STRUCTURAL AND DYNAMIC STUDIES OF MEMBRANE DOMAINS IN MAST CELLS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 这是一个应用Acert先进的ESR方法来获得有关IgE-FERI介导的肥大细胞激活所涉及的膜结构域的详细结构和动力学信息的项目。它基于过去的合作，清楚地展示了我们在耐洗涤剂膜(与脂筏相关)(GE等，BiPhys J.，77：925,1999)和质膜小泡(GE等，BiPhys)中获得各种自旋标记脂质的高分辨率ESR谱的能力。J.85：1278,2003)，并展示了从旋转速率常数、序参数和其他物理表征中揭示的独特的类相特性。我们过去对RBL肥大细胞(和其他三种细胞类型)的测量首次显示了活细胞中有序和无序脂质的独特区域(Swamy等人，BiPhys)。J.90：4452-4465,2006)。在这项合作中，我们用自旋标记ESR研究了抗原介导的受体激活对质膜动态结构的影响。我们将在质膜囊泡和活细胞的比较研究中使用我们的2D-Eldor方法的更高的敏感性，并评估不同相类区域之间的脂质交换率。我们能够结合更简单的亚细胞膜制备和已定义的模型膜来检查整个细胞的质膜，从而能够进一步表征膜域并改进我们的脂筏概念，这似乎有助于IgE-FceRI信号转导。

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.