Phospholipid Diffusion Coefficients of Cushioned Model Membranes Determined via Z-Scan Fluorescence Correlation Spectroscopy

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• 作者：Sarah M. Sterling ; Edward S. Allgeyer ; J枚rg Fick ; Igor Prudovsky ; Michael D. Mason ; David J. Neivandt
• 刊名：Langmuir
• 出版年：2013
• 出版时间：June 25, 2013
• 年：2013
• 卷：29
• 期：25
• 页码：7966-7974
• 全文大小：456K
• 年卷期：v.29,no.25(June 25, 2013)
• ISSN：1520-5827

文摘

Model cellular membranes enable the study of biological processes in a controlled environment and reduce the traditional challenges associated with live or fixed cell studies. However, model membrane systems based on the air/water or oil/solution interface do not allow for incorporation of transmembrane proteins or for the study of protein transport mechanisms. Conversely, a phospholipid bilayer deposited via the Langmuir鈥揃lodgett/Langmuir鈥揝chaefer method on a hydrogel layer is potentially an effective mimic of the cross section of a biological membrane and facilitates both protein incorporation and transport studies. Prior to application, however, such membranes must be fully characterized, particularly with respect to the phospholipid bilayer phase transition temperature. Here we present a detailed characterization of the phase transition temperature of the inner and outer leaflets of a chitosan supported model membrane system. Specifically, the lateral diffusion coefficient of each individual leaflet has been determined as a function of temperature. Measurements were performed utilizing z-scan fluorescence correlation spectroscopy (FCS), a technique that yields calibration-free diffusion information. Analysis via the method of Wawrezinieck and co-workers revealed that phospholipid diffusion changes from raftlike to free diffusion as the temperature is increased鈥攁n insight into the dynamic behavior of hydrogel supported membranes not previously reported.