Surfactant-like properties of an amphiphilic α-helical peptide leading to lipid nanodisc formation
| Autor: | Masahiko Abe, Hideki Sakai, Toshiaki Taira, Dai Kitamoto, Kenichi Aburai, Tomohiro Imura, Yohei Tsukui, Kenichi Sakai |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
chemistry.chemical_classification
Vesicle Peptide Surfaces and Interfaces Condensed Matter Physics Protein Structure Secondary chemistry.chemical_compound Surface-Active Agents Dynamic light scattering chemistry Pulmonary surfactant Amphiphile Electrochemistry Peptide synthesis Biophysics Organic chemistry Nanoparticles General Materials Science Lipid bilayer Peptides Hydrophobic and Hydrophilic Interactions Spectroscopy Nanodisc |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 30(16) |
| ISSN: | 1520-5827 |
| Popis: | Nanodiscs are self-assembled discoidal nanoparticles composed of amphiphilic α-helical scaffold proteins or peptides that wrap themselves around the circumference of a lipid bilayer in a beltlike manner. In this study, an amphiphilic helical peptide that mimics helix 10 of human apoA-I was newly synthesized by solid phase peptide synthesis using Fmoc chemistry, and its physicochemical properties, including surface tension, self-association, and solubilization abilities, were evaluated and related directly to nanodisc formation. The synthesized peptide having hydrophobic and hydrophilic faces behaves like a general surfactant, affording a critical association concentration (CAC) of 2.7 × 10(-5) M and a γCAC of 51.2 mN m(-1) in aqueous solution. Interestingly, only a peptide solution above its CAC was able to microsolubilize L-α-dimyristoylphosphatidylcholine (DMPC) vesicles, and lipid nanodiscs with an average diameter of 9.5 ± 2.7 nm were observed by dynamic light scattering and negative stain transmission electron microscopy. Moreover, the ζ potentials of the lipid nanodiscs were measured for the first time as a function of pH, and the values changed from positive (20 mV) to negative (-30 mV). In particular, nanodisc solutions at acidic pH 4 (20 mV) or basic pH 9 (-20 mV) were found to be stable for more than 6 months as a result of the electrostatic repulsion between the particles. |
| Databáze: | OpenAIRE |
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