Manni Marco M, Cano Ainara, Alonso Cristina, Goñi Félix M
Unidad de Biofísica (CSIC, UPV/EHU), and Departamento de Bioquímica, Universidad del País Vasco, Aptdo. 644, 48080 Bilbao, Spain.
OWL, Parque Tecnológico de Bizkaia, Bizkaia, Spain.
Chem Phys Lipids. 2015 Oct;191:68-74. doi: 10.1016/j.chemphyslip.2015.08.011. Epub 2015 Aug 28.
A comparative lipidomic study has been performed of whole Madin-Darby canine kidney epithelial cells and of the detergent-resistant membrane fraction (DRM) obtained after treating the cells with the non-ionic detergent Triton X-100. The DRM were isolated following a standard procedure that is extensively used in cell biology studies. Significant differences were found in the lipid composition of the whole cells and of DRM. The latter were enriched in all the analyzed sphingolipid classes: sphingomyelins, ceramides and hexosylceramides. Diacylglycerols were also preferentially found in DRM. The detergent-resistant fraction was also enriched in saturated over unsaturated fatty acyl chains, and in sn-1 acyl chains containing 16 carbon atoms, over the longer and shorter ones. The glycerophospholipid species phosphatidylethanolamines and phosphatidylinositols, that were mainly unsaturated, did not show a preference for DRM. Phosphatidylcholines were an intermediate case: the saturated, but not the unsaturated species were found preferentially in DRM. The question remains on whether these DRM, recovered from detergent-membrane mixtures by floatation over a sucrose gradient, really correspond to membrane domains existing in the cell membrane prior to detergent treatment.
对整个马-达二氏犬肾上皮细胞以及在用非离子去污剂曲拉通X-100处理细胞后获得的耐去污剂膜组分（DRM）进行了一项脂质组学比较研究。按照细胞生物学研究中广泛使用的标准程序分离出DRM。在整个细胞和DRM的脂质组成中发现了显著差异。DRM富含所有分析过的鞘脂类：鞘磷脂、神经酰胺和己糖神经酰胺。二酰基甘油也优先存在于DRM中。耐去污剂组分在饱和脂肪酸酰基链与不饱和脂肪酸酰基链的比例上也更高，并且在含有16个碳原子的sn-1酰基链中含量较高，而不是更长或更短的酰基链。主要为不饱和的甘油磷脂种类磷脂酰乙醇胺和磷脂酰肌醇对DRM没有偏好。磷脂酰胆碱情况居中：饱和的而非不饱和的磷脂酰胆碱种类优先存在于DRM中。通过在蔗糖梯度上漂浮从去污剂-膜混合物中回收的这些DRM是否真的对应于去污剂处理前细胞膜中存在的膜结构域，这个问题仍然存在。
