Assimilation of xylose, mannose, and mannitol for synthesis of glucuronoxylomannan of Cryptococcus neoformans determined by 13C nuclear magnetic resonance spectroscopy.
Cryptococcus neoformans NIH 409 was cultured in a defined medium containing D-[1-13C]xylose (Xyl), D-[1-13C]mannose (Man), or D-[1-13C]mannitol as the sole carbon source. The distribution of 13C in the Man, Xyl, glucuronic acid (GlcA), and O-acetyl constituents of native and de-O-acetylated glucuronoxylomannan (GXM) was determined by one-dimensional 13C nuclear magnetic resonance spectroscopy. The carbon chain of Man was incorporated intact into GXM since 13C was observed only in carbon 1 of Man, GlcA, and Xyl. The carbon chain of mannitol was incorporated intact into GXM since 13C was observed only in carbons 1 and 6. This was expected since mannitol has an axis of symmetry. The carbon chain of Xyl was identified only in carbons 1 and 3 of Man, GlcA, and Xyl. This pattern of labeling is consistent with the assimilation of Xyl through the pentophosphate pathway.
Cherniak
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Laboratory for Biological and Chemical Sciences, Department of Chemistry, Georgia State University, Atlanta, Georgia 30303, USA. cherniak@gsu.edu
O'Neill
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Sheng
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D000107:Acetylation; D002247:Carbon Isotopes; D003455:Cryptococcus neoformans / Q000378:metabolism*; D005965:Glucuronates / Q000032:analysis; D020723:Glucuronic Acid; D008353:Mannitol / Q000378:metabolism*; D008358:Mannose / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011134:Polysaccharides / Q000096:biosynthesis*; D014994:Xylose / Q000378:metabolism*
D002247:Carbon Isotopes; D005965:Glucuronates; D011134:Polysaccharides; D008353:Mannitol; C027478:glucuronoxylomannan; D020723:Glucuronic Acid; D014994:Xylose; D008358:Mannose