PHASE-TRANSITIONS IN MONOGLYCERIDE BILAYERS - A LIGHT-SCATTERING STUDY
PHASE-TRANSITIONS IN MONOGLYCERIDE BILAYERS - A LIGHT-SCATTERING STUDY
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DOI：
10.1016/s0006-3495(86)83716-x
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发表时间：
1986-04-01
影响因子：
3.4
通讯作者：
EARNSHAW, JC
中科院分区：
文献类型：
--
作者：
CRAWFORD, GE;EARNSHAW, JC
利用热激膜波动的准弹性光散射研究了单油酸甘油单层的热致相变。在某些情况下，光谱和强度信息都是从观测得来的。对于无溶剂双分子层，在张力、粘度和厚度、脂质取向有序参数和介电各向异性的组合以及侧向压缩模量等几个膜参数中观察到过渡性变化。这些变化，特别是膜厚度和各向异性/有序组合的变化，清楚地表明脂质分子中的链熔化转变。链熔转变温度为16.6 +-。0.03.degree。C (.DELTA。T1/2 = 1.5度。C)。其他变化集中在12.5度和16.6度左右。C，暗示涉及两个阶段的过渡。基于朗道方法的膜粘度过渡前波动分析表明，在过渡时膜接近临界点（T* = 12.7度）。C)。对于结构中含有正癸烷的膜，可获得的信息较少。在这种情况下，膜张力的变化比无溶剂的情况要小得多，而且转变范围大大扩大。这些效应与溶剂包裹导致双分子层内“相互作用体积”的增加是一致的。
Thermotropic phase transitions in single planar bilayers of glycerol mono-oleate have been investigated using quasi-elastic light scattering from thermally excited membrane fluctuations. In certain cases both spectroscopic and intensity information were derived from the observations. For solvent-free bilayers transitional changes were observed in several membrane parameters: in tension, viscosity and thickness, in a combination of lipid orientational order parameter and dielectric anisotropy, and in the lateral compression modulus. These changes, particularly those in membrane thickness and in the anisotropy/order combination, were clearly indicative of a chain-melting transition in the lipid molecules. The chain-melting transition temperature was identified as 16.6 .+-. 0.03.degree. C (.DELTA.T1/2 = 1.5.degree. C). The other changes tended to cluster around 12.5 and 16.6.degree. C, suggesting that a two-stage transition was involved. Analysis of pretransitional fluctuations in membrane viscosity, based on a Landau approach, suggested that at the transition the membrane was close to a critical point (T* = 12.7.degree. C). Less information was accessible for membranes containing n-decane within their structure. In this case, the change in membrane tension was much smaller than in the solvent-free case and the transition was considerably broadened. These effects accord with an increase in ''interactive volume'' within the bilayer due to solvent inclusion.