title: Efficient replacement of plasma membrane outer leaflet phospholipids and sphingolipids in cells with exogenous lipids.
abstract: Our understanding of membranes and membrane lipid function has lagged far behind that of nucleic acids and proteins, largely because it is difficult to manipulate cellular membrane lipid composition. To help solve this problem, we show that methyl-α-cyclodextrin (MαCD)-catalyzed lipid exchange can be used to maximally replace the sphingolipids and phospholipids in the outer leaflet of the plasma membrane of living mammalian cells with exogenous lipids, including unnatural lipids. In addition, lipid exchange experiments revealed that 70-80% of cell sphingomyelin resided in the plasma membrane outer leaflet; the asymmetry of metabolically active cells was similar to that previously defined for erythrocytes, as judged by outer leaflet lipid composition; and plasma membrane outer leaflet phosphatidylcholine had a significantly lower level of unsaturation than phosphatidylcholine in the remainder of the cell. The data also provided a rough estimate for the total cellular lipids residing in the plasma membrane (about half). In addition to such lipidomics applications, the exchange method should have wide potential for investigations of lipid function and modification of cellular behavior by modification of lipids.
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215.
authors.forename: Guangtao
authors.identifier: 0000-0002-5460-1288
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215.
authors.forename: JiHyun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215.
authors.forename: Johnna R
authors.initials: JR
authors.lastname: St Clair
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Brown
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215 Erwin.London@stonybrook.edu.
authors.forename: Erwin
authors.initials: E
authors.lastname: London
mesh_terms: D000072283:A549 Cells / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D003505:Cyclodextrins / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008051:Lipid Bilayers / Q000378:metabolism; D050356:Lipid Metabolism / Q000502:physiology*; D008055:Lipids / Q000502:physiology; D013058:Mass Spectrometry; D008563:Membrane Lipids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D049294:Phospholipid Transfer Proteins / Q000378:metabolism* / Q000502:physiology; D010743:Phospholipids / Q000378:metabolism; D013107:Sphingolipids / Q000378:metabolism; D013109:Sphingomyelins; D047391:alpha-Cyclodextrins / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D003505:Cyclodextrins; D008051:Lipid Bilayers; D008055:Lipids; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; D013107:Sphingolipids; D013109:Sphingomyelins; D047391:alpha-Cyclodextrins; C032613:alpha-cyclodextrin
keywords: lipid asymmetry; lipid exchange; mass spectrometry; methyl-alpha-cyclodextrin; plasma membrane outer leaflet