Volume 108, Number 2, October 2014
|Number of page(s)||6|
|Section||Interdisciplinary Physics and Related Areas of Science and Technology|
|Published online||14 October 2014|
Protein unfolding and refolding as transitions through virtual states
1 G. Millán Institute, Fluid Dynamics, Nanoscience and Industrial Mathematics, Universidad Carlos III de Madrid E-28911, Leganés, Spain
2 Departamento de Matemática Aplicada, Universidad Complutense de Madrid - E-28040, Madrid, Spain
3 Física Teórica, Universidad de Sevilla - Apartado de Correos 1065, E-41080, Sevilla, Spain
Received: 24 May 2014
Accepted: 26 September 2014
Single-molecule atomic force spectroscopy probes elastic properties of titin, ubiquitin and other relevant proteins. We explain bioprotein folding dynamics under both length- and force-clamp by modeling polyprotein modules as particles in a bistable potential, weakly connected by harmonic spring linkers. Multistability of equilibrium extensions provides the characteristic sawtooth force-extension curve. We show that abrupt or stepwise unfolding and refolding under force-clamp conditions involve transitions through virtual states (which are quasi-stationary domain configurations) modified by thermal noise. These predictions agree with experimental observations.
PACS: 87.15.Cc – Folding: thermodynamics, statistical mechanics, models, and pathways / 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 87.14.et – Generic models (lattice, HP, etc.)
© EPLA, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.