title: Aglycon diversity of brain sterylglucosides: structure determination of cholesteryl- and sitosterylglucoside.
abstract: To date, sterylglucosides have been reported to be present in various fungi, plants, and animals. In bacteria, such as Helicobacter pylori, proton NMR spectral analysis of isolated 1-O-cholesteryl-β-d-glucopyranoside (GlcChol) demonstrated the presence of an α-glucosidic linkage. By contrast, in animals, no detailed structural analysis of GlcChol has been reported, in part because animal-derived samples contain a high abundance of glucosylceramides (GlcCers)/galactosylceramides, which exhibit highly similar chromatographic behavior to GlcChol. A key step in vertebrate GlcChol biosynthesis is the transglucosylation reaction catalyzed by glucocerebrosidase (GBA)1 or GBA2, utilizing GlcCer as a glucose donor. These steps are expected to produce a β-glucosidic linkage. Impaired GBA1 and GBA2 function is associated with neurological disorders, such as cerebellar ataxia, spastic paraplegia, and Parkinson's disease. Utilizing a novel three-step chromatographic procedure, we prepared highly enriched GlcChol from embryonic chicken brain, allowing complete structural confirmation of the β-glucosidic linkage by1H-NMR analysis. Unexpectedly, during purification, two additional sterylglucoside fractions were isolated. NMR and GC/MS analyses confirmed that the plant-type sitosterylglucoside in vertebrate brain is present throughout embryonic development. The aglycon structure of the remaining sterylglucoside (GSX-2) remains elusive due to its low abundance. Together, our results uncovered unexpected aglycon heterogeneity of sterylglucosides in vertebrate brain.
authors.affiliation: Laboratory for Molecular Membrane Neuroscience, RIKEN Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Hisako
authors.initials: H
authors.lastname: Akiyama
authors.affiliation: Laboratory for Molecular Membrane Neuroscience, RIKEN Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: JEOL Ltd., Akishima, Tokyo 196-8558, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Itoh
authors.affiliation: Laboratory for Molecular Membrane Neuroscience, RIKEN Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sayano
authors.affiliation: Laboratory for Molecular Membrane Neuroscience, RIKEN Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ohashi
authors.affiliation: Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Peter
authors.initials: P
authors.lastname: Greimel
authors.affiliation: Laboratory for Molecular Membrane Neuroscience, RIKEN Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan hirabaya@riken.jp.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirabayashi
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002784:Cholesterol / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism; D005699:Galactosylceramides / Q000737:chemistry* / Q000378:metabolism; D005776:Gaucher Disease / Q000378:metabolism / Q000473:pathology; D005962:Glucosylceramidase / Q000737:chemistry* / Q000378:metabolism; D005963:Glucosylceramides / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D012855:Sitosterols / Q000737:chemistry / Q000378:metabolism
chemical_list: D005699:Galactosylceramides; D005963:Glucosylceramides; D012855:Sitosterols; D002784:Cholesterol; D005962:Glucosylceramidase
keywords: brain lipids; cholesterol; glycolipids; mass spectrometry; matrix-assisted laser desorption/ionization-tandem mass spectrometry; sterols, glucosylceramide