Kastl Katja, Menke Manuela, Lüthgens Eike, Faiss Simon, Gerke Volker, Janshoff Andreas, Steinem Claudia
Institut für Analytische Chemie, Chemo- und Biosensorik, Universität Regensburg, 93040 Regensburg, Germany.
Chembiochem. 2006 Jan;7(1):106-15. doi: 10.1002/cbic.200500265.
The kinetics of annexin A1 binding to solid-supported lipid bilayers consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine (POPS; 4:1) has been investigated as a function of the calcium ion concentration in the bulk phase. Quartz crystal microbalance measurements in conjunction with scanning force microscopy, fluorescence microscopy, and computer simulations indicate that at a given Ca2+ concentration annexin A1 adsorbs irreversibly on membrane domains enriched in POPS. By contrast, annexin A1 adsorbs reversibly on the POPC-enriched phase, which is composed of single POPS molecules embedded within a POPC matrix. The overall area occupied by the POPS-enriched phase is controlled by the CaCl2 concentration. Monte Carlo simulations suggest that the area of the POPS-enriched phase increases by a factor of 7 when the Ca2+ concentration is changed from 0.01 to 1 mM.
已研究了膜联蛋白A1与由1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱（POPC）/1-棕榈酰-2-油酰-sn-甘油-3-磷酸丝氨酸（POPS；4:1）组成的固体支持脂质双层结合的动力学，作为本体相中钙离子浓度的函数。石英晶体微天平测量结合扫描力显微镜、荧光显微镜和计算机模拟表明，在给定的Ca2+浓度下，膜联蛋白A1不可逆地吸附在富含POPS的膜结构域上。相比之下，膜联蛋白A1可逆地吸附在富含POPC的相中，该相由嵌入POPC基质中的单个POPS分子组成。富含POPS相所占的总面积由CaCl2浓度控制。蒙特卡罗模拟表明，当Ca2+浓度从0.01 mM变为1 mM时，富含POPS相的面积增加7倍。
