Search results for "complexe"
showing 10 items of 920 documents
Cryptogein affects expression of alpha3, alpha6 and beta1 20S proteasome subunits encoding genes in tobacco.
2001
Twelve a and b 20S proteasome subunits cDNAs showing 70–82% identity with the corresponding genes in Arabidopsis or rice, and features of eukaryotic proteasome subunits were cloned in tobacco. Only b1-tcI 7, a3 and a6, 20S proteasome subunits encoding genes were up-regulated by cryptogein, a proteinaceous elicitor of plant defence reactions. These results led to the hypothesis that the activation of b1-tcI 7, a3 and a6 could induce a specific proteolysis involved in the hypersensitive response and systemic acquired resistance monitored by cryptogein. In eukaryotes, the 26S proteasome is the central multicatalytic proteinase complex comprising two subcomplexes: the 20S core particle that per…
Differential Expression of the Aspergillus fumigatus pksP Gene Detected In Vitro and In Vivo with Green Fluorescent Protein
2001
ABSTRACT Aspergillus fumigatus is an important pathogen of immunocompromised hosts, causing pneumonia and invasive disseminated disease with high mortality. To be able to analyze the expression of putative virulence-associated genes of A. fumigatus , the use of the enhanced green fluorescent protein (EGFP) as a reporter was established. Two 5′ sequences, containing the putative promoters of the pyrG gene, encoding orotidine-5′-phosphate decarboxylase, and the pksP gene, encoding a polyketide synthase involved in both pigment biosynthesis and virulence of A. fumigatus , were fused with the egfp gene. The P pksP - egfp construct was integrated via homologous recombination into the genomic pks…
Enzyme-Mediated Controlled Release Systems by Anchoring Peptide Sequences on Mesoporous Silica Supports
2011
[EN] Gated community: Peptides anchored to the surface of silica mesoporous supports by a valid procedure act as gatekeepers. In this way, "zero release" supports that selectively deliver the cargo in the presence of a suitable peptidase are obtained (see picture, red spheres: cargo, colored chains: peptides). © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Nickel precursors based on diamagnetic and paramagnetic di(imine)pyridine ligands for magnetic materials: Synthesis, X-ray structures and magnetic st…
2018
International audience; Structural characterization and spectroscopic studies of the (2-acetyl-6-(1-TEMPO-imino)ethyl)pyridine (pat) and the 2,6-bis(1-TEMPO-imino)ethyl)pyridine (pbtMe) ligands are presented. Their electrochemical properties are also discussed. Two new nickel complexes, [NiII(dip)(CH3CN)(H2O)2](BF4)2 (1) (dip = 2,6-(di-iminepyridine)) and [NiII(pbtMe)(CH3CN)3](BF4)2 (2) have been characterized by X-ray diffraction. The reaction of 1 with the tetraethyl ammonium pentacyanopropenide salt (Et4N)(pcp) affords the new compound [NiII(pcp)(dip)(CH3CN)](pcp) (3) for which X-ray diffraction studies evidence an usual bridging μ2 coordination mode for the pentacyanopropenide anion, le…
Interaction of Human Phagocytes with Pigmentless Aspergillus Conidia
2000
ABSTRACT A defect in the pksP gene of Aspergillus fumigatus is associated with the loss of conidial pigmentation, a profound change of the conidial surface structure, and reduced virulence. The structural change of the conidial surface structure was not observed in similar A. nidulans wA mutants. Our data indicate that the pigment of both species is important for scavenging reactive oxygen species and for protection of conidia against oxidative damage.
Low Density Lipoprotein Receptor-related Protein (LRP) Interacts with Presenilin 1 and Is a Competitive Substrate of the Amyloid Precursor Protein (A…
2005
Presenilin 1 (PS1) is a critical component of the gamma-secretase complex, which is involved in the cleavage of several substrates including the amyloid precursor protein (APP) and the Notch receptor. Recently, the low density receptor-related protein (LRP) has been shown to be cleaved by a gamma-secretase-like activity. We postulated that LRP may interact with PS1 and tested its role as a competitive substrate for gamma-secretase. In this report we show that LRP colocalizes and interacts with endogenous PS1 using coimmunoprecipitation and fluorescence lifetime imaging microscopy. In addition, we found that gamma-secretase active site inhibitors do not disrupt the interaction between LRP an…
Revisited BIA-MS combination: Entire "on-a-chip" processing leading to the proteins identification at low femtomole to sub-femtomole levels
2008
International audience; We present the results of a study in which biomolecular interaction analysis (BIA, Biacore 2000) was combined with mass spectrometry (MS) using entire "on-a-chip" procedure. Most BIA-MS studies included an elution step of the analyte prior MS analysis. Here, we report a low-cost approach combining Biacore analysis with homemade chips and MS in situ identification onto the chips without elution step. First experiments have been made with rat serum albumin to determine the sensitivity and validation of the concept has been obtained with an antibody/antigen couple. Our "on-a-chip" procedure allowed complete analysis by MS-MS of the biochip leading to protein identificat…
Porphyrin and phthalocyanine photosensitizers designed for targeted photodynamic therapy of colorectal cancer
2020
Colorectal cancer is of particular concern due to its high mortality rate count. Recent investigations on targeted phototherapy involving novel photosensitizers and drug-delivery systems have provided promising results and realistic prospects for a successful medical treatment. New research trends have been focused particularly on development of advanced molecular systems offering effective photoactive species which could be selectively delivered directly into the affected cells. Porphyrins and phthalocyanines have been considered extremely attractive for this purpose due to their molecular versatility, excellent photochemical properties and multifunctional nature. In this review it has bee…
Metal complexes of a novel heterocyclic benzimidazole ligand formed by rearrangement-cyclization of the corresponding Schiff base. Electrosynthesis, …
2018
The electrochemical oxidation of anodic metals (M = cobalt, nickel, copper, zinc and cadmium) in a solution of the ligand 1H-anthra[1,2-d]imidazol-6,11-dione-2-[2-hydroxyphenyl] [H2L] afforded homoleptic [ML] compounds. The addition to the electrochemical cell of coligands (L′) such as 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) allowed the synthesis, in one step, of heteroleptic [MLL′] compounds. The crystal structures of H2L (1), [CoL(MeOH)]2 (2), [CoL(phen)]2 (3), [NiL(bpy)]2 (4), [CuL(bpy)] (5), [CuL(phen)] (6) and [CdL(bpy)]2 (7) have been determined by X-ray diffraction techniques. The crystal structures of 2, 3, 4 and 7 consist of dimeric species in which both metallic atoms …
Lipoprotein-induced phenoloxidase-activity in tarantula hemocyanin.
2015
Phenoloxidases play vital roles in invertebrate innate immune reactions, wound closure and sclerotization processes in arthropods. In chelicerates, where phenoloxidases are lacking, phenoloxidase-activity can be induced in the oxygen carrier hemocyanin in vitro by proteolytic cleavage, incubation with the artificial inducer SDS, or lipids. The role of protein-protein interaction has up to now received little attention. This is remarkable, as lipoproteins - complexes of proteins and lipids - are present at high concentrations in arthropod hemolymph. We characterized the three lipoproteins present in tarantula hemolymph, two high-density lipoproteins and one very high-density lipoprotein, and…