59-56-3Relevant articles and documents
Kinetic and NMR spectroscopic study of the chemical stability and reaction pathways of sugar nucleotides
Jaakkola, Juho,Nieminen, Anu,Kivel?, Henri,Korhonen, Heidi,T?htinen, Petri,Mikkola, Satu
, p. 178 - 193 (2020/12/21)
The alkaline cleavage of two types of sugar nucleotides has been studied by 1H and 31P NMR in order to obtain information on the stability and decomposition pathways in aqueous solutions under alkaline conditions. The reaction of glucose 1-UDP is straightforward, and products are easy to identify. The results obtained with ribose 5-UDP and ribose 5-phosphate reveal, in contrast, a more complex reaction system than expected, and the identification of individual intermediate species was not possible. Even though definite proof for the mechanisms previously proposed could not be obtained, all the spectroscopic evidence is consistent with them. Results also emphasise the significant effect of conditions, pH, ionic strength, and temperature, on the reactivity under chemical conditions.
Toward Automated Enzymatic Glycan Synthesis in a Compartmented Flow Microreactor System
Heinzler, Raphael,Fisch?der, Thomas,Elling, Lothar,Franzreb, Matthias
supporting information, p. 4506 - 4516 (2019/08/20)
Immobilized microfluidic enzyme reactors (IMER) are of particular interest for automation of enzyme cascade reactions. Within an IMER, substrates are converted by paralleled immobilized enzyme modules and intermediate products are transported for further conversion by subsequent enzyme modules. By optimizing substrate conversion in the spatially separated enzyme modules purification of intermediate products is not necessary, thus shortening process time and increasing space-time yields. The IMER enables the development of efficient enzyme cascades by combining compatible enzymatic reactions in different arrangements under optimal conditions and the possibility of a cost-benefit analysis prior to scale-up. These features are of special interest for automation of enzymatic glycan synthesis. We here demonstrate a compartmented flow microreactor system using six magnetic enzyme beads (MEBs) for the synthesis of the non-sulfated human natural killer cell-1 (HNK-1) glycan epitope. MEBs are assembled to build compartmented enzyme modules, consisting of enzyme cascades for the synthesis of uridine 5′- diphospho-α- d-galactose (UDP-Gal) and uridine 5′-diphospho-α-d-glucuronic acid (UDP-GlcA), the donor substrates for the Leloir glycosyltransferases β4-galactosyltransferase and β3-glucuronosyltransferase, respectively. Glycan synthesis was realized in an automated microreactor system by a cascade of individual enzyme module compartments each performing under optimal conditions. The products were analyzed inline by an MS-system connected to the microreactor. The high synthesis yield of 96% for the non-sulfated HNK-1 glycan epitope indicates the excellent performance of the automated enzyme module cascade. Furthermore, combinations of other MEBs for nucleotide sugars synthesis with MEBs of glycosyltransferases have the potential for a fully automated and programmed glycan synthesis in a compartmented flow microreactor system. (Figure presented.).
A mutant of phosphomannomutase1 retains full enzymatic activity, but is not activated by IMP: Possible implications for the disease PMM2-CDG
Citro, Valentina,Cimmaruta, Chiara,Liguori, Ludovica,Viscido, Gaetano,Cubellis, Maria Vittoria,Andreotti, Giuseppina
, (2017/12/28)
The most frequent disorder of glycosylation, PMM2-CDG, is caused by a deficiency of phosphomannomutase activity. In humans two paralogous enzymes exist, both of them require mannose 1,6-bis-phosphate or glucose 1,6-bis-phosphate as activators, but only phospho-mannomutase1 hydrolyzes bis-phosphate hexoses. Mutations in the gene encoding phos-phomannomutase2 are responsible for PMM2-CDG. Although not directly causative of the disease, the role of the paralogous enzyme in the disease should be clarified. Phosphoman-nomutase1 could have a beneficial effect, contributing to mannose 6-phosphate isomerization, or a detrimental effect, hydrolyzing the bis-phosphate hexose activator. A pivotal role in regulating mannose-1phosphate production and ultimately protein glycosylation might be played by inosine monophosphate that enhances the phosphatase activity of phosphoman-nomutase1. In this paper we analyzed human phosphomannomutases by conventional enzymatic assays as well as by novel techniques such as 31P-NMR and thermal shift assay. We characterized a triple mutant of phospomannomutase1 that retains mutase and phosphatase activity, but is unable to bind inosine monophosphate.