%0 Journal Article %A Fauré, Régis %A Saura-Valls, Marc %A Brumer, Harry %A Planas, Antoni %A Cottaz, Sylvain %A Driguez, Hugues %D 2006 %T Synthesis of a Library of Xylogluco-Oligosaccharides for Active-Site Mapping of Xyloglucan endo-Transglycosylase %U https://acs.figshare.com/articles/journal_contribution/Synthesis_of_a_Library_of_Xylogluco_Oligosaccharides_for_Active_Site_Mapping_of_Xyloglucan_i_endo_i_Transglycosylase/3071878 %R 10.1021/jo0525682.s001 %2 https://acs.figshare.com/ndownloader/files/4777663 %K chemical synthesis %K enzyme %K Synthesi %K oligosaccharide %K degradation %K compound %K OH %K yield %K unsubstituted %K terminal glucosyl units %K fluoride %K reaction product %K Humicola insolens %K donor synthon %K enzymatically %K residue %K XET %K plant cell wall biosynthesis %K lactosyl motif %K efficiency %K acceptor %K galactose %K building blocks %K synthesizing %K Cel 7B E 197A glycosynthase %K xyloglucan polymers %K Constituting %K site %K target molecules %K Mapping %K modification %K mapping %K condensation %K lactose %K Xyloglucan %X Complex oligosaccharides containing α-d-xylosyl-(1→6)-β-d-glucosyl residues and unsubstituted β-(1→4)-linked d-glucosyl units were readily synthesized using enzymatic coupling catalyzed by the Cel7B E197A glycosynthase from Humicola insolens. Constituting this library required four key steps:  (1) preparing unprotected building blocks by chemical synthesis or enzymatic degradation of xyloglucan polymers; (2) generating the donor synthon in the enzymatic coupling by temporarily introducing a lactosyl motif on the 4-OH of the terminal glucosyl units of the xylogluco-oligosaccharides; (3) synthesizing the corresponding α-fluorides, followed by their de-O-acetylation and the glycosynthase-catalyzed condensation of these donors onto various acceptors; and (4) enzymatically releasing lactose or galactose from the reaction product, affording the target molecules in good overall yields. These complex oligosaccharides proved useful for mapping the active site of a key enzyme in plant cell wall biosynthesis and modification:  the xyloglucan endo-transglycosylase (XET). We also report some preliminary enzymatic results regarding the efficiency of these compounds. %I ACS Publications