Cadenhead D A, Müller-Landau F
Biochim Biophys Acta. 1976 Aug 4;443(1):10-8. doi: 10.1016/0005-2736(76)90487-9.
Pure and mixed monomolecular films of a cell membrane spin label probe, 12-nitroxide stearic acid have been studied where myristic acid was selected as the host lipid. The behavior of 12-nitroxide stearic acid at the air water interface is understood in terms of two molecular configurations: erect (with only the carboxyl group in the interface) and bent (with both the carboxyl group and the oxazolidine ring in the interface). In mixed films both of these conformations play a role at high surface pressures. At low probe concentrations, 12-nitroxide stearic acid is primarily in an erect conformation, while at high probe concentrations the reverse is true. This particular host lipid appears capable of erecting the probe molecule with only small concentrations of myristic acid. In a condensed host lipid, the probe is partially immiscible, and segregates to form a heterogeneous film from which it is readily collapsed. The probe is seen to perturb the molecular packing in this mixed system and the perturbation to be dependent on both the molecular shape and nature of the probe.
以肉豆蔻酸作为主体脂质，对细胞膜自旋标记探针12 - 氮氧硬脂酸的纯单分子膜和混合单分子膜进行了研究。12 - 氮氧硬脂酸在气 - 水界面的行为可通过两种分子构型来理解：直立构型（仅羧基在界面中）和弯曲构型（羧基和恶唑烷环都在界面中）。在混合膜中，这两种构象在高表面压力下起作用。在低探针浓度下，12 - 氮氧硬脂酸主要呈直立构型，而在高探针浓度下则相反。这种特定的主体脂质似乎只需少量肉豆蔻酸就能使探针分子直立。在凝聚的主体脂质中，探针部分不混溶，并分离形成异质膜，该异质膜很容易塌陷。可以看出，探针扰乱了这个混合体系中的分子排列，且这种扰乱取决于探针的分子形状和性质。
