Clary L, Ravily V, Santaella C, Vierling P
Laboratoire de Chimie Bio-Organique, ESA 6001 CNRS, Université de Nice, Sophia-Antipolis, Faculté des Sciences, France.
J Control Release. 1998 Feb 12;51(2-3):259-67. doi: 10.1016/s0168-3659(97)00179-x.
The permeability to the H+/Na+ exchange of fluorinated phospholipid-based membranes has been evaluated by measuring the dissipation rate of a liposomal transmembrane pH gradient in the presence of Na+. The fluorinated liposomes are made from fluorocarbon/hydrocarbon or fluorocarbon/fluorocarbon double-chain ether-connected glycerophosphocholines or amido-connected phosphocholines deriving from diaminopropanol or serine. The fluorocarbon/hydrocarbon mixed-chain phospholipids, as compared to the fluorocarbon/fluorocarbon ones, form membranes that are substantially more able to maintain a transmembrane pH gradient in the presence of NA+ and display a lower Na+ permeability. However, these membranes are more permeable to the H+/Na/ exchange than conventional DSPC (1,2-distearoylphosphatidylcholine) ones. Our results indicate a detrimental impact of the membrane fluorination degree on H+/Na+ permeability: the lower the fluorination degree of the membrane, the lower its H+/Na+ permeability. Concerning structure/permeability relationships, it appears that the replacement of the ester connecting bond in their fluorinated phosphatidylcholine analogues for an ether or amide one lowers the transmembrane H+/Na+ exchange.
通过在存在Na⁺的情况下测量脂质体跨膜pH梯度的消散速率，评估了基于氟化磷脂的膜对H⁺/Na⁺交换的渗透性。氟化脂质体由碳氟化合物/碳氢化合物或碳氟化合物/碳氟化合物双链醚连接的甘油磷酸胆碱或衍生自二氨基丙醇或丝氨酸的酰胺连接的磷酸胆碱制成。与碳氟化合物/碳氟化合物的磷脂相比，碳氟化合物/碳氢化合物混合链磷脂形成的膜在存在Na⁺时更能维持跨膜pH梯度，并且显示出较低的Na⁺渗透性。然而，这些膜比传统的DSPC（1,2-二硬脂酰磷脂酰胆碱）膜对H⁺/Na⁺交换更具渗透性。我们的结果表明膜氟化程度对H⁺/Na⁺渗透性有不利影响：膜的氟化程度越低，其H⁺/Na⁺渗透性越低。关于结构/渗透性的关系，似乎在其氟化磷脂酰胆碱类似物中用醚键或酰胺键取代酯连接键会降低跨膜H⁺/Na⁺交换。
