The interaction of water with the phospholipid head group and its relationship to the lipid electrical conductivity
The interaction of water with the phospholipid head group and its relationship to the lipid electrical conductivity
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DOI：
10.1016/j.chemphyslip.2004.05.003
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发表时间：
2004-09-01
影响因子：
3.4
通讯作者：
Smith, RL
中科院分区：
文献类型：
--
作者：
Jendrasiak, GL;Smith, RL
我们已经研究了水与脂质头基的相互作用，通过重量法测量脂质水吸附和横向直流电导率的增加，由此水合。我们已经对具有质子化或氘代烃链的二肉豆蔻酰磷脂酰胆碱（DMPC）进行了这一研究。这些研究也进行了两个阳离子脂质具有相当不同的极性头基团。所有三种脂质都表现为强吸水剂，并且当每个脂质吸附前1-3个沃茨时，所有三种脂质都显示电导率的急剧对数增加。这种增长通常是5-6个数量级。在最初的1-3个沃茨被吸附后，电导率随着额外的水吸附而逐渐增加。这种电行为也被发现为弱水吸附剂，似乎是独立的头基组合物。电导率行为表明两种类型的水与头基相互作用。我们的研究还表明，胆碱样成分是负责的脂质的强结合水的性质，虽然，磷酸盐和胆碱作出显着的贡献，吸附水的总量。然而，导电性行为并不取决于这两种头基组分的存在。(C)2004爱思唯尔爱尔兰有限公司保留所有权利。
We have studied the interaction of water with the lipid head group by gravimetrically measuring the lipid water adsorption and the lateral dc electrical conductivity increase resulting from this hydration. We have done this for dimyristoyl phosphatidylcholine (DMPC) having protonated or deuterated hydrocarbon chains. These studies were also done for two cationic lipids having rather different polar head groups. All three lipids behave as strong water adsorbers and all three display a steep, logarithmic increase in the conductivity as the first 1-3 waters per lipid are adsorbed. This increase is usually 5-6 orders of magnitude. After the initial 1-3 waters are adsorbed, the conductivity increases much more gradually, upon additional water adsorption. This electrical behavior is also found for weak water adsorbers and appears to be independent of the head group composition. The conductivity behavior suggests two types of water interacting with the head group. Our studies also indicate that a choline-like component is responsible for the strong water binding nature of the lipids, although, both phosphate and choline make significant contributions to the total amount of adsorbed water. The conductivity behavior, however, does not depend on the presence of both these head group components. (C) 2004 Elsevier Ireland Ltd. All rights reserved.