Zidovetzki R, Atiya A W, De Boeck H
Department of Biology, University of California, Riverside 92521.
Membr Biochem. 1989;8(3):177-86. doi: 10.3109/09687688909025830.
The interactions of CaCl2 or MgCl2 with multilamellar phospholipid bilayers were studied by 2H-NMR. Two model membrane systems were used: (1) dipalmitoylphosphatidylcholine (DPPC) bilayers and (2) bilayers composed of a mixture of phosphatidylcholine and phosphatidylglycerol at a molar ratio of 5:1. Addition of 0.25 M CaCl2 to DPPC bilayers resulted in significant uniform increase of the order parameters of the lipid side chains; the effect of 0.25 M MgCl2 was insignificant. Both phosphatidylcholine and phosphatidylglycerol components of the mixed bilayers were affected by the presence of 0.25 M CaCl2 and, to a much smaller degree, by MgCl2. The addition of Ca2+ induced significantly larger increase of the order parameters of the phosphatidylcholine component. The results are consistent with the long-range effects of Ca2+ binding on the packing of the lipid membranes.
通过2H-NMR研究了CaCl2或MgCl2与多层磷脂双层的相互作用。使用了两种模型膜系统：（1）二棕榈酰磷脂酰胆碱（DPPC）双层和（2）由摩尔比为5:1的磷脂酰胆碱和磷脂酰甘油混合物组成的双层。向DPPC双层中添加0.25 M CaCl2会导致脂质侧链的序参数显著均匀增加；0.25 M MgCl2的影响不显著。混合双层中的磷脂酰胆碱和磷脂酰甘油成分均受到0.25 M CaCl2的影响，而受MgCl2的影响程度要小得多。Ca2+的添加导致磷脂酰胆碱成分的序参数显著更大幅度的增加。这些结果与Ca2+结合对脂质膜堆积的远程效应一致。
