3482-57-3Relevant articles and documents
p-Aminophenyl β-cellobioside as an affinity ligand for exo-type cellulases
Sangseethong, Kunruedee,Penner, Michael H.
, p. 245 - 250 (1998)
p-Aminophenyl β-cellobioside (PAPC) is shown to be an effective affinity ligand for the chromatographic fractionation of cellobiohydrolases (CBHs). A crude cellulase preparation from the filamentous fungus Trichoderma reesei served as a representative sou
Acceptor-induced modification of regioselectivity in CGTase-catalyzed glycosylations of p-nitrophenyl-glucopyranosides
Strompen, Simon,Miranda-Molina, Alfonso,López-Munguía, Agustín,Castillo, Edmundo,Saab-Rincón, Gloria
, p. 46 - 54 (2015/03/05)
Cyclodextrin glycosyltransferases (CGTase) are reported to selectively catalyze α(1→4)-glycosyl transfer reactions besides showing low hydrolytic activity. Here, the effect of the anomeric configuration of the glycosyl acceptor on the regioselectivity of
Glycosynthases from Thermotoga neapolitana β-glucosidase 1A: A comparison of α-glucosyl fluoride and in situ-generated α-glycosyl formate donors
Pozzo, Tania,Plaza, Merichel,Romero-Garcia, Javier,Faijes, Magda,Karlsson, Eva Nordberg,Planas, Antoni
, p. 132 - 139 (2014/07/21)
TnBgl1A from the thermophile Thermotoga neapolitana is a dimeric β-glucosidase that belongs to glycoside hydrolase family 1 (GH1), with hydrolytic activity through the retaining mechanism, and a broad substrate specificity acting on β-1,4-, β-1,3- and β-1,6-linkages over a range of glyco-oligosaccharides. Three variants of the enzyme (TnBgl1A-E349G, TnBgl1A-E349A and TnBgl1A-E349S), mutated at the catalytic nucleophile, were constructed to evaluate their glycosynthase activity towards oligosaccharide synthesis. Two approaches were used for the synthesis reactions, both of which utilized 4-nitrophenyl β-d-glucopyranoside (4NPGlc) as an acceptor molecule: the first using an α-glucosyl fluoride donor at low temperature (35 °C) in a classical glycosynthase reaction, and the second by in situ generation of the glycosyl donor with (4NPGlc), where formate served as the exogenous nucleophile under higher temperature (70 °C). Using the first approach, TnBgl1A-E349G and TnBgl1A-E349A synthesized disaccharides with β-1,3-linkages in good yields (up to 61%) after long incubations (15 h). However, the GH1 glycosynthase Bgl3-E383A from a mesophilic Streptomyces sp., used as reference enzyme, generated a higher yield at the same temperature with both a shorter reaction time and a lower enzyme concentration. The second approach yielded disaccharides for all three mutants with predominantly β-1,3-linkages (up to 45%) but also β-1,4-linkages (up to 12.5%), after 7 h reaction time. The TnBgl1A glycosynthases were also used for glycosylation of flavonoids, using the two described approaches. Quercetin-3-glycoside was tested as an acceptor molecule and the resultant product was quercetin-3,4′-diglycosides in significantly lower yields, indicating that TnBgl1A preferentially selects 4NPGlc as the acceptor.
