Observing the translocation of a mitochondria-penetrating peptide with solid-state NMR
| Autor: | Lauren E. Marbella, Megan M. Spence, Hyo Soon Cho |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
Magnetic Resonance Spectroscopy
Lipid Bilayers Biophysics Peptide Target peptide 010402 general chemistry 01 natural sciences Biochemistry 03 medical and health sciences Lipid bilayer Inner mitochondrial membrane 030304 developmental biology Penetrating peptides chemistry.chemical_classification 0303 health sciences Manganese Membrane Proteins Nuclear magnetic resonance spectroscopy Cell Biology Transmembrane protein Peptide Fragments 0104 chemical sciences Mitochondria Protein Transport Translocation mechanism Membrane Solid state NMR spectroscopy Electroporation Membrane protein chemistry Mitochondrial Membranes Mitochondria targeting |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. (8):1674-1682 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/j.bbamem.2013.03.027 |
| Popis: | A new class of penetrating peptides that can target the mitochondria with high specificity was recently discovered. In this work, we developed a model inner mitochondrial membrane, equipped with a transmembrane gradient, suitable for solid-state NMR experiments. Using solid-state NMR, we observed a mitochondria-penetrating peptide interacting with the model inner mitochondrial membrane to gain insight into the mechanism of translocation. The paramagnetic relaxation effect due to Mn2+ ions on 13C magic angle spinning NMR was used to measure the insertion depth of the peptide and its distribution in each monolayer of the membrane. We found that at low peptide concentration the peptide binds to the outer leaflet and at high concentration, it crosses the hydrophobic bilayer core and is distributed in both leaflets. In both concentration regimes, the peptide binds at the C2 position on the lipid acyl chain. The mitochondria-penetrating peptide crossed to the inner leaflet of the model membranes without disrupting the lamellarity. These results provide evidence that supports the electroporation model of translocation. We estimated the energy associated with crossing the inner mitochondrial membrane. We found that the transmembrane potential provides sufficient energy for the peptide to cross the hydrophobic core, which is the most unfavorable step in translocation. |
| Databáze: | OpenAIRE |
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