Maček Lebar Alenka, Miklavčič Damijan, Kotulska Malgorzata, Kramar Peter
Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia.
Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wrocław, Poland.
Membranes (Basel). 2021 Apr 5;11(4):263. doi: 10.3390/membranes11040263.
Basic understanding of the barrier properties of biological membranes can be obtained by studying model systems, such as planar lipid bilayers. Here, we study water pores in planar lipid bilayers in the presence of transmembrane voltage. Planar lipid bilayers were exposed to fast and slow linearly increasing voltage and current signals. We measured the capacitance, breakdown voltage, and rupture time of planar lipid bilayers composed of 1-pamitoyl 2-oleoyl phosphatidylcholine (POPC), 1-pamitoyl 2-oleoyl phosphatidylserine (POPS), and a mixture of both lipids in a 1:1 ratio. Based on the measurements, we evaluated the change in the capacitance of the planar lipid bilayer corresponding to water pores, the radius of water pores at membrane rupture, and the fraction of the area of the planar lipid bilayer occupied by water pores.planar lipid bilayer capacitance, which corresponds to water pores, water pore radius at the membrane rupture, and a fraction of the planar lipid bilayer area occupied by water pores. The estimated pore radii determining the rupture of the planar lipid bilayer upon fast build-up of transmembrane voltage are 0.101 nm, 0.110 nm, and 0.106 nm for membranes composed of POPC, POPS, and POPC:POPS, respectively. The fraction of the surface occupied by water pores at the moment of rupture of the planar lipid bilayer The fraction of an area that is occupied by water pores at the moment of planar lipid bilayer rupture is in the range of 0.1-1.8%.
通过研究模型系统，如平面脂质双层，可以获得对生物膜屏障特性的基本理解。在这里，我们研究了跨膜电压存在下平面脂质双层中的水通道。将平面脂质双层暴露于快速和缓慢线性增加的电压和电流信号。我们测量了由1-棕榈酰-2-油酰磷脂酰胆碱（POPC）、1-棕榈酰-2-油酰磷脂酰丝氨酸（POPS）以及这两种脂质按1:1比例混合组成的平面脂质双层的电容、击穿电压和破裂时间。基于这些测量，我们评估了与水通道相对应的平面脂质双层电容的变化、膜破裂时水通道的半径以及水通道在平面脂质双层中所占面积的比例。平面脂质双层电容，它对应于水通道、膜破裂时的水通道半径以及水通道在平面脂质双层中所占的面积比例。对于由POPC、POPS和POPC:POPS组成的膜，在跨膜电压快速建立时决定平面脂质双层破裂的估计孔半径分别为0.101nm、0.110nm和0.106nm。平面脂质双层破裂瞬间水通道所占表面的比例 平面脂质双层破裂瞬间水通道所占面积的比例在0.1 - 1.8%的范围内。
