Disease relevance of Xylobiose

• Recombinant XYLA, purified from Escherichia coli harbouring xynA, had a M(r) of 53,000 and hydrolysed oat-spelt xylan to xylobiose and xylose [1].
• A cellulase/xylanase-negative mutant of Streptomyces lividans 1326 defective in cellobiose and xylobiose uptake is mutated in a gene encoding a protein homologous to ATP-binding proteins [2].
• Detailed structural analysis of glycosidase/inhibitor interactions: complexes of Cex from Cellulomonas fimi with xylobiose-derived aza-sugars [3].
• Adjacent genes encoding xylobiose uptake and hydrolysis were cloned from Klebsiella oxytoca M5A1 and are functionally expressed in ethanologenic E. coli [4].
• In addition, kinetic parameters for hydrolysis of the natural substrates xylobiose and xylotriose were obtained using this assay for a glycosyl hydrolase family 39 beta-xylosidase from Thermoanaerobacterium sp. strain JW/SL YS485 (Swiss-Prot accession no. O30360) [5].

Psychiatry related information on Xylobiose

• Xylobiose was the major product from xylan at 40 degrees C and its proportion in the xylan hydrolyzates increased with the reaction time; at 12 h, over 60% of the reaction products was xylobiose [6].

High impact information on Xylobiose

• Analysis of the various substrate binding sites shows that the +3 and -3 subsites are rearranged as compared to those of a family 8 homolog, while the xylobiose complex suggests the existence of a +4 subsite [7].
• It is thus proposed that the active transport system for cellobiose and xylobiose is affected in mutant strain 10-164 [2].
• ARAf and XYL1 have highest specificity for p-nitrophenyl-alpha-L-arabinofuranoside and XYL4 for p-nitrophenyl-beta-D-xylopyranoside and natural substrates such as xylobiose and xylotetraose [8].
• Both catalytic domains cleaved xylotriose, xylotetraose, and xylopentaose but had no activity on xylobiose [9].
• The main xylooligosaccharide products released using the action of endoxylanase alone on oat-spelt xylan were identified as xylobiose and xylopentose. alpha-l-Arabinofuranosidase was able to release arabinose and xylobiose from oat-spelt xylan [10].

Chemical compound and disease context of Xylobiose

• Xylose, xylobiose, xylan, and glucuronic acid showed no significant suppressive activities on mouse gastric inflammation at a dose of 100 mg/kg body weight [11].

Biological context of Xylobiose

• The major end product of xylan hydrolysis was xylobiose [12].
• Regulation of the respective genes via Xyr1 is not affected by the substances mediating induction (xylose, xylobiose, and sophorose) and is indispensable for all modes of gene expression (basal, derepressed, and induced) [13].
• Two xylanases showed relatively broad substrate specificity and were able to degrade also crystalline cellulose. beta-D-Xylosidase showed optimal activity at pH 6.7 to 7.0 and at 42 degrees C. The Km for o-nitrophenyl-beta-D-xylopyranoside was 0.22 mM and xylotriose was hydrolyzed more rapidly than xylobiose [14].

Associations of Xylobiose with other chemical compounds

• In a high-performance liquid chromatography analysis, xylose was detected as the main product of the yeast strain codisplaying XYNII and XylA, while xylobiose and xylotriose were detected as the main products of a yeast strain displaying XYNII on the cell surface [15].
• Potential substrates include the soluble xylodextrins (xyloside, xylooligosaccharide) and xylobiose that are produced by treatments designed to expose cellulose for subsequent enzymatic hydrolysis [4].
• During the enzymatic hydrolysis of xylobiose, the reaction product of both enzymes was found to be beta-D-xylose proving that the hydrolysis is proceeding via a retaining reaction mechanism [16].

Analytical, diagnostic and therapeutic context of Xylobiose

• Tyr(6), Tyr(10), Tyr(89), Tyr(164), and Trp(172) are proposed as substrate-binding residues, a finding consistent with structural sequence alignments of family 11 xylanases and with the three-dimensional structure of the A. niger xylanase in complex with the modeled xylobiose [17].
• Binding properties of xylobiose and xylotriose to the active site were measured using isothermal titration calorimetry (ITC) [18].
• The major products of xylan hydrolysis by the purified complex were determined to be xylobiose and xylotriose by thin-layer chromatography [19].
• HPLC analysis of the digestion products of oNP-X2 or pNP-X2 showed that the xylanase hydrolyzed each of the substrates only at the ether bond between nitrophenol and xylobiose [20].

References