24960-16-5Relevant academic research and scientific papers
Crystal structures and functional studies clarify substrate selectivity and catalytic residues for the unique orphan enzyme N-acetyl-D-mannosamine dehydrogenase
Sola-Carvajal, Agustin,Gil-Ortiz, Fernando,Garcia-Carmona, Francisco,Rubio, Vicente,Sanchez-Ferrer, Alvaro
, p. 499 - 511 (2014)
NAMDH (N-acetyl-D-mannosamine dehydrogenase), from the soil bacteroidete Flavobacterium sp. 141-8, catalyses a rare NAD+ -dependent oxidation of ManNAc (N-acetyl-Dmannosamine) into N-acetylmannosamino-lactone, which spontaneously hydrolyses into N-acetylmannosaminic acid. NAMDH belongs to the SDR (short-chain dehydrogenase/reductase) superfamily and is the only NAMDH characterized to date. Thorough functional, stability, site-directed mutagenesis and crystallographic studies have been carried out to understand better the structural and biochemical aspects of this unique enzyme. NAMDH exhibited a remarkable alkaline pH optimum (pH 9.4) with a high thermal stability in glycine buffer (Tm =64°C) and a strict selectivity towards ManNAc and NAD+ . Crystal structures of ligand-free and ManNAc- and NAD + -bound enzyme forms revealed a compact homotetramer having point 222 symmetry, formed by subunits presenting the characteristic SDR α3β7α3 sandwich fold. A highly developed C-terminal tail used as a latch connecting nearby subunits stabilizes the tetramer. A dense network of polar interactions with the substrate including the encasement of its acetamido group in a specific binding pocket and the hydrogen binding of the sugar 4OH atom ensure specificity for ManNAc. The NAMDH-substrate complexes and site-directed mutagenesis studies identify the catalytic tetrad and provide useful traits for identifying new NAMDH sequences.
Discovery of Two Novel Oxidases Using a High-Throughput Activity Screen
Rembeza, Elzbieta,Boverio, Alessandro,Fraaije, Marco W.,Engqvist, Martin K. M.
, (2021/11/23)
Discovery of novel enzymes is a challenging task, yet a crucial one, due to their increasing relevance as chemical catalysts and biotechnological tools. In our work we present a high-throughput screening approach to discovering novel activities. A screen of 96 putative oxidases with 23 substrates led to the discovery of two new enzymes. The first enzyme, N-acetyl-D-hexosamine oxidase (EC 1.1.3.29) from Ralstonia solanacearum, is a vanillyl alcohol oxidase-like flavoprotein displaying the highest activity with N-acetylglucosamine and N-acetylgalactosamine. Before our discovery of the enzyme, its activity was an orphan one - experimentally characterized but lacking the link to amino acid sequence. The second enzyme, from an uncultured marine euryarchaeota, is a long-chain alcohol oxidase (LCAO, EC 1.1.3.20) active with a range of fatty alcohols, with 1-dodecanol being the preferred substrate. The enzyme displays no sequence similarity to previously characterised LCAOs, and thus is a completely novel representative of a protein with such activity.
Chemo-enzymatic approach to access diastereopure α-substituted GlcNAc derivatives
Wang, Su-Yan,Laborda, Pedro,Lu, Ai-Min,Wang, Meng,Duan, Xu-Chu,Liu, Li,Voglmeir, Josef
, p. 423 - 434 (2017/08/23)
The formation of diastereopure α-substituted GlcNAc derivatives in a simple and straightforward way is a challenging task. Herein, we report the chemical synthesis of diastereomeric α/β-substituted GlcNAc derivatives under non-anhydrous atmosphere using u
