2474-58-0Relevant academic research and scientific papers
Examining the role of phosphate in glycosyl transfer reactions of Cellulomonas uda cellobiose phosphorylase using d-glucal as donor substrate
Wildberger, Patricia,Brecker, Lothar,Nidetzky, Bernd
experimental part, p. 224 - 232 (2012/09/07)
Cellobiose phosphorylase from Cellulomonas uda (CuCPase) is shown to utilize d-glucal as slow alternative donor substrate for stereospecific glycosyl transfer to inorganic phosphate, giving 2-deoxy-α-d-glucose 1-phosphate as the product. When performed in D2O, enzymatic phosphorolysis of d-glucal proceeds with incorporation of deuterium in equatorial position at C-2, implying a stereochemical course of reaction where substrate becomes protonated from below its six-membered ring through stereoselective re side attack at C-2. The proposed catalytic mechanism, which is supported by results of docking studies, involves direct protonation of d-glucal by the enzyme-bound phosphate, which then performs nucleophilic attack on the reactive C-1 of donor substrate. When offered d-glucose next to d-glucal and phosphate, CuCPase produces 2-deoxy-β-d-glucosyl-(1→4)-d-glucose and 2-deoxy-α-d-glucose 1-phosphate in a ratio governed by mass action of the two acceptor substrates present. Enzymatic synthesis of 2-deoxy-β-d-glucosyl-(1→4)-d-glucose is effectively promoted by catalytic concentrations of phosphate, suggesting that catalytic reaction proceeds through a quaternary complex of CuCPase, d-glucal, phosphate, and d-glucose. Conversion of d-glucal and phosphate presents a convenient single-step synthesis of 2-deoxy-α-d-glucose 1-phosphate that is difficult to prepare chemically.
Substrate specificity of galactokinase from Streptococcus pneumoniae TIGR4 towards galactose, glucose, and their derivatives
Zou, Yang,Wang, Wenjun,Cai, Li,Chen, Leilei,Xue, Mengyang,Zhang, Xiaomei,Shen, Jie,Chen, Min
, p. 3540 - 3543 (2012/07/03)
Galactokinases (GalKs) have attracted significant research attention for their potential applications in the enzymatic synthesis of unique sugar phosphates. The galactokinase (GalKSpe4) cloned from Streptococcus pneumoniae TIGR4 presents a remarkably broad substrate range including 14 diverse natural and unnatural sugars. TLC and MS studies revealed that GalKSpe4 had relaxed activity towards galactose derivatives with modifications on the C-6, 4- or 2-positions. Additionally, GalKSpe4 can also tolerate glucose while glucose derivatives with modifications on the C-6, 4- or 2-positions were unacceptable. More interestingly, GalKSpe4 can phosphorylate l-mannose in moderate yield (43%), while other l-sugars such as l-Gal cannot be recognized by this enzyme. These results are very significant because there is rarely enzyme reported that can phosphorylate such uncommon substrates as l-mannose.
The preparation of deoxy derivatives of mannose-1-phosphate and their substrate specificity towards recombinant GDP-mannose pyrophosphorylase from Salmonella enterica, group B
Watt, Gregory M.,Flitsch, Sabine L.,Fey, Sven,Elling, Lothar,Kragl, Udo
, p. 621 - 628 (2007/10/03)
2-Deoxy-α-D-glucose-1-phosphate, 3-deoxy-α-D-arabino-hexose-1-phosphate, 4-deoxy-α-D-lyxo-hexose-1-phosphate, and α-D-lyxose-1-phosphate were synthesised chemically, and evaluated as substrates for a recombinant GDP-mannose pyrophosphorylase (Salmonella enterica, group B, cloned in Escherichia coli). The deoxy derivatives were all substrates for the enzyme, with slightly reduced V(max) values but significantly higher K(m) values than those recorded for the native substrate, mannose-1-phosphate. The pyrophosphorylase was used for the synthesis of GDP-mannose analogues GDP-2-deoxy-glucose and GDP-lyxose on a milligram scale. Copyright (C) 2000 Elsevier Science Ltd.
Further syntheses employing phosphorylase
Evers, Britta,Thiem, Joachim
, p. 857 - 863 (2007/10/03)
Maltopentaose was immobilized on silica gel and used as a recyclable primer in the reaction of glycogen phosphorylase with D-glucal. An improved method to obtain 2-deoxy-α-D-arabino-hexopyranosyl phosphate (4) by using this catalyst as well as the specific synthesis of low molecular weight, water-soluble 2-deoxy-maltooligosaccharides (12, 13, 14 and 15) are described. Further investigations with modified phosphorylase substrates showed that mannosyl phosphate (16) can be slowly transferred to the primer maltotetraose. α-1,4-Mannosyl-maltotetraose (17) and its degradation product α-1,4-mannosyl-maltose (18) were identified.
Synthesis of galactose-terminated oligosaccharides by use of galactosyltransferase
Thiem,Wiemann
, p. 141 - 145 (2007/10/02)
Galactosyltransferase catalyzes the galactosylation of oligosaccharides terminated by glucose and by 2-acetamido-2-deoxy glucopyranose, respectively. Variations concerning the acceptor substrate as well as the donor substrate are described.
