Calorimetric investigation of the behavior of interlamellar water in phospholipid-water systems
Calorimetric investigation of the behavior of interlamellar water in phospholipid-water systems
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DOI：
10.1016/s0040-6031(97)00334-1
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发表时间：
1998-01-05
影响因子：
3.5
通讯作者：
Kodama, M
中科院分区：
文献类型：
--
作者：
Aoki, H;Kodama, M
用差示扫描量热法(DSC)研究了不同极性基团磷脂酰乙醇胺(PE)、磷脂酰胆碱(PC)和磷脂酰甘油(PG)与水的相互作用。融冰DSC曲线表明，在三种不同水分含量(40 g%)的脂水体系的凝胶相中，存在不可冻结和可冻结两种类型的水分子与膜内和膜间的脂头基团相互作用。根据计算机程序和体水分子数对冰融曲线进行解卷积，然后根据解卷积组分的热变估计不可冻结和可冻结层间水分子的数目。非冻结性层间水分子数按PE(2.3H2O/Lid)、PG(4.0H2O/Lift)和PC(5.5H2O/Lip.)的顺序增加，即三头基团所占有效面积增加的顺序。然而，对于可冻结的层间水，观察到了明显的不同：PG体系的这种水分子数持续增加到40g%，而PE和PC体系的极限水分子数分别为3.7和4.5H2O/脂质。这一差异很好地解释了双层片层数目的不同，即PG体系为单层片层，PE和PC体系为多层片层。(C)1998年，爱思唯尔科学公司出版。
The interaction of water and three phospholipids with different polar-head groups, phosphatidylethanolamine (PE), phosphatidylcholine (PC) and phosphatidylgylcerol (PG) were investigated by differential scanning calorimetry (DSC). Ice-melting DSC curves showed that two types of water molecules, nonfreezable and freezable, interacting with lipid-head groups in intra-, and inter-bilayers are present in the gel phase of three lipid-water systems of varying water content up to 40 g%. The ice-melting curves were deconvoluted according to a computer program and the number of bulk water molecules and subsequently the number of nonfreezable and freezable interlamellar water molecules was estimated from enthalpy changes of deconvoluted components. The number of nonfreezable interlamellar water molecules increased in the order of PE (2.3 H2O/ lipid, PG (4.0 H2O/lipid) and PC (5.5 H2O/lipid), that is, in the order of an increase in the effective area occupied by the three-head groups. However, a distinct difference was observed for the freezable interlamellar water: the number of this water molecules of PG system continuously increases up to 40 g%, in contrast with their limiting number of 3.7 and 4.5 H2O/lipid for PE and PC systems, respectively. This difference accounted well for a difference in the multiplicity of bilayer lamellar, that is, a single lamellar for PG system and a multilamellar for PE and PC systems shown by electron microscopy. (C) 1998 Published by Elsevier Science B.V.