Glycosyl hydrolases synthesis

Trincone, A. and Giordano, A. (2006) Glycosyl hydrolases and glycosyltransferases in the synthesis of oligosaccharides. Current Organic Chemistry, 10, 1163-1193. 

In this chapter the study of three glycosyl hydrolases from this archaeon, focussing on their use in the synthesis of oligosaccharides, will be described. 

Moracci, M., Trincone, A., Cobucci-Ponzano, B., Perugino, G., Ciaramella, M., and Rossi, M. (2001) Enzymatic synthesis of oligosaccharides by two glycosyl hydrolases of Sulfolobus solfataricus. Extremophiles. 5 145-152. 

Scheme 4.26 Glycosyl hydrolases in oligosaccharide synthesis, (i) = /V-acetylhexo from A. oryzae, (ii) = p-mannosamine from A. orzyae.

Trincone A, Giordano A. Glycosyl hydrolases and glycosyltrans-ferases in the synthesis of oligosaccharides. Curr. Org. Chem. 2006 10 1163-1193. 

Kobayashi, S., Kiyosada, T., Shoda, S.-L Synthesis of artificial chitin irreversible catalytic behavior of a glycosyl hydrolase through a transition state analogue substrate. J. Am. Chem. Soc. 118, 13113-13114 (1996)... 

Figure 7 Enzyme-catalyzed glycoside synthesis via (a) a glycosyltransferase and (b) glycosidase (glycosyl hydrolase and transglycosidase).

We have achieved the synthesis of structurally well-defined natural and unnatural oligo- and polysaccharides via enzymatic polymerization utilizing natural glycosyl hydrolases as catalysts (26-57) cellulose and xylan prepared by cellulase (52-54), an amylose oligomer by amylase (55), chitin by chitinase (56, 57), altematingly 6-(9-methylated cellulose by cellulase (55), and a cellulose-... 

Glycopeptides containing glycosyl L-aspara-gine, L-serine, and L-threonine, developments in, 50,277-310 Glycoside hydrolases, mechanistic information firm studies with reversible and irreversible inhibitors, 48, 319-384 Glycoside synthesis, anomeric-oxygen activation for (trichloroacetimidate method), 50,21 -123... 

In this case the predominance of glycosylation of C4-carbinols over substrate hydrolysis is in a mixture where the molar concentration of water was more than 3000 times that of the a-maltosyl fluoride. In other experiments the substrate concentration could be further reduced at least 5-fold without altering the fact of a substantially greater extent of maltosidic linkage synthesis than hydrolysis. We now are referring to a very dilute 4 mM, solution of substrate with which, if the hydrolase concept were valid, hydrolysis ought to have been predominant. 

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