title: Characterization of a new beta(1-3)-glucan branching activity of Aspergillus fumigatus.
abstract: A new HPLC method was developed to separate linear from beta(1-6)-branched beta(1-3)-glucooligosaccharides. This methodology has permitted the isolation of the first fungal beta(1-6)/beta(1-3)-glucan branching transglycosidase using a cell wall autolysate of Aspergillus fumigatus (Af). The encoding gene, AfBGT2 is an ortholog of AfBGT1, another transglycosidase of A. fumigatus previously analyzed (Mouyna, I., Hartland, R. P., Fontaine, T., Diaquin, M., Simenel, C., Delepierre, M., Henrissat, B., and Latgé, J. P. (1998) Microbiology 144, 3171-3180). Both enzymes release laminaribiose from the reducing end of a beta(1-3)-linked oligosaccharide and transfer the remaining chain to another molecule of the original substrate. The AfBgt1p transfer occurs at C-6 of the non-reducing end group of the acceptor, creating a kinked beta(1-3;1-6) linear molecule. The AfBgt2p transfer takes place at the C-6 of an internal group of the acceptor, resulting in a beta(1-3)-linked product with a beta(1-6)-linked side branch. The single Afbgt2 mutant and the double Afbgt1/Afbgt2 mutant in A. fumigatus did not display any cell wall phenotype showing that these activities were not responsible for the construction of the branched beta(1-3)-glucans of the cell wall.
authors: Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France.
authors: Amandine
authors: A
authors: Gastebois
authors: Isabelle
authors: I
authors: Mouyna
authors: Catherine
authors: C
authors: Simenel
authors: Cécile
authors: C
authors: Clavaud
authors: Bernadette
authors: B
authors: Coddeville
authors: Muriel
authors: M
authors: Delepierre
authors: Jean-Paul
authors: JP
authors: Latgé
authors: Thierry
authors: T
authors: Fontaine
mesh_terms: D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000235:genetics; D015153:Blotting, Western; D002473:Cell Wall / Q000201:enzymology; D044602:Cellulases / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D006031:Glycosylation; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010641:Phenotype; D047071:beta-Glucans / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D047071:beta-Glucans; D044602:Cellulases; D004693:Glucan Endo-1,3-beta-D-Glucosidase