Observing Peptide-Induced Lipid Accumulation in a Single-Component Zwitterionic Lipid Bilayer
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- 作者：Junjun Tan ; Shuji Ye ; Yi Luo
- 刊名：Journal of Physical Chemistry C
- 出版年：2015
- 出版时间：December 24, 2015
- 年：2015
- 卷：119
- 期：51
- 页码：28523-28529
- 全文大小：476K
- ISSN：1932-7455
文摘
Membrane domain formation plays a key role in various cellular functions and biological events. Lateral accumulation of lipids and proteins in biological membranes is one of the most important factors that control the domain formation. However, compared to numerous reports on the lipid aggregation or accumulation formed in the membranes composed of multiple components of lipids and cholesterol, the lipid accumulation in one-component phospholipid bilayer system is still rare. In this study, we demonstrate that short peptides can induce the lipid accumulation in a single-component zwitterionic lipid bilayer. By investigating the interaction between a short peptide of mastoparan (MP, a G-protein-activating peptide) and neutral phosphocholine lipid bilayers using sum frequency generation vibrational spectroscopy (SFG-VS), we have found that MP can cause a local accumulation of lipid molecules at the outer leaflet of the lipid bilayer, resulting in more than 10 times intensity increase in the signals from the CD3 vibrational modes with respect to that of lipid monolayer at the air surface. We have validated that the lipid accumulation behavior originates from a specific hydrophobic-mismatching interaction in which the peptide is too short to span the lipid bilayer. Our results suggest that other mechanisms that do not involve perforation exist for the interactions between peptides and membranes. This finding broadens the range of systems and our basic understanding on lipid accumulation.