Search results for "lcsh:Biochemistry"
showing 9 items of 39 documents
“ One Ring to Bind Them All ”—Part I: The Efficiency of the Macrocyclic Scaffold for G-Quadruplex DNA Recognition
2010
International audience; Macrocyclic scaffolds are particularly attractive for designing selective G-quadruplex ligands essentially because, on one hand, they show a poor affinity for the "standard" B-DNA conformation and, on the other hand, they fit nicely with the external G-quartets of quadruplexes. Stimulated by the pioneering studies on the cationic porphyrin TMPyP4 and the natural product telomestatin, follow-up studies have developed, rapidly leading to a large diversity of macrocyclic structures with remarkable-quadruplex binding properties and biological activities. In this review we summarize the current state of the art in detailing the three main categories of quadruplex-binding …
Use of Specific Chemical Reagents for Detection of Modified Nucleotides in RNA
2011
International audience; Naturally occurring cellular RNAs contain an impressive number of chemically distinct modified residues which appear posttranscriptionally, as a result of specific action of the corresponding RNA modification enzymes. Over 100 different chemical modifications have been identified and characterized up to now. Identification of the chemical nature and exact position of these modifications is typically based on 2D-TLC analysis of nucleotide digests, on HPLC coupled with mass spectrometry, or on the use of primer extension by reverse transcriptase. However, many modified nucleotides are silent in reverse transcription, since the presence of additional chemical groups fre…
Immunoaffinity purification and characterization of mitochondrial membrane-bound D-3-hydroxybutyrate dehydrogenase from Jaculus orientalis.
2008
Abstract Background The interconversion of two important energy metabolites, 3-hydroxybutyrate and acetoacetate (the major ketone bodies), is catalyzed by D-3-hydroxybutyrate dehydrogenase (BDH1: EC 1.1.1.30), a NAD+-dependent enzyme. The eukaryotic enzyme is bound to the mitochondrial inner membrane and harbors a unique lecithin-dependent activity. Here, we report an advanced purification method of the mammalian BDH applied to the liver enzyme from jerboa (Jaculus orientalis), a hibernating rodent adapted to extreme diet and environmental conditions. Results Purifying BDH from jerboa liver overcomes its low specific activity in mitochondria for further biochemical characterization of the e…
“One Ring to Bind Them All”—Part II: Identification of Promising G-Quadruplex Ligands by Screening of Cyclophane-Type Macrocycles
2010
A collection of 26 polyammonium cyclophane-type macrocycles with a large structural diversity has been screened for G-quadruplex recognition. A two-step selection procedure based on the FRET-melting assay was carried out enabling identification of macrocycles of high affinity (ΔT1/2up to30°C) and high selectivity for the human telomeric G-quadruplex. The four selected hits possess sophisticated architectures, more particularly the presence of a pendant side-arm as well as the existence of a particular topological arrangement appear to be strong determinants of quadruplex binding. These compounds are thus likely to create multiple contacts with the target that may be at the origin of their h…
Resveratrol, MicroRNAs, Inflammation, and Cancer
2011
MicroRNAs are short noncoding RNAs that regulate the expression of many target genes posttranscriptionally and are thus implicated in a wide array of cellular and developmental processes. The expression ofmiR-155ormiR-21is upregulated during the course of the inflammatory response, but these microRNAs are also considered oncogenes due to their upregulation of expression in several types of tumors. Furthermore, it is now well established that inflammation is associated with the induction or the aggravation of nearly 25% of cancers. Therefore, the above microRNAs are thought to link inflammation and cancer. Recently, resveratrol (trans-3,4′,5-trihydroxystilbene), a natural polyphenol with ant…
Perception of mineral character in Sauvignon blanc wine: inter-individual differences
2014
Revue non indexée dans le JCR.; Of the descriptors employed to characterize wine organoleptically, minerality is arguably one of the most enigmatic. The aim of the work described in this article was to delineate the nature of perceived minerality in Sauvignon wine, specifically its sensorial reality for experienced wine professionals from France and New Zealand. Participants evaluated 16 Sauvignon blanc wines (8 French; 8 New Zealand) under three conditions, ortho-nasal olfaction, palate only (Nose-clip condition), and by full tasting (global perception). Data from the global condition only are reported here. Key results include: i) that although there were quantitative differences in perce…
miRNA-23b as a biomarker of culture-positive neonatal sepsis
2020
Abstract Background Neonatal sepsis remains an important cause of morbidity and mortality. The ability to quickly and accurately diagnose neonatal sepsis based on clinical assessments and laboratory blood tests remains difficult, where haemoculture is the gold standard for detecting bacterial sepsis in blood culture. It is also very difficult to study because neonatal samples are lacking. Methods Forty-eight newborns suspected of sepsis admitted to the Neonatology Department of the Mother-Child Specialized Hospital of Tlemcen. From each newborn, a minimum of 1–2 ml of blood was drawn by standard sterile procedures for blood culture. The miRNA-23b level in haemoculture was evaluated by RT-qP…
In Silico Analysis of Microarray-Based Gene Expression Profiles Predicts Tumor Cell Response to Withanolides
2012
Withania somnifera (L.) Dunal (Indian ginseng, winter cherry, Solanaceae) is widely used in traditional medicine. Roots are either chewed or used to prepare beverages (aqueous decocts). The major secondary metabolites of Withania somnifera are the withanolides, which are C-28-steroidal lactone triterpenoids. Withania somnifera extracts exert chemopreventive and anticancer activities in vitro and in vivo. The aims of the present in silico study were, firstly, to investigate whether tumor cells develop cross-resistance between standard anticancer drugs and withanolides and, secondly, to elucidate the molecular determinants of sensitivity and resistance of tumor cells towards withanolides. Usi…
A Novel Pathophysiological Mechanism Contributing to Trigeminal Neuralgia
2016
Trigeminal neuralgia (TN) is a form of neuropathic pain that affects the fifth cranial nerve, the most widely distributed nerve in the head. Although TN has been associated with a variety of pathological conditions, neurovascular compression on the trigeminal nerve, as it exits the brain stem, is the most frequent reported cause. This compression provides a progressive demyelination of the nerve and a subsequent aberrant neural transmission. Although several studies have clarified some physiopathological mechanisms underlying TN, the molecular basis remains vague. Very recently the substitution of methionine 136 by valine (MET126Val) in sodium channel Nav1.6 in a case study of typical TN ha…