Arabinofuranosidases Arabinoxylans

Terminal L-arabinosidic linkages in L-arabinose conjugates are also hydrolyzed by the enzyme. The enzyme of R. fiava releases L-arabinose from the polysaccharide of the water shield (Brasenia schreberi J. F. Gmel)38 and from the cotyledon of Tora bean (Phaseolus vulgaris).39 Some 70 to 80% of the side chains of the arabinoxylan in rice cell-wall are composed of L-arabinose. When the a-L-arabinofuranosidase from R. 

Arabinofuranosidases. a-L-arabinofura-nosidases (EC 3.2.1.55) cleave a-L-arabinofu-ranosides from the arabinoxylan xylose backbone and have been shown to enhance the release of ferulic and coumaric acid from arabi-... 

Wood, T. M. and McCrae, S. I., Arabinoxylan-degrading enzyme system of the fungus Aspergillus awamori purification and properties of an alpha-L-arabinofuranosidase. Appl Microbiol Biotechnol 1996,45 (4), 538-45. 

Schwarz, W. H., Bronnenmeier, K., Krause, B., Lottspeich, F., and Staudenbauer, W. L., Debranching of arabinoxylan properties of the thermoactive recombinant alpha-L-arabinofuranosidase from Clostridium stercorar-ium (ArfB). Appl Microbiol Biotechnol 1995, 43 (5), 856-60. 

The D-xylanases of rumen microbial origin are all of the endo type, and degrade D-xylan, arabinoxylan, hemicellulose B, and xylo-oligosaccharides of d.p. 2=3, mainly to X2 and D-xylose X2 remains unattacked. The D-xylanases were found38,42 to have a higher affinity for linear D-xylans than for the branched hemicelluloses, namely, arabinoxylan and a branched B fraction from Trifolium pratense (red clover). The presence of L-arabinose, D-galactose, and uronic acid substituents on the D-xylan backbone thus appears to inhibit the action of these D-xylanases. The D-xylan was not effectively hydrolyzed until the side-group substituents had mostly been removed, for example, by arabinofuranosidase action on arabinoxylan.44... 

Sorensen H.R., Meyer A.S., Pedersen S., Enzymatic hydrolysis of water-soluble wheat arabinoxylan. 1. Synergy between alpha-L-arabinofuranosidases, endo-1, 4-beta-xylanases, and beta-xylosidase activities, Biotechnol. Bioeng., 81(6), 2003, 726-731. 

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