Lindblom Göran, Orädd Greger, Filippov Andrey
Department of Chemistry, Biophysical Chemistry, Umeå University, Sweden.
Chem Phys Lipids. 2006 Jun;141(1-2):179-84. doi: 10.1016/j.chemphyslip.2006.02.011. Epub 2006 Mar 20.
Pulsed field gradient (pfg)-NMR measurements of the lipid lateral diffusion coefficients in several macroscopically aligned bilayer systems were summarized from previous and new studies. The aim was to carry out a comparison of the translational dynamics for bilayers with various mixtures of l,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), l,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and chicken egg yolk sphingomyelin (eSM), with or without cholesterol. New useful information was obtained on the dynamics in these lipid bilayers that has not been previously appreciated. Thus, we were able to propose that the driving force behind the phase separation into l(d)and l(o)phases evolves from the increasing difficulty to incorpotate DOPC into a highly ordered phase. Our results suggest that DOPC has a preference to be located in a disordered phase, while DPPC and eSM prefer the ordered phase. Quite unexpectedly, CHOL seems to partition into both phases to roughly the same extent, indicating that CHOL has no particular preference for any of the l(d)or l(o) phases, and there are no specific interactions between CHOL and saturated lipids.
总结了以往及最新研究中对几种宏观排列的双层系统中脂质侧向扩散系数的脉冲场梯度（pfg）-核磁共振测量结果。目的是比较含有不同比例的1,2-二油酰基-sn-甘油-3-磷酸胆碱（DOPC）、1,2-二棕榈酰基-sn-甘油-3-磷酸胆碱（DPPC）和鸡卵黄鞘磷脂（eSM）的双层膜，在有或没有胆固醇情况下的平移动力学。获得了这些脂质双层膜动力学方面新的有用信息，这些信息以前未被认识到。因此，我们能够提出，相分离成l(d)相和l(o)相背后的驱动力源于将DOPC纳入高度有序相的难度增加。我们的结果表明，DOPC倾向于位于无序相，而DPPC和eSM更喜欢有序相。非常出乎意料的是，胆固醇似乎在两个相中大致以相同程度分配，这表明胆固醇对l(d)相或l(o)相没有特别偏好，并且胆固醇与饱和脂质之间没有特定相互作用。
