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

该子项目是利用 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来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 在生物膜中，当lo + ld相共存（“筏”）时，域的尺寸似乎比光的波长小得多，即至少一个尺寸< 300 nm。 在SM/POPC/chol或DSPC/POPC/chol或DSPC/SOPC/chol的化学定义的混合物中，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合物区域内均匀出现。 然而，FRET和单一染料荧光研究表明在明确定义的边界相分离。 通过使用自旋标记的磷脂，“16-PC”，我们检查了超精细分裂的样品在DSPC/POPC/胆固醇的假定的相边界，并与超精细分裂在DSPC/DOPC/胆固醇，其中大的相域中观察到的GUV跨相边界。

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.