6819-07-4Relevant articles and documents
Glycosynthase-Mediated Assembly of Xylanase Substrates and Inhibitors
Goddard-Borger, Ethan D.,Fiege, Brigitte,Kwan, Emily M.,Withers, Stephen G.
experimental part, p. 1703 - 1711 (2012/06/29)
An exo-β-xylosidase mutant with glycosynthase activity was created to aid in the synthesis of xylanase substrates and inhibitors. Simple monosaccharides were easily elaborated into di-, tri- and tetrasaccharides by using this enzyme. Some products proved
A new archaeal β-glycosidase from Sulfolobus solfataricus: Seeding a novel retaining β-glycan-specific glycoside hydrolase family along with the human non-lysosomal glucosylceramidase GBA
Cobucci-Ponzano, Beatrice,Aurilia, Vincenzo,Riccio, Gennaro,Henrissat, Bernard,Coutinho, Pedro M.,Strazzulli, Andrea,Padula, Anna,Corsaro, Maria Michela,Pieretti, Giuseppina,Pocsfalvi, Gabriella,Fiume, Immacolata,Cannio, Raffaele,Rossi, Mose,Moracci, Marco
experimental part, p. 20691 - 20703 (2011/04/23)
Carbohydrate active enzymes (CAZymes) are a large class of enzymes, which build and breakdown the complex carbohydrates of the cell.Onthe basis of their amino acid sequences they are classified in families and clans that show conserved catalytic mechanism, structure, and active site residues, but may vary in substrate specificity. We report here the identification and the detailed molecular characterization of a novel glycoside hydrolase encoded from the gene sso1353 of the hyperthermophilic archaeon Sulfolobus solfataricus. This enzyme hydrolyzes aryl β-gluco- and β-xylosides and the observation of transxylosylation reactions products demonstrates that SSO1353 operates via a retaining reaction mechanism. The catalytic nucleophile (Glu-335) was identified through trapping of the 2-deoxy-2-fluoroglucosyl enzyme intermediate and subsequent peptide mapping, while the general acid/base was identified as Asp-462 through detailed mechanistic analysis of a mutant at that position, including azide rescue experiments. SSO1353 has detectable homologs of unknown specificity among Archaea, Bacteria, and Eukarya and shows distant similarity to the non-lysosomal bile acid β-glucosidase GBA2 also known as glucocerebrosidase. On the basis of our findings we propose that SSO1353 and its homologs are classified in a new CAZy family, named GH116, which so far includes β-glucosidases (EC 3.2.1.21), β-xylosidases (EC 3.2.1.37), and glucocerebrosidases (EC 3.2.1.45) as known enzyme activities.
Enzymatic transglycosylation of xylose using a glycosynthase
Kim, Young-Wan,Chen, Hongming,Withers, Stephen G.
, p. 2735 - 2741 (2007/10/03)
The application of the hyperactive glycosynthase derived from Agrobacterium sp. β-glucosidase (AbgE358G-2F6) to the synthesis of xylo-oligosaccharides by using α-D-xylopyranosyl fluoride as donor represents the first successful use of glycosynthase techno
Enzymatic synthesis of β-xylanase substrates: Transglycosylation reactions of the β-xylosidase from Aspergillus sp.
Eneyskaya, Elena V.,Brumer III, Harry,Backinowsky, Leon V.,Ivanen, Dina R.,Kulminskaya, Anna A.,Shabalin, Konstantin A.,Neustroev, Kirill N.
, p. 313 - 325 (2007/10/03)
A β-D-xylosidase with molecular mass of 250±5 kDa consisting of two identical subunits was purified to homogeneity from a cultural filtrate of Aspergillus sp. The enzyme manifested high transglycosylation activity in transxylosylation with p-nitrophenyl β-D-xylopyranoside (PNP-X) as substrate, resulting in regio- and stereoselective synthesis of p-nitrophenyl (PNP) β-(1→4)-D-xylooligosaccharides with dp 2-7. All transfer products were isolated from the reaction mixtures by HPLC and their structures established by electrospray mass spectrometry and 1H and 13C NMR spectroscopy. The glycosides synthesised, β-Xyl-1→(4-β-Xyl-1→)n4-β-Xyl-OC 6H4NO2-p (n=1-5), were tested as chromogenic substrates for family 10 β-xylanase from Aspergillus orizae (XynA) and family 11 β-xylanase I from Trichoderma reesei (XynT) by reversed-phase HPLC and UV-spectroscopy techniques. The action pattern of XynA against the foregoing PNP β-(1→4)-D-xylooligosaccharides differed from that of XynT in that the latter released PNP mainly from short PNP xylosides (dp 2-3) while the former liberated PNP from the entire set of substrates synthesised.
An efficient chemical-enzymatic synthesis of 4-nitrophenyl β- xylobioside: A chromogenic substrate for xylanases
Mechaly, Adva,Belakhov, Valery,Shoham, Yuval,Baasov, Timor
, p. 111 - 115 (2007/10/03)
4-Nitrophenyl-β-xylobioside was synthesized by an improved short chemical-enzymatic method, based on the use of xylobiose as a starting material. Xylobiose was prepared following extensive enzymatic digestion of birchwood xylan with xylanase T-6. The resulting digest, containing mainly xylobiose and xylose, was directly subjected to an acetylation step, which after silica gel chromatography, provided highly pure hexaacetate of xylobiose. Bromination with HBr in acetic acid gave in quantitative yields the corresponding bromide, which after the coupling and deprotection steps, afforded the target 4-nitrophenyl-β-xylobioside.
Synthesis of 2- and 4-nitrophenyl β-glycosides of β-(1 → 4)-D-xylo-oligosaccharides of dp 2-4
Takeo,Ohguchi,Hasegawa,Kitamura
, p. 231 - 244 (2007/10/03)
2- and 4-Nitrophenyl β-D-xylopyranosides (4 and 5) were transformed, via dibutyltin oxide-mediated acylation, into the corresponding 2,3-di-O-benzoyl derivatives 11 and 15. Xylobiose and xylotriose were easily isolated by charcoal column chromatography from a commercially available material and converted into the di- and trisaccharide methyl 1-thio-β-glycosides 36 and 37. The 2- and 4-nitrophenyl β-glycosides of the β-(1 → 4)-D-xylo-oligosaccharides of dp 2-4 were synthesized by N-iodosuccinimide-silver triflate-promoted condensation using 11 and 15 as the glycosyl acceptors and ethyl 1-thio-β-D-xylopyranoside triacetate 16, 36, and 37 as the glycosyl donors. Also described are an improved preparation of 4 and 5, and the synthesis of 1-naphthyl β-D-xylopyranoside, as well as an alternative approach to the 2- and 4-nitrophenyl β-xylobiosides.
A short synthesis of β-xylobiosides
Ziser, Lothar,Withers, Stephen G.
, p. 9 - 18 (2007/10/02)
Benzyl 2,3,2',3',4'-penta-O-acetyl-β-xylobioside, 2-nitrophenyl β-xylobioside, 4-nitrophenyl β-xylobioside, and 2-iodobenzyl 1-thio-β-xylobioside were synthesized via a short and highly selective route. β-D-Xylopyranosides were selectively 4-O-triethylsil
