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Abstract We have used high resolution AFM based dynamic force spectroscopy to investigate peptide-lipid membrane interactions by measuring the detachment (last-rupture) force distribution,P(F), and the corresponding force dependent rupture rate,k(F), for two different peptides and lipid bilayers. The measured quantities, which differed considerably for different peptides, lipid-membranes, AFM tips (prepared under identical conditions), and retraction speeds of the AFM cantilever, could not be described in terms of the standard theory, according to which detachment occurs along a single pathway, corresponding to a diffusive escape process across a free energy barrier. In particular, the prominent retraction speed dependence ofk(F) was a clear indication that peptide-lipid membrane dissociation occurs stochastically along several detachment pathways. Thereby, we have formulated a general theoretical approach for describingP(F) andk(F), by assuming that peptide detachment from lipid membranes occurs, with certain probability, along a few dominant diffusive pathways. This new method was validated through a consistent interpretation of the experimental data. Furthermore, we have found that for moderate retraction speeds at intermediate force values,k(F) exhibits catch-bond behavior (i.e. decreasing detachment rate with increasing force). According to the proposed model this behavior is due to the stochastic mixing of individual detachment pathways which do not convert or cross during rupture. To our knowledge, such catch-bond mechanism has not been proposed and demonstrated before for a peptide-lipid interaction.
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This content will become publicly available on January 23, 2026
Fully atomistic molecular dynamics modeling of photoswitchable azo-PC lipid bilayers: structure, mechanical properties, and drug permeation
A phenol molecule is shown at its free energy minimum in atransazo-PC lipid bilayer, where it interacts with the azobenzene groups that are incorporated into one of the two phosphatidylcholine lipid tails.
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- PAR ID:
- 10631194
- Publisher / Repository:
- RSC publishing
- Date Published:
- Journal Name:
- Nanoscale
- Volume:
- 17
- Issue:
- 4
- ISSN:
- 2040-3364
- Page Range / eLocation ID:
- 2032 to 2042
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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