 Crystals of BGlu0 with inhibitor were streak-seeded into 00% ( w/v ) PEG MME 0000 , 0 . 0 M ammonium sulfate , 0 . 0 M MES pH 0 . 0 to yield larger crystals . Score: 0.00 Title: Enzymatic synthesis of cello-oligosaccharides by rice BGlu0 { beta } -glucosidase glycosynthase mutants . Journal: Year: 0000 Type: ARTICLE Literature: oryza Field: abstract Doc ID: pub00000000 Accession (PMID): 00000000 Abstract: Rice ( BGlu0 ) beta-glucosidase is a glycosyl hydrolase family 0 enzyme that acts as an exoglucanase on beta- ( 0 , 0 ) - and short beta- ( 0 , 0 ) -linked gluco-oligosaccharides . Mutations of BGlu0 beta-glucosidase at glutamate residue 000 of its natural precursor destroyed the enzymes catalytic activity , but the enzyme could be rescued in the presence of the anionic nucleophiles formate and azide , which verifies that this residue is the catalytic nucleophile . The catalytic activities of three candidate mutants , E000G , E000S , and E000A , in the presence of the nucleophiles were compared . The E000G mutant had approximately 00 and 0000-fold higher catalytic efficiency than E000A and E000S , respectively . All three mutants could catalyze the synthesis of mixed length oligosaccharides by transglucosylation , when alpha-glucosyl fluoride was used as donor and pNP-cellobioside as acceptor . The E000G mutant gave the fastest transglucosylation rate , which was approximately 0 and 00 fold faster than E000S and E000A , respectively , and gave yields of up to 00-00 % insoluble products with a donor : acceptor ratio of 0 : 0 . ( 00 ) C-NMR , methylation analysis and electrospray ionization mass spectrometry showed that the insoluble products were beta- ( 0 , 0 ) -linked oligomers with a degree of polymerization ( DP ) of 0 to at least 00 . The BGlu0 E000G glycosynthase was found to prefer longer chain length oligosaccharides that occupy at least three sugar residue binding subsites as acceptors for productive transglucosylation . This is the first report of a beta-glucansynthase derived from an exoglycosidase that can produce long chain cello-oligosaccharides , which likely reflects the extended oligosaccharide binding site of rice BGlu0 beta-glucosidase . Matching Sentences: [ Sen. 0, subscore: 0.00 ]: Rice ( BGlu0 ) beta-glucosidase is a glycosyl hydrolase family 0 enzyme that acts as an exoglucanase on beta- ( 0 , 0 ) - and short beta- ( 0 , 0 ) -linked gluco-oligosaccharides . 