Structural Characterization of Long Unit-Chains of Amylopectin

Hanashiro, Isao; Matsugasako, Jun-ichi; Egashira, Tamami; Takeda, Yasuhito

doi:10.5458/jag.52.233

Cited by 41 publications

(31 citation statements)

References 19 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They also form complexes with iodine resulting in overestimated amylose contents [182]. EL-chains were found in indica rice varieties, but not in japonica rice varieties [182], and also in, e.g., cassava, potato, barley, and wheat [109,[183][184][185][186][187]. Finally, the C-chain in amylopectin preparations has generally a broad size-distribution between DP 15~120, with a peak around DP 40 [188].…”

Section: Chain Categoriesmentioning

confidence: 99%

Understanding Starch Structure: Recent Progress

Bertoft¹

2017

Agronomy

598

299

View full text Add to dashboard Cite

Starch is a major food supply for humanity. It is produced in seeds, rhizomes, roots and tubers in the form of semi-crystalline granules with unique properties for each plant. Though the size and morphology of the granules is specific for each plant species, their internal structures have remarkably similar architecture, consisting of growth rings, blocklets, and crystalline and amorphous lamellae. The basic components of starch granules are two polyglucans, namely amylose and amylopectin. The molecular structure of amylose is comparatively simple as it consists of glucose residues connected through α-(1,4)-linkages to long chains with a few α-(1,6)-branches. Amylopectin, which is the major component, has the same basic structure, but it has considerably shorter chains and a lot of α-(1,6)-branches. This results in a very complex, three-dimensional structure, the nature of which remains uncertain. Several models of the amylopectin structure have been suggested through the years, and in this review two models are described, namely the "cluster model" and the "building block backbone model". The structure of the starch granules is discussed in light of both models.

show abstract

Section: Chain Categoriesmentioning

confidence: 99%

Understanding Starch Structure: Recent Progress

Bertoft¹

2017

Agronomy

598

299

View full text Add to dashboard Cite

show abstract

“…The first peak seemed to be degraded to a rather similar extent for the three amylopectins while the extent of trimming of the second peak, which accounts for ca. 80 90% of the ELC fraction on a molar basis, 14) differed greatly among the specimens. Since hydrolysis by β amylase, an exo type enzyme, is hindered by the presence of side chains, 25) the difference can be explained by the number of side chains attached to ELC and or the position (how far from a non reducing end) of side chains on ELC.…”

Section: Structure Of Extra-long Chains (Elcs) Of Amylopectinmentioning

confidence: 99%

“…ELCs were fractionated by butanol precipitation of debranched amylopectin 14) from line WAB3 5 and cvs. IR36 and Yumetoiro, and then analyzed with HPSEC (Fig.…”

Section: Structure Of Extra-long Chains (Elcs) Of Amylopectinmentioning

confidence: 99%

“…IR36 and IR42. 14) To probe how these ELCs are connected to amylopectin molecules, β amylase limit dextrin (β LD) was prepared and trimming of ELCs by the enzyme was estimated by comparison of CL distributions of amylopectin and its limit dextrin (Fig. 5).…”

Section: Structure Of Extra-long Chains (Elcs) Of Amylopectinmentioning

confidence: 99%

“…13) ELC was obtained after butanol precipitation of debranched amylopectin. 14) Pseudomonas isoamylase and Klebsiella pullulanase were purchased from Hayashibara Biochemical Laboratories , Inc . (Okayama, Japan).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Structures of Endosperm Starch from a Rice wx Cultivar Expressing Wx.ALPHA. Transgene

Hanashiro¹,

Wakayama²,

Hasegawa³

et al. 2009

J. Appl. Glycosci.

Self Cite

View full text Add to dashboard Cite

Amylose content of starch is a crucial factor determining various properties of starch and grains of rice (Oryza sativa L.). For example, correlation with amylose content and pasting properties of starch 1 3) or cooked rice textures 4,5) have been reported in the literature. Thus, as in other crops, attempts to manipulate amylose content have been common practice for generating rice starches with novel functionalities. Since rice has a relatively narrow range of amylose contents among major cereal crops, generating a real "high amylose" rice starch is expected to confer unique properties. In the previous studies, transgenic lines expressing the Wx a (WxR ) transgene, which encodes granule bound starch synthase I (GBSSI), in endosperms of wx cultivars were generated, 6,7) and we examined the effects of the transgene on the structures and pasting properties of starch, showing that the expressed GBSSI synthesized amylose and extra long chains (ELC) of amylopectin. 8) The aim of this study is to confirm the effects of the introduced GBSSI on structures of the starch components, using a transgenic line established independently from the lines used in the previous study 9) with a different vector and transformation method. Some selected starches were also examined for comparison: Wx b carrying cv. Nipponbare, Wx a−Y224S carrying cv. Labelle, and Wx a carrying cvs. IR36 and Yumetoiro, among which only cv. Labelle was used in the previous study. Further, besides ELC content, some structural characteristics, including difference in branched nature, of ELC synthesized in the transgenic line are compared with those of cvs. IR36 and Yumetoiro, both of which have been shown to have a significant amount of ELC. 10,11) MATERIALS AND METHODS Materials

show abstract

On the Architecture of Starch Granules Revealed by Iodine Binding and Lintnerization. Part 2: Molecular Structure of Lintnerized Starches

Bertoft,

Annor,

Vamadevan

et al. 2024

Biopolymers

View full text Add to dashboard Cite

This investigation validated iodine binding in combination with lintnerization for studying the structural nature of the amorphous areas in starch granules. Lintners of four iodine vapor‐stained and non‐stained amylose‐containing starches and their waxy counterparts were analyzed by high‐performance anion‐exchange chromatography (HPAEC). The composition of the lintners was strongly affected by the absence of amylose in barley and potato starch but not in maize and cassava starch. Iodine‐stained waxy lintners possessed increased number of long B2 chains. β‐Limit dextrins of the lintners were very variable in composition. Iodine inclusion complexes washed out from the granular residues in the lintners (mostly from amylose‐containing barley and maize starches) were also analyzed. Acid‐soluble complexes from both amylose‐containing and waxy starches possessed a lot of material with a degree of polymerization (DP) around 60 and a periodicity in size of DP 8–12. Such long chains were only minor components in water‐soluble complexes of amylose‐containing barley and maize starch lintners, and they lacked the size periodicity. Models of the principal structure of the acid and water‐soluble complexes are suggested. It is concluded that acid hydrolysis of iodine‐stained starch granules is a useful tool in structural analyses of the molecular composition of amorphous parts of starch granules.

show abstract

Structural Characterization of Long Unit-Chains of Amylopectin

Cited by 41 publications

References 19 publications

Understanding Starch Structure: Recent Progress

Understanding Starch Structure: Recent Progress

Structures of Endosperm Starch from a Rice wx Cultivar Expressing Wx.ALPHA. Transgene

On the Architecture of Starch Granules Revealed by Iodine Binding and Lintnerization. Part 2: Molecular Structure of Lintnerized Starches

Contact Info

Product

Resources

About