Building Custom Polysaccharides in Vitro with an Efficient, Broad-Specificity Xyloglucan Glycosynthase and a Fucosyltransferase

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• 作者：Oliver Spadiut ; Farid M. Ibatullin ; Jonelle Peart ; Fredrika Gullfot ; Carlos Martinez-Fleites ; Marcus Ruda ; Chunlin Xu ; Gustav Sundqvist ; Gideon J. Davies ; Harry Brumer
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：July 20, 2011
• 年：2011
• 卷：133
• 期：28
• 页码：10892-10900
• 全文大小：902K
• 年卷期：v.133,no.28(July 20, 2011)
• ISSN：1520-5126

文摘

The current drive for applications of biomass-derived compounds, for energy and advanced materials, has led to a resurgence of interest in the manipulation of plant polymers. The xyloglucans, a family of structurally complex plant polysaccharides, have attracted significant interest due to their intrinsic high affinity for cellulose, both in muro and in technical applications. Moreover, current cell wall models are limited by the lack of detailed structure鈥損roperty relationships of xyloglucans, due to a lack of molecules with well-defined branching patterns. Here, we have developed a new, broad-specificity 鈥渪yloglucan glycosynthase鈥? selected from active-site mutants of a bacterial endoxyloglucanase, which catalyzed the synthesis of high molar mass polysaccharides, with complex side-chain structures, from suitable glycosyl fluoride donor substrates. The product range was further extended by combination with an Arabidopsis thaliana 伪(1鈫?)-fucosyltransferase to achieve the in vitro synthesis of fucosylated xyloglucans typical of dicot primary cell walls. These enzymes thus comprise a toolkit for the controlled enzymatic synthesis of xyloglucans that are otherwise impossible to obtain from native sources. Moreover, this study demonstrates the validity of a chemo-enzymatic approach to polysaccharide synthesis, in which the simplicity and economy of glycosynthase technology is harnessed together with the exquisite specificity of glycosyltransferases to control molecular complexity.