Ege Canay, Ratajczak Maria K, Majewski Jaroslaw, Kjaer Kristian, Lee Ka Yee C
Department of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Biophys J. 2006 Jul 1;91(1):L01-3. doi: 10.1529/biophysj.106.085134. Epub 2006 May 5.
It has been postulated that for a binary mixture of phospholipid and cholesterol, phospholipid/cholesterol complexes are formed. Using grazing incidence x-ray diffraction, we have obtained evidence for lipid/cholesterol ordering in model membranes. Scattering features consistent with the existence of lipid/cholesterol complexes persist to high surface pressures even though fluorescence microscopy suggests a homogeneously fluid phase. Contrary to pure phospholipid and cholesterol systems, the resulting lattice spacing, integrated scattering intensity, and coherence lengths of these complexes are almost independent of surface pressure. Furthermore, the single peak observed in these mixed systems is very broad, suggesting that the extent of order for a single scattering structure only persists over a few molecules. This observation is consistent with these complexes being dynamic structures.
据推测，对于磷脂和胆固醇的二元混合物，会形成磷脂/胆固醇复合物。利用掠入射X射线衍射，我们已经获得了模型膜中脂质/胆固醇有序排列的证据。尽管荧光显微镜显示为均一的流体相，但与脂质/胆固醇复合物存在相一致的散射特征在高表面压力下依然存在。与纯磷脂和胆固醇体系不同，这些复合物的晶格间距、积分散射强度和相干长度几乎与表面压力无关。此外，在这些混合体系中观察到的单峰非常宽，这表明单一散射结构的有序程度仅在少数分子上持续存在。这一观察结果与这些复合物是动态结构相一致。
