title: Lipids that determine detergent resistance of MDCK cell membrane fractions.
abstract: 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.
authors: Unidad de Biofísica (CSIC, UPV/EHU), and Departamento de Bioquímica, Universidad del País Vasco, Aptdo. 644, 48080 Bilbao, Spain.
authors: Marco M
authors: MM
authors: Manni
authors: OWL, Parque Tecnológico de Bizkaia, Bizkaia, Spain.
authors: Ainara
authors: A
authors: Cano
authors: OWL, Parque Tecnológico de Bizkaia, Bizkaia, Spain.
authors: Cristina
authors: C
authors: Alonso
authors: Unidad de Biofísica (CSIC, UPV/EHU), and Departamento de Bioquímica, Universidad del País Vasco, Aptdo. 644, 48080 Bilbao, Spain. Electronic address: felix.goni@ehu.es.
authors: Félix M
authors: FM
authors: Goñi
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003902:Detergents / Q000737:chemistry* / Q000378:metabolism; D004285:Dogs; D061985:Madin Darby Canine Kidney Cells; D021962:Membrane Microdomains / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000032:analysis; D010714:Phosphatidylethanolamines / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D025341:Principal Component Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013107:Sphingolipids / Q000032:analysis
chemical_list: D003902:Detergents; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D013107:Sphingolipids
keywords: DRM; Diacylglycerols; Lipid chain-length; Lipid rafts; Lipid unsaturation; Lipidomics; Phospholipids; Sphingolipids