Anomalous versus slowed-down Brownian diffusion in the ligand-binding equilibriumReportar como inadecuado




Anomalous versus slowed-down Brownian diffusion in the ligand-binding equilibrium - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

* Corresponding author 1 BEAGLE - Artificial Evolution and Computational Biology LIRIS - Laboratoire d-InfoRmatique en Image et Systèmes d-information, Inria Grenoble - Rhône-Alpes, LBBE - Laboratoire de Biométrie et Biologie Evolutive, CarMeN - Laboratoire de recherche en cardiovasculaire, métabolisme, diabétologie et nutrition 2 CarMeN - Laboratoire de recherche en cardiovasculaire, métabolisme, diabétologie et nutrition 3 LIRIS - Laboratoire d-InfoRmatique en Image et Systèmes d-information 4 Inria Grenoble - Rhône-Alpes

Abstract : Measurements of protein motion in living cells and membranes consistently report transient anomalous diffusion subdiffusion which converges back to a Brownian motion with reduced diffusion coefficient at long times, after the anomalous diffusion regime. Therefore, slowed-down Brownian motion could be considered the macroscopic limit of transient anomalous diffusion. On the other hand, membranes are also heterogeneous media in which Brownian motion may be locally slowed-down due to variations in lipid composition. Here, we investigate whether both situations lead to a similar behavior for the reversible ligand-binding reaction in 2d. We compare the long-time equilibrium properties obtained with transient anomalous diffusion due to obstacle hindrance or power-law distributed residence times continuous-time random walks to those obtained with space-dependent slowed-down Brownian motion. Using theoretical arguments and Monte-Carlo simulations, we show that those three scenarios have distinctive effects on the apparent affinity of the reaction. While continuous-time random walks decrease the apparent affinity of the reaction, locally slowed-down Brownian motion and local hinderance by obstacles both improve it. However, only in the case of slowed-down Brownian motion, the affinity is maximal when the slowdown is restricted to a subregion of the available space. Hence, even at long times equilibrium, these processes are different and exhibit irreconcilable behaviors when the area fraction of reduced mobility changes.





Autor: Hédi Soula - Bertrand Caré - Guillaume Beslon - Hugues Berry -

Fuente: https://hal.archives-ouvertes.fr/



DESCARGAR PDF




Documentos relacionados