Bondar O P, Rowe E S
Veterans Affairs Medical Center, Kansas City, MO 64128, USA.
Biochim Biophys Acta. 1998 Mar 13;1370(2):207-17. doi: 10.1016/s0005-2736(97)00264-2.
Phosphatidylethanol (Peth) is formed in biological membranes when ethanol replaces water in the transphosphatidylation reaction catalyzed by phospholipase D. This charged lipid accumulates in the presence of ethanol, and it has unusual properties that can influence membrane structure and function. We have previously shown that dimyristoylphosphatidylethanol (DMPeth) and dipalmitoylphosphatidylethanol (DPPeth) form the interdigitated gel phase in the presence of Tris-HCl [O.P. Bondar, E.S. Rowe, Biophys. J., 71 (1996) 1440-1449]. In the present investigation, differential scanning calorimetry (DSC) and fluorescence have been used to investigate the effect of cholesterol on the phase behavior of DPPeth and DMPeth. Our results show that cholesterol prevents the formation of the interdigitated phase in the presence of Tris-HCl, and that ethanol counters this influence and restores the ability of these lipids to interdigitate. Pyrene-PC fluorescence probe was used in this investigation and gave results that were in agreement with the conclusions based on the DSC study.
磷脂酰乙醇（Peth）是在磷脂酶D催化的转磷脂酰基反应中，乙醇取代水时在生物膜中形成的。这种带电荷的脂质在乙醇存在时会积累，并且具有可影响膜结构和功能的特殊性质。我们之前已经表明，在Tris-HCl存在下，二肉豆蔻酰磷脂酰乙醇（DMPeth）和二棕榈酰磷脂酰乙醇（DPPeth）形成交错凝胶相[O.P. Bondar，E.S. Rowe，《生物物理杂志》，71（1996）1440 - 1449]。在本研究中，差示扫描量热法（DSC）和荧光法被用于研究胆固醇对DPPeth和DMPeth相行为的影响。我们的结果表明，胆固醇在Tris-HCl存在下可阻止交错相的形成，而乙醇可抵消这种影响并恢复这些脂质交错的能力。本研究中使用了芘 - PC荧光探针，其结果与基于DSC研究得出的结论一致。
