IR spectroscopic study of the structure and phase behavior of long-chain diacylphosphatidylcholines in the gel state.
IR spectroscopic study of the structure and phase behavior of long-chain diacylphosphatidylcholines in the gel state.
复制标题
凝胶态长链二酰基磷脂酰胆碱的结构和相行为的红外光谱研究。
DOI：
10.1016/s0006-3495(96)79512-7
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Mendelsohn,R
中科院分区：
文献类型：
--
作者：
Snyder,RG;Liang,GL;Strauss,HL;Mendelsohn,R
具有长度为18至24个碳的偶数酰基链的简单线性饱和二酰基磷脂酰胆碱的完全水合分散体可以存在于低温、高度有序的正交相（G（o））中，其不同于通常在较短链中发现的L β相（Gd）。用红外光谱研究了这些分散体的温度行为。G（o）相中的链堆积与结晶正构烷烃的正交相几乎相同。随着温度的升高，G（o）相在比Tm低约45摄氏度处经历向Gd的转变。这种转变发生在较高的温度下，并随着链长的增加而变得尖锐。发现Gd相中的链包装以可以用亚晶胞设置角的分布来表示的方式是无序的。Gd相在低于Tm的温度下转化为具有六边形链堆积的相（Gh）。结果支持和扩展的24-碳二酰基磷脂酰胆碱凝胶最近的X-射线衍射研究。
Fully hydrated dispersions of simple linear saturated diacylphosphatidylcholines with even-numbered acyl chains of lengths from 18 to 24 carbons can exist in a low-temperature, highly ordered, orthorhombic phase (G(o)) that differs from the L beta phase (Gd) normally found for shorter chains. The temperature behavior of these dispersions has been studied by infrared spectroscopy. Chain packing in the G(o) phase was found to be nearly identical to that of the orthorhombic phase of crystalline n-alkanes. With increasing temperature, the G(o) phase undergoes a transition to Gd at approximately 45 degrees C below Tm. This transition occurs at a higher temperature and becomes sharper with increasing chain length. Chain packing in the Gd phase was found to be disordered in a way that can be expressed in terms of a distribution of subcell setting angles. The Gd phase converts to a phase (Gh) with hexagonal-like chain packing at temperatures below Tm. The results support and extend those of a recent x-ray diffraction study of the 24-carbon diacyclphosphatidylcholine gel.