title: Substrate specificities of alpha-L-arabinofuranosidases produced by two species of Aspergillus niger.
abstract: Precise substrate specificities of alpha-L-arabinofuranosidases from Aspergillus niger 5-16 and Aspergillus niger (Megazyme) were investigated. Both enzymes hydrolyzed arabinan and debranched-arabinan at almost the same rate. The alpha-L-Arabinofuranosidase from A. niger (Megazyme) preferentially released arabinosyl side-chains of arabinan. The enzyme tore off both arabinoses attached to O-alpha-L-arabinofuranosyl-(1-->3)-O-beta-D-xylopyranosyl-(1--> 4)-D-xylopyranose and O-beta-D-xylopyranosyl-(1-->4)-[O-alpha-L- arabinofuranosyl-(1-->3)]-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose, but did not tear off xylosyl-arabinose from O-beta-D-xylopyranosyl-(1-->2)-O-alpha-L-arabinofuranosyl-(1-->3) -O-beta-D-xylopyranosyl-(1-->4)-O-beta-D-xylopyranosyl-(1-->4)-D- xylopyranose. The enzyme from A. niger (Megazyme) hydrolyzed methyl 2-O-, methyl 3-O- and methyl 5-O-alpha-L-arabinofuranosyl-alpha-L-arabinofuranosides to arabinose and methyl alpha-L-arabinofuranoside in the order of (1-->5)->(1-->2)->(1-->3)-linkages. On the other hand, alpha-L-arabinofuranosidase from A. niger 5-16 successively liberated the arabinose of arabinan from non-reducing terminals. The enzyme hydrolyzed in the order of (1-->2- > (1-->3)- > (1-->5)-linkages. Both of the enzymes hydrolyzed the (1-->3)-linkage more than the (1-->5)-linkage of methyl 3,5-di-O-alpha-L-arabinofuranosyl-alpha-L-arabinofuranoside.
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kaneko
authors.forename: T
authors.initials: T
authors.lastname: Ishii
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: I
authors.initials: I
authors.lastname: Kusakabe
mesh_terms: D001087:Arabinonucleosides / Q000378:metabolism; D001234:Aspergillus niger / Q000201:enzymology*; D002240:Carbohydrate Sequence; D006026:Glycoside Hydrolases / Q000096:biosynthesis / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001087:Arabinonucleosides; D009844:Oligosaccharides; D011134:Polysaccharides; C030080:araban; D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase