- Chemoenzymatic synthesis of Gal(β1-3)Gal(β1-4)Xyl(β)-L-Ser and Gal(β1-3)Gal(β1-4)Xyl(β)-MU by the use of β-D-galactosidase
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The title trisaccharide-serine conjugate 1 constituting the linkage region between glycosaminoglycan and protein in proteoglycan, was synthesized via a trisaccharide p-nitrophenyl (PNP) glycoside prepared by stepwise enzymatic transglycosidation to Xyl-PNP with a β-D-galactosidase. In the second transglycosidation step, partial protection of the disaccharide intermediate, Gal-Xyl-PNP, furnished selective galactosylation at the 3'-position. Cleavage of the PNP group after peracetylation, chemical coupling with serine and final deprotection afforded 1. Fluorescence labeled trisaccharide, Gal(β1-3)Gal(β1-4)Xyl(β)-MU (MU: 4-methylumbelliferyl) (2) was also synthesized in a simalar way.
- Fukase, Koichi,Yasukochi, Takashi,Suda, Yasuo,Yoshida, Masao,Kusumoto, Shoichi
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- Glycosynthase with broad substrate specificity-an efficient biocatalyst for the construction of oligosaccharide library
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A versatile glycosynthase (TnG-E338A) with strikingly broad substrate scope has been developed from Thermus nonproteolyticus β-glycosidase (TnG) by using site-directed mutagenesis. The practical utility of this biocatalyst has been demonstrated by the facile generation of a small library containing various oligosaccharides and a steroidal glycoside (total 25 compounds) in up to 100 % isolated yield. Moreover, an array of eight gluco-oligosaccharides has been readily synthesized by the enzyme in a one-pot, parallel reaction, which highlights its potential in the combinatorial construction of a carbohydrate library that will assist glycomic and glycotherapeutic research. Significantly, the enzyme provides a means by which glycosynthase technology may be extended to combinatorial chemistry.
- Wei, Jinhua,Lv, Xun,Lue, Yang,Yang, Gangzhu,Fu, Lifeng,Yang, Liu,Wang, Jianjun,Gao, Jianhui,Cheng, Shuihong,Duan, Qian,Jin, Cheng,Li, Xuebing
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supporting information
p. 2414 - 2419
(2013/05/23)
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- Acceptor-dependent regioselectivity of glycosynthase reactions by Streptomyces E383A β-glucosidase
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The nonnucleophilic mutant E383A β-glucosidase from Streptomyces sp. has proven to be an efficient glycosynthase enzyme, catalyzing the condensation of α-glucosyl and α-galactosyl fluoride donors to a variety of acceptors. The enzyme has maximal activity
- Faijes, Magda,Saura-Valls, Marc,Perez, Xavi,Conti, Marta,Planas, Antoni
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p. 2055 - 2065
(2007/10/03)
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- Enzymatic syntheses and selective hydrolysis of O-β-d- galactopyranosides using a marine mollusc β-galactosidase
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The use of crude extract of the hepatopancreas of Aplysia fasciata, a large mollusc belonging to the order Anaspidea containing a β-galactosidase activity, was reported for the synthesis of different galactosides. Good yields with polar acceptors and the
- Giordano, Assunta,Tramice, Annabella,Andreotti, Giuseppina,Mollo, Ernesto,Trincone, Antonio
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p. 139 - 143
(2007/10/03)
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- Chemoenzymatic synthesis of a trisaccharide-serine conjugate, gal(β1-3)gal(β1-4)xyl(β1-o)-l-ser, use of galactosyl fluoride as a donor for transglycosylation
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The trisaccharide - serine conjugate [Gal(β1-3)Gal(β1-4)Xyl(β-Ser], constituting the linkage region between the glycosaminoglycan and protein in proteoglycan, was synthesized by using enzymatic transglycosylation with a β-D-galactosidase as a key reaction. The yields of transglycosylation were much improved by using galactosyl fluoride as a donor in comparison with those obtained by a conventional p-nitrophenyl (PNP) galactoside. After enzymatic synthesis of Gal(β1-3)Gal(β1-4)Xyl(β)-PNP, cleavage of the PNP group of the fully acetylated trisaccharide, chemical coupling with serine, and final deprotection afforded Gal(β1-3)Gal(β1-4)Xyl(β)-Ser.
- Fukase,Yasukochi,Kusumoto
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p. 1123 - 1128
(2007/10/03)
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- Nitropyridyl glycosides: New glycosyl donors for enzymatic transglycosylation
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New glycosyl donors, 3-nitro-2-pyridyl and 5-nitro-2-pyridyl glycosides, proved to be effective for transglycosylation reaction catalyzed by glycosidases, such as β-galactosidase, β-glucosidase, and N-acetyl-β- hexosaminidase. The high solubility in water and the high reactivity of the nitropyridyl glycosides enabled the reactions under high concentrations of the donors and consequently rapid glycosyl transfer to glycosyl acceptors. The yields of the transglycosylated products with the nitropyridyl glycosides were much higher than those with conventional p-nitrophenyl glycosides.
- Yasukochi, Takashi,Inaba, Chikako,Fukase, Koichi,Kusumoto, Shoichi
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p. 6585 - 6589
(2007/10/03)
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