Degradation of feruloylated oligosaccharides from sugar-beet pulp and wheat bran by ferulic acid esterases from Aspergillus niger.
The activity of two forms of ferulic acid esterase (FAE) from Aspergillus niger on a synthetic feruloylated substrate (methyl ferulate) and on 11 different feruloylated oligosaccharides from sugar-beet pulp and wheat bran was determined. The enzymes exhibited different specificities for the various feruloylated substrates and were more active on certain substrates of cell-wall origin than on methyl ferulate. Both enzymes preferred the arabinose residue to which ferulic acid is attached in the furanose form. FAE-I had no clear preference for the type of linkage involved between the ferulic acid units and the oligosaccharide chain. In contrast, FAE-III had a clear requirement for ferulic acid to be attached to O-5 of the Ara f ring while no catalysis was observed when ferulic acid was attached to O-2. Both enzymes showed maximum activity on feruloylated trisaccharides. An increase in the length of the oligosaccharide chain did not preclude catalysis, but feruloylated oligosaccharides of a dp > 3 were hydrolysed at a reduced rate. Our results support the hypothesis that different kinds of ferulic acid esterases exist with different specificities for the oligosaccharide chain of the feruloylated substrates.
Ralet
M C
MC
Institut National de la Recherche Agronomique, Laboratoire de Biochimie et Technologie des Glucides, Nantes, France.
Faulds
C B
CB
Williamson
G
G
Thibault
J F
JF
D001234:Aspergillus niger / Q000201:enzymology*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002265:Carboxylic Ester Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D003373:Coumaric Acids / Q000032:analysis*; D004043:Dietary Fiber / Q000032:analysis*; D007700:Kinetics; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D010945:Plants, Edible / Q000737:chemistry*
D003373:Coumaric Acids; D004043:Dietary Fiber; D009844:Oligosaccharides; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase