| 1. |
- Teze, David, et al.
(author)
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Rational Enzyme Design without Structural Knowledge : A Sequence-Based Approach for Efficient Generation of Transglycosylases
- 2021
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In: Chemistry: A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 27:40, s. 10323-10334
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Journal article (peer-reviewed)abstract
- Glycobiology is dogged by the relative scarcity of synthetic, defined oligosaccharides. Enzyme-catalysed glycosylation using glycoside hydrolases is feasible but is hampered by the innate hydrolytic activity of these enzymes. Protein engineering is useful to remedy this, but it usually requires prior structural knowledge of the target enzyme, and/or relies on extensive, time-consuming screening and analysis. Here we describe a straightforward strategy that involves rational rapid in silico analysis of protein sequences. The method pinpoints 6-12 single mutant candidates to improve transglycosylation yields. Requiring very little prior knowledge of the target enzyme other than its sequence, the method is generic and procures catalysts for the formation of glycosidic bonds involving various d / l -, α/β-pyranosides or furanosides, and exo - and endo -action. Moreover, mutations validated in one enzyme can be transposed to others, even distantly related enzymes.
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| 2. |
- Teze, David, et al.
(author)
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The catalytic acid-base in GH109 resides in a conserved GGHGG loop and allows for comparable α-retaining and β-inverting activity in an N-acetylgalactosaminidase from Akkermansia muciniphila
- 2019
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In: ChemRxiv. - : American Chemical Society (ACS).
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Other publication (other academic/artistic)abstract
- The study describes the first glycoside hydrolase that exhibits comparable levels of activity on α- and β-linked saccharide substrates. This enzyme, assigned into GH109, is encoded by the genome of the human gut symbiont Akkermansia muciniphila that is a model primary degrader of the heavily O-glycosylated mucin glycoprotein that coats the epithelial enterocytes.The elusive catalytic acid/base catalyst in GH109 enzymes is identified as a histidine that is presented by a flexible loop that positions it for catalysis on both α- and β-substrates. This dual activity may be an evolutionary adaptation to extend the range of substrates targeted by a single non-canonical NAD+-dependant GH.
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| 3. |
- Teze, David, et al.
(author)
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The Catalytic Acid-Base in GH109 Resides in a Conserved GGHGG Loop and Allows for Comparable α-Retaining and β-Inverting Activity in an N-Acetylgalactosaminidase from Akkermansia muciniphila
- 2020
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In: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 10:6, s. 3809-3819
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Journal article (peer-reviewed)abstract
- Enzymes active on glycosidic bonds are defined according to the stereochemistry of both substrates and products of the reactions they catalyze. The CAZy classification further assigns these enzymes into sequence-based families sharing a common stereochemistry for substrates (either α- or β-) and products (i.e., inverting or retaining mechanism). Here we describe the N-acetylgalactosaminidases AmGH109A and AmGH109B (i.e., GH109: glycoside hydrolase family 109) from the human gut symbiont Akkermansia muciniphila. Notably, AmGH109A displays α-retaining and β-inverting N-acetylgalactosaminidase activities with comparable efficiencies on natural disaccharides. This dual specificity could provide an advantage in targeting a broader range of host-derived glycans. We rationalize this discovery through bioinformatics, structural, mutational, and computational studies, unveiling a histidine residing in a conserved GGHGG motif as the elusive catalytic acid-base of the GH109 family.
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