46 research outputs found
A structural study of the complex between neuroepithelial cell transforming gene 1 (Net1) and RhoA reveals a potential anticancer drug hot spot
Silver-staining of proteins in polyacrylamide gels: a general overview.: overview of silver staining methods for proteins
International audienceOn the basis of the physico-chemical principles underlying silver-staining of proteins, which are recalled in this paper, several methods of silver-staining of proteins after SDS electrophoresis in polyacrylamide gels or isoelectric focusing were tested. The most valuable protocols are presented in this report, including standard methods for unsupported gels and new methods devised for thin (0.5 mm) supported gels for SDS electrophoresis or isoelectric focusing and for staining of small peptides. Generally speaking, the most rapid methods were found to be less sensitive and less reproducible than more time-consuming ones. Among the long methods, those using silver-diammine complex gave the most uniform sensitivity. They require however special home-made gels and cannot be applied to several electrophoretic systems (e.g. systems using tricine or bicine as the trailing ion, or isoelectric focusing in immobilized pH gradients). For these reasons, protocols based on silver nitrate are of a more general use and might be favored. Future trends for silver-staining will also be discussed
La cryo-microscopie, une alternative Ă la cristallographie aux rayons X ?
International audience> De rĂ©centes avancĂ©es technologiques rĂ©vo-lutionnent le domaine des biologistes structu-ralistes. Plus prĂ©cisĂ©ment, des progrĂšs spec-taculaires liĂ©s au dĂ©veloppement de nouvelles technologies de capture d'images de microscope Ă©lectronique (la dĂ©tection directe d'Ă©lectrons) ainsi que la mise Ă disposition de nouveaux logiciels d'analyse d'images ont conduit Ă une percĂ©e en terme de rĂ©solution en cryo-micros-copie Ă©lectronique Ă transmission. Il est ainsi possible de calculer relativement rapidement des structures Ă haute rĂ©solution de molĂ©cules biologiques dont l'Ă©tude rĂ©siste aux mĂ©thodes plus classiques comme la diffraction des rayons X ou la rĂ©sonance magnĂ©tique nuclĂ©aire (RMN). Ces structures ainsi obtenues peuvent aussi venir en complĂ©ment des informations structurales dĂ©jĂ dĂ©crites par d'autres mĂ©thodes. Certaines de ces nouvelles structures rĂ©solues grĂące Ă la cryo-microscopie Ă©lectronique rĂ©vĂšlent pour la premiĂšre fois le fonctionnement prĂ©cis de mĂ©ca-nismes essentiels au bon dĂ©roulement physiolo-gique d'une cellule. La capacitĂ© Ă rĂ©soudre ces structures Ă la rĂ©solution du dĂ©tail atomique est une condition essentielle pour le dĂ©veloppement de nouveaux mĂ©dicaments ayant comme cible thĂ©rapeutique ces protĂ©ines d'intĂ©rĂȘt. GrĂące Ă ces avancĂ©es techniques que nous rĂ©sumons ici, des questions biologiques et mĂ©dicales sont maintenant devenues accessibles, ce qui Ă©tait inconcevable il y a seulement cinq ans
Cryo-electron microscopy and X-ray crystallography: complementary approaches to structural biology and drug discovery
International audienc
Cryo-electron microscopy and X-ray crystallography: complementary approaches to structural biology and drug discovery
International audienc
Non-detergent sulphobetaines enhance the recovery of membrane and/or cytoskeleton-associated proteins and active proteases from erythrocytes infected by Plasmodium falciparum
International audienceA better understanding of the causative agent's biology and the definition of new targets for the development of drugs and/or specific immune responses is necessary to face the spred of drug-resistant malaria in developing countries and the absence of an efficient vaccine against this most important infectious disease. Non-detergent sulphobetaines enhance the recovery and isoelectric focussing of active Plasmodium falciparum proteases, cytoskeleton-associated proteins and Maurer's cleft-associated proteins. This is a significant advantage for the purification of such proteins and might help pinpoint their role for red blood cell rupture and merozoite release
A chemical library to screen protein and protein-ligand crystallization using a versatile microfluidic platform
International audienceHere, we describe a plug-and-play microfluidic platform, suitable for protein crystallization. The droplet factory is designed to generate hundreds of droplets as small as a few nanoliters (2 to 10nL) for screening and optimization of crystallization conditions. Commercially-available microfluidic junctions and tubing are combined to create the appropriate geometry. In addition, a " chemical library " is produced in tubing. The microfluidic geometry for a " crystallization agent-based chemical library " is validated by screening crystallization conditions of lysozyme. The microfluidic geometry for a " ligand-based chemical library " is also explored to co-crystallize the protein QR2 with a ligand, for the purposes of structure-based drug design. This platform mixes aqueous phases (containing the protein and the crystallization agent) and organic phases (containing the ligand), during the droplet generation and circulation without using any surfactant. The droplet composition is controlled by the respective flow-rates of the different solutions, and checked by measuring on-line absorbance. The low volumes involved in the crystallization trials, the speed of execution and the absence of a microfabrication stage make our platform a cheap, easy-to-use and versatile tool for crystallization studies
Outpatient management of primary spontaneous pneumothorax
International audienceThe outpatient management of primary spontaneous pneumothorax (PSP) is still debated. The risk of a tension pneumothorax is used to justify active treatment like chest-tube drainage, although outpatient management can reduce both the time in hospital and the cost of treatment. It is also likely to be the patientâs choice. This report is a reappraisal of the situations for which outpatient management, by monitoring alone, or using minimally invasive techniques, can be considered