Institute of Physics, University of Sao Paulo, CP 66318, 05314-970, São Paulo, Brazil.
J Phys Chem B. 2011 Jan 20;115(2):269-77. doi: 10.1021/jp108653e. Epub 2010 Dec 21.
The solubilization of lipid bilayers by detergents was studied with optical microscopy of giant unilamellar vesicles (GUVs) composed of palmitoyl oleoyl phosphatidylcholine (POPC). A solution of the detergents Triton X-100 (TX-100) and sodium dodecyl sulfate (SDS) was injected with a micropipette close to single GUVs. The solubilization process was observed with phase contrast and fluorescence microscopy and found to be dependent on the detergent nature. In the presence of TX-100, GUVs initially showed an increase in their surface area, due to insertion of TX-100 with rapid equilibration between the two leaflets of the bilayer. Then, above a solubility threshold, several holes opened, rendering the bilayer a lace fabric appearance, and the bilayer gradually vanished. On the other hand, injection of SDS caused initially an increase in the membrane spontaneous curvature, which is mainly associated with incorporation of SDS in the outer layer only. This created a stress in the membrane, which caused either opening of transient macropores with substantial decrease in vesicle size or complete vesicle bursting. In another experimental setup, the extent of solubilization/destruction of a collection of GUVs was measured as a function of either TX-100 or SDS concentration.
用含有十六烷基三甲基溴化铵（CTAB）和十二烷基硫酸钠（SDS）的缓冲溶液孵育 GUVs，研究了 GUVs 的稳定性。在不同的孵育时间后，通过荧光显微镜观察 GUVs 的形态变化。结果表明，SDS 可以快速破坏 GUVs 的稳定性，而 CTAB 则需要较长的孵育时间才能达到相同的效果。此外，我们还发现 SDS 对 GUVs 的破坏作用是不可逆的，而 CTAB 则可以在一定程度上恢复 GUVs 的稳定性。
