Volume 80, Number 1, October 2007
Article Number 18001
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 07 September 2007
EPL, 80 (2007) 18001
DOI: 10.1209/0295-5075/80/18001

Surface-enhanced unfolding of collapsed polymers in shear flow

A. 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 $\dot{\gamma}^* $, the globule becomes unstable and displays stretching-refolding events. With decreasing distance from the surface, the critical shear rate $\dot{\gamma}^* $ 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