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. 2012 Jul 6;70(3):425–457. doi: 10.1007/s00018-012-1060-z

Fig. 5.

Fig. 5

Biosynthesis flow sheet of globo-series neutral GSLs and structures of Gb3Cer, Gb4Cer, and Forssman GSL. a The β1,4-galactosyltransferase (β1,4GalT) adds a galactose to glucosylceramide (GlcCer) yielding lactosylceramide (Lc2Cer). Lc2Cer is elongated by galactose through the action of α1,4-galactosyltransferase (α1,4GalT) or Gb3Cer synthase. Gb3Cer is then further prolongued by β1,3-N-acetylgalactosaminyltransferase (β1,3GalNAcT) or Gb4Cer synthase which transfers N-acetylgalactosamine (GalNAc) to Gb3Cer. Forssman GSL is formed by the transfer of N-acetylgalactosamine (GalNAc) to Gb4Cer in α-configuration by α1,3-N-acetylgalactosaminyltransferase (α1,3GalNAcT). b Structures of Gb3Cer, Gb4Cer and Forssman GSL depicted in the Haworth projection. Gb3Cer and Gb4Cer occur in human endothelial cells preferentially with C24 or C16 fatty acids but constant sphingosine (d18:1) in their ceramide portions. The symbolic representation system according to Varki [361] and the Consortium for Functional Glycomics [362] is used. Reprinted with permission from Müthing et al. [56], copyright 2012 Oxford University Press