Filipin-induced lesions in planar phospholipid bilayers imaged by atomic force microscopy.
Filipin-induced lesions in planar phospholipid bilayers imaged by atomic force microscopy.
复制标题
通过原子力显微镜成像的平面磷脂双层中菲律宾诱导的损伤。
DOI：
10.1016/s0006-3495(98)77627-1
复制
发表时间：
1998
影响因子：
3.4
通讯作者：
Castanho,MA
中科院分区：
文献类型：
--
作者：
Santos,NC;Ter-Ovanesyan,E;Zasadzinski,JA;Prieto,M;Castanho,MA
菲律平是一种具有抗真菌活性的大环内酯多烯，属于与抗生素B和制霉菌素相同的抗生素家族。尽管光谱和电子显微镜研究其与天然膜和膜模型系统的相互作用，其生化作用的几个方面，如膜甾醇的作用，仍然是完全理解。我们已经使用原子力显微镜（AFM）研究的影响，菲律宾对二棕榈酰磷脂酰乙醇胺双层胆固醇的存在和不存在。通过Langmuir-Blodgett沉积在云母上制备双层，并在水下成像。结果表明，菲律宾引起的病变只能在膜与胆固醇。与电子显微镜结果密切一致，我们已经报道了膜中存在密集的圆形突起，平均直径为19 nm（用AFM针尖进行卷积校正），高度为0.4 nm。还检测到较大的圆形突起（直径90 nm，高度2.5 nm）和甜甜圈状病变。这些结果表明，菲律宾诱导的病变，以前观察到的电子显微镜膜不偏样品制备产生的文物。菲林聚集体在水溶液中也可以首次成像。这些多分散的球形结构中观察到的样品与和没有胆固醇。
Filipin is a macrolide polyene with antifungal activity belonging to the same family of antibiotics as amphotericin B and nystatin. Despite the spectroscopy and electron microscopy studies of its interaction with natural membranes and membrane model systems, several aspects of its biochemical action, such as the role of membrane sterols, remain to be completely understood. We have used atomic force microscopy (AFM) to study the effect of filipin on dipalmitoylphosphatidylethanolamine bilayers in the presence and absence of cholesterol. The bilayers were prepared by Langmuir-Blodgett deposition over mica and imaged under water. It was shown that filipin-induced lesions could only be found in membranes with cholesterol. In close agreement with electron microscopy results, we have reported the presence of densely packed circular protrusions in the membrane with a mean diameter of 19nm (corrected for convolution with AFM tip) and 0.4nm height. Larger circular protrusions (90nm diameter and 2.5nm height) and doughnut-shaped lesions were also detected. These results demonstrate that filipin-induced lesions in membranes previously observed by electron microscopy are not biased by artifacts resulting from sample preparation. Filipin aggregates in aqueous solution could also be imaged for the first time. These polydisperse spherical structures were observed in samples with and without cholesterol.