Diedrich D L, Cota-Robles E H
J Bacteriol. 1974 Sep;119(3):1006-18. doi: 10.1128/jb.119.3.1006-1018.1974.
The outer membranes and cytoplasmic membranes of the marine bacterium Pseudomonas BAL-31 were separated by washing the cells three times in 0.5 M NaCl and twice in 0.5 M sucrose. Electron microscopy during the removal of membranes revealed that the outer membranes fragmented in a regular manner to give rise to fairly uniform vesicles measuring approximately 140 nm in diameter. Isolated outer membranes had a buoyant density in sucrose of 1.230 g per cm(3), whereas the cytoplasmic membranes had a density of 1.194 g per cm(3). The removal of the outer membrane during the application of this procedure was monitored by measuring the release of 2-keto-3-deoxyoctulosonic acid and phospholipid. The cells lost 85.5% of their 2-keto-3-deoxyoctulosonic acid and 47.3% of their phospholipid during this treatment. Complete recovery of outer membrane material could be achieved. The removal of 25.5% of the 2-keto-3-deoxyoctulosonic acid and 0.9% of the phospholipid rendered the cells sensitive to lysis with Triton X-100. The phospholipid composition of the outer membrane was calculated to be 78.9% phosphatidylethanolamine and 16.1% phosphatidylglycerol. The phospholipid composition of the cytoplasmic membrane proved to be 71.5% phosphatidylethanolamine and 23.5% phosphatidylglycerol. The fatty acid composition was also found to be quantitatively heterogeneous between the two membranes.
通过用0.5M NaCl洗涤细胞三次，再用0.5M蔗糖洗涤两次，分离出海洋细菌假单胞菌BAL-31的外膜和细胞质膜。在去除膜的过程中进行电子显微镜观察发现，外膜以规则的方式破碎，产生直径约为140nm的相当均匀的囊泡。分离出的外膜在蔗糖中的浮力密度为每立方厘米1.230克，而细胞质膜的密度为每立方厘米1.194克。通过测量2-酮-3-脱氧辛酸和磷脂的释放来监测该过程中对外膜的去除。在此处理过程中，细胞损失了85.5%的2-酮-3-脱氧辛酸和47.3%的磷脂。可以实现外膜物质的完全回收。去除25.5%的2-酮-3-脱氧辛酸和0.9%的磷脂使细胞对用 Triton X-100裂解敏感。计算出外膜的磷脂组成是78.9%的磷脂酰乙醇胺和16.1%的磷脂酰甘油。事实证明，细胞质膜的磷脂组成是71.5%的磷脂酰乙醇胺和23.5%的磷脂酰甘油。还发现两种膜之间的脂肪酸组成在数量上是异质的。
