Saddle-curvature instability of lipid bilayer induced by amphipathic peptides: a molecular model
| Autor: | Guilherme Volpe Bossa, Rachel Downing, Sylvio May |
|---|---|
| Přispěvatelé: | North Dakota State University, Universidade Estadual Paulista (Unesp) |
| Rok vydání: | 2020 |
| Předmět: |
Molecular model
Lipid Bilayers 02 engineering and technology Molecular Dynamics Simulation Curvature Quantitative Biology::Subcellular Processes Surface tension 03 medical and health sciences Molecular dynamics Protein Domains Amphiphile Lipid bilayer 030304 developmental biology Quantitative Biology::Biomolecules Physics::Biological Physics 0303 health sciences Chemistry General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrostatics Condensed Matter::Soft Condensed Matter Membrane Chemical physics lipids (amino acids peptides and proteins) 0210 nano-technology Antimicrobial Cationic Peptides Protein Binding |
| Zdroj: | Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP |
| ISSN: | 1744-6848 1744-683X |
| DOI: | 10.1039/d0sm00499e |
| Popis: | Made available in DSpace on 2020-12-12T01:25:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-07 Amphipathic peptides that partition into lipid bilayers affect the curvature elastic properties of their host. Some of these peptides are able to shift the Gaussian modulus to positive values, thus triggering an instability with respect to the formation of saddle curvatures. To characterize the generic aspects of the underlying mechanism, we employ a molecular lipid model that accounts for the interfacial tension between the polar and apolar regions of the membrane, for interactions between the lipid headgroups, and for the energy to stretch or compress the hydrocarbon chains. Peptides are modeled as cylinders that partition into the host membrane in a parallel orientation where they diminish the space available to the lipid headgroups and chains. The penetration depth into the membrane is determined by the angular size of the peptide's hydrophilic region. We demonstrate that only peptides with a small angular size of their hydrophilic region have an intrinsic tendency to render the Gaussian modulus more positive, and we identify conditions at which the Gaussian modulus adopts a positive sign upon increasing the peptide concentration. Our model allows us to also incorporate electrostatic interactions between cationic peptides and anionic lipids on the level of the linear Debye-Hückel model. We show that electrostatic interactions tend to shift the Gaussian modulus toward more positive values. Steric and electrostatic lipid-peptide interactions jointly decrease the effective interaction strength in the headgroup region of the host membrane thus suggesting a generic mechanisms of how certain amphipathic peptides are able to induce the formation of saddle curvatures. Department of Physics North Dakota State University Department of Physics São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences Department of Physics São Paulo State University (UNESP) Institute of Biosciences Humanities and Exact Sciences |
| Databáze: | OpenAIRE |
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