STRUCTURAL AND DYNAMIC STUDIES OF MEMBRANE DOMAINS IN MAST CELLS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 这是一个应用ACERT先进的ESR方法来获得有关IgE-FeRI介导的肥大细胞活化的膜结构域的详细结构和动力学信息的项目。它是基于过去的合作，清楚地证明了我们获得抗洗涤剂膜（与脂筏相关）内各种自旋标记脂质的高分辨率ESR光谱的能力（Ge等人，Biophys J.，77：925，1999）和质膜囊泡（Ge等人，Biophys. J.85：1278，2003），并证明了从旋转速率常数、序参数和其他物理表征中揭示的独特的类相性质。我们过去对RBL肥大细胞（和三种其他细胞类型）的测量首次显示了活细胞中有序和无序脂质的不同区域（Swamy等人，Biophys. J. 90：4452-4465，2006）。 在这项合作中，我们正在研究的影响抗原介导的受体激活质膜动态结构的自旋标记ESR。我们将使用我们的2D-ELDOR方法在质膜囊泡和活细胞的比较研究中更高的灵敏度，并评估不同类相区域之间的脂质交换率。我们结合更简单的亚细胞膜制备物和确定的模型膜检查全细胞质膜的能力使得能够进一步表征膜结构域并改进我们的脂筏概念，其似乎促进IgE-FceRI信号传导。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a project to apply ACERT's advanced ESR methods to gain detailed structural and dynamical information about the membrane domains involved in IgE-FeRI mediated activation of mast cells. It is based on the past collaboration that clearly demonstrates our capacity to obtain high resolution ESR spectra of a variety of spin labeled lipids within detergent resistant membranes (related to lipid rafts) (Ge et al, Biophys J., 77: 925, 1999) and plasma membrane vesicles (Ge et al, Biophys. J. 85: 1278, 2003) and to demonstrate distinctive phase-like properties as revealed from rotational rate constants, order parameters, and other physical characterization. Our past measurements on RBL mast cells (and three other cell types) showed for the first time distinctive regions of ordered and disordered lipids in living cells (Swamy et al, Biophys. J. 90: 4452-4465, 2006). In this collaboration we are investigating the effect of antigen-mediated receptor activation on the plasma membrane dynamic structure by spin label ESR. We will use the greater sensitivity of our 2D-ELDOR methods in comparative studies on plasma membrane vesicles and live cells and assess lipid exchange rates between the different phase-like regions. Our capacity to examine the plasma membranes of whole cells in conjunction with simpler subcellular membrane preparations and defined model membranes enables further characterization of membrane domains and refinement of our concepts of lipid rafts that appear to facilitate IgE-FceRI signaling.