Search results for " bifunctional"
showing 6 items of 6 documents
2,8-Diazido-ATP — a short-length bifunctional photoaffinity label for photoaffinity cross-linking of a stable F1 in ATP synthase (from thermophilic b…
1995
Abstract To demonstrate the direct interfacial position of nucleotide binding sites between subunits of proteins we have synthesized the bifunctional photoaffinity label 2,8-diazidoadenosine 5′-triphosphate (2,8-DiN3ATP). UV irradiation of the F1-ATPase (TF1) from the thermophilic bacterium PS3 in the presence of 2,8-DiN3ATP results in a nucleotide-dependent inactivation of the enzyme and in a nucleotide-dependent formation of α-β crosslinks. The results confirm an interfacial localization of all the nucleotide binding sites on TF1.
The analysis of modified peroxisome proliferator responsive elements of the peroxisomal bifunctional enzyme in transfected HepG2 cells reveals two re…
1995
AbstractPeroxisome proliferators (PPs) are non-genotoxic carcinogens in rodents. They can induce the expression of numerous genes via the heterodimerization of two members of the steroid hormone receptor superfamily, called the peroxisome proliferator-activated receptor (PPAR) and the 9-cis retinoic acid receptor (RXR). Many of the PP responsive genes possess a peroxisome proliferator response element (PPRE) formed by two TGACCT-related motifs. The bifunctional enzyme (HD) PPRE contains 3 such motifs, creating DR1 and DR2 sequences. PPAR and RXR regulate transcription via the DR1 element while DR2 modulates the expression of the gene via auxiliary factors in HepG2 cells.
Peroxisomal and mitochondrial status of two murine oligodendrocytic cell lines (158N, 158JP): potential models for the study of peroxisomal disorders…
2009
International audience; In some neurodegenerative disorders (leukodystrophies) characterized by myelin alterations, the defect of peroxisomal functions on myelin-producing cells (oligodendrocytes) are poorly understood. The development of in vitro models is fundamental to understanding the physiopathogenesis of these diseases. We characterized two immortalized murine oligodendrocyte cell lines: a normal (158N) and a jimpy (158JP) cell line mutated for the proteolipid protein PLP/DM20. Fluorescence microscopy, flow cytometry, and western blotting analysis allow to identify major myelin proteins (PLP colocalizing with mitochondria; myelin basic protein), oligodendrocyte (CNPase and myelin oli…
The peroxisome proliferator response element (PPRE) present at positions -681/-669 in the rat liver 3-ketoacyl-CoA thiolase B gene functionally inter…
2000
Although previous data showed that the putative thiolase B PPRE located at -681/-669 bind the PPARalpha-RXRalpha heterodimer in vitro (Kliewer et al. (1992) Nature 358, 771-774), there is no evidence about the functional role of this element. By gel mobility-shift assay, we found an interaction of this PPRE with not only PPARalpha but also with HNF-4. By transfection of cells with the putative PPRE-driven luciferase reporter vector and PPARalpha, we found no significant activation of the luciferase gene expression, in contrast to the case with reporter expression driven by the PPRE of the peroxisomal bifunctional enzyme. On the other hand, HNF-4 activated the luciferase gene expression driv…
Epigenetic agents as an adjunct to active chemotherapy in hematological tumor cell lines
2012
Epigenetic therapy is a new promising area in cancer research that is based on the use of a series of molecules capable of affecting tumor cell growth, differentiation and death by modifying the cellular mechanisms underlying the control of gene expression. Significant enhancement of traditional anticancer drug effects has been also reported by several authors. Our recent research focused on the identification of new epigenetic agent-containing drug combinations to be employed in the therapy of leukemia. The results showed that the new combination of an histone deacetylase (HDAC) inhibitor and the ribonucleotide reductase (RR) inhibitor 3’-methyl-adenosine (3’-Me-Ado) is endowed with a sign…
Organocatalysts Fold to Generate an Active Site Pocket for the Mannich Reaction
2017
Catalysts containing urea, thiourea and tertiary amine groups fold into a three-dimensional organized structure in solution both in the absence as well as in the presence of substrates or substrate analogues, as indicated by solution NMR and computational studies. These foldamer catalysts promote Mannich reactions with both aliphatic and aromatic imines and malonate esters. Hammett plot and secondary kinetic isotope effects provide evidence for the C-C bond forming event as the turnoverlimiting step of the Mannich reaction. Computational studies suggest two viable pathways for the C-C bond formation step, differing in the activation modes of the malonate and imine substrates. The results sh…