Nöll G G
J Membr Biol. 1976 Jun 30;27(4):335-46. doi: 10.1007/BF01869144.
A newly constructed cell, which allows simultaneous measurements of optical and electrical properties, was used to study bimolecular black membranes composed of beef heart mitochondrial lipids and their interaction with cytochrome c. The results show that these highly charged membranes are stable only in relatively limited ranges of boundary conditions. In 0.1 n KCl their maximum direct current (dc) resistance is 7 X 10(8) Ohm cm2 +/- 10%; the series capacity at 1 kHz is 0.43 muF/cm2 +/- 3%; the entire thickness, determined by optical reflectivity, is 5.8 +/- 0.2 nm. The interaction between oxidized cytochrome c and these lipid membranes is primarily of electrostatic nature, and dependent on the presence of highly charged phospholipids, such as diphosphatidyl glycerol (cardiolipin) and phosphatidyl ethanolamine. The attachment of cytochrome c maximally causes a 2.5-fold increase in reflectivity, without any noticeable change in the capacity. This leads to a subsequent instability of the membrane (i.e., rupture) preceded by a rapid increase of the dc conductivity. This behavior is far less pronounced with reduced cytochrome c.
一种新构建的能够同时测量光学和电学性质的细胞被用于研究由牛心线粒体脂质组成的双分子黑膜及其与细胞色素c的相互作用。结果表明，这些高电荷膜仅在相对有限的边界条件范围内稳定。在0.1 n KCl中，它们的最大直流电阻为7×10⁸欧姆·厘米²±10%；1 kHz时的串联电容为0.43微法/厘米²±3%；由光学反射率确定的总厚度为5.8±0.2纳米。氧化型细胞色素c与这些脂质膜之间的相互作用主要是静电性质的，并且依赖于高电荷磷脂的存在，如二磷脂酰甘油（心磷脂）和磷脂酰乙醇胺。细胞色素c的附着最大可使反射率增加2.5倍，而电容没有任何明显变化。这导致膜随后不稳定（即破裂），之前直流电导率会迅速增加。还原型细胞色素c的这种行为则不那么明显。
