Substrate specificity of three recombinant α-L-arabinofuranosidases from Bifidobacterium adolescentis and their divergent action on arabinoxylan and arabinoxylan oligosaccharides.

Division of Gene Technology, Katholieke Universiteit Leuven, Leuven, Belgium.
Biochemical and Biophysical Research Communications (Impact Factor: 2.28). 10/2010; 402(4):644-50. DOI: 10.1016/j.bbrc.2010.10.075
Source: PubMed

ABSTRACT Bifidobacterium adolescentis possesses several arabinofuranosidases able to hydrolyze arabinoxylans (AX) and AX oligosaccharides (AXOS), the latter being bifidogenic carbohydrates with potential prebiotic properties. We characterized two new recombinant arabinofuranosidases, AbfA and AbfB, and AXH-d3, a previously studied arabinofuranosidase from B. adolescentis. AbfA belongs to glycoside hydrolase family (GH) 43 and removed arabinose from the C(O)2 and C(O)3 position of monosubstituted xylose residues. Furthermore, hydrolytic activity of AbfA was much larger towards substrates with a low amount of arabinose substitutions. AbfB from GH 51 only cleaved arabinoses on position C(O)3 of disubstituted xyloses, similar to GH 43 AXH-d3, making it to our knowledge, the first reported enzyme with this specificity in GH 51. AbfA acted synergistically with AbfB and AXH-d3. In combination with AXH-d3, it released 60% of arabinose from wheat AX. Together with recent studies on other AXOS degrading enzymes from B. adolescentis, these findings allowed us to postulate a mechanism for the uptake and hydrolysis of bifidogenic AXOS by this organism.

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    • "resistant to enzymatic degradation in the intestinal lumen and therefore reach distal portions of the intestine. Different Bifidobacterium species are capable of metabolizing complex oligosaccharides usually from plant origin such as cellodextrins and amyloses (Pokusaeva et al., 2011), raffinose (Dinoto et al., 2006), arabinooligosaccharides (Lagaert et al., 2010; Van Laere et al., 1997), xylooligosaccharides (Gilad et al., 2010), fructooligosaccharides and inulin (Omori et al., 2010; Perrin et al., 2001; Rossi et al., 2005), galactans and galactooligosaccharides (GOS; (Barboza et al., 2009; Goulas et al., 2009a; Hinz et al., 2005; O'Connell Motherway et al., 2011)) among several others. "
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