Antonov Valerij F, Anosov Andrej A, Norik Vladimir P, Korepanova Evgenija A, Smirnova Elena Y
Department of Medical and Biological Physics, Sechenov Moscow Medical Academy, Russia.
Eur Biophys J. 2003 Mar;32(1):55-9. doi: 10.1007/s00249-002-0266-7. Epub 2002 Dec 19.
Electrical capacitance of the planar bilayer lipid membrane (BLM) formed from hydrogenated egg lecithin (HEL) has been studied during many passages through the phase transition temperature. In contrast to the BLM from individual synthetic phospholipids, membranes from HEL did not demonstrate any capacitance change at the phase transition temperature maximum, as measured by differential scanning calorimeter at 52 degrees C. Instead, two temperatures have been discerned by capacitance records: thickening at 42-43 degrees C and thinning at 57-59 degrees C. The first temperature region is close to the transition temperature of dipalmitoyllecithin, whereas the second is close to that of distearoyllecithin, two main components of the HEL. It was suggested that capacitance measurements were able to reveal a phase separation in the BLM from HEL which was not detected by differential scanning calorimetry. The phase transition of the BLM from the liquid crystal state to the gel state is followed by thickening of the bilayer structure, partly due to a gauche- trans transition of lipid molecules but mainly due to redistribution of the solvent n-decane.
在氢化卵磷脂（HEL）形成的平面双层脂质膜（BLM）多次通过相变温度的过程中，对其电容进行了研究。与由单个合成磷脂形成的BLM不同，HEL形成的膜在相变温度最大值处未显示出任何电容变化，该相变温度最大值是通过差示扫描量热法在52℃下测得的。相反，通过电容记录识别出了两个温度：在42 - 43℃时变厚，在57 - 59℃时变薄。第一个温度区域接近二棕榈酰卵磷脂的转变温度，而第二个温度区域接近二硬脂酰卵磷脂的转变温度，这是HEL的两个主要成分。有人提出，电容测量能够揭示HEL形成的BLM中的相分离，而差示扫描量热法未检测到这种相分离。BLM从液晶态到凝胶态的相变伴随着双层结构的增厚，部分原因是脂质分子的gauche - trans转变，但主要原因是溶剂正癸烷的重新分布。
