ELECTRO-MECHANICAL PERMEABILIZATION OF LIPID VESICLES - ROLE OF MEMBRANE TENSION AND COMPRESSIBILITY
ELECTRO-MECHANICAL PERMEABILIZATION OF LIPID VESICLES - ROLE OF MEMBRANE TENSION AND COMPRESSIBILITY
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DOI：
10.1016/s0006-3495(89)82898-x
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发表时间：
1989-05-01
影响因子：
3.4
通讯作者：
HOCHMUTH, RM
中科院分区：
文献类型：
--
作者：
NEEDHAM, D;HOCHMUTH, RM
采用一种简单的微移液管技术测定了三种不同重构膜的膜张力对膜破裂的临界电场强度的影响：硬脂酰磷脂酰胆碱（SOPC）、红细胞（RBC）脂质提取物和SOPC胆固醇（CHOL）为1:1。对于这些膜，弹性面积膨胀模量从。200至600 dyn/cm，裂解张力从5.7 dyn/cm增加到13.2 dyn/cm，即随着胆固醇含量的增加，膜变得更有凝聚力。在膜张力为零的情况下，随着胆固醇从1.1 V增加到1.8 V，击穿所需的临界膜电压VC也随之增加。我们用双层扩张性来模拟这种行为。膜面积可以通过拉伸或电压应力来增加。两者都能在膜中储存弹性能量，并最终在临界面积膨胀或临界能量时导致破裂。该模型预测了击穿时的张力和电压之间的关系，并对所研究的三种重构膜系统进行了实验验证。
A simple micropipet technique was used to determine the critical electric field strength for membrane breakdown as a function of the applied membrane tension for three different reconstituted membranes: stearoyloleoylphosphatidylcholine (SOPC), red blood cell (RBC) lipid extract, and SOPC cholesterol (CHOL), 1:1. For these membranes the elastic area expansivity modulus increases from .apprx. 200 to 600 dyn/cm, and the tension at lysis increases from 5.7 to 13.2 dyn/cm, i.e., the membranes become more cohesive with increasing cholesterol content. The critical membrane voltage, VC, required for breakdown was also found to increase with increasing cholesterol from 1.1 to 1.8 V at zero membrane tension. We have modeled the behavior in terms of the bilayer expansitivity. Membrane area can be increased by either tensile or electrocompressive stresses. Both can store elastic energy in the membrane and eventually cause breakdown at a critical area dilation or critical energy. The model predicts a relation between tension and voltage at breakdown and this relation is verified experimentally for the three reconstituted membrane systems studied here.