title: Localization of sphingomyelin in cholesterol domains by imaging mass spectrometry.
abstract: The location of each lipid in a palmitoyloleoylphosphatidylcholine/18:0 sphingomyelin/cholesterol monolayer system is laterally resolved using imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS) without the necessity of adding fluorescent labels. This system of coexisting immiscible liquid phases shows cholesterol domains with sizes and shapes comparable to those in the fluorescence microscopy literature. The results show that SM localizes with cholesterol and that palmitoyloleoylphosphatidylcholine is excluded. Moreover, the segregation is not complete, and there is a small amount of both phospholipids distributed throughout.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, USA.
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: McQuaw
authors.forename: Leiliang
authors.initials: L
authors.lastname: Zheng
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Ewing
authors.forename: Nicholas
authors.initials: N
authors.lastname: Winograd
mesh_terms: D002784:Cholesterol / Q000737:chemistry*; D013058:Mass Spectrometry; D008567:Membranes, Artificial; D013109:Sphingomyelins / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D013109:Sphingomyelins; D002784:Cholesterol