| Title: |
Unraveling Hydrophobic Interactions at the Molecular Scale Using Force Spectroscopy and Molecular Dynamics Simulations |
| Authors: |
Stock, P.; Monroe, J.; Utzig, T.; Smith, D.; Shell, M.; Valtiner, M. |
| Source: |
ACS Nano |
| Publication Year: |
2017 |
| Collection: |
Max Planck Society: MPG.PuRe |
| Description: |
Interactions between hydrophobic moieties steer ubiquitous processes in aqueous media, including the self-organization of biologic matter. Recent decades have seen tremendous progress in understanding these for macroscopic hydrophobic interfaces. Yet, it is still a challenge to experimentally measure hydrophobic interactions (HIs) at the single-molecule scale and thus to compare with theory. Here, we present a combined experimental simulation approach to directly measure and quantify the sequence dependence and additivity of HIs in peptide systems at the single-molecule scale. We combine dynamic single-molecule force spectroscopy on model peptides with fully atomistic, both equilibrium and nonequilibrium, molecular dynamics (MD) simulations of the same systems. Specifically, we mutate a flexible (GS)(5) peptide scaffold with increasing numbers of hydrophobic leucine monomers and measure the peptides' desorption from hydrophobic self-assembled monolayer surfaces. Based on the analysis of nonequilibrium work-trajectories, we measure an interaction free energy that scales linearly with 3.0-3.4 k(B)T per leucine. In good agreement, simulations indicate a similar trend with 2.1 k(B)T per leucine, while also providing a detailed molecular view into HIs. This approach potentially provides a roadmap for directly extracting qualitative and quantitative single-molecule interactions at solid/liquid interfaces in a wide range of fields, including interactions at biointerfaces and adhesive interactions in industrial applications. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Availability: |
http://hdl.handle.net/11858/00-001M-0000-002D-C185-E |
| Accession Number: |
edsbas.50513073 |
| Database: |
BASE |