1668-09-3Relevant articles and documents
Determination of kinetic parameters for maltotriose and higher malto-oligosaccharides in the reactions catalyzed by α-D-glucan phosphorylase from potato
Suganuma,Kitazono,Yoshinaga,Fujimoto,Nagahama
, p. 213 - 220 (1991)
For kinetic studies on its synthetic and phosphorolytic reactions, α-D-glucan phosphorylase from potatoes was purified chromatographically until free of D-enzyme. Purified maltotriose (G3) is a poor primer in the phosphorylase-catalyzed synthetic reaction, showing an anomalous time course and making previous attempts to determine its kinetic parameters unsuccessful. In the present work the true rate of the G3-primed reaction was obtained from linear plots obtained by incorporating a sufficient quantity of β-amylase in the digest to eliminate the more rapidly reacting G4 formed from the G3. A K(m) value of 9.4 ± 0.8 mM for G3 was calculated from the data by a nonlinear least-squares method. Kinetic parameters for a series of higher malto-oligosaccharides (G4-G8) were also determined in both the synthetic and the phosphorolytic directions. A large change in the values of K(m) and V/e was seen on going from G3 to G4 for the synthetic reaction, and from G4 to G5 for the phosphorolytic. For the higher saccharides the V/e values do not vary strongly with increasing d.p., while the K(m) values tend to decrease, as has seen in the reactions of other plant phosphorylases. For kinetic studies on its synthetic and phosphorolytic reactions α-D-glucan phosphorylase from potatoes was purified chromatographically until free of D-enzyme. Purified maltotriose (G3) is a poor primer in the phosphorylase-catalyzed synthetic reaction, showing an anomalous time course and making previous attempts to determine its kinetic parameters unsuccessful. In the present work the true rate of the G3-primed reaction was obtained from linear plots obtained by incorporating a sufficient quantity of β-amylase in the digest to eliminate the more rapidly reacting G4 formed from the G4 A Km value of 9.4 ± 0.8 mM for G3 was calculated from the data by a nonlinear least-squares method. Kinetic parameters for a series of higher malto-oligosaccharides (G4-G3) were also determined in both the synthetic and the phosphorolytic directions. A large change in the values of Km and V/e was seen on going from G3 to G4 for the synthetic reaction, and from G4 to G3 for the phosphorolytic. For the higher saccharides the V/e values do not vary strongly with increasing d.p.. while the Km values tend to decrease, as has seen in the reactions of other plant phosphorylases.
Automated Assembly of Starch and Glycogen Polysaccharides
Delbianco, Martina,Seeberger, Peter H.,Zhu, Yuntao
supporting information, p. 9758 - 9768 (2021/06/30)
Polysaccharides are Nature's most abundant biomaterials essential for plant cell wall construction and energy storage. Seemingly minor structural differences result in entirely different functions: cellulose, a β (1-4) linked glucose polymer, forms fibrils that can support large trees, while amylose, an α (1-4) linked glucose polymer forms soft hollow fibers used for energy storage. A detailed understanding of polysaccharide structures requires pure materials that cannot be isolated from natural sources. Automated Glycan Assembly provides quick access to trans-linked glycans analogues of cellulose, but the stereoselective installation of multiple cis-glycosidic linkages present in amylose has not been possible to date. Here, we identify thioglycoside building blocks with different protecting group patterns that, in concert with temperature and solvent control, achieve excellent stereoselectivity during the synthesis of linear and branched α-glucan polymers with up to 20 cis-glycosidic linkages. The molecules prepared with the new method will serve as probes to understand the biosynthesis and the structure of α-glucans.
Phosphorylase-catalyzed N-formyl-α-glucosaminylation of maltooligosaccharides
Kawazoe, Satoshi,Izawa, Hironori,Nawaji, Mutsuki,Kaneko, Yoshiro,Kadokawa, Jun-ichi
experimental part, p. 631 - 636 (2010/09/20)
This paper describes the phosphorylase-catalyzed enzymatic N-formyl-α-glucosaminylation of maltooligosaccharides for direct incorporation of 2-deoxy-2-formamido-α-d-glucopyranose units into maltooligosaccharides. When the reaction of 2-deoxy-2-formamido-α-d-glucopyranose-1-phosphate (GlcNF-1-P) as the glycosyl donor and maltotetraose as a glycosyl acceptor was performed in the presence of phosphorylase, the N-formyl-α-d-glucosaminylated pentasaccharide was produced, as confirmed by MALDI-TOF MS. Furthermore, the glucoamylase-catalyzed reaction of the crude products supported that the 2-deoxy-2-formamido-α-d-glucopyranoside unit was positioned at the non-reducing end of the pentasaccharide. The pentasaccharide was isolated from the crude products and its structure was further determined by the 1H NMR analysis. On the other hand, when the phosphorylase-catalyzed reactions of maltotriose and maltopentaose using GlcNF-1-P were conducted, no N-formyl-α-glucosaminylation took place in the former system, whereas the latter system gave N-formyl-α-d-glucosaminylated oligosaccharides with various degrees of polymerization. These results could be explained by the recognition behavior of phosphorylase toward maltooligosaccharides.
Kinetics of maltooligosaccharide hydrolysis in subcritical water
Khajavi, Shabnam Haghighat,Ota, Shuji,Kimura, Yukitaka,Adachi, Shuji
, p. 3663 - 3667 (2007/10/03)
The kinetics of the hydrolysis of maltooligosaccharides with a degree of polymerization (DP) of 3-6 in subcritical water was studied using a tubular reactor at temperatures between 200 and 260°C and at a constant pressure of 10 MPa. The maltooligosaccharide disappearance and product formation at residence times shorter than 50 s could be expressed by first-order kinetics. The rate constants for the hydrolysis of each maltooligosaccharide were evaluated. There was a tendency that the exo-site glucosidic bond was hydrolyzed faster than the endo-site one irrespective of the DP of the maltooligosaccharide. The hydrolysis of the maltooligosaccharides was consecutively preceded, and the time dependence of the hydrolysis for maltooligosaccharides with different DPs could be calculated by simultaneously solving the mass balance equations for all the possible saccharides.
