Tylopeptin B peptide antibiotic in lipid membranes at low concentrations: Self-assembling, mutual repulsion and localization
| Autor: | Natalia E. Sannikova, Sergei A. Dzuba, Marta De Zotti, Fernando Formaggio, Victoria N. Syryamina, Marina Gobbo |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
DEER
Biophysics Peptide 010402 general chemistry Free fatty acids 01 natural sciences Biochemistry law.invention chemistry.chemical_compound law 0103 physical sciences Molecule Electron paramagnetic resonance POPC Peptaibols chemistry.chemical_classification 010304 chemical physics Electron Spin Resonance Spectroscopy Cell Biology Resonance (chemistry) EPR ESEEM Peptide-lipid interactions Spin labels 0104 chemical sciences Anti-Bacterial Agents Membrane chemistry Permeability (electromagnetism) Phosphatidylcholines Membrane channel |
| Zdroj: | Biochimica et biophysica acta. Biomembranes. 1863(9) |
| ISSN: | 1879-2642 |
| Popis: | The medium-length peptide Tylopeptin B possesses activity against Gram-positive bacteria. It binds to bacterial membranes altering their mechanical properties and increasing their permeability. This action is commonly related with peptide self-assembling, resulting in the formation of membrane channels. Here, pulsed double electron-electron resonance (DEER) data for spin-labeled Tylopeptin B in palmitoyl-oleoyl-glycero-phosphocholine (POPC) model membrane reveal that peptide self-assembling starts at concentration as low as 0.1 mol%; above 0.2 mol% it attains a saturation-like dependence with a mean number of peptides in the cluster = 3.3. Using the electron spin echo envelope modulation (ESEEM) technique, Tylopeptin B molecules are found to possess a planar orientation in the membrane. In the peptide concentration range between 0.1 and 0.2 mol%, DEER data show that the peptide clusters have tendency of mutual repulsion, with a circle of inaccessibility of radius around 20 nm. It may be proposed that within this radius the peptides destabilize the membrane, providing so the peptide antimicrobial activity. Exploiting spin-labeled stearic acids as a model for free fatty acids (FFA), we found that at concentrations of 0.1–0.2 mol% the peptide promotes formation of lipid-mediated FFA clusters; further increase in peptide concentration results in dissipation of these clusters. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect