Publication Cover
Molecular Physics
An International Journal at the Interface Between Chemistry and Physics
Volume 118, 2020 - Issue 19-20: Special Issue of Molecular Physics in Honour of Jürgen Gauss
117
Views
0
CrossRef citations to date
0
Altmetric
Research Articles

Force-dependent folding pathways in mechanically interlocked calixarene dimers via atomistic force quench simulations

&
Article: e1743886 | Received 12 Dec 2019, Accepted 06 Mar 2020, Published online: 15 Apr 2020
 

Abstract

Single-molecule force spectroscopy and molecular simulations are well-established techniques to study the mechanical unfolding of supramolecular complexes in various fields of biomolecular physics. In the present study, we investigate the details of the force-dependent folding transition of a well-studied model system, a calix[4]arene catenane dimer, using atomistic force quench simulations. This protocol allows us to reach a range of much smaller forces than possible with the more common force ramp simulations where the force is changed with a constant velocity. We find that the folding pathway changes its character as a function of external force. For small forces (on the order of 50 pN), the folding transition occurs via the transition to a metastable intermediate structure in about 30% of the simulations. We characterise the structure of this intermediate and demonstrate its relevance by considering the averaged potential of mean force of the system as a function of a well-defined reaction coordinate. When the force increases, the importance of the intermediate diminishes and for high external forces (500 pN), our results can be interpreted in terms of a simple two-state model, that has also been used in earlier simulations on the same system.

GRAPHICAL ABSTRACT

Acknowledgements

We dedicate this paper to Jürgen Gauss on the occasion of his 60th birthday. We thank him for his continuing support and advice. The authors gratefully acknowledge the computing time granted on the supercomputer MOGON at Johannes Gutenberg-University Mainz (hpc.uni-mainz.de).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support by the Deutsche Forschungsgemeinschaft (DFG) via grant No. Di693/3-1 and TRR 146 is acknowledged.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.