AFM studies of water-soluble wheat arabinoxylans--effects of esterase treatment.
The degradation products of water-soluble wheat arabinoxylans treated with Aspergillus niger ferulic acid esterase (FAEA-able to cleave 5,5'- and 8-O-4'-ferulic acid dimers) have been characterised by atomic force microscopy (AFM) and size exclusion chromatography. The AFM images of arabinoxylans confirmed that a small proportion ( approximately 15%) of the population of arabinoxylan molecules contain xylan-based branches attached to the xylan-based backbone. Treatment with FAEA reduced the contour length of the molecules suggesting that certain dimeric ferulic acid linkages may play a previously unconfirmed role in the elongation of arabinoxylans. Overnight treatment with FAEA led to a reduction in the density of branches suggesting that they may also be linked to the backbone through phenolic linkages.
Institute of Food Research, Norwich Research Park, Colney Lane, Norwich NR4 7UA, UK.
Elizabeth L
EL
Adams
Paul A
PA
Kroon
Gary
G
Williamson
Victor J
VJ
Morris
D001234:Aspergillus niger / Q000201:enzymology; D002138:Calibration; D002236:Carbohydrate Conformation; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry; D004950:Esterases / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D010426:Pentosan Sulfuric Polyester / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D013997:Time Factors; D014908:Triticum / Q000378:metabolism*; D014990:Xylans / Q000737:chemistry*
D003373:Coumaric Acids; D011994:Recombinant Proteins; D014990:Xylans; D010426:Pentosan Sulfuric Polyester; C085118:arabinoxylan; C004999:ferulic acid; D004950:Esterases; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase