title: Shear-flow-induced unfolding of polymeric globules.
abstract: The behavior of a single collapsed polymer under shear flow is examined using hydrodynamic simulations and scaling arguments. Below a threshold shear rate gamma[.]{*}, the chain remains collapsed and only deforms slightly, while above gamma[.]{*} the globule exhibits unfolding/refolding cycles. Hydrodynamics are crucial: In the free draining case, gamma[.]{*} scales with the globule radius R as gamma[.]{*} approximately R{-1}, while in the presence of hydrodynamic interactions gamma[.]{*} approximately R. Experiments on the globular von Willebrand protein confirm the presence of an unfolding transition at a well-defined critical shear rate.
authors.affiliation: Physics Department, Technical University Munich, 85748 Garching, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Alexander-Katz
authors.forename: M F
authors.initials: MF
authors.lastname: Schneider
authors.forename: S W
authors.initials: SW
authors.lastname: Schneider
authors.forename: A
authors.initials: A
authors.lastname: Wixforth
authors.forename: R R
authors.initials: RR
authors.lastname: Netz
mesh_terms: D006801:Humans; D007700:Kinetics; D015233:Models, Statistical; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry*; D011489:Protein Denaturation; D017510:Protein Folding; D013314:Stress, Mechanical; D013997:Time Factors; D014841:von Willebrand Factor / Q000737:chemistry
chemical_list: D011108:Polymers; D014841:von Willebrand Factor