Lau A, McLaughlin A, McLaughlin S
Biochim Biophys Acta. 1981 Jul 20;645(2):279-92. doi: 10.1016/0005-2736(81)90199-1.
The ability of Stern equation to describe the adsorption of divalent cations to phosphatidylglycerol membranes was tested by combining 31P-NMR and electrophoretic mobility measurements. In 0.1 M sodium chloride both the 31P-NMR and the zeta potential data are well described by the Stern equation. 31P-NMR and 13C-NMR results indicate that cobalt forms inner-sphere complexes only with the phosphate group of phosphatidylglycerol molecules and that a substantial fraction of the adsorbed cobalt ions form outer-sphere complexes. Evidence is presented that suggests the alkaline earth cations also bind to phospholipids mainly by forming outer sphere complexes. Electrophoretic mobility measurements were performed with several different divalent cations. In all cases the zeta potentials in 0.1 M sodium chloride were well described by the Stern equation. The intrinsic 1:1 association constants (M-1) for the phosphatidylglycerol complexes decreased in the sequence: Mn2+, 11.5; Ca2+, 8.5; Ni2+, 7.5; Co2+, 6.5; Mg2+, 6.0; Ba2+, 5.5 and Sr2+, 5.0.
通过结合³¹P-NMR和电泳迁移率测量，测试了斯特恩方程描述二价阳离子吸附到磷脂酰甘油膜上的能力。在0.1 M氯化钠中，³¹P-NMR和ζ电位数据均能很好地用斯特恩方程描述。³¹P-NMR和¹³C-NMR结果表明，钴仅与磷脂酰甘油分子的磷酸基团形成内球配合物，且大部分吸附的钴离子形成外球配合物。有证据表明碱土金属阳离子也主要通过形成外球配合物与磷脂结合。用几种不同的二价阳离子进行了电泳迁移率测量。在所有情况下，0.1 M氯化钠中的ζ电位均能很好地用斯特恩方程描述。磷脂酰甘油配合物的固有1:1缔合常数（M⁻¹）按以下顺序降低：Mn²⁺，11.5；Ca²⁺，8.5；Ni²⁺，7.5；Co²⁺，6.5；Mg²⁺，6.0；Ba²⁺，5.5和Sr²⁺，5.0。
