Synthesis of Janus compounds for the recognition of G-U mismatched nucleobase pairs

The design and synthesis of two Janus-type heterocycles with the capacity to simultaneously recognize guanine and uracyl in G-U mismatched pairs through complementary hydrogen bond pairing is described. Both compounds were conveniently functionalized with a carboxylic function and efficiently attached to a tripeptide sequence by using solid-phase methodologies. Ligands based on the derivatization of such Janus compounds with a small aminoglycoside, neamine, and its guanidinylated analogue have been synthesized, and their interaction with Tau RNA has been investigated by using several biophysical techniques, including UV-monitored melting curves, fluorescence titration experiments, and 1H NMR. The overall results indicated that Janus-neamine/guanidinoneamine showed some preference for the +3 mutated RNA sequence associated with the development of some tauopathies, although preliminary NMR studies have not confirmed binding to G-U pairs. Moreover, a good correlation has been found between the RNA binding affinity of such Janus-containing ligands and their ability to stabilize this secondary structure upon complexation

Bayesian Modeling of the Yeast SH3 Domain Interactome Predicts Spatiotemporal Dynamics of Endocytosis Proteins

A genome-scale specificity and interaction map for yeast SH3 domain-containing proteins reveal how family members show selective binding to target proteins and predicts the dynamic localization of new candidate endocytosis proteins

Restauration d'images dégradées de profils métalliques obtenues à l'aide de capteurs plats à courants de Foucault

Nous présentons dans cette communication une application d'un capteur magnétique dont l'élément sensible est une bobine plate gravée sur un circuit imprimé. Cette application concerne la mise en oeuvre d'un dispositif capable de restituer des formes simples de profils métalliques. Nous présentons les différentes étapes de cette réalisation, ainsi que l'élaboration d'un algorithme de déconvolution permettant l'obtention d'un modèle du dispositif et son inversion pour la restauration des signaux d'entrées dégradés par celui-ci

Surface modification and dispersion of nanocrystalline cellulose in organic media

Peer reviewed: YesNRC publication: Ye

Helical rosette nanotubes : Topographical and chemical roles in osteoblast attachment

Success in surgical joint replacements has resulted in a huge demand amongst patients. Coupled with the lowered average age of patients requiring hip replacements, younger patients are demanding longer life expectancy from such devices. The increasing need and demand for more durable implants have led to new formulations of high performance nanomaterials (materials with basic structural units of 1-100 nm). Nanotubes in particular have shown great promise because they: 1) have sizes that approach biological structures and 2) possess efficient channels for displaying chemistries relevant to living systems at high densities and well-controlled spatial distribution. Helical rosette nanotubes (HRN) are a new class of soft organic nanomaterials composed of a guanine-cytosine building block that self-assembles in aqueous environments into stable nanotubular structures with an inner diameter of ~1.1 nm. HRN can be decorated with biologically active chemical functionalities such as cell attracting peptide fragments. Previously, we have showed that HRN coated Ti can enhance OB attachment. In addition, proteins were seen to interact favorably with HRN networks in a manner favorable toward OB attachment. Furthermore, in the absence of proteins, HRN were seen to play the role of proteins in promoting OB attachment. The studies herein, attempt to understand the role of the lysine clusters on HRN toward OB attachment. Results show that OB do respond to lysine and molecular orientation considerations were shown to be important. Detailed structural considerations from molecular modeling further present the possibility of topographical influences (nanotube network architecture) towards OB attachment.Peer reviewed: YesNRC publication: Ye