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

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在生物膜中，当10+1d相共存时(“筏”)，区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. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.