Search results for "binding"

Regulation of tartrate metabolism by TtdR and relation to the DcuS–DcuR-regulated C4-dicarboxylate metabolism of Escherichia coli

2009

Escherichia coli catabolizes l-tartrate under anaerobic conditions to oxaloacetate by the use of l-tartrate/succinate antiporter TtdT and l-tartrate dehydratase TtdAB. Subsequently, l-malate is channelled into fumarate respiration and degraded to succinate by the use of fumarase FumB and fumarate reductase FrdABCD. The genes encoding the latter pathway (dcuB, fumB and frdABCD) are transcriptionally activated by the DcuS–DcuR two-component system. Expression of the l-tartrate-specific ttdABT operon encoding TtdAB and TtdT was stimulated by the LysR-type gene regulator TtdR in the presence of l- and meso-tartrate, and repressed by O2 and nitrate. Anaerobic expression required a functional fn…

Characterization of the CtsR stress response regulon in Lactobacillus plantarum.

2010

ABSTRACT Lactobacillus plantarum ctsR was characterized. ctsR was found to be cotranscribed with clpC and induced in response to various abiotic stresses. ctsR deletion conferred a heat-sensitive phenotype with peculiar cell morphological features. The transcriptional pattern of putative CtsR regulon genes was examined in the Δ ctsR mutant. Direct CtsR-dependent regulation was demonstrated by DNA-binding assays using recombinant CtsR and the promoters of the ctsR - clpC operon and hsp1 .

Shed membrane vesicles and selective localization of gelatinases and MMP-9/TIMP-1 complexes.

1999

DNA Binding Studies and Cytotoxicity of a Dinuclear PtII Diazapyrenium- Based Metallo-supramolecular Rectangular Box

2012

The interaction with native DNA of a 2,7-diazapyrenium-based ligand 1 and its Pt II rectangular metal- lacycle 2 is explored through circular and linear dichroism and fluorescence spectroscopies. The metal-free ligand 1 binds through intercalation, with a binding constant of approximately 5 � 10 5 m � 1 , whereas the metallacycle 2 binds and bends the DNA with a bind- ing constant of 7 � 10 6 m � 1 . PCR assays show that metallo-supramolecular box 2 interferes with DNA transactions in vitro whereas the intercalator 1 does not. The metallacycle is active against four human cancer cell lines, with IC50 values ranging between 3.1 and 19.2 mm and shows similar levels of efficacy, but a differen…

New heteronuclear gold(I)-platinum(II) complexes with cytotoxic properties: are two metals better than one?

2014

A series of mono- and heterodinuclear gold(I) and platinum(II) complexes with a new bipyridylamine-phosphine ligand have been synthesized and characterized. The X-ray structures of the ligand precursor 4-iodo-N,N-di(pyridin-2-yl)benzamide, and of one gold derivative are reported. All the complexes display antiproliferative properties in vitro in human cancer cells in the range of cisplatin or higher, which appear to correlate with compounds' uptake. Interestingly, studies of the interactions of the compounds with models of DNA indicate different mechanisms of actions with respect to cisplatin. The biological activity study of these complexes provides useful information about the interest of…

Kavapyrone enriched extract fromPiper methysticum as modulator of the GABA binding site in different regions of rat brain

1994

Regional differences in the modulation of [3H] muscimol binding to GABAA receptor complexes by kavapyrones, compounds of the rhizome of the plant Piper methysticum which possess sedative activity, were demonstrated using membrane fractions obtained from target brain centers of kavapyrone action: hippocampus (HIP), amygdala (AMY) and medulla oblongata (MED), and from brain centers outside the main kavapyrone effects as frontal cortex (FC) and cerebellum (CER). The kava extract enhanced the binding of [3H] muscimol in a concentration-dependent manner with maximal potentiation of 358% over control in HIP followed by AMY and MED (main target brain centers). Minimal stimulation was observed in C…

In human and rat lung membranes [35s]GTPγS binding is a tool for pharmacological characterization of G protein-coupled devucleotide receptors

1999

The P2Y receptor family is activated by extracellular nucleotides such as ATP and UTP. P2Y receptors regulate physiological functions in numerous cell types. In lung, the P2Y2 receptor subtype plays a role in controlling Cl- and fluid transport. Besides ATP or UTP, also diadenosine tetraphosphate (Ap4A), a stable nucleotide, seems to be of physiological importance. In membrane preparations from human and rat lung we applied several diadenosine polyphosphates to investigate whether they act as agonists for G protein-coupled receptors. We assessed this by determining the stimulation of [35S]GTPgammaS binding. Stimulation of [35S]GTPgammaS binding to G proteins has already been successfully ap…

Microanalytical method for studying paintings by use of fluorescence spectroscopy combined with principal component analysis

2013

Abstract The study of several different naturally aged films of organic painting materials, is described. Materials studied include drying oils (walnut, poppy seed and linseed oil) resin-based paint varnishes (the triterpenoid dammar and the diterpenoids sandarac and turpentine) and protein-based binding media (egg yolk and casein). A not expensive methodology for a rapid identification of binding media and varnishes, that applies principal component analysis (PCA) to Excitation Emission (EE) fluorescence spectra, is proposed. PCA was performed on a data matrix where the rows represent studied materials and columns the variables; the variables include the fluorescence intensities associated…

RNAbinding proteins involved in nerve cell differentiation.

2009

La teneur en lipides du régime affecte les capacitésd'absorption intestinale et la triglycéridémie postprandiale: contribution du récepteur nucléaire…

2007

The dietary long chain fatty acid have crucial functions into the organism such as energysource, eicosanoïdes synthesis, gene regulation). The fat disposal is essential and depend onintestinal barrier. It is well known that intestinal fat absorption is efficient. However, we don'tif the high triglycerides bioavailability of gut is attributable to inborn properties or to acquiredproperties. To answer this question, mice were subjected to a high-fat diet (40%, w/w) during21 days. We have shown that high-fat induces : 1) intestinal LCFA uptake, 2) intestinalmitotic index which leads to an increase of intestinal relative mass, 3) expression of genesinvolved in fatty uptake (Fatty Acid Transport…