Influence of chain length of short monodisperse amyloses on the formation of A- and B-type X-ray diffraction patterns

Pfannemüller, B.

doi:10.1016/0141-8130(87)90034-1

Cited by 138 publications

(60 citation statements)

References 15 publications

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“…Streb et al (2008) proposed that AMY3 shortens external chains of the glucans made by SSs and BEs so that they cannot form double helices with their neighbors. This idea is consistent with models for amylopectin, in which a suitable CLD is a critical factor in the formation of the secondary and higher-order crystalline structures (Gidley and Bulpin, 1987;Pfannemüller, 1987). Thus, factors that affect the CLD, such as a failure to sufficiently elongate new branches or concomitant chain degradation by amylases, should also affect crystallinity.…”

supporting

confidence: 69%

“…do not form double helices) unless mixed with longer chains (Gidley and Bulpin, 1987). It has also been shown that longer chains (DP 14-20) crystallize more rapidly than shorter ones (DP 10-13; Pfannemüller, 1987). It therefore seems likely that the different crystallization capacities of the glucans from the ssisa mutants are caused by the observed differences in exterior chain length, with longer exterior chains made by SS2 and SS3 enhancing crystallization and shorter chains made by SS1 preventing it.…”

Section: External Chain Length As a Determinant For Glucan Insolubilitymentioning

confidence: 90%

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Genetic Evidence That Chain Length and Branch Point Distributions Are Linked Determinants of Starch Granule Formation in Arabidopsis

Pfister

Eicke

et al. 2014

Plant Physiology

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The major component of starch is the branched glucan amylopectin. Structural features of amylopectin, such as the branching pattern and the chain length distribution, are thought to be key factors that enable it to form semicrystalline starch granules. We varied both structural parameters by creating Arabidopsis (Arabidopsis thaliana) mutants lacking combinations of starch synthases (SSs) SS1, SS2, and SS3 (to vary chain lengths) and the debranching enzyme ISOAMYLASE1-ISOAMYLASE2 (ISA; to alter branching pattern). The isa mutant accumulates primarily phytoglycogen in leaf mesophyll cells, with only small amounts of starch in other cell types (epidermis and bundle sheath cells). This balance can be significantly shifted by mutating different SSs. Mutation of SS1 promoted starch synthesis, restoring granules in mesophyll cell plastids. Mutation of SS2 decreased starch synthesis, abolishing granules in epidermal and bundle sheath cells. Thus, the types of SSs present affect the crystallinity and thus the solubility of the glucans made, compensating for or compounding the effects of an aberrant branching pattern. Interestingly, ss2 mutant plants contained small amounts of phytoglycogen in addition to aberrant starch. Likewise, ss2ss3 plants contained phytoglycogen, but were almost devoid of glucan despite retaining other SS isoforms. Surprisingly, glucan production was restored in the ss2ss3isa triple mutants, indicating that SS activity in ss2ss3 per se is not limiting but that the isoamylase suppresses glucan accumulation. We conclude that loss of only SSs can cause phytoglycogen production. This is readily degraded by isoamylase and other enzymes so it does not accumulate and was previously unnoticed.Starch, the major storage carbohydrate in plants, is composed of two a-1,4-and a-1,6-linked glucan polymers: moderately branched amylopectin and predominantly linear amylose. Amylopectin, which constitutes approximately 80% of most starches, is synthesized by three enzyme activities. Starch synthases (SSs) transfer the glucosyl moiety of ADP-Glc to a glucan chain, forming a new a-1,4 glucosidic linkage, extending the linear chains. Branching enzymes (BEs) cleave some a-1,4 linkages and reattach chains of six Glc units or more via a-1,6 linkages, creating branch points. Debranching enzymes (DBEs) hydrolyze some of these branches, tailoring the structure of the polymer. However, the way in which the individual enzymes work together to create crystallizationcompetent amylopectin remains unclear.The coordinated actions of SSs, BEs, and DBEs are thought to produce a glucan with a tree-like architecture in which the branch points are nonrandomly positioned. According to models of amylopectin, clusters of unbranched chain segments are formed. Within these clusters, adjacent chains form double helices, which align in parallel giving rise to crystalline lamellae. These alternate with amorphous lamellae containing the branch points and chain segments that span the clusters . In the context of this amylopectin model, glucan cha...

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supporting

confidence: 69%

Section: External Chain Length As a Determinant For Glucan Insolubilitymentioning

confidence: 90%

Genetic Evidence That Chain Length and Branch Point Distributions Are Linked Determinants of Starch Granule Formation in Arabidopsis

Pfister

Eicke

et al. 2014

Plant Physiology

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“…2-10 and Table 2-8; (2) Chain length of amylopectin (Hizukuri, 1985(Hizukuri, , 1996Gidley and Bulpin, 1987;Gidley and Cooke, 1991;Pfannemueller, 1987;Hanashiro et al, 1996). A type usually has a shorter average chain length, DP23-29; B type has a longer average chain length, DP30 -44 (Gernat et al, 1993); C type displays intermediate chain length, DP26 -36 (Hizukuri et al, 1983;Hizukuri, 1985).…”

Section: Chain Length Distributionmentioning

confidence: 99%

Relationship between ?-amylase degradation and the structure and physicochemical properties of legume starches

Zhou

2004

Carbohydrate Polymers

147

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“…Hizukuri et al (1983) and Hizukuri (1986) have also shown that the average chain length of amylopectin isthemajordeterminantofaystalline polymorphism. Basedonastudywithaseriesofshortchainamylosesofuniform length, Pfannemuller (1987) showed that the degree of crystallinity and the formation of'A'and 'B'typeamylose is largely dependent on chain length. The most remarkable observation of this study was an abrupt change from 'B' to 'A' pattern in going from DP 13 to DP 12.…”

Section: Fig 218 13c Cpimas Nmr Spectra Of (A) Amorphous Starch (Bmentioning

confidence: 99%

The effect of hydroxypropylation on the structure and physicochemical properties of native, defatted and heat-moisture treated potato starches

Perera

Hoover

Martı́n

1997

Food Research International

119

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Native potato starch was physically modified by heat-moisture treatment (1WC, 16h, 30% moisture) and defatting (75%. n-propanol water, 7h). The changes in structure and physicochemical properties on heat-moisture treatment and defatting were monitored by scanning eleclron microscopy (SEM), X-ray diffraction, differential scanning calorimetry (OSC), Brabender viscosities, swelling fador (SF) and amylose leaching (AML). SEM showed that neither defatting nor heat-moisture treatment altered the size, shape or the surface appearance of the native starch granule. Heat-moisture treatment decreased Xray diffraction intensities and altered the 'B' type X-ray diffraction pattern to 'A+B'. The clecrease in X-ray intensities on heat-moisture treatment is indicative of aystallite disruption and/or rearrangement of double helices. The gelatinization enthalpy (aH), Brabender viscosity (at 95°C), SF and AML decreased on heat-moisture treatment. whereas gelatinization transition temperatures (GTT), and thermal stability inaeased. Defatting inaeased the Xray diffraction intensities and altered the X-ray pattern from 'B' to 'A+B'. The increased X-ray intensities on defatting is indicative of interactions between amylose -amylose (AM-AM), amylopectin -amylopectin (AMP-AMP) and amylose -amylopectin (AM-AMP) chains. These interactions in tum, increased

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Influence of chain length of short monodisperse amyloses on the formation of A- and B-type X-ray diffraction patterns

Cited by 138 publications

References 15 publications

Genetic Evidence That Chain Length and Branch Point Distributions Are Linked Determinants of Starch Granule Formation in Arabidopsis

Genetic Evidence That Chain Length and Branch Point Distributions Are Linked Determinants of Starch Granule Formation in Arabidopsis

Relationship between ?-amylase degradation and the structure and physicochemical properties of legume starches

The effect of hydroxypropylation on the structure and physicochemical properties of native, defatted and heat-moisture treated potato starches

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