Patil G S, Cornwell D G
J Lipid Res. 1977 Jan;18(1):1-5.
The surface properties of fatty acid and fatty acid-alcohol mixtures were examined at 22-24 degrees C. At pH 12, sodium stearate forms a rigid surface film that generates an equilibrium spreading pressure of 16.5 dynes/cm. At pH 12, stearate-alkaline earth cation films collapse at the air-water interface and do not generate significant equilibrium spreading pressures. The rate of film collapse depends on the counterion decreasing in the sequence Ba2+ greater than Sr2+ greater than Ca2+. Stearate-stearyl alcohol mixtures form solid (condensed) films that are relatively stable and behave initially as homogeneous surfaces in their selectivities for counterions. Stearate-oleyl alcohol mixtures form fluid (expanded) films that are unstable. Lateral phase separations occur rapidly in fluid films and the stearate-alkaline earth cation phase collapses. The rate of film collapse in the fluid mixtures also depends on the counterion decreasing in the sequence Ba2+ greater than Ca2+. These surface properties suggest how a lipid anion may function as an ionophore in the translocation of alkaline earth cations.
在22 - 24摄氏度下研究了脂肪酸和脂肪酸 - 醇混合物的表面性质。在pH值为12时，硬脂酸钠形成刚性表面膜，产生16.5达因/厘米的平衡铺展压力。在pH值为12时，硬脂酸 - 碱土金属阳离子膜在气 - 水界面处坍塌，不会产生显著的平衡铺展压力。膜坍塌的速率取决于抗衡离子，其顺序为Ba2 +大于Sr2 +大于Ca2 +。硬脂酸 - 硬脂醇混合物形成相对稳定的固体（凝聚）膜，并且在对抗衡离子的选择性方面最初表现为均匀表面。硬脂酸 - 油醇混合物形成不稳定的流体（膨胀）膜。流体膜中会迅速发生横向相分离，并且硬脂酸 - 碱土金属阳离子相坍塌。流体混合物中膜坍塌的速率也取决于抗衡离子，顺序为Ba2 +大于Ca2 +。这些表面性质表明了脂质阴离子在碱土金属阳离子转运中作为离子载体可能发挥的作用。
