Enzyme-Based Organic Synthesis. Cheanyeh Cheng

Enzyme-Based Organic Synthesis - Cheanyeh Cheng


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by in situ regenerating and recycling of sugar nucleotides.

      Source: Modified from Wong et al. [21].

Chemical reaction depicting beta-1,4-GalT catalyzed galactosylation of natural glycosides and concomitant transfer of glucose.

      Source: Based on Křen and Thiem [15]; Křen [22]; Riva [23].

Chemical reaction depicting two-step synthesis of glycogen with glycogenin functioning as an autocatalytic initiator.

      Source: Based on Hurley et al. [27]; Smythe and Cohen [28].

      Besides in vitro synthesis of glycoproteins, in vivo synthesis method using suppressor tRNA has been described for the recombinant production of neoglycoproteins and glycoproteins [35]. The strategy to produce unique glycoforms in E. coli has been reported by evolving an orthogonal synthetase‐tRNA pair that genetically encodes a glycosylated amino acid in responds to the amber stop codon (TAG). Further, a naturally occurring homogeneous glycoprotein can be produced in E. coli via the direct incorporation of the core glycosyl amino acids N‐acetylglucosamine‐β‐serine and N‐acetylgalactosamine‐α‐threonine [30, 31, 36, 37]. The sugar chains of these glycoproteins can be further elongated in vitro using glycosyltransferase.

      Glycolipids are responsible for the organism’s toxic and immunological properties. Like glycoproteins, glycolipids reside in cell membranes with their carbohydrate segments extending into the fluid surrounding the cells. In this location they function as receptors that are essential for recognizing chemical messengers, other cells, pathogens, and drugs [38]. The synthesis of glycolipid oligosaccharides is performed in the Golgi apparatus by a complex membrane‐bound glycosyltransferases together with sugar nucleotide transporters and ceramide‐bound accepter [39, 40]. The details are not discussed here for their fewer industrial applications.


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