1668-09-3Relevant academic research and scientific papers
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.
Chemoenzymic synthesis of (1→3,1→4)-β-D-glucooligosaccharides for subsite mapping of (1→3,1→4)-β-D-glucan endohydrolases
Hrmova, Maria,Fincher, Geoffrey B.,Viladot, Josep-Luis,Planas, Antoni,Driguez, Hugues
, p. 3571 - 3576 (1998)
A series of unsubstituted (1→3,1→4)-β-D-glucooligosaccharides, designed for subsite mapping in which the number of glucosyl-binding subsites and the subsite-binding/transition state activation affinities at individual subsites of plant and bacterial (1→3,1→4)-β-D-glucan 4-glucanohydrolases (EC 3.2.1.73) can be determined, has been synthesised through chemical and enzymic procedures. A recombinant (1→3,1→4)-β-D-glucan 4-glucanohydrolase from Bacillus licheniformis has been used in organic media to catalyse the condensation of 3-O-β-D-glucopyranosyl-β-D-glucopyranosyl fluoride (Glcβ3GlcβF, compound 1) with cellobiose (Glcβ4Glc, 2), cellotriose (Glcβ4Glcβ4Glc, 3), cellotetraose (Glcβ4Glcβ4Glcβ4Glc, 4) and cellopentaose (Glcβ4Glcβ4Glcβ4Glcβ4Glc, 5), to produce the (1→3,1→4)-β-D-glucooligosaccharides, Glcβ3Glcβ4Glcβ4Glc 6, Glcβ3Glcβ4Glcβ4Glcβ4Glc 7, Glcβ3Glcβ4Glcβ4Glcβ4Glcβ4Glc 8, Glcβ3Glcβ4Glcβ4Glcβ4Glcβ4Glcβ4Glc 9. Synthesised oligosaccharides 6-9 were isolated in yields of 15-45%, compared with compound 1. In a second series of syntheses, a cellodextrin phosphorylase (EC 2.4.1.49) from Clostridium thermocellum was used to sequentially transfer glucosyl residues from α-D-glucopyranosyl phosphate 10 to the 4-position of the non-reducing terminus of the trisaccharide Glcβ3Glcβ4Glc 11, to generate the (1→3,1→4)-β-D-glucooligosaccharides, Glcβ4Glcβ3Glcβ4Glc 12, Glcβ4Glcβ4Glcβ3Glcβ4Glc 13, Glcβ4Glcβ4Glcβ4Glcβ3Glcβ4Glc 14 in 14, 10 and 5% yield, respectively, from compound 11.
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.
Efficient chemoenzymatic oligosaccharide synthesis by reverse phosphorolysis using cellobiose phosphorylase and cellodextrin phosphorylase from Clostridium thermocellum
Nakai, Hiroyuki,Hachem, Maher Abou,Petersen, Bent O.,Westphal, Yvonne,Mannerstedt, Karin,Baumann, Martin J.,Dilokpimol, Adiphol,Schols, Henk A.,Duus, Jens ?.,Svensson, Birte
experimental part, p. 1818 - 1826 (2011/08/21)
Inverting cellobiose phosphorylase (CtCBP) and cellodextrin phosphorylase (CtCDP) from Clostridium thermocellum ATCC27405 of glycoside hydrolase family 94 catalysed reverse phosphorolysis to produce cellobiose and cellodextrins in 57% and 48% yield from α-d-glucose 1-phosphate as donor with glucose and cellobiose as acceptor, respectively. Use of α-d-glucosyl 1-fluoride as donor increased product yields to 98% for CtCBP and 68% for CtCDP. CtCBP showed broad acceptor specificity forming β-glucosyl disaccharides with β-(1→4)- regioselectivity from five monosaccharides as well as branched β-glucosyl trisaccharides with β-(1→4)-regioselectivity from three (1→6)-linked disaccharides. CtCDP showed strict β-(1→4)-regioselectivity and catalysed linear chain extension of the three β-linked glucosyl disaccharides, cellobiose, sophorose, and laminaribiose, whereas 12 tested monosaccharides were not acceptors. Structure analysis by NMR and ESI-MS confirmed two β-glucosyl oligosaccharide product series to represent novel compounds, i.e. β-d-glucopyranosyl-[(1→4)- β-d-glucopyranosyl]n-(1→2)-d-glucopyranose, and β-d-glucopyranosyl-[(1→4)-β-d-glucopyranosyl]n- (1→3)-d-glucopyranose (n = 1-7). Multiple sequence alignment together with a modelled CtCBP structure, obtained using the crystal structure of Cellvibrio gilvus CBP in complex with glucose as a template, indicated differences in the subsite +1 region that elicit the distinct acceptor specificities of CtCBP and CtCDP. Thus Glu636 of CtCBP recognized the C1 hydroxyl of β-glucose at subsite +1, while in CtCDP the presence of Ala800 conferred more space, which allowed accommodation of C1 substituted disaccharide acceptors at the corresponding subsites +1 and +2. Furthermore, CtCBP has a short Glu496-Thr500 loop that permitted the C6 hydroxyl of glucose at subsite +1 to be exposed to solvent, whereas the corresponding longer loop Thr637-Lys648 in CtCDP blocks binding of C6-linked disaccharides as acceptors at subsite +1. High yields in chemoenzymatic synthesis, a novel regioselectivity, and novel oligosaccharides including products of CtCDP catalysed oligosaccharide oligomerisation using α-d-glucosyl 1-fluoride, all together contribute to the formation of an excellent basis for rational engineering of CBP and CDP to produce desired oligosaccharides.
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.
Expression, purification, and characterization of the maltooligosyltrehalose trehalohydrolase from the thermophilic archaeon Sulfolobus solfataricus ATCC 35092
Fang, Tsuei-Yun,Tseng, Wen-Chi,Guo, Meng-Shin,Shih, Tong-Yuan,Hung, Xing-Guang
, p. 7105 - 7112 (2008/02/03)
The maltooligosyltrehalose trehalohydrolase (MTHase) mainly cleaves the α-1,4-glucosidic linkage next to the α-1,1-linked terminal disaccharide of maltooligosyltrehalose to produce trehalose and the maltooligosaccharide with lower molecular mass. In this study, the treZ gene encoding MTHase was PCR-cloned from Sulfolobus solfataricus ATCC 35092 and then expressed in Escherichia coli. A high yield of the active wild-type MTHase, 13300 units/g of wet cells, was obtained in the absence of IPTG induction. Wild-type MTHase was purified sequentially using heat treatment, nucleic acid precipitation, and ion-exchange chromatography. The purified wild-type MTHase showed an apparent optimal pH of 5 and an optimal temperature at 85°C. The enzyme was stable at pH values ranging from 3.5 to 11, and the activity was fully retained after a 2-h incubation at 45-85°C. The kcat values of the enzyme for hydrolysis of maltooligosyltrehaloses with degree of polymerization (DP) 4-7 were 193, 1030, 1190, and 1230 s-1, respectively, whereas the kcat values for glucose formation during hydrolysis of DP 4-7 maltooligosaccharides were 5.49, 17.7, 18.2, and 6.01 s-1, respectively. The KM values of the enzyme for hydrolysis of DP 4-7 maltooligosyltrehaloses and those for maltooligosaccharides are similar at the same corresponding DPs. These results suggest that this MTHase could be used to produce trehalose at high temperatures.
Study of the action of human salivary alpha-amylase on 2-chloro-4-nitrophenyl α-maltotrioside in the presence of potassium thiocyanate
Suganuma, Toshihiko,Maeda, Yoshiaki,Kitahara, Kanefumi,Nagahama, Tomonori
, p. 219 - 227 (2007/10/03)
The degradation mechanism of a synthetic substrate, 2-chloro-4-nitrophenyl α-maltotrioside (CNP-G3), by human salivary alpha-amylase (HSA) was investigated by kinetic and product analyses. It was observed that the enzyme attacked the various CNP-maltooligosaccharides (CNP-G3, to CNP-G6) releasing free CNP. Addition of 500 mM potassium thiocyanate (KSCN) was also found to greatly increase the rates of CNP-release. It was the fastest with CNP-G3, and, in the presence of KSCN, was almost comparable to that of degradation of maltopentaose (G5). On the other hand, addition of KSCN decreased the rate of cleavage between glucan-glucan bonds in maltopentaose. Product analysis showed that KSCN addition altered the cleavage distribution which occurred 100% at the bond between CNP and G3, and that product distribution of free CNP was largely dependent on substrate concentration. Formation of CNP-G6, a larger product than the original substrate CNP-G3, was found to be present in the digest at high concentrations of substrate and in the presence of KSCN. Based on these results, a degradation pathway for CNP-G3 involving transglycosylation besides direct hydrolysis is proposed. The increase of the CNP-release by the addition of KSCN would result from a corresponding increase in the interaction between the CNP moiety and the corresponding subsite near the catalytic site, as well as the enhancement of the catalytic efficiency.
Subsite Structure of Chalara paradoxa Glucoamylase and Interaction of the Glucoamylase with Cyclodextrins
Monma, Mitsuru,Yamamoto, Yoshihiro,Kainuma, Keiji
, p. 1503 - 1508 (2007/10/02)
The action of Chalara paradoxa glucoamylase (raw-starch-digesting enzyme) was studied with linear and cyclic maltodextrins.Subsite affinities (Ai) of the amylase were evaluated by the subsite theory.The active site was considered to be made up of seven subsites: A1 = 0.05 kcal/mol, A2 = 4.99 kcal/mol, A3 = 1.30 kcal/mol, A4 = 0.77 kcal/mol, A5 = 0.33 kcal/mol, A6 = 0.21 kcal/mol and A7 = 0.21 kcal/mol.Inhibitions by alpha-, beta-, and gamma-cyclodextrins were competitive for starch digestion by C. paradoxa glucoamylase.The inhibitor constants (Ki) of α-, β-, and γ-cyclodextrin for the amylase were 8.9, 1.4, and 3.9 mM, respectively.The Michaelis constant (Km) of 6-O-α-maltosyl-α-cyclodextrin digestion was 0.79 mM for the amylase.
