The Formation of Oligosaccharides by Enzymic Transglycosylation

Edelman, J.

doi:10.1002/9780470122624.ch5

Cited by 33 publications

(7 citation statements)

References 81 publications

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“…However, this is not the case, because these enzymes require nucleotide sugars as donor substrates, which are still not readily available despite recent progress [5,6]. using co-solvents and reducing water activity), thus forcing transglycosylation against hydrolysis [2,7]. Other CAZymes that are frequently used for glycosynthesis are glycoside hydrolases (GHs), which are more abundant than GTs and cover an extremely wide range of substrate specificities.…”

Section: Enzymes Available To the Synthetic Glycochemistmentioning

confidence: 99%

Glycosynthesis in a waterworld: new insight into the molecular basis of transglycosylation in retaining glycoside hydrolases

Bissaro

Monsan

Fauré

et al. 2015

Biochemical Journal

141

152

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Carbohydrates are ubiquitous in Nature and play vital roles in many biological systems. Therefore the synthesis of carbohydrate-based compounds is of considerable interest for both research and commercial purposes. However, carbohydrates are challenging, due to the large number of sugar subunits and the multiple ways in which these can be linked together. Therefore, to tackle the challenge of glycosynthesis, chemists are increasingly turning their attention towards enzymes, which are exquisitely adapted to the intricacy of these biomolecules. In Nature, glycosidic linkages are mainly synthesized by Leloir glycosyltransferases, but can result from the action of non-Leloir transglycosylases or phosphorylases. Advantageously for chemists, non-Leloir transglycosylases are glycoside hydrolases, enzymes that are readily available and exhibit a wide range of substrate specificities. Nevertheless, non-Leloir transglycosylases are unusual glycoside hydrolases in as much that they efficiently catalyse the formation of glycosidic bonds, whereas most glycoside hydrolases favour the mechanistically related hydrolysis reaction. Unfortunately, because non-Leloir transglycosylases are almost indistinguishable from their hydrolytic counterparts, it is unclear how these enzymes overcome the ubiquity of water, thus avoiding the hydrolytic reaction. Without this knowledge, it is impossible to rationally design non-Leloir transglycosylases using the vast diversity of glycoside hydrolases as protein templates. In this critical review, a careful analysis of literature data describing non-Leloir transglycosylases and their relationship to glycoside hydrolase counterparts is used to clarify the state of the art knowledge and to establish a new rational basis for the engineering of glycoside hydrolases.

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Section: Enzymes Available To the Synthetic Glycochemistmentioning

confidence: 99%

Glycosynthesis in a waterworld: new insight into the molecular basis of transglycosylation in retaining glycoside hydrolases

Bissaro

Monsan

Fauré

et al. 2015

Biochemical Journal

141

152

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“…Because they catalyze highly specific reactions and use prevalent substrates, transglycosylases have been considered an attractive option for the synthesis of carbohydrates for various research or commercial applications (Cote and Tao, 1990; Edelman, 1956). Unfortunately, the use of transglycosylases for synthetic purposes has been limited by the reality that these enzymes are relatively rare in nature and the fact that the ones that have been characterized act on a limited substrate repertoire.…”

Section: Introductionmentioning

confidence: 99%

Transferase Versus Hydrolase: The Role of Conformational Flexibility in Reaction Specificity

et al. 2017

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Summary Active in the aqueous cellular environment where a massive excess of water is perpetually present, enzymes that catalyze the transfer of an electrophile to a non-water nucleophile (transferases) require specific strategies to inhibit mechanistically related hydrolysis reactions. To identify principles that confer transferase versus hydrolase reaction specificity, we exploited two enzymes that use highly similar catalytic apparatuses to catalyze the transglycosylation (a transferase reaction) or hydrolysis of α-1,3-glucan linkages in the cyclic tetrasaccharide cycloalternan (CA). We show that substrate binding to non-catalytic domains and a conformationally stable active site promote CA transglycosylation, whereas a distinct pattern of active site conformational change is associated with CA hydrolysis. These findings defy the classic view of induced fit conformational change and illustrate a mechanism by which a stable hydrophobic binding site can favor transferase activity and disfavor hydrolysis. Application of these principles could facilitate the rational reengineering of transferases with desired catalytic properties.

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“…However, inconsistencies with regard to the nomenclature of FOS synthesizing enzymes exist. The terms fructosyltransferase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/4/1/9.html), invertase or β‐ fructofuranosidase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC3/2/1/26.html) are used because, in addition to sucrose hydrolysis, some β‐fructofuranosidases exhibit transferase activity at high substrate concentrations which results in the formation of FOSs . Different EC activities pertaining to enzymes acting on β‐ d ‐fructofuranosides are classified in family GH32.…”

Section: Introductionmentioning

confidence: 99%

Sequence and structure‐based prediction of fructosyltransferase activity for functional subclassification of fungal GH32 enzymes

et al. 2015

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Sucrolytic enzymes catalyse sucrose hydrolysis or the synthesis of fructooligosaccharides (FOSs), a prebiotic in human and animal nutrition. FOS synthesis capacity differs between sucrolytic enzymes. Amino-acidsequence-based classification of FOS synthesizing enzymes would greatly facilitate the in silico identification of novel catalysts, as large amounts of sequence data lie untapped. The development of a bioinformatics tool to rapidly distinguish between high-level FOSs synthesizing predominantly sucrose hydrolysing enzymes from fungal genomic data is presented. Sequence comparison of functionally characterized enzymes displaying lowand high-level FOS synthesis revealed conserved motifs unique to each group. New light is shed on the sequence context of active site residues in three previously identified conserved motifs. We characterized two enzymes predicted to possess low-and high-level FOS synthesis activities based on their conserved motif sequences. FOS data for the enzymes confirmed our successful prediction of their FOS synthesis capacity. Structural comparison of enzymes displaying low-and high-level FOS synthesis identified steric hindrance between nystose and a long loop region present only in low-level FOS synthesizers. This loop is proposed to limit the synthesis of FOS species with higher degrees of polymerization, a phenomenon observed among enzymes displaying low-level FOS synthesis. Conserved sequence motifs surrounding catalytic residues and a distant structural determinant were identifiers of FOS synthesis capacity and allow for functional annotation of sucrolytic enzymes directly from amino acid sequence. The tool presented may also be useful to study the structure-function relationships of b-fructofuranosidases by identifying mutations present in a group of closely related enzymes displaying similar function.

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The Formation of Oligosaccharides by Enzymic Transglycosylation

Cited by 33 publications

References 81 publications

Glycosynthesis in a waterworld: new insight into the molecular basis of transglycosylation in retaining glycoside hydrolases

Glycosynthesis in a waterworld: new insight into the molecular basis of transglycosylation in retaining glycoside hydrolases

Transferase Versus Hydrolase: The Role of Conformational Flexibility in Reaction Specificity

Sequence and structure‐based prediction of fructosyltransferase activity for functional subclassification of fungal GH32 enzymes

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