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hal-00720515, version 1

Anomalous versus non-homogeneous diffusion in the ligand-binding equilibrium: when size matters

Hédi Soula (Author to contact preferably) 1, 2, Bertrand Caré () 1, 2, 3, Guillaume Beslon () 3, Hugues Berry (Author to contact preferably) 1

Abstract: Measurements of protein motion in living cells and membranes consistently report transient anomalous subdiffusion which converges back to a Brownian motion with reduced diffusion constant at long times, after the subdiffusion regime. On the other hand, membranes are also non-homogeneous 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 to those obtained with slowed-down Brownian motion. We show that both processes increase the apparent affinity of the reaction. However, 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, these two processes are different: size matters for slowed-down Brownian motion, not for transient anomalous subdiffusion.

  • 1:  BEAGLE (Insa Lyon / INRIA Grenoble Rhône-Alpes / UCBL)
  • INRIA – Institut National des Sciences Appliquées (INSA) - Lyon – Université Claude Bernard - Lyon I
  • 2:  Laboratoire de recherche en cardiovasculaire, métabolisme, diabétologie et nutrition (CARMEN)
  • INSERM : U1060 – Institut national de la recherche agronomique (INRA) – Institut National des Sciences Appliquées (INSA) - Lyon – Université Claude Bernard - Lyon I – Hospices Civils de Lyon
  • 3:  Laboratoire d'InfoRmatique en Images et Systèmes d'Information (LIRIS)
  • CNRS : UMR5205 – Université Claude Bernard - Lyon I – Université Lumière - Lyon II – Institut National des Sciences Appliquées (INSA) - Lyon – Ecole Centrale de Lyon
  • Domain : Life Sciences/Quantitative Methods
    Physics/Physics/Biological Physics
    Computer Science/Bioinformatics
 
  • hal-00720515, version 1
  • http://hal.inria.fr/hal-00720515
  • oai:hal.inria.fr:hal-00720515
  • From: Hugues Berry <>
  • Submitted on: Tuesday, 24 July 2012 16:53:46
  • Updated on: Tuesday, 24 July 2012 17:21:08