Syntheses and testing of substrates and mechanism-based inactivators for xylanases

Article abstract of DOI:10.1016/0008-6215(95)00080-D

The syntheses of the 2,5- and 3,4-dinitrophenyl β-xylobiosides by two separate routes are described, as well as the syntheses of the 2,4-dinitrophenyl β-glycosides of 2-chloro-2-deoxyxylobiose and 2-deoxy-2-fluoro-xylobiose.Both the 3,4- and 2,5-dinitrophenyl β-xylobiosides proved to be good substrates for the Bacillus subtilis xylanase, with k_cat/K_m values of 1.0 and 34.4 mM^-1s^-1, respectively.Excellent time-dependent inactivation of the exoxylanase/glucanase from Cellulomonas fimi was provided by 2,4-dinitrophenyl 2-deoxy-2-fluoro-β-xylobioside, according to inactivation parameters of k_i = 0.057 min^-1 and K_i = 0.0035 mM.Keywords: Aryl β-xylobiosides; 2-Deoxy-2-halo-β-D-xylopyranosides; 2-Deoxy-2-halo-β-xylobiosides; Substrate; Inactivator; Glycosidase inhibitors; Endo-xylanase <β-(1<*>4)-Xylan xylanohydrolase, EC 3.2.1.8>