Glycosynthase

M. Jahn, D. Stoll, R. A. Warren, L. Szabo, P. Singh, H. J. Gilbert, V. M. Ducros, G. J. Davies, and S. G. Withers, Expansion of the glycosynthase repertoire to produce defined manno-oligosaccharides, Chem. Commun. (Camb.), 12 (2003) 1327-1329. 

M. Faijes, X. Perez, O. Perez, and A. Planas, Glycosynthase activity of Bacillus licheniformis 1,3-1,4-beta-glucanase mutants Specificity, kinetics, and mechanism, Biochemistry, 42 (2003) 13304—13318. 

Scheme 6 Reaction mechanism of wild-type inverting xylanase from Bacillus halodurans (A) and two derived glycosynthases, Asp263Cys,143 (B), and Tyrl98Phe,144 (C).

Besides (thio)glycosynthases and thioglycoligases, several other mutant glycosidases were produced with abolished hydrolytic activity in favour of synthesis transsialidase from Trypanosoma rangeli37 or p-transglycosidase from Thermits thermophilus.153 A new p-fucosidase activity was introduced into E. coli p-galactosidase by genetic manipulation.37... 

Procedure 1 Glycosynthase-assisted Synthesis of Glycosylated Derivatives of 2-Deoxy-2-fluoro-j5-laminaribiosyl Fluoride... 

The use of glycosynthases as biocatalysts for the formation of glycosidic linkages has proven to be an effective and versatile tool for the preparation of complex oligosaccharides. The procedure is simple and reproducible and can be applied to a number of substrates involving carbohydrate and noncarbohydrate moieties. 

Scaffidi, A., Stubbs, K.A. and Stick, R.V., Synthesis of some glycosylated derivatives of 2-deoxy-2-fluoro-/ -laminaribiosyl fluoride another success for glycosynthases. Aust. J. Chem., 2007, 60, 83. 

J.K. Fairweather, M. Faijes, FI. Driguez, A. Planas, Specificity studies of bacillus 1,3-1,4-beta-glucanases and application to glycosynthase-catalyzed transglycosylation, Chembiochem 3 (2002) 866-873. 

Stephen G. Withers (Canada) Enzymatic cleavage and formation of glycosidic bonds from glycosidases and lyases to transferases and glycosynthases 2004—Made jointly to Anne Imberty (France) and Thomas Peters (Germany) Forty ways to bind your sugar ... 

Mayer C, Jakeman DL, Mah M et al (2001) Directed evolution of new glycosynthases from Agrobacterium (3-glucosidase a general screen to detect enzymes for oligosaccharide synthesis. Chem Biol 8 437 143... 

Figure 3. Reaction mechanism of retaining (A) and inverting (B) P-glycosynthases. R alcohol.

The ability of the hyperthermophilic glycosynthases to promote the synthesis of oligosaccharides is a clear example of how the unique characteristics of stability to high temperatures and acidic pH of the glycosidases from hyperthermophilic archaea allows the development of a novel strategy for the chemo-enzymatic synthesis of oligosaccharides. 

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