Morigaki Kenichi, Tawa Keiko
Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda 563-8577, Japan.
Biophys J. 2006 Aug 15;91(4):1380-7. doi: 10.1529/biophysj.106.086074. Epub 2006 May 26.
Substrate-supported planar lipid bilayers are generated most commonly by the adsorption and transformation of phospholipid vesicles (vesicle fusion). We have recently demonstrated that simultaneous measurements of surface plasmon resonance (SPR) and surface plasmon fluorescence spectroscopy (SPFS) are highly informative for monitoring lipid membranes on solid substrates. SPR and SPFS provide information on the amount and topography of adsorbed lipid membranes, respectively. In this study, the vesicle fusion process was studied in detail by measuring SPR-SPFS at a higher rate and plotting the obtained fluorescence intensity versus film thickness. We could track the initial adsorption of vesicles, the onset of vesicle rupture occurring at certain vesicle coverage of the surface, and the autocatalytic transformation into planar bilayers. We also monitored vesicle fusion of the same vesicle suspensions by quartz crystal microbalance with dissipation monitoring (QCM-D). We compared the results obtained from SPR-SPFS and QCM-D to highlight the unique information provided by SPR-SPFS.
底物支撑的平面脂质双层最常见的生成方式是磷脂囊泡的吸附和转化（囊泡融合）。我们最近证明，同时测量表面等离子体共振（SPR）和表面等离子体荧光光谱（SPFS）对于监测固体底物上的脂质膜具有很高的信息量。SPR和SPFS分别提供有关吸附脂质膜的数量和形貌的信息。在本研究中，通过以更高的速率测量SPR-SPFS并绘制获得的荧光强度与膜厚度的关系图，对囊泡融合过程进行了详细研究。我们可以追踪囊泡的初始吸附、在表面特定囊泡覆盖率时发生的囊泡破裂的起始，以及向平面双层的自催化转化。我们还通过具有耗散监测的石英晶体微天平（QCM-D）监测了相同囊泡悬浮液的囊泡融合。我们比较了从SPR-SPFS和QCM-D获得的结果，以突出SPR-SPFS提供的独特信息。
