Structural studies on a lipoarabinogalactan of Crithidia fasciculata.
The monosaccharide D-arabinopyranose has only been found in glycoconjugates of the trypanasomatid parasites Leishmania major, Endotrypanum schaudinni and Crithidia fasciculata. The donor molecule for the relevant arabinosyltransferases is known to be GDP-alpha-D-Arap in L. major and C. fasciculata, and the latter organism is being used to study the biosynthesis of GDP-alpha-D-Arap. In this study, we describe the structure of the terminal product of arabinose metabolism in C. fasciculata, namely lipoarabinogalactan. This molecule was purified by hydrophobic-interaction chromatography and studied by a variety of techniques, including gas chromatography-mass spectrometry, electrospray mass spectrometry and chemical and enzymic digestions. These data show that lipoarabinogalactan contains a previously described D-arabino-D-galactan polysaccharide component covalently attached to a glycosylphosphatidylinositol type of membrane anchor that is similar to, but not identical with, that found in the lipophosphoglycans of the Leishmania.
Schneider
P
P
Department of Biochemistry, University of Dundee, U.K.
Treumann
A
A
Milne
K G
KG
McConville
M J
MJ
Zitzmann
N
N
Ferguson
M A
MA
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D016831:Crithidia fasciculata / Q000737:chemistry*; D005685:Galactans / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure
D005685:Galactans; D008070:Lipopolysaccharides; C005653:arabinogalactan