Prix et distinctions
Cell fate decisions and cellular functions are dictated by the spatiotemporal dynamics of molecular signaling networks. However, the techniques available to examine the spatiotemporal properties of these intracellular processes remain limited. Here we report a method to artificially control in space and time such signaling pathways using magnetic nanoparticles conjugated to key regulatory proteins.
Living systems rely on chains of energy transfer to maintain their metabolism from an energy source. This task requires functionally-identified components and organizations. However propagation of a sustained energy flux throughout a cascade of reaction cycles has never been reproduced at steady-state in a simple chemical system.
We showed, using first-principle molecular dynamics simulations, that the standard Marcus theory of charge transfer reaction in solution, relying on a linear solvent response approximation, and involving two parameters, the reorganization energy and the reaction free-energy parameter, may fail when the solvation has a different character in the reactant and product state. Such situation arise for even simple half oxydo- reduction reactions involving the Cu+/Cu2+ or Ag/Ag+ couples in water. We proposed theoretical extensions that exhibit the correct non-linear response behavior and reproduce the simulation results quantitatively, whereas Marcus theory breaks down.
Reactive oxygen and nitrogen species (ROS and RNS) produced by macrophages are essential for protecting a human body against bacteria and viruses through digestion of ingested bodies in specific vacuoles. However, the issue concerning the potential leakage of ROS/RNS from vacuoles has been raised as a tentative explanation to some illness (e.g., gout). The purpose of this work was to investigate quantitatively and kinetically this issue.
Apparue au milieu du XXe siècle, la simulation moléculaire est aujourd’hui un outil largement utilisé pour aider à interpréter et comprendre des résultats expérimentaux, tester de nouvelles théories, ou prédire le comportement physique ou chimique de la matière.