed at various temperatures and buffers in order to extract proton-independent reaction enthalpies of nickel binding to each of the studied protein fragments. We bring up the problem of ITC results of nickel binding to the Hpn-like protein being not always compatible with those from potentiometry and MS regarding the stoichiometry and affinity. The roles of the ATCUN motif and multiple His…
Expression profiling of glial genes during Drosophila embryogenesis
2006
AbstractIn the central nervous system of Drosophila, the induction of the glial cell fate is dependent on the transcription factor glial cells missing (gcm). Though a considerable number of other genes have been shown to be expressed in all or in subsets of glial cells, the course of glial cell differentiation and subtype specification is only poorly understood. This prompted us to design a whole genome microarray approach comparing gcm gain-of-function and, for the first time, gcm loss-of-function genetics to wildtype in time course experiments along embryogenesis. The microarray data were analyzed with special emphasis on the temporal profile of differential regulation. A comparison of bo…
Local dynamics of DNA probed with optical absorption spectroscopy of bound ethidium bromide
1997
We have studied the local dynamics of calf thymus double-helical DNA by means of an "optical labeling" technique. The study has been performed by measuring the visible absorption band of the cationic dye ethidium bromide, both free in solution and bound to DNA, in the temperature interval 360-30 K and in two different solvent conditions. The temperature dependence of the absorption line shape has been analyzed within the framework of the vibronic coupling theory, to extract information on the dynamic properties of the system; comparison of the thermal behavior of the absorption band of free and DNA-bound ethidium bromide gave information on the local dynamics of the double helix in the prox…
Dynamic force spectroscopy: analysis of reversible bond-breaking dynamics
2008
The problem of diffusive bond-dissociation in a double well potential under application of an external force is scrutinized. We compute the probability distribution of rupture forces and present a detailed discussion of the influence of finite rebinding probabilities on the dynamic force spectrum. In particular, we focus on barrier crossing upon extension, i.e. under linearly increased load, and upon relaxation starting from completely separated bonds. For large loading rates the rupture force and the rejoining force depend on the loading rate in the expected manner determined by the shape of the potential. For small loading rates the mean forces obtained from pull and relax modes approach …
Quaternary relaxations in sol-gel encapsulated hemoglobin studied via NIR and UV spectroscopy.
2007
In this work, we study the kinetics of the R --T transition in hemoglobin using a combination of near-infrared and near-ultraviolet spectroscopy. We use a sol-gel encapsulation protocol to decelerate the conformational transitions and to avoid spectral perturbations arising from ligand migration and recombination. We monitor two spectroscopic markers: band III in the near-IR, which is a fine probe of the heme pocket conformation, and the tryptophan band in the near-UV, which probes the formation of the Trpbeta37-Aspalpha94 hydrogen bond, characteristic of the T structure, at the critical alpha1beta2 subunit interface. The time evolution of these two bands is monitored after deoxygenation of…
Cyclic AMP-induced Chromatin Changes Support the NFATc-mediated Recruitment of GATA-3 to the Interleukin 5 Promoter
2008
Elevated intracellular cyclic AMP levels, which suppress the proliferation of naive T cells and type 1 T helper (Th1) cells are a property of T helper 2 (Th2) cells and regulatory T cells. While cyclic AMP signals interfere with the IL-2 promoter induction, they support the induction of Th2-type genes, in particular of il-5 gene. We show here that cyclic AMP signals support the generation of three inducible DNase I hypersensitive chromatin sites over the il-5 locus, including its promoter region. In addition, cyclic AMP signals enhance histone H3 acetylation at the IL-5 promoter and the concerted binding of GATA-3 and NFATc to the promoter. This is facilitated by direct protein-protein inte…
Interaction between flavour compounds and beta-lactoglobulin: approach by NMR and 2D/3D-QSAR studies of ligands
2004
author cannot archive publisher's version/PDF; International audience; Interactions between flavour compounds and beta-lactoglobulin (BLG) have been the subject of several studies, but there are no unanimous binding site explanations. In our laboratory, interactions between BLG, and two flavour compounds, beta-ionone and gamma-decalactone, were studied by 2D-NMR spectroscopy. It appears that several amino acids affected by binding of gamma-decalactone are buried in the central cavity, whereas binding of beta-ionone affects amino acids located in a groove near the outer surface of the protein. 2D/3D-QSAR studies were performed using QSAR+ module of Cerius2 and Catalyst. The QSAR equation pr…
New qsar models for polyhalogenated aromatics
1994
Electronic properties of polychlorinated dibenzo p dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated diphenyl ethers (PCDEs) were calculated using the semi-empirical AM1 method The calculated electronic descriptors — the energy of the lowest unoccupied molecular orbital (ELUMO), the energy of the highest occupied molecular orbital (EHOMO), the ELUMO-EHOMO gap (dE), and molecular polarizability — are related to the Ah receptor binding affinity values of PCDDs, PCDFs, and PCBs and immunotoxicity values for PCDEs The quantitative structure activity relationships (QSARs) based on chlorine substitution patterns were also constructed, an…
A topological substructural approach for the prediction of P-glycoprotein substrates
2006
A topological substructural molecular design approach (TOPS-MODE) has been used to predict whether a given compound is a P-glycoprotein (P-gp) substrate or not. A linear discriminant model was developed to classify a data set of 163 compounds as substrates or nonsubstrates (91 substrates and 72 nonsubstrates). The final model fit the data with sensitivity of 82.42% and specificity of 79.17%, for a final accuracy of 80.98%. The model was validated through the use of an external validation set (40 compounds, 22 substrates and 18 nonsubstrates) with a 77.50% of prediction accuracy; fivefold full cross-validation (removing 40 compounds in each cycle, 80.50% of good prediction) and the predictio…