Mukai Masaru, Regen Steven L
Department of Chemistry, Lehigh University , Bethlehem, Pennsylvania 18015, United States.
Langmuir. 2015 Nov 24;31(46):12674-8. doi: 10.1021/acs.langmuir.5b03174. Epub 2015 Nov 13.
The interactions between an exchangeable mimic of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), Phos(±), with an exchangeable mimic of cholesterol, Chol, have been analyzed in fluid bilayers by means of nearest-neighbor recognition measurements. These interactions have been found to be very similar to those of an exchangeable mimic of 1,2-dipalmitoyl-sn-glycerol-3-phospho-(1'rac-glycerol) (DPPG), Phos(-), interacting with Chol. Thus, both phospholipids have a similar preference for becoming nearest-neighbors of Chol in the liquid-ordered (l0) phase, and both mix, ideally, with Chol in the liquid-disordered (ld) phase. These findings, together with the almost negligible screening effects found for the latter, provide strong evidence that electrostatic forces play a minor role in the preference that both phospholipids have in becoming a favored nearest-neighbor of Chol. They also imply that the main driving force for forming the liquid-ordered phase, and for defining the lateral organization of this phase, is an intrinsic affinity that high-melting lipids and cholesterol have for each other.
通过最近邻识别测量，在流体双层膜中分析了1,2 - 二棕榈酰 - sn - 甘油 - 3 - 磷酸胆碱（DPPC）的可交换模拟物Phos(±)与胆固醇的可交换模拟物Chol之间的相互作用。已发现这些相互作用与1,2 - 二棕榈酰 - sn - 甘油 - 3 - 磷酸 -（1'rac - 甘油）（DPPG）的可交换模拟物Phos(-)与Chol相互作用的情况非常相似。因此，两种磷脂在液晶相（l0）中成为Chol最近邻的偏好相似，并且在液晶无序相（ld）中都理想地与Chol混合。这些发现，连同对后者几乎可忽略不计的屏蔽效应，提供了有力证据，表明静电力在两种磷脂成为Chol偏好的最近邻的偏好中起次要作用。它们还意味着形成液晶相以及定义该相横向组织的主要驱动力是高熔点脂质和胆固醇之间的内在亲和力。
