title: Non-exponential kinetics of unfolding under a constant force.
abstract: We examine the population dynamics of naturally folded globular polymers, with a super-hydrophobic "core" inserted at a prescribed point in the polymer chain, unfolding under an application of external force, as in AFM force-clamp spectroscopy. This acts as a crude model for a large class of folded biomolecules with hydrophobic or hydrogen-bonded cores. We find that the introduction of super-hydrophobic units leads to a stochastic variation in the unfolding rate, even when the positions of the added monomers are fixed. This leads to the average non-exponential population dynamics, which is consistent with a variety of experimental data and does not require any intrinsic quenched disorder that was traditionally thought to be at the origin of non-exponential relaxation laws.
authors.affiliation: Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bell
authors.affiliation: Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Eugene M
authors.initials: EM
authors.lastname: Terentjev
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D008968:Molecular Conformation; D058767:Protein Unfolding; D013269:Stochastic Processes; D025801:Ubiquitin / Q000737:chemistry
chemical_list: D001704:Biopolymers; D025801:Ubiquitin