Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
AKB: Biologische Physik
AKB 40: Poster Session II
AKB 40.18: Poster
Mittwoch, 29. März 2006, 16:30–19:30, P3
Probability for specific bond formation for a Brownian particle in linear shear flow above a wall — •Christian Korn1,2 and Ulrich S. Schwarz1,2 — 1University of Heidelberg, Im Neuenheimer Feld 293, D-69120 Heidelberg, Germany — 2Max Planck Institute of Colloids and Interfaces, D-14424, Potsdam, Germany
Cohesion in biological systems and biotechnological applications is
usually provided by specific bonds between receptors and ligands.
The formation of these bonds requires a physical transport process which
brings receptors and ligands to sufficient proximity for binding.
As a non-trivial example here we study the motion of
a rigid spherical Brownian particle in linear shear flow carrying receptors
for ligands covering a planar boundary wall. This situation is relevant
for the binding of white blood cells to blood vessel walls, which
can be studied quantitatively in flow chambers.
The appropriate mobility matrix follows from the Stokes equation
and is position-dependent due to the presence of the wall.
This leads to a non-trivial multiplicative noise term in the
corresponding Langevin equation.
We determine the mean time for receptor-ligand encounter as a function of
the Péclet numbers, which describe the transition from diffusive to deterministic
transport. We also show in quantitative detail how the results are influenced by the
values of receptor and ligand coverage.