Ratajczak Maria K, Chi Eva Y, Frey Shelli L, Cao Kathleen D, Luther Laura M, Lee Ka Yee C, Majewski Jaroslaw, Kjaer Kristian
Department of Physics, Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637, USA.
Phys Rev Lett. 2009 Jul 10;103(2):028103. doi: 10.1103/PhysRevLett.103.028103. Epub 2009 Jul 8.
X-ray diffraction of sphingomyelin-dihydrocholesterol (SM-DChol) monolayers revealed short-ranged ( approximately 25 A) 2D ordering. These nanoclusters show two distinct regions: below the cusp point of the phase diagram (35 mol% DChol), a constant d spacing was observed; above the cusp, the d spacing increases linearly with DChol in accordance to Vegard's law for binary alloys. The components in this lipidic alloy are thus a 65ratio35 SM-DChol entity and excess DChol. Reflectivity data further support the emergence above the cusp of an uncomplexed DChol population with greater vertical mobility.
鞘磷脂-二氢胆固醇（SM-DChol）单层的X射线衍射显示出短程（约25埃）二维有序性。这些纳米团簇显示出两个不同的区域：在相图的尖点（35摩尔％二氢胆固醇）以下，观察到恒定的d间距；在尖点以上，根据二元合金的维加德定律，d间距随二氢胆固醇线性增加。因此，这种脂质合金中的成分是65比35的SM-DChol实体和过量的二氢胆固醇。反射率数据进一步支持了在尖点以上出现具有更大垂直迁移率的未复合二氢胆固醇群体。
