Surface-enhanced unfolding of collapsed polymers in shear flowA. Alexander-Katz1, 2 and R. R. Netz1
1 Physics Department, TU Munich - D-85748 Garching, Germany
2 Laboratoire Matière Molle & Chimie, ESPCI, CNRS, UMR 7167 - 10 rue Vauquelin, 75005 Paris, France
received 14 June 2007; accepted in final form 14 August 2007; published October 2007
published online 7 September 2007
Using hydrodynamic simulations we study the shear-induced unfolding of a collapsed polymer near a planar wall. Above a well-defined threshold shear rate , the globule becomes unstable and displays stretching-refolding events. With decreasing distance from the surface, the critical shear rate goes down, which is rationalized within a scaling analysis in terms of increased hydrodynamic stress due to a surface-induced slowing-down of globule rotation and translation. Our results are relevant for protein-assisted blood clotting in capillary vessels.
87.15.-v - Biomolecules: structure and physical properties.
82.37.-j - Single molecule kinetics.
© Europhysics Letters Association 2007