First Principles Insight into the α-Glucan Structures of Starch: Their Synthesis, Conformation, and Hydration

Damager, Iben; Engelsen, Søren Balling; Blennow, Andreas; Møller, Birger Lindberg; Motawia, Mohammed Saddik

doi:10.1021/cr900227t

Cited by 101 publications

(61 citation statements)

References 326 publications

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“…These two macromolecules are the basis of the aggregation and granule structure of starch and provide an excellent conceptual approach to the understanding of the structure-processing-property relationships of natural polymers (P erez & Bertoft, 2010;Wu, Witt, & Gilbert, 2013;Liao et al, 2014). Amylose is a linear molecular with a few long branches, whereas amylopectin is highly branched, containing~5% branching points and a large number of short branches (Damager, Engelsen, Blennow, Lindberg Møller, & Motawia, 2010). The outer parts of amylopectin branches (A and B 1 chains) form clusters of double helices, which build up the crystalline lamellae; and the internal parts (B 2 , B 3 and C chains) locate in the amorphous lamellae (Jane, Xu, Radosavljevic, & Seib, 1992).…”

Section: Introductionmentioning

confidence: 99%

“…The outer parts of amylopectin branches (A and B 1 chains) form clusters of double helices, which build up the crystalline lamellae; and the internal parts (B 2 , B 3 and C chains) locate in the amorphous lamellae (Jane, Xu, Radosavljevic, & Seib, 1992). The alternating crystalline and amorphous lamellae with ã 9 nm repeat distance collectively form the semi-crystalline growth rings in a starch granule (Calvert, 1997;Damager et al, 2010). Amylose is in either amorphous or single helical conformation and is interspersed among amylopectin molecules (Jane et al, 1992;Lopez-Rubio, Flanagan, Gilbert, & Gidley, 2008).…”

Section: Introductionmentioning

confidence: 99%

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Shear degradation of corn starches with different amylose contents

et al. 2017

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a b s t r a c tThis work investigated the effect of shear on the starch degradation, with a particular focus on the changes in molecular and lamellar structures. Corn starches with different amylose/amylopectin ratios (waxy corn starch, or WCS: 1:99; normal corn starch, or NCS: 25:75; and Gelose 80 starch, or G80: 80:20) were used as model materials to be processed using a Haake twin-rotor mixer for different times. Molecular and lamellar structural analysis was performed using size-exclusion chromatography (SEC) and small-angle X-ray scattering (SAXS). The degree of damage of starch at the granule level was evaluated by an assay kit. The results showed that amylose molecules in starch granules did not change significantly, while amylopectin molecules degraded to a stable size caused by the shear treatment. The average thickness of semi-crystalline lamellae disappeared rapidly during processing. A typical positive deviation from Porod's law at a high q region was observed, attributed to the presence of thermal density fluctuations or mixing within phases. Nonetheless, the degree of mixing within phases for the processed samples was lower than the native starch. The study of the mass fractal structure indicated that the scattering objects of the processed starches were more compact than those of the native counterparts. Furthermore, waxy corn starch (containing mostly amylopectin) experienced the greatest granule damage than the other starches. All the results showed that the rigid crystal structure in amylopectin is more sensitive to the shear treatment than the flexible amorphous structure in amylose. This mechanistic understanding at the microstructure level is helpful in designing the processing of starch-based foods or plastics with desired functional properties.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Shear degradation of corn starches with different amylose contents

et al. 2017

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“…The analysis of the StGWD3 day/night expression cycle in leaves of S. tuberosum, along with earlier studies on the significance of the phosphorylation in in vitro processes, may prove the hypothesis that the phosphorylated substrate changes its conformation through the activity of GWD1/ GWD3 (PWD) and becomes more accessible to amylolytic enzymes, thereby may initialise the process of starch grain decomposition (Edner et al 2007;Dudkiewicz et al 2008;Hejazi et al 2008Hejazi et al , 2009Damager et al 2010). The initial stage of degradation is important because the native starch grain, with its semi-crystalline structure, is not a good substrate for amylases or starch phosphorylase (Tester et al 2004).…”

Section: The Role Of Glucan Water Dikinasesmentioning

confidence: 87%

“…NMR analyses ) demonstrated that GWD3 (PWD) selectively phosphorylates the C-3-position of glucosyl residues, whereas GWD1 always introduces the phosphate group at the C-6 position. It is worth emphasising that the C-3-bound phosphate is rarely found in nature (Damager et al 2010). The recently combined NMR and molecular modelling approaches (Hansen et al 2008(Hansen et al , 2009 have indicated that the C-3 phosphorylation of maltose moieties strongly influences the conformation equilibrium of the maltosidic linkage when the hydration effects are considered (Hansen et al 2009;Damager et al 2010).…”

Section: The Role Of Glucan Water Dikinasesmentioning

confidence: 99%

“…It is worth emphasising that the C-3-bound phosphate is rarely found in nature (Damager et al 2010). The recently combined NMR and molecular modelling approaches (Hansen et al 2008(Hansen et al , 2009 have indicated that the C-3 phosphorylation of maltose moieties strongly influences the conformation equilibrium of the maltosidic linkage when the hydration effects are considered (Hansen et al 2009;Damager et al 2010). The main effect is presumably steric, but the configuration of the structural water network is also altered, which results in problems with the accommodation of 3 0 -Ophosphate groups in the helix and leads to a local disruption effect.…”

Section: The Role Of Glucan Water Dikinasesmentioning

confidence: 99%

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Analysis of the expression, subcellular and tissue localisation of phosphoglucan, water dikinase (PWD/GWD3) in Solanum tuberosum L.: a bioinformatics approach for the comparative analysis of two α-glucan, water dikinases (GWDs) from Solanum tuberosum L.

et al. 2012

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Analysis of the expression, subcellular and tissue localisation of phosphoglucan, water dikinase (PWD/GWD3) in Solanum tuberosum L.: a bioinformatics approach for the comparative analysis of two a-glucan, water dikinases (GWDs) from Solanum tuberosum L. Abstract There are several important factors affecting the rate of starch decomposition in plants, including the circadian clock, the regulation of gene expression, the regulation of enzyme activities and starch phosphorylation by glucan, water dikinase activities (GWDs). One isoform of glucan, water dikinase named GWD3 or PWD (EC 2.7.9.5) was isolated for the first time from Arabidopsis thaliana, and now we report its isolation and identification in Solanum tuberosum L. leaves and tubers. We compare StGWD3 sequence to the other GWDs sequences using bioinformatics tools and propose also structural models for the starch-binding domains in StGWD3 and StGWD1. The StGWD3 gene expression and protein were localised in different heterotrophic and autotrophic potato tissues and organs using in situ RT-PCR and immunolocalisation methods, respectively. Diurnal changes in the transcript abundance of StGWD3 in leaves were analysed using quantitative real-time PCR and they appeared to be typical for most genes involved in starch degradation in chloroplasts.Keywords Starch degradation Á Cold-sweetening Á Potato Electronic supplementary material The online version of this article

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Plant α‐glucan phosphatases SEX4 and LSF2 display different affinity for amylopectin and amylose

et al. 2016

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These authors contributed equally to the work. The plant glucan phosphatases Starch EXcess 4 (SEX4) and Like Sex Four2 (LSF2) apply different starch binding mechanisms. SEX4 contains a carbohydrate binding module, and LSF2 has two surface binding sites (SBSs). We determined K Dapp for amylopectin and amylose, and K D for b-cyclodextrin and validated binding site mutants deploying affinity gel electrophoresis (AGE) and surface plasmon resonance. SEX4 has a higher affinity for amylopectin; LSF2 prefers amylose and b-cyclodextrin. SEX4 has 50-fold lower K Dapp for amylopectin compared to LSF2. Molecular dynamics simulations and AGE data both support long-distance mutual effects of binding at SBSs and the active site in LSF2.

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First Principles Insight into the α-Glucan Structures of Starch: Their Synthesis, Conformation, and Hydration

Cited by 101 publications

References 326 publications

Shear degradation of corn starches with different amylose contents

Shear degradation of corn starches with different amylose contents

Analysis of the expression, subcellular and tissue localisation of phosphoglucan, water dikinase (PWD/GWD3) in Solanum tuberosum L.: a bioinformatics approach for the comparative analysis of two α-glucan, water dikinases (GWDs) from Solanum tuberosum L.

Plant α‐glucan phosphatases SEX4 and LSF2 display different affinity for amylopectin and amylose

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