title: Cell membrane localization of sterols with conventional and unusual side chains in two marine demosponges.
abstract: Subcellular fractionation by differential centrifugation was performed on two previously unstudied marine sponges that predominantly contain either conventional (Reniera sp.) or unconventional (Pseudaxinyssa sp.) sterols. Direct evidence for the presence of unconventional sterols with C24 alkylated side chains in the cellular membranes of Pseudaxinyssa sp. is provided, but the presence of unconventional sterols in sponge membranes is shown not to be a universal feature of the Porifera. Possible structural and functional roles of unconventional lipid molecules in sponge cell membranes are discussed.
authors.affiliation: Department of Chemistry, Stanford University, CA 94305.
authors.forename: M P
authors.initials: MP
authors.lastname: Lawson
authors.forename: I L
authors.initials: IL
authors.lastname: Stoilov
authors.forename: J E
authors.initials: JE
authors.lastname: Thompson
authors.forename: C
authors.initials: C
authors.lastname: Djerassi
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000032:analysis; D008563:Membrane Lipids / Q000032:analysis*; D011161:Porifera / Q000032:analysis*; D013261:Sterols / Q000032:analysis*; D013347:Subcellular Fractions / Q000032:analysis
chemical_list: D008563:Membrane Lipids; D013261:Sterols