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International Journal of Biological... Jul 2023Investigation on amylopectin molecular structure is gaining importance for understanding starch property. Lotus seeds are a novel starch source with high apparent...
Investigation on amylopectin molecular structure is gaining importance for understanding starch property. Lotus seeds are a novel starch source with high apparent amylose content. Current understanding on the molecular structure of amylopectin in lotus seed starch is scarce. This study compared the molecular structure of a range of lotus seed amylopectins with those of maize and potato amylopectins. Internal structures of these amylopectins were compared via investigating the chain length distribution of their β-limit dextrins. The average lengths and molar compositions of unit chains in lotus seed amylopectins and their β-limit dextrins fell generally between those of maize and potato. The average chain lengths of lotus seed, maize, and potato amylopectins were 19.95 (on average), 19.11, and 21.19 glucosyl residues, respectively. Lotus seed amylopectins had higher weight proportion of clustered unsubstituted chains (44.94 % on average) than those of potato (43.99 %) and maize amylopectins (42.95 %). Results of correlation analysis indicated that apparent amylose content of LS was related to structural characteristics of its amylopectin due to the presence of long external chains. The results of this study are of fundamental importance for the utilization of lotus seed starch as a novel starch source.
Topics: Amylopectin; Amylose; Dextrins; Molecular Structure; Starch; Seeds; Zea mays
PubMed: 37257534
DOI: 10.1016/j.ijbiomac.2023.125105 -
British Poultry Science Oct 20221. Research has confirmed that amylopectin (AP) is more easily digested than amylose (AM) because AP polymers have more intramolecular hydrogen bonds and less surface...
1. Research has confirmed that amylopectin (AP) is more easily digested than amylose (AM) because AP polymers have more intramolecular hydrogen bonds and less surface area. Studying the relationship between the amylose:amylopectin (AM:AP) ratio and intestine digestion in goslings can provide useful information for effective utilisation of starch.2. A total of 288 healthy male Jiangnan White Goslings, aged three days old, were randomly allotted to four groups, which included six pen replicates per treatment with 12 goslings per replicate. Four diets were formulated with maize, long-grained rice and glutinous rice as starch sources, with AM:AP ratios of 0.12, 0.23, 0.34, and 0.45. starch digestion of the four diets was measured, as well as the effect of AM:AP ratio on growth performance, serum amino-acid concentration and intestinal microbiota diversity of goslings.3. In terms of starch digestion, the increase in dietary AM:AP ratio resulted in a decrease followed by an increase in both rapidly and slowly digestible starch. The glucose release rate at an AM:AP ratio of 0.34 showed a steady upward trend.4. The study showed that increasing the AM:AP ratio resulted in a quadratic increase in body weight (BW) and average daily feed intake (ADFI; P < 0.05). Goslings fed diets with an AM:AP ratio of 0.34 had lower (P < 0.05) histidine and valine serum concentrations compared with the other three starch sources. Higher AM was beneficial to jejunal microbial and diversity. The species colonisation level of the jejunum microbiota samples at an AM:AP ratio of 0.34 was higher than that in the other groups.5. The results indicated that diets with an AM:AP ratio of 0.34 improved the growth performance and intestinal microbiota diversity of goslings. This may have been due to the higher level of resistant starch in amylose, which resulted in a slow release of intestinal glucose that acted as a substrate for the microbial species, thus providing conditions that were more conducive to growth.
Topics: Animals; Male; Amylopectin; Amylose; Chickens; Diet; Digestion; Gastrointestinal Microbiome; Geese; Glucose; Histidine; Resistant Starch; Starch; Valine
PubMed: 35583929
DOI: 10.1080/00071668.2022.2079398 -
International Journal of Biological... Jul 2019Analytical techniques such HPSEC, DSC, and TGA have been employed for amylose determination in starch samples, though spectrophotometry by iodine binding is most...
Analytical techniques such HPSEC, DSC, and TGA have been employed for amylose determination in starch samples, though spectrophotometry by iodine binding is most commonly used. The vast majority of these techniques require an analytical curve, using amylose and amylopectin standards with physicochemical properties similar to those found in the original starch. The current study aimed to obtain the amylose and amylopectin fractions from potato, banana, corn, and cassava starches, characterize them, and evaluate their behavior via thermogravimetric curves. Blue amylose iodine complex and HPSEC-DRI methods have obtained high purity amylose and amylopectin fractions. All molecular weights of the obtained amylose and amylopectin fractions were similar to those presented in other reports. Different results were obtained by deconvolution of the amylopectin polymodal distribution. All amyloses presented as semi-crystalline V-type polymorphs, while all amylopectin fractions were amorphous. The T of all V presented were directly proportional to their respective crystalline index. TGA evaluations have shown that selective precipitation of amylose with 1-butanol strongly changes its thermal behavior. Therefore, the separation procedure used was an ineffective pathway for obtaining standards for thermal studies.
Topics: Amylopectin; Amylose; Manihot; Musa; Solanum tuberosum; Zea mays
PubMed: 30880053
DOI: 10.1016/j.ijbiomac.2019.03.086 -
Biochemistry Aug 2021Glucan phosphatases are members of a functionally diverse family of dual-specificity phosphatase (DSP) enzymes. The plant glucan phosphatase Starch Excess4 (SEX4) binds... (Comparative Study)
Comparative Study
Glucan phosphatases are members of a functionally diverse family of dual-specificity phosphatase (DSP) enzymes. The plant glucan phosphatase Starch Excess4 (SEX4) binds and dephosphorylates glucans, contributing to processive starch degradation in the chloroplast at night. Little is known about the complex kinetics of SEX4 when acting on its complex physiologically relevant glucan substrate. Therefore, we explored the kinetics of SEX4 against both insoluble starch and soluble amylopectin glucan substrates. SEX4 displays robust activity and a unique sigmoidal kinetic response to amylopectin, characterized by a Hill coefficient of 2.77 ± 0.63, a signature feature of cooperativity. We investigated the basis for this positive kinetic cooperativity and determined that the SEX4 carbohydrate-binding module (CBM) dramatically influences the binding cooperativity and substrate transformation rates. These findings provide insights into a previously unknown but important regulatory role for SEX4 in reversible starch phosphorylation and further advances our understanding of atypical kinetic mechanisms.
Topics: Allosteric Site; Amylopectin; Arabidopsis; Arabidopsis Proteins; Brassica; Carbohydrate Metabolism; Dual-Specificity Phosphatases; Glucans; Kinetics; Models, Molecular; Phosphoric Monoester Hydrolases; Phosphorylation; Protein Binding; Protein Domains; Protein Stability; Solanum tuberosum
PubMed: 34319705
DOI: 10.1021/acs.biochem.1c00307 -
Journal of Materials Chemistry. B Jan 2021Self-adhesiveness is highly desirable for conformal and seamless wearable electronics. Here, a starch-tackifying method is proposed to obtain adhesive and robust...
Self-adhesiveness is highly desirable for conformal and seamless wearable electronics. Here, a starch-tackifying method is proposed to obtain adhesive and robust hydrogel conductors with the assistance of amylopectin (Amy). The conductive hydrogels are composed of Amy/poly(acrylamide-acrylic acid) polymer networks, which can be assembled into wearable sensors. The hydrogels rely on physical interactions such as hydrogen bonding that can be generated on the surface of the material, including skin, to exhibit robust and repeatable self-adhesive behaviors. Besides, the construction of a covalent and dynamic dual cross-linking network endows the hydrogel with good mechanical properties to bear repeated stretching and flexible deformation. In particular, the hydrogel is assembled into a wearable stretchable and compressible sensor and exhibits a repeatable and stable resistance signal variation for detecting both large and tiny scale human activities and physiological signals, such as bending of joints, speaking, walking, and jumping. Accordingly, the amylopectin-enabled skin-mounted hydrogel sensor can be considered as an ideal choice for human movement monitoring and personal health diagnosis.
Topics: Amylopectin; Biocompatible Materials; Humans; Hydrogels; Materials Testing; Molecular Structure; Monitoring, Physiologic; Particle Size; Skin; Surface Properties; Wearable Electronic Devices
PubMed: 33415324
DOI: 10.1039/d0tb02460k -
Plant Molecular Biology Jul 2023Amylopectin is a highly branched glucan which accounts for approximately 65-85% of starch in most plant tissues. It is crucially important to understand the biosynthetic... (Review)
Review
Amylopectin is a highly branched glucan which accounts for approximately 65-85% of starch in most plant tissues. It is crucially important to understand the biosynthetic process of this glucan in regulating the structure and functional properties of starch granules. Currently, the most accepted ideas of structural feature and biosynthesis of amylopectin are that amylopectin is composed of a branched element called "cluster" and that the essential process of amylopectin biosynthesis is to reproduce a new cluster from the existing cluster. The present paper proposes a model explaining the whole process of amylopectin biosynthesis as to how the new cluster is reproduced by concerted actions of multiple isoforms of starch biosynthetic enzymes, particularly by combinations of distinct roles of starch branching enzyme (BE) isoforms. This model proposes for the first time the molecular mechanism as to how the formation of a new cluster is initiated, and the reason why BEI can play a major role in this step. This is because BEI has a rather broad chain-length preference compared to BEIIb, because a low preference of BEI for the substrate chain-length is advantageous for branching a couple of elongated chains that are not synchronously formed and thus these chains having varied lengths could be safely attacked by this isoform. On the contrary, it is unlikely that BEIIb is involved in this reaction because it can react to only short chains having degree of polymerization of 12-14. BEIIa is possibly able to complement the role of BEI to some extent, because BEIIa can attack basically short chains but its chain-length preference is lower compared with BEIIb. The model implies that the first branches mainly formed by BEI to construct the amorphous lamellae whereas the second branches predominantly formed by BEIIb are located mainly in the crystalline lamellae. This paper provides new insights into the roles of BEI, BEIIb, and BEIIa in amylopectin biosynthesis in cereal endosperm.
Topics: Amylopectin; 1,4-alpha-Glucan Branching Enzyme; Isoenzymes; Starch; Glucans; Reproduction; Oryza
PubMed: 37294528
DOI: 10.1007/s11103-023-01352-6 -
International Journal of Biological... Nov 2020Starch ghost, an insoluble structure of gelatinized starch, plays an important role in the applications of starch. In this review, we summarized the preparation,... (Review)
Review
Starch ghost, an insoluble structure of gelatinized starch, plays an important role in the applications of starch. In this review, we summarized the preparation, morphology, structure, properties and applications of starch ghost. The preparation steps of starch ghost include gelatinization, purification and preservation, and many factors influence the yield of starch ghost. The morphology and content of starch ghost can be influenced by many factors like starch resource and amylose content. Ghosts from non-waxy starches are composed of amylopectin with long branch-chains and amylose. These molecules cross-link to each other to reinforce the structure, and tend to form B-type double helix in ghosts from high-amylose starches. Some surface proteins that bind tightly to starch granules are also present in starch ghost. Protein and lipid are thought to have limited effects on the structural stability, but they make a big difference in the morphology of starch ghost. Starch ghost shows a different resistance to amylase among various starches, but it can be further digested under the high shear force. The mechanical, enzymatic hydrolysis and electrochemical properties of starch ghost make it widely used as emulsifier, stabilizer, thickener and starch-based films or gels in food and non-food processing industries.
Topics: Amylases; Amylopectin; Amylose; Digestion; Gelatin; Hydrolysis; Starch; Zea mays
PubMed: 32950526
DOI: 10.1016/j.ijbiomac.2020.09.077 -
Food Chemistry Jun 2020The structures and physicochemical properties of ginkgo starches from seven cultivars were investigated and their relationships analyzed. The ginkgo starches had oval or...
The structures and physicochemical properties of ginkgo starches from seven cultivars were investigated and their relationships analyzed. The ginkgo starches had oval or irregular shapes, size distributions with a unimodal peak, and an A-type crystal pattern. The fine structures, crystalline structures, and physicochemical properties varied significantly among these ginkgo starches. Pearson correlation analysis and a PCA loading plot indicated that amylopectin A-chains and amylose had negative effects on the IR ratio, I, and D, while amylopectin B-chains had a clear positive effect on the relative crystallinity. Furthermore, the amylopectin short B1-chains and long B-chains contributed amorphous and single-helix structures, respectively. The thermal properties of the ginkgo starches were mainly influenced by the amylopectin B-chains and I, while the pasting properties were mainly influenced by amylopectin B-chains and helical structures. These results indicated that the starch fine structures and crystalline structures had significant effects on the physicochemical properties.
Topics: Amylopectin; Amylose; Crystallography, X-Ray; Ginkgo biloba; Species Specificity; Starch
PubMed: 31982853
DOI: 10.1016/j.foodchem.2019.125082 -
International Journal of Molecular... Feb 2023Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the...
Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the effective solutions. Duckweed has the advantages of fast growth, high starch content and no occupation of arable land, so it is a promising starchy energy plant. A new submerged duckweed mutant () with abundant starch accumulation was obtained, whose content of amylopectin accounts for 84.04% of the starch granules. Compared with the wild type (), the branching degree of starch in mutant was significantly increased by 19.6%. Chain length DP 6-12, DP 25-36 and DP > 36 of amylopectin significantly decreased, while chain length DP 13-24 significantly increased. Average chain length of wild-type and mutant starches were greater than DP 22. Moreover, the crystal structure and physical properties of starch have changed markedly in mutant. For example, the starch crystallinity of mutant was only 8.94%, while that of wild-type was 22.3%. Compared with wild type, water solubility of starch was significantly reduced by 29.42%, whereas swelling power significantly increased by 97.07% in mutant. In order to further analyze the molecular mechanism of efficient accumulation of amylopectin in mutant, metabolome and transcriptome were performed. The results showed that glucose accumulated in mutant, then degradation of starch to glucose mainly depends on α-amylase. At night, the down-regulated β-amylase gene resulted in the inhibition of starch degradation. The starch and sucrose metabolism pathways were significantly enriched. Up-regulated expression of , , , , and provide sufficient substrate for starch synthesis in mutant. From the 0H to 16H light treatment, granule-bound starch synthase () gene was inhibited, on the contrary, the starch branching enzyme () gene was induced. Differential expression of and may be an important reason for the decrease ratio of amylose/amylopectin in mutant. Taken together, our results indicated that the mutant can accumulate the amylopectin efficiently, potentially through altering the differential expression of , and . This study also provides theoretical guidance for creating crop germplasm with high amylopectin by means of synthetic biology in the future.
Topics: Amylopectin; Starch; Amylose; 1,4-alpha-Glucan Branching Enzyme; Araceae; Starch Synthase
PubMed: 36769258
DOI: 10.3390/ijms24032934 -
International Journal of Biological... Jun 2023Starch is a polysaccharide with varying amylose-to-amylopectin ratios as a function of its biological sources. It is characterized by low shear stress resistance, poor... (Review)
Review
Starch is a polysaccharide with varying amylose-to-amylopectin ratios as a function of its biological sources. It is characterized by low shear stress resistance, poor aqueous/organic solubility and gastrointestinal digestibility which limit its ease of processing and functionality display as an oral drug delivery vehicle. Modulation of starch composition through genetic engineering primarily alters amylose-to-amylopectin ratio. Greater molecular properties changes require chemical and enzymatic modifications of starch. Acetylation reduces water solubility and enzymatic digestibility of starch. Carboxymethylation turns starch acid-insoluble and aggregative at low pHs. The summative effects are sustaining drug release in the upper gut. Acid-insoluble carboxymethylated starch can be aminated to provide an ionic character essential for hydrogel formation which further reduces its drug release. Ionic starch can coacervate with oppositely charged starch, non-starch polyelectrolyte or drug into insoluble, controlled-release complexes. Enzymatically debranched and resistant starch has a small molecular size which confers chain aggregation into a helical hydrogel network that traps the drug molecules, protecting them from biodegradation. The modified starch has been used to modulate the intestinal/colon-specific or controlled systemic delivery of oral small molecule drugs and macromolecular therapeutics. This review highlights synthesis aspects of starch and starch derivatives, and their outcomes and challenges of applications in oral drug delivery.
Topics: Starch; Amylopectin; Amylose; Drug Delivery Systems; Solubility
PubMed: 37085071
DOI: 10.1016/j.ijbiomac.2023.124506