@article { ISI:000181004700003, title = {Enzymatic synthesis of beta-xylanase substrates: transglycosylation reactions of the beta-xylosidase from Aspergillus sp.}, journal = {CARBOHYDRATE RESEARCH}, volume = {338}, number = {4}, year = {2003}, month = {FEB 7}, pages = {313-325}, type = {Article}, abstract = {A beta-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 P-D-xylopyranoside (PNP-X) as substrate, resulting in regio- and stereoselective synthesis of p-nitrophenyl (PNP) beta-(1 {\textendash}> 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 H-1 and C-13 NMR spectroscopy. The glycosides synthesised, beta-Xyl-1 {\textendash}> (4-beta-Xyl-1 {\textendash}>)(n)4-beta-Xyl-OC6H4NO2-p (n = 1 - 5), were tested as chromogenic substrates for family 10 beta-xylanase from Aspergillus orizae (XynA) and family 11 beta-xylanase I from Trichoderma reesei (XynT) by reversed-phase HPLC and UV-spectroscopy techniques. The action pattern of XynA against the foregoing PNP beta-(1 {\textendash}> 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. (C) 2002 Elsevier Science Ltd. All rights reserved.}, issn = {0008-6215}, doi = {10.1016/S0008-6215(02)00467-6}, author = {Eneyskaya, EV and Brumer, H and Backinowsky, LV and Ivanen, DR and Kulminskaya, AA and Shabalin, KA and Neustroev, KN} }