Your browser has javascript turned off or blocked. This will lead to some parts of our website to not work properly or at all. Turn on javascript for best performance.

The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Anders Irbäck. Photo.

Anders Irbäck

Professor

Anders Irbäck. Photo.

Unfolding times for proteins in a force clamp

Author

  • Stefano Luccioli
  • Alberto Imparato
  • Simon Mitternacht
  • Anders Irbäck
  • Alessandro Torcini

Summary, in English

The escape process from the native valley for proteins subjected to a constant stretching force is examined using a model for a beta barrel. For a wide range of forces, the unfolding dynamics can be treated as one-dimensional diffusion, parametrized in terms of the end-to-end distance. In particular, the escape times can be evaluated as first passage times for a Brownian particle moving on the protein free-energy landscape, using the Smoluchowski equation. At strong forces, the unfolding process can be viewed as a diffusive drift away from the native state, while at weak forces thermal activation is the relevant mechanism. An escape-time analysis within this approach reveals a crossover from an exponential to an inverse Gaussian escape-time distribution upon passing from weak to strong forces. Moreover, a single expression valid at weak and strong forces can be devised both for the average unfolding time as well as for the corresponding variance. The analysis offers a possible explanation of recent experimental findings for the proteins ddFLN4 and ubiquitin.

Department/s

  • Computational Biology and Biological Physics

Publishing year

2010

Language

English

Publication/Series

Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)

Volume

81

Issue

1

Document type

Journal article

Publisher

American Physical Society

Topic

  • Biophysics

Status

Published

ISBN/ISSN/Other

  • ISSN: 1539-3755