Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation.
St. Petersburg State University, Petergof, 198504, Russian Federation.
Sci Rep. 2019 Nov 5;9(1):16034. doi: 10.1038/s41598-019-52551-5.
The one-sided addition of fengycin (FE) to planar lipid bilayers mimicking target fungal cell membranes up to 0.1 to 0.5 μM in the membrane bathing solution leads to the formation of well-defined and well-reproducible single-ion channels of various conductances in the picosiemens range. FE channels were characterized by asymmetric conductance-voltage characteristic. Membranes treated with FE showed nonideal cationic selectivity in potassium chloride bathing solutions. The membrane conductance induced by FE increased with the second power of the lipopeptide aqueous concentration, suggesting that at least FE dimers are involved in the formation of conductive subunits. The pore formation ability of FE was not distinctly affected by the molecular shape of membrane lipids but strongly depended on the presence of negatively charged species in the bilayer. FE channels were characterized by weakly pronounced voltage gating. Small molecules known to modify the transmembrane distribution of electrical potential and the lateral pressure profile were used to modulate the channel-forming activity of FE. The observed effects of membrane modifiers were attributed to changes in lipid packing and lipopeptide oligomerization in the membrane.
在模拟靶真菌细胞膜的平面脂质双层中，将单片面添加到膜浴溶液中至 0.1 至 0.5 μM，导致在皮西门子范围内形成各种电导的明确定义和可重复的单离子通道。FE 通道的特征是不对称电导-电压特性。用 FE 处理的膜在氯化钾浴溶液中表现出非理想的阳离子选择性。FE 诱导的膜电导随脂肽水相浓度的二次方增加，表明至少 FE 二聚体参与形成导电亚基。FE 的孔形成能力不受膜脂分子形状的明显影响，但强烈依赖于双层中带负电荷物质的存在。FE 通道的电压门控作用不明显。已知能够改变跨膜电势分布和横向压力分布的小分子被用来调节 FE 的通道形成活性。观察到的膜修饰剂的影响归因于膜中脂质堆积和脂肽寡聚化的变化。
