Production of α-Galactosylceramide by a Prominent Member of the Human Gut Microbiota (original) (raw)
Figure 1
Chemical structures of the B. fragilis sphingolipids and related molecules.
(A) B. fragilis produces the phosphosphingolipid ceramide phosphoryl-ethanolamine (CPE, top) and the corresponding free ceramide (ceramideBf, middle), which are similar in structure to the most abundant (4,5-dehydro) and third-most abundant (4,5-dihydro) forms of sphingomyelin in human plasma (bottom). (B) B. fragilis produces the glycosphingolipid α-galactosylceramide (α-GalCerBf, top), which is similar in structure to the sponge-derived α-galactosylceramide agelasphin-9b (middle) and a widely used derivative of agelasphin-9b, KRN7000 (bottom). Chemical groups that vary among the molecules in each column are colored red and blue for B. fragilis and non–B. fragilis sphingolipids, respectively. CPE, ceramideBf, and α-GalCerBf were each purified as inseparable mixtures of varying lipid chain length. The proposed structures of the most abundant species are shown here.