Gambale F, Marchetti C, Usai C, Robello M, Gorio A
J Neurosci Res. 1984;12(2-3):355. doi: 10.1002/jnr.490120222.
We have analyzed the effects induced in different phospholipid planar bilayers by monosialoganglioside micelles containing the ionophore gramicidin D. The membrane conductance increases after the addition of GM1 micelles at various ionophore/ganglioside ratios. We believe this fact may be ascribed to gramicidin molecules that incorporate into the bilayer together with gangliosides. In the presence of micelles the mean lifetime and the amplitude of the gramicidin single channel did not present relevant modifications when dioleoylphosphatidylcholine or phosphatidylserine were used to form the bilayer. Calcium proved to trigger the interaction between phosphatidylethanolamine membranes and GM1 micelles containing gramicidin. In this case the ionic pore presents a longer lifetime and a lower amplitude with respect to pure gramicidin. We suggest that different properties developed by gramicidin may depend on structural organization of gangliosides when incorporated into the phospholipid bilayer.
我们分析了含有离子载体短杆菌肽D的单唾液酸神经节苷脂胶束对不同磷脂平面双层膜所产生的影响。在不同的离子载体/神经节苷脂比例下加入GM1胶束后，膜电导增加。我们认为这一事实可能归因于与神经节苷脂一起掺入双层膜的短杆菌肽分子。当使用二油酰磷脂酰胆碱或磷脂酰丝氨酸形成双层膜时，在胶束存在的情况下，短杆菌肽单通道的平均寿命和幅度没有出现相关变化。事实证明，钙会引发磷脂酰乙醇胺膜与含有短杆菌肽的GM1胶束之间的相互作用。在这种情况下，与纯短杆菌肽相比，离子孔的寿命更长，幅度更低。我们认为，短杆菌肽所呈现出的不同特性可能取决于其掺入磷脂双层膜时神经节苷脂的结构组织。
