Pectinmethylesterases Pinzon-Latorre, David; Deyholos, Michael K
PloS one,
08/2014, Letnik:
9, Številka:
8
Journal Article
Recenzirano
Flax phloem fibers achieve their length by intrusive-diffusive growth, which requires them to penetrate the extracellular matrix of adjacent cells. Fiber elongation therefore involves extensive ...remodelling of cell walls and middle lamellae, including modifying the degree and pattern of methylesterification of galacturonic acid (GalA) residues of pectin. Pectin methylesterases (PME) are important enzymes for fiber elongation as they mediate the demethylesterification of GalA in muro, in either a block-wise fashion or in a random fashion. Our objective was to identify PMEs and PMEIs that mediate phloem fiber elongation in flax. For this purpose, we measured transcript abundance of candidate genes at nine different stages of stem and fiber development and found sets of genes enriched during fiber elongation and maturation as well as during xylem development. We expressed one of the flax PMEIs in E. coli and demonstrated that it was able to inhibit most of the native PME activity in the upper portion of the flax stem. These results identify key genetic components of the intrusive growth process and define targets for fiber engineering and crop improvement.
From first-hand understanding of pectin molecular structure and physiological effects up to new production methods and applications, significant insightful knowledge of pectin polysaccharide and ...pectin-derived oligosaccharides has emerged in the last decade (2010–2020). These developments open the route to new and unexpected applications of this uniquely complex heteropolysaccharide ubiquitous in plants and fruits, well beyond its traditional use as food hydrocolloid. This study provides a unified perspective on the new science and technology of pectin and its extraction by-products. Furthermore, we offer an insight into forthcoming pectin uses from an expanded perspective, taking into account selected technology and economic factors that we believe will shortly impact the pectin production and uptake in many countries.
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•A unified perspective on the new science and technology of pectin.•New developments open the route to new and unexpected applications of this uniquely complex heteropolysaccharide.•Study offers an insight into forthcoming pectin uses from an expanded perspective taking into account selected technology and economic factors.•Pectin extraction by-products, particularly pectin oligosaccharides and polyphenols, are key bioproducts broadening the applicability of pectin.•Pectin industrial production will shortly include new green chemistry and green engineering technologies.
Scope
Acute pancreatitis (AP) is a common clinical acute abdominal disease. The intestinal injury associated with AP will aggravate the condition retroactively. This study investigates whether the ...low‐methoxyl pectin (LMP) isolated from lemon could attenuate AP and associated intestinal injury.
Methods and results
Experimental AP was induced in BALB/c mice by caerulien (CAE) hyperstimulation. Nutritional prophylactic group was pre‐fed with 5% LMP supplemented forage 3 days before AP induction. We found that LMP supplementation attenuated the severity of AP as evidenced by reduced serum amylase and lipase levels, pancreatic edema and myeloperoxidase activity. The protective effect was also confirmed by histological examination of pancreatic damage. LMP suppressed the production of pancreatic proinflammatory cytokines including TNF‐α, IL‐1β, and IL‐6. Moreover, LMP supplementation restored AP‐associated disruption of intestinal barrier integrity as evidenced by upregulation of tight junction modulatory proteins occludin, zonula occludens (ZO)‐1, antimicrobial peptides β‐defensin‐1 (DEFB1) and CRAMP as well as increase in SCFAs production. LMP supplemented mice with AP exhibited suppressed intestinal inflammation as shown by decreased ileal and colon cytokine production compared with CAE group.
Conclusion
Our results support dietary LMP supplementation as an effective nutritional intervention for AP and associated intestinal injury.
Low‐methoxyl pectin (LMP) supplementation alleviates the severity of experimental acute pancreatitis (AP) as evidenced by reduced serum amylase and lipase levels, pancreatic edema, and myeloperoxidase activity. LMP modulates the inflammatory responses during AP by inhibiting pancreatic, systemic, and intestinal levels of pro‐inflammatory cytokines TNF‐α, IL‐1β, and IL‐6. Furthermore, LMP supplementation increases the production of short chain fatty acids (SCFAs) in the colon and normalizes AP‐induced intestinal barrier dysfunction by enhancing the expression of tight junction proteins (ZO‐1, occludin) and antimicrobial peptides (DEFB1, CRAMP) in the ileum and colon.
•The plasma TC levels were significantly decreased by HP, HPH and HPPS.•HPPS was more effective than HP and HPH to decrease plasma TC levels of hamsters.•HPPS and HPH significantly decreased hepatic ...TC levels.•HPPS and HPH significantly increased the fecal bile acid levels.•HP had higher cholesterol excretion capacities than HPH and HPPS.
This study aims to compare the effects of feeding haw pectin (HP), haw pectin hydrolyzates (HPH), and haw pectin pentasaccharide (HPPS) on the cholesterol metabolism of hypercholesterolemic hamsters induced by high-cholesterol diets. The animals were fed a standard diet (SD), high-cholesterol diet (HCD), or HCD plus HP, HPH, or HPPS at a dose of 300mg/kg body weight for 4weeks. Results showed that HPPS was more effective than HP and HPH in decreasing the body weight gain (by 38.2%), liver weight (by 16.4%), and plasma and hepatic total cholesterol (TC; by 23.6% and 27.3%, respectively) of hamsters. In addition, the bile acid levels in the feces were significantly higher by 39.8% and 132.8% in the HPH and HPPS groups than in the HCD group. Such changes were not noted in the HP group. However, the HP group had higher cholesterol excretion capacities than the HPH and HPPS groups by inhibiting cholesterol absorption in the diet, with a 21.7% increase in TC excretion and a 31.1% decrease in TC absorption. Thus, HPPS could be a promising anti-atherogenic dietary ingredient for the development of functional food to improve cholesterol metabolism.
Pectins are plant cell wall natural heteropolysaccharides composed mainly of α-1-4 d-galacturonic acid units, which may or may not be methyl esterified, possesses neutral sugars branching that harbor ...functional moieties. Physicochemical features as pH, temperature, ions concentration, and cosolute presence, affect directly the extraction yield and gelling capacity of pectins. The chemical and structural features of this polysaccharide enables its interaction with a wide range of molecules, a property that scientists profit from to form new composite matrices for target/controlled delivery of therapeutic molecules, genes or cells. Considered a prebiotic dietary fiber, pectins meetmany regulations easily, regarding health applications within the pharmaceutical industry as a raw material and as an agent for the prevention of cancer. Thus, this review lists many emergent pectin-based composite materials which will probably palliate the impact of obesity, diabetes and heart disease, aid to forestall actual epidemics, expand the ken of food additives and food products design.
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•Texture of half-beans was established to minimize bean-to-bean variations.•Distribution patterns of pectic cross-linkages in cotyledon cell wall.•Microscopic evidence for chelated ...Ca2+ pectin in HTC common beans.•Microscopic evidence for ester-bound feruloylated pectin during HTC development.
In this study, pectin changes during Red haricot bean storage under high temperature and high humidity conditions were investigated to understand the hard-to-cook (HTC) development from a microstructural point of view. First, to ensure repeatability of the microscopy results, a classification of the fresh and stored beans (aged at 35 °C and 83% relative humidity) into different hardening levels (the Non-aged, Aged and Very-hard aged sample) was performed based on the texture values of cooked half-cotyledons. Cell wall strength of the cotyledons was evaluated, showing that the aged samples (HTC seeds) exhibit stronger cell walls with more/stronger pectic cross-linkages than the Non-aged sample. After a sequential pectin extraction aiming at removing pectin fractions of different solubility, cell wall autofluorescence and immunolabeling of JIM7, LM9 and 2F4 epitopes in the residual materials were examined. Upon ageing, the samples exhibited an increased Ca2+-pectin and ferulic acid-pectin crosslinking, these pectic complexes being accumulated primarily at the intercellular spaces. The results suggest a contribution of both the pectin-cation-phytate hypothesis and the involvement of phenolic-pectin crosslinks in HTC development at the cotyledon during storage of common beans.
•Eggplant wastes (peels and calyxes) were used for pectin extraction.•Galactans and arabinans were the main side chains in the structure of EPP and ECP.•EPP was determined to be more linear than ...ECP.•Both of the pectin samples were good in most of the functionalities.•FT-IR and 1H NMR suggested the presence of high methylated pectin in samples.
In the present study, the various properties of pectin extracted using microwave-assisted extraction (MAE) from eggplant peel and eggplant calyx (as food processing wastes of eggplant) were compared with each other. The eggplant peel pectin (EPP) exhibited higher extraction yield (29.17%) than eggplant calyx pectin (ECP; 18.36%). Both of EPP and ECP were high in methoxyl and rich in galacturonic acid. HPLC analysis showed that EPP was high in HG (homogalacturonan) (58.6%), while ECP was high in RG-I (rhamnogalacturonan-I) (44.9%). Also, higher phenolic contents were observed for EPP in comparing with ECP. Approximately in all of the functionalities (WHC (water holding capacity) and OHC (oil holding capacity), emulsifying and foaming properties, and antioxidant activity), EPP showed higher value rather than ECP. 1H NMR (hydrogen-1 nuclear magnetic resonance), FT-IR (Fourier transform-infrared) and XRD (x-ray diffraction) spectra confirmed the presence of high methylated crystalline pectin in both EPP and ECP.
Four extraction methods of hot-water (HWE), ultrasound-assisted (UAE), microwave-assisted (MAE), and ultrasound-microwave assisted (UMAE) were utilized to determine the best technique to extract ...pectin from the common fig (Ficus carica L.) skin. UMAE (11.71%) significantly showed a more extraction yield than MAE (9.26%), UAE (8.74%), and HWE (6.05%). A significant dose-dependent antioxidant capacity for pectins 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical scavenging activity was found. The UMAE-pectin with the maximum galacturonic acid content (76.85%) and molecular weight (6.91 × 103 kDa) presented the highest emulsifying activity (61.2–61.3%) and emulsion stability (94.3–95.2%) with a monomodal droplet size distribution at cold and ambient storage temperatures. A non-Newtonian shear-thinning behavior was detected at 1.5–3.0% pectic-solutions. X-ray diffraction (XRD) analysis showed a non-crystalline nature for pectins extracted by UMAE. FTIR spectroscopy and HPLC photodiode array detector revealed that conventional and novel extraction technologies do not change the chemical structure and monosaccharide composition of pectin significantly.
•Traditional and novel technologies to extract pectin from common fig skin.•The best extraction method: ultrasound-microwave assisted extraction (UMAE).•Pectins were classified as low-methoxyl types with high galacturonic acid content.•Pectin of common fig skin: The strong antioxidant and emulsification capacities•FTIR spectrum, XRD pattern and molecular weight of extracted pectins were assessed.
Citrus pectins were studied by enzymatic fingerprinting using a simultaneous enzyme treatment with endo-polygalacturonase (endo-PG) from Kluyveromyces fragilis and pectin lyase (PL) from Aspergillus ...niger to reveal the methyl-ester distribution patterns over the pectin backbone. Using HILIC-MS combined with HPAEC enabled the separation and identification of the diagnostic oligomers released. Structural information on the pectins was provided by using novel descriptive parameters such as degree of blockiness of methyl-esterified oligomers by PG (DBPGme) and degree of blockiness of methyl-esterified oligomers by PL (DBPLme). This approach enabled us to clearly differentiate citrus pectins with various methyl-esterification patterns. The simultaneous use of PG and PL showed additional information, which is not revealed in digests using PG or PL alone. This approach can be valuable to differentiate pectins having the same DM and to get specific structural information on pectins and therefore to be able to better predict their physical and biochemical functionalities.
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