Characterization of glucuronic acid containing glycolipid in Aspergillus fumigatus mycelium.
A glucuronic acid containing glycerolipid was isolated from the filamentous fungi Aspergillus fumigatus. This acidic glycolipid was extracted from the membrane of mycelium and purified by two successive chromatographic steps on DEAE-Sephadex and Silica columns. Chemical structural analysis was performed using methylation, gas-chromatography, gas-chromatography-mass spectrometry, nano-electrospray mass spectrometry and (1)H/(13)C NMR spectra. The corresponding structure is a 3-(O-alpha-glucuronyl)-1,2-diacyl-sn-glycerol, where acyl chains are mainly C(16:0), C(18:0), C(18:1), and C(18:2). This alpha-GlcA-diacylglycerol is not present in fungal conidia. This acidic glycerolipid is described here for the first time in a fungal species. Two homologs of UDP-glucose dehydrogenase that convert UDP-glucose into UDP-glucuronic acid, are present in A. fumigatus genome, UGD1 and UGD2. Gene deletion showed that only UGD1 is essential for the biosynthesis of GlcA-DG. However, no particular phenotype has been observed in the Ugd1Delta mutant. Biological function of this acidic glycolipid remains unknown in A. fumigatus.
Fontaine
Thierry
T
Institut Pasteur, Paris, France. tfontain@pasteur.fr
Lamarre
Claude
C
Simenel
Catherine
C
Lambou
Karine
K
Coddeville
Bernadette
B
Delepierre
Muriel
M
Latgé
Jean-Paul
JP
D001232:Aspergillus fumigatus / Q000235:genetics / Q000378:metabolism*; D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D020723:Glucuronic Acid / Q000737:chemistry*; D006017:Glycolipids / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D025282:Mycelium / Q000235:genetics / Q000378:metabolism*
D006017:Glycolipids; D020723:Glucuronic Acid