ESR STUDIES OF PHASE STRUCTURES IN DSPC/POPC/CHOL AND DSPC/DOPC/CHOL MIXTURES

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。 在生物膜中，当固相共存时(“筏”)，域的大小似乎比光的波长小得多，即至少一个维度的尺寸&lt；300 nm。在化学定义的SM/POPC/CHOL，或DSPC/POPC/CHOL，或DSPC/SOPC/CHOL的混合物中，在荧光显微镜下，巨大的单层囊泡(GUV)在可能出现脂筏的整个组成区域内看起来是均匀的。然而，FRET和单染料荧光研究表明，在明确的边界上存在相分离。通过使用自旋标记的磷脂“16-PC”，我们研究了样品在DSPC/POPC/CHOL中跨相界面的超精细分裂，并与在DSPC/DOPC/CHOL中的跨相界面的超精细分裂进行了比较，其中在GUV中观察到了大的相区。

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. In biological membranes, when lo + ld phases coexist ("rafts"), the size of the domains seems to be much smaller than the wavelength of light, i.e. at least one dimension of size < 300 nm. In chemically-defined mixtures of SM/POPC/chol, or DSPC/POPC/chol, or DSPC/SOPC/chol, giant unilamellar vesicles (GUVs) appear uniform in fluorescence microscopy over the entire composition region where lipid rafts could occur. However, FRET and single dye fluorescence studies indicate phase separation at well-defined boundaries. By use of a spin-labeled phospholipid, "16-PC", we examine the hyperfine splitting of samples across the putative phase boundaries in DSPC/POPC/chol, and compare with the hyperfine splitting across phase boundaries in DSPC/DOPC/chol, where large phase domains are observed in GUVs.