Journal articles: 'Enzyme de modification des pectines'

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Kim, Yu-Jin, Ho Young Jeong, Seung-Yeon Kang, Jeniffer Silva, Eui-Jung Kim, Soon Ki Park, Ki-Hong Jung, and Chanhui Lee. "Physiological Importance of Pectin Modifying Genes During Rice Pollen Development." International Journal of Molecular Sciences 21, no. 14 (July 8, 2020): 4840. http://dx.doi.org/10.3390/ijms21144840.

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Although cell wall dynamics, particularly modification of homogalacturonan (HGA, a major component of pectin) during pollen tube growth, have been extensively studied in dicot plants, little is known about how modification of the pollen tube cell wall regulates growth in monocot plants. In this study, we assessed the role of HGA modification during elongation of the rice pollen tube by adding a pectin methylesterase (PME) enzyme or a PME-inhibiting catechin extract (Polyphenon 60) to in vitro germination medium. Both treatments led to a severe decrease in the pollen germination rate and elongation. Furthermore, using monoclonal antibodies toward methyl-esterified and de-esterified HGA epitopes, it was found that exogenous treatment of PME and Polyphenon 60 resulted in the disruption of the distribution patterns of low- and high-methylesterified pectins upon pollen germination and during pollen tube elongation. Eleven PMEs and 13 PME inhibitors (PMEIs) were identified by publicly available transcriptome datasets and their specific expression was validated by qRT-PCR. Enzyme activity assays and subcellular localization using a heterologous expression system in tobacco leaves demonstrated that some of the pollen-specific PMEs and PMEIs possessed distinct enzymatic activities and targeted either the cell wall or other compartments. Taken together, our findings are the first line of evidence showing the essentiality of HGA methyl-esterification status during the germination and elongation of pollen tubes in rice, which is primarily governed by the fine-tuning of PME and PMEI activities.

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Seghini, Maria Carolina, Jacopo Tirillò, Maria Paola Bracciale, Fabienne Touchard, Laurence Chocinski-Arnault, Antonio Zuorro, Roberto Lavecchia, and Fabrizio Sarasini. "Surface Modification of Flax Yarns by Enzymatic Treatment and Their Interfacial Adhesion with Thermoset Matrices." Applied Sciences 10, no. 8 (April 23, 2020): 2910. http://dx.doi.org/10.3390/app10082910.

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The aim of this study was to assess the effects of commercially available and relatively inexpensive enzyme preparations based on endo 1,4-β-xylanase, pectinase and xyloglucanase on the thermal (TGA), morphological (SEM), chemical (FT-IR) and mechanical (single yarn tensile tests) properties of flax yarns. The preparation based on pectinase and xyloglucanase provided the best results, resulting in the effective removal of hydrophilic components such as hemicellulose and pectin, the individualization of yarns and increased thermal stability at the expense of a reduction in mechanical properties, depending on the treatment parameters. Single yarn fragmentation tests pointed out an improved interfacial adhesion after enzymatic treatment, with reduced debonding length values of 18% for an epoxy matrix and up to 36% for a vinylester resin compared to untreated flax yarns.

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Muñoz-Blandón, Oscar, Margarita Ramírez-Carmona, Beatriz Cuartas-Uribe, and José Antonio Mendoza-Roca. "Evaluation of Original and Enzyme-Modified Fique Fibers as an Azo Dye Biosorbent Material." Water 14, no. 7 (March 25, 2022): 1035. http://dx.doi.org/10.3390/w14071035.

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As natural fibers, low-cost biosorbents have proven to be an effective and clean tool to remove textile dyes from wastewater. In this research, the Reactive Black 5 removal ability of original and enzyme-modified natural fibers were assessed. A fiber extracted from a Colombian fique plant (Furcraea sp.) was employed. The effects of fique fiber protonation with different solvents and dye solution pH on RB5 removal were evaluated. The biosorbent chemical composition was modified using the commercial enzymes pectinase, ligninase, and xylanase. The point of zero charge (PZC) of the original and modified material was measured, and the dye removal capacity of the three enzyme-modified fibers was determined. Fiber protonation with 0.1 M HCl and a dye solution with pH of 2.4 increased the RB5 elimination to 49.1%. The change in the fiber chemical composition led to a reduction in the PZC from 5.5 to a 4.7–4.9 range. Pectinase-pretreated fique fibers presented the highest dye removal of 66.29%, representing a 36% increase in RB5 dye removal. Although the original fique fiber showed RB5 dye removal ability, its enzymatic modification changed the charge distribution on the fiber surface, improving the capture of dye molecules. Enzyme modification can be applied to obtain new functionalities for plant fibers as biosorbent materials.

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Morais, Patrícia Lígia Dantas de, Luiz Carlos de Oliveira Lima, Maria Raquel Alcântara de Miranda, José Donizete Alves, Ricardo Elesbão Alves, and José Daniel Silva. "Enzyme activities and pectin breakdown of sapodilla submitted to 1-methylcyclopropene." Pesquisa Agropecuária Brasileira 43, no. 1 (January 2008): 15–20. http://dx.doi.org/10.1590/s0100-204x2008000100003.

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The objective of this work was to investigate the influence of 1-methylcyclopropene (1-MCP) at 300 nL L-1 on activities of cell wall hidrolytic enzymes and pectin breakdown changes which Sapodilla (Manilkara zapota cv. Itapirema 31) cell wall undergoes during ripening. Sapodilla were treated with ethylene antagonist 1-MCP at 300 nL L-1 for 12 hours and then, stored under a modified atmosphere at 25º C for 23 days. Firmness, total and soluble pectin and cell wall enzymes were monitored during storage. 1-MCP at 300 nL L-1 for 12 hours delayed significantly softening of sapodilla for 11 days at 25º C. 1-MCP postharvest treatment affected the activities of cell wall degrading enzymes pectinmethylesterase and polygalacturonase and completely suppressed increases in beta-galactosidase for 8 days, resulting in less pectin solubilization. Beta-galactosidase seems relevant to softening of sapodilla and is probably responsible for modification of both pectin and xyloglucan-cellulose microfibril network.

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Shin, Yesol, Andrea Chane, Minjung Jung, and Yuree Lee. "Recent Advances in Understanding the Roles of Pectin as an Active Participant in Plant Signaling Networks." Plants 10, no. 8 (August 19, 2021): 1712. http://dx.doi.org/10.3390/plants10081712.

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Pectin is an abundant cell wall polysaccharide with essential roles in various biological processes. The structural diversity of pectins, along with the numerous combinations of the enzymes responsible for pectin biosynthesis and modification, plays key roles in ensuring the specificity and plasticity of cell wall remodeling in different cell types and under different environmental conditions. This review focuses on recent progress in understanding various aspects of pectin, from its biosynthetic and modification processes to its biological roles in different cell types. In particular, we describe recent findings that cell wall modifications serve not only as final outputs of internally determined pathways, but also as key components of intercellular communication, with pectin as a major contributor to this process. The comprehensive view of the diverse roles of pectin presented here provides an important basis for understanding how cell wall-enclosed plant cells develop, differentiate, and interact.

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Werchefani, Mouna, Catherine Lacoste, Hafedh Belguith, Ali Gargouri, and Chedly Bradai. "Effect of chemical and enzymatic treatments of alfa fibers on polylactic acid bio-composites properties." Journal of Composite Materials 54, no. 30 (July 13, 2020): 4959–67. http://dx.doi.org/10.1177/0021998320941579.

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Poor interfacial adhesion between vegetable fibers and bio-based thermoplastics is recognized as a serious drawback for biocomposite materials. To be applicable for a large-scale production, one should consider appropriate methods of natural fiber handling. This study presented poly(lactic acid) (PLA) reinforced with Alfa short fibers and four types of fiber treatment were selected. The effect of these treatments on the tensile properties and the morphology of biocomposites was studied. Composite samples were produced using a twin-screw extruder and an injection molding machine with a fiber percentage of 20 wt %. Prior to composite manufacture, Alfa fibers were subjected to mechanical, chemical and enzymatic modifications. The comparison of enzyme treated fibers and NaOH treated fibers was investigated by means of biochemical and morphological analyses. It was observed that enzymes decompose lignin, pectin and hemicelluloses from the fiber bundles interface leading to the reduction of technical fiber diameter and length. The elimination of these hydrophilic components resulted also in an increase of the water resistance of treated fibers. A bigger fiber-matrix interface area was thus created, which facilitated fiber-matrix adhesion and enhanced mechanical characteristics of the composites. SEM micrographs showed homogeneous distribution of treated fibers in the polymer matrix. Tensile strength of PLA biocomposites filled with pectinase treated fibers was increased by 27% over untreated samples. The data proved that enzymatic treatment can be used as an effective and ecofriendly strategy of fiber modification for natural fiber-reinforced composite production. These materials can be used in several domains such as construction, automotive applications and packaging industries.

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Volchok, Anastasia, Alexandra Rozhkova, Ivan Zorov, Sergey Shcherbakov, and Arkady Sinitsyn. "Production of fruit wines using novel enzyme preparations." OENO One 49, no. 3 (September 30, 2015): 205. http://dx.doi.org/10.20870/oeno-one.2015.49.3.80.

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Aim: This work describes the activities of new-generation enzymatic preparations in fruit-berry substrates engineered for use in the fruit-wine industry. The enzymes were produced after genetic modification and selection of fungi Penicillium verruculosum, which produce efficient cellulase and pectinase enzymatic complexes. Methods and results: This paper covers the main characteristics of novel multi-enzyme complexes and the results of in-lab fruit-wine production with addition of enzymatic preparations, which could be used on an industrial scale. The juice yield and the content of suspended materials in the enzymatically treated samples were compared. Experiments included the sensory analysis of produced juices and fruit wines.Conclusion: Results show a significant increase in juice yield from the fruit pulp processed with the enzymatic preparations, without any negative effect on the quality and organoleptic attributes of the final product.Significance and impact of the study: The obtained data clearly show that the use of the new-generation enzymatic preparations in the fruit-wine industry is effective.

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Western, Tamara L. "Changing spaces: the Arabidopsis mucilage secretory cells as a novel system to dissect cell wall production in differentiating cellsThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology." Canadian Journal of Botany 84, no. 4 (April 2006): 622–30. http://dx.doi.org/10.1139/b06-008.

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As the outer boundary of plant cells, the cell wall is integral to all aspects of plant growth, development, and interactions with the environment. Dicot primary cell walls are composed of a network of cellulose, hemicellulose and proteins embedded in a matrix of acidic pectins. Pectins are synthesized in the Golgi apparatus by the sequential addition of nucleotide sugars by glycosyltransferases, following which they are secreted to the apoplast. During their differentiation, the mucilage secretory cells (MSCs) of the Arabidopsis seed coat undergo sequential biosynthesis and secretion of a primarily pectinaceous mucilage followed by secondary cell wall production. Several genes affecting MSC differentiation have been identified with roles ranging from the production of nucleotide sugar substrates for pectin synthesis to putative cell wall modification enzymes to transcription factors required to control MSC differentiation. These preliminary studies of the MSCs demonstrate that they will play a valuable role in gene discovery related to cell wall production and modification. Furthermore, they have the potential to become an important system in which to study the interaction and regulation of pectin biosynthetic factors in differentiating cells. These results will contribute to answering the important question of how cell wall production and modification occur throughout a growing plant living in a complex environment.

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MATTHEW, J., S. HOWSON, M. KEENAN, and P. BELTON. "Improvement of the gelation properties of sugarbeet pectin following treatment with an enzyme preparation derived from Aspergillus niger — Comparison with a chemical modification." Carbohydrate Polymers 12, no. 3 (1990): 295–306. http://dx.doi.org/10.1016/0144-8617(90)90070-9.

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Kim, Yang, Martin A. K. Williams, Ashley L. Galant, Gary A. Luzio, Brett J. Savary, Prasanna Vasu, and Randall G. Cameron. "Nanostructural modification of a model homogalacturonan with a novel pectin methylesterase: Effects of pH on nanostructure, enzyme mode of action and substrate functionality." Food Hydrocolloids 33, no. 1 (August 2013): 132–41. http://dx.doi.org/10.1016/j.foodhyd.2013.02.015.

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Cameron, Randall G., Gary A. Luzio, Prasanna Vasu, Brett J. Savary, and Martin A. K. Williams. "Enzymatic Modification of a Model Homogalacturonan with the Thermally Tolerant Pectin Methylesterase from Citrus: 1. Nanostructural Characterization, Enzyme Mode of Action, and Effect of pH." Journal of Agricultural and Food Chemistry 59, no. 6 (March 23, 2011): 2717–24. http://dx.doi.org/10.1021/jf104845j.

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Rolanda, Gabriela, Lusiana Batubara, Indah Saraswati, and Kusmiyati Tjahjono DK. "THE EFFECT OF ROSELLA DRIED CALYX INFUSION (HIBISCUS SABDARIFFA) IN LOWERING LDL CHOLESTEROL SERUM LEVEL ON CIGARETTE SMOKE EXPOSED MALE SPRAGUE DAWLEY RATS." DIPONEGORO MEDICAL JOURNAL (JURNAL KEDOKTERAN DIPONEGORO) 11, no. 1 (January 29, 2022): 42–47. http://dx.doi.org/10.14710/dmj.v11i1.31224.

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Background: Cigarettes increase cardiovascular risks by modifying lipid profiles through oxidation, alternating lipoprotein composition, and fat metabolizing enzyme activity. Vascular dysfunction can primarily identified by LDL cholesterol composition shift, one of atherosclerosis predictor. Rosella is a multifunctional herb that widely used as a pleasant tea. Aside from its rich components, anthocyanin, pectin, PCA and hibiscus acid are playing the role keys in lowering LDL cholesterol through lipid metabolism enzyme activity modification. Rosella is easy to find, relatively cheap, tasteful and also categorized as food-grade FDA approved.Aim: To investigate the effect of rosella infusion in decreasing LDL cholesterol serum on cigarettes exposed male Sprague dawley rat.Methods: This study is a true experimental study design with post-test only controlled group design. After 7 days of adaptation, a total of 30 male Sprague dawley rats were randomly divided into 5 groups (n=6 per group); KN received no special treatment; KP exposed to 4 rods of cigarette smoke/day; experimental groups (P1, P2, P3) exposed to 4 rods of cigarette smoke/day and rosella dried calyx infusion with 250, 500 and 1000 mg/kg respectively for 30 consecutive days. LDL cholesterol levels are measured using the CHOD-PAP method. Collected data were analyzed statistically using One Way ANOVA Test.Results: There is a significant difference between all experimental groups (p=0,00) in the post-hoc test.Conclusion: These lines of evidence suggest that rosella infusion significantly decreases LDL Cholesterol serum level in cigarettes exposed Sprague dawley rats in a dose-dependent manner.Keywords: Cigarettes smoke, LDL cholesterol, Rosella calyx infusion

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Ning, Tong, Chengjie Chen, Ganjun Yi, Houbin Chen, Yudi Liu, Yanjie Fan, Jing Liu, et al. "Changes in Homogalacturonan Metabolism in Banana Peel during Fruit Development and Ripening." International Journal of Molecular Sciences 23, no. 1 (December 27, 2021): 243. http://dx.doi.org/10.3390/ijms23010243.

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Though numerous studies have focused on the cell wall disassembly of bananas during the ripening process, the modification of homogalacturonan (HG) during fruit development remains exclusive. To better understand the role of HGs in controlling banana fruit growth and ripening, RNA-Seq, qPCR, immunofluorescence labeling, and biochemical methods were employed to reveal their dynamic changes in banana peels during these processes. Most HG-modifying genes in banana peels showed a decline in expression during fruit development. Four polygalacturonase and three pectin acetylesterases showing higher expression levels at later developmental stages than earlier ones might be related to fruit expansion. Six out of the 10 top genes in the Core Enrichment Gene Set were HG degradation genes, and all were upregulated after softening, paralleled to the significant increase in HG degradation enzyme activities, decline in peel firmness, and the epitope levels of 2F4, CCRC-M38, JIM7, and LM18 antibodies. Most differentially expressed alpha-1,4-galacturonosyltransferases were upregulated by ethylene treatment, suggesting active HG biosynthesis during the fruit softening process. The epitope level of the CCRC-M38 antibody was positively correlated to the firmness of banana peel during fruit development and ripening. These results have provided new insights into the role of cell wall HGs in fruit development and ripening.

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Brummell, David A. "Cell wall disassembly in ripening fruit." Functional Plant Biology 33, no. 2 (2006): 103. http://dx.doi.org/10.1071/fp05234.

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Fruit softening during ripening involves a coordinated series of modifications to the polysaccharide components of the primary cell wall and middle lamella, resulting in a weakening of the structure. Degradation of polysaccharides and alterations in the bonding between polymers cause an increase in cell separation and a softening and swelling of the wall, which, combined with alterations in turgor, bring about fruit softening and textural changes. A wide range in the extent of cell wall pectic modifications has been observed between species, whereas the depolymerisation of xyloglucan is relatively limited and more consistent. The earliest events to be initiated are usually a loss of pectic galactan side chains and the depolymerisation of matrix glycans, which may begin before ripening, followed by a loss of pectic arabinan side chains and pectin solubilisation. The depolymerisation of pectins may begin during early to mid-ripening, but is usually most pronounced late in ripening. However, some of these events may be absent or occur at very low levels in some species. Cell wall swelling may be related to a loosening of the xyloglucan–cellulose network and to pectin solubilisation, and these processes combined with the loss of pectic side chains increase wall porosity. An increase in wall porosity later in ripening may allow increased access of degradative enzymes to their substrates.

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Western, Tamara L. "The sticky tale of seed coat mucilages: production, genetics, and role in seed germination and dispersal." Seed Science Research 22, no. 1 (September 26, 2011): 1–25. http://dx.doi.org/10.1017/s0960258511000249.

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AbstractThe production of hydrophilic mucilages by the seed coat or pericarp, which are released upon seed hydration, is a commonly found adaptation in angiosperms, known as myxodiaspory. These are composed primarily of pectins and hemicelluloses that undergo substantive swelling upon hydration. Synthesized in the Golgi apparatus and secreted to an apoplastic space via secretory vesicles, mucilages can also contain cellulose microfibrils or cellulosic fibres that are synthesized at the plasma membrane in association with microtubules. Investigation of mucilage production in, and differentiation of, the mucilage secretory cells of the genetic model plantArabidopsis thalianahas identified a number of regulatory genes and enzymes involved in pectin synthesis and secretion,in muropectin modification and secondary cell wall synthesis. Studies of the role of mucilages in both a number of species and in Arabidopsis mutants affected in its production suggest that they have multiple ecological roles. These include facilitation of seed hydration, mediation of germination under waterlogged conditions, prevention of seed dispersal or predation by adherence to soil, and promotion of seed dispersal by attachment to animals. The precise role of mucilages appears to be dependent on species and their environmental context.

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Jiang, S., P. Park, and H. Ishii. "Ultrastructural Study on Acibenzolar-S-Methyl-Induced Scab Resistance in Epidermal Pectin Layers of Japanese Pear Leaves." Phytopathology® 98, no. 5 (May 2008): 585–91. http://dx.doi.org/10.1094/phyto-98-5-0585.

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The infection behavior of Japanese pear scab pathogen Venturia nashicola race 1 was studied ultrastructurally in acibenzolar-S-methyl (ASM)-pretreated susceptible Japanese pear (cv. Kousui) leaves to determine the mechanism of ASM-induced scab resistance. On ASM-pretreated leaf surfaces, the infection behavior (conidial germination and appressorial formation) was similar to that on distilled water (DW)-pretreated leaves prior to cuticle penetration by the pathogen. However, after penetration, differentiated behavior was found in epidermal pectin layers and middle lamellae of the ASM-pretreated leaves. Subcuticular hyphae in epidermal pectin layers and middle lamellae of ASM-pretreated pear leaves were observed at lower frequency than in DW-treated leaves. The results indicated that fungal growth was suppressed in ASM-pretreated pear leaves. In the pectin layers of ASM- and DW-pretreated leaves, some hyphae showed morphological modifications, which were used as criteria to judge collapse of hyphal cells, including plasmolysis, necrotic cytoplasm, and cell wall destruction. More hyphae had collapsed in ASM-pretreated leaves than in DW-treated ones. In addition, the cell walls of collapsed hyphae broke into numerous fibrous and amorphous pieces, suggesting that ASM-induced scab resistance might be associated with cell-wall-degrading enzymes from pear plants. In addition, results from morphometrical analysis suggested that the activity or production of pectin-degrading enzyme from hyphae were inhibited by ASM application when compared with DW treatment.

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Valcárcel, M. C., and V. Palacios. "Influence of `Novarom G' Pectinase β-glycosidase Enzyme on the Wine Aroma of four White Varieties." Food Science and Technology International 14, no. 5_suppl (October 2008): 95–102. http://dx.doi.org/10.1177/1082013208095325.

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Knowledge of the aroma precursors in enology has been fundamental in studying the aromatic potential of grape varieties. These precursors, represented fundamentally by the glycosidically-bound aroma compounds, are present in the grape at higher concentrations than the free or volatile forms. Acid hydrolysis of these precursors is not a viable way to produce significant chemical modifications in terpenes, but enzymatic hydrolysis is the best technique to increase the concentration of the free aroma fraction in wines. As a result, current studies are focused on the use of β-glycosidase enzymes to hydrolyze and release these aroma precursors as a way to improve the characteristics and sensory quality of wines. This work describes the influence that the application of `Novarom G' β-glycosidase enzyme has on the aromatic composition of monovarietal wines from four white varieties: Palomino fino, Sauvignon blanc, Traminer, and Viura. The grapes were cultivated in an experimental vineyard at the IFAPA Centro `Rancho de la Merced' (Jerez de la Frontera). Enzyme-treated wines showed significant differences in comparison to the controls in terms of analytical data: the terpenes and 2-phenylethanol concentrations increased in all varieties. The resulting wines had a more floral and fruity aroma and an improved sensory quality.

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Li, Taotao, Dingding Shi, Qixian Wu, Chunxiao Yin, Fengjun Li, Youxia Shan, Xuewu Duan, and Yueming Jiang. "Mechanism of Cell Wall Polysaccharides Modification in Harvested ‘Shatangju’ Mandarin (Citrus reticulate Blanco) Fruit Caused by Penicillium italicum." Biomolecules 9, no. 4 (April 24, 2019): 160. http://dx.doi.org/10.3390/biom9040160.

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Modification of cell wall polysaccharide in the plant plays an important role in response to fungi infection. However, the mechanism of fungi infection on cell wall modification need further clarification. In this study, the effects of Penicillium italicum inoculation on ‘shatangju’ mandarin disease development and the potential mechanism of cell wall polysaccharides modification caused by P. italicum were investigated. Compared to the control fruit, P. italicum infection modified the cell wall polysaccharides, indicated by water-soluble pectin (WSP), acid-soluble pectin (ASP), hemicellulose and lignin contents change. P. italicum infection enhanced the activities of polygalacturonase (PG), pectin methylesterase (PME), and the expression levels of xyloglucanendotransglucosylase/hydrolase (XTH) and expansin, which might contribute to cell wall disassembly and cellular integrity damage. Additionally, higher accumulation of reactive oxygen species (ROS) via decreasing antioxidant metabolites and the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) also contributed to the cell wall polysaccharides modification. Meanwhile, the gene expression levels of hydroxyproline-rich glycoprotein (HRGP) and germin-like protein (GLP) were inhibited by pathogen infection. Altogether, these findings suggested that cell wall degradation/modification caused by non-enzymatic and enzymatic factors was an important strategy for P. italicum to infect ‘shatangju’ mandarin.

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Gallego-Giraldo, Lina, Chang Liu, Sara Pose-Albacete, Sivakumar Pattathil, Angelo Gabriel Peralta, Jenna Young, Jan Westpheling, et al. "ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1) releases latent defense signals in stems with reduced lignin content." Proceedings of the National Academy of Sciences 117, no. 6 (January 23, 2020): 3281–90. http://dx.doi.org/10.1073/pnas.1914422117.

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There is considerable interest in engineering plant cell wall components, particularly lignin, to improve forage quality and biomass properties for processing to fuels and bioproducts. However, modifying lignin content and/or composition in transgenic plants through down-regulation of lignin biosynthetic enzymes can induce expression of defense response genes in the absence of biotic or abiotic stress. Arabidopsis thaliana lines with altered lignin through down-regulation of hydroxycinnamoyl CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) or loss of function of cinnamoyl CoA reductase 1 (CCR1) express a suite of pathogenesis-related (PR) protein genes. The plants also exhibit extensive cell wall remodeling associated with induction of multiple cell wall-degrading enzymes, a process which renders the corresponding biomass a substrate for growth of the cellulolytic thermophile Caldicellulosiruptor bescii lacking a functional pectinase gene cluster. The cell wall remodeling also results in the release of size- and charge-heterogeneous pectic oligosaccharide elicitors of PR gene expression. Genetic analysis shows that both in planta PR gene expression and release of elicitors are the result of ectopic expression in xylem of the gene ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1), which is normally expressed during anther and silique dehiscence. These data highlight the importance of pectin in cell wall integrity and the value of lignin modification as a tool to interrogate the informational content of plant cell walls.

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Gwanpua, Sunny George, Sandy Van Buggenhout, Bert E. Verlinden, Stefanie Christiaens, Avi Shpigelman, Victor Vicent, Zahra Jamsazzadeh Kermani, Bart M. Nicolai, Marc Hendrickx, and Annemie Geeraerd. "Pectin modifications and the role of pectin-degrading enzymes during postharvest softening of Jonagold apples." Food Chemistry 158 (September 2014): 283–91. http://dx.doi.org/10.1016/j.foodchem.2014.02.138.

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Zhang, Zichen, Aabid Manzoor Shah, Hassan Mohamed, Yao Zhang, Nino Tsiklauri, and Yuanda Song. "Genomic Studies of White-Rot Fungus Cerrena unicolor SP02 Provide Insights into Food Safety Value-Added Utilization of Non-Food Lignocellulosic Biomass." Journal of Fungi 7, no. 10 (October 5, 2021): 835. http://dx.doi.org/10.3390/jof7100835.

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Cerrena unicolor is an ecologically and biotechnologically important wood-degrading basidiomycete with high lignocellulose degrading ability. Biological and genetic investigations are limited in the Cerrena genus and, thus, hinder genetic modification and commercial use. The aim of the present study was to provide a global understanding through genomic and experimental research about lignocellulosic biomass utilization by Cerrena unicolor. In this study, we reported the genome sequence of C. unicolor SP02 by using the Illumina and PacBio 20 platforms to obtain trustworthy assembly and annotation. This is the combinational 2nd and 3rd genome sequencing and assembly of C. unicolor species. The generated genome was 42.79 Mb in size with an N50 contig size of 2.48 Mb, a G + C content of 47.43%, and encoding of 12,277 predicted genes. The genes encoding various lignocellulolytic enzymes including laccase, lignin peroxidase, manganese peroxidase, cytochromes P450, cellulase, xylanase, α-amylase, and pectinase involved in the degradation of lignin, cellulose, xylan, starch, pectin, and chitin that showed the C. unicolor SP02 potentially have a wide range of applications in lignocellulosic biomass conversion. Genome-scale metabolic analysis opened up a valuable resource for a better understanding of carbohydrate-active enzymes (CAZymes) and oxidoreductases that provide insights into the genetic basis and molecular mechanisms for lignocellulosic degradation. The C. unicolor SP02 model can be used for the development of efficient microbial cell factories in lignocellulosic industries. The understanding of the genetic material of C. unicolor SP02 coding for the lignocellulolytic enzymes will significantly benefit us in genetic manipulation, site-directed mutagenesis, and industrial biotechnology.

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Adlercreutz, Patrick. "Enzyme-catalysed Lipid Modification." Biotechnology and Genetic Engineering Reviews 12, no. 1 (December 1994): 231–54. http://dx.doi.org/10.1080/02648725.1994.10647913.

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Marzo, Cristina, Ana Belén Díaz, Ildefonso Caro, and Ana Blandino. "Effect of Several Pretreatments on the Lactic Acid Production from Exhausted Sugar Beet Pulp." Foods 10, no. 10 (October 12, 2021): 2414. http://dx.doi.org/10.3390/foods10102414.

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Exhausted sugar beet pulp (ESBP), a by-product of the sugar industry, has been used as a substrate to produce lactic acid (LA). Due to the fact that ESBP contains a high percentage of pectin and hemicellulose, different pretreatments were studied to solubilize them and to facilitate the access to cellulose in the subsequent enzymatic hydrolysis. Several pretreatments were studied, specifically biological, oxidant with alkaline hydrogen peroxide (AHP), and thermochemical with acid (0.25, 0.5, or 1% w/v of H2SO4). Pretreated ESBP was enzymatically hydrolysed and fermented with the strain Lactiplantibacillus plantarum for LA production. The hydrolysis was carried out with the commercial enzymes Celluclast®, pectinase, and xylanase, for 48 h. After that, the hydrolysate was supplemented with yeast extract and calcium carbonate before the bacteria inoculation. Results showed that all the pretreatments caused a modification of the fibre composition of ESBP. In most cases, the cellulose content increased, rising from 25% to 68% when ESBP was pretreated thermochemically at 1% w/v H2SO4. The production of LA was enhanced when ESBP was pretreated thermochemically. However, it was reduced when biological and AHP pretreatments were applied. In conclusion, thermochemical pretreatment with 1% w/v H2SO4 had a positive impact on the production of LA, increasing its concentration from 27 g/L to 50 g/L.

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Osete-Alcaraz, Andrea, Encarna Gómez-Plaza, Pilar Martínez-Pérez, Florent Weiller, Julia Schückel, William G. T. Willats, John P. Moore, José M. Ros-García, and Ana B. Bautista-Ortín. "The Influence of Hydrolytic Enzymes on Tannin Adsorption-Desorption onto Grape Cell Walls in a Wine-Like Matrix." Molecules 26, no. 3 (February 2, 2021): 770. http://dx.doi.org/10.3390/molecules26030770.

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This study evaluates the capacity of four hydrolytic enzymes to limit the interactions between grape cell-walls and tannins and/or to favor tannin desorption. Adsorption and desorption tests were conducted by mixing a commercial seed tannin with purified skin cell-walls from Syrah grapes, in the presence or absence of hydrolytic enzymes, in a model-wine solution. The effects of the enzymes were evaluated by measuring the tannins in solution by High Performance Liquid Chromatography (HPLC) and the changes in the cell wall polysaccharide network by Comprehensive Microarray Polymer Profiling (COMPP) while the polysaccharides liberated from cell walls were analyzed by Size Exclusion Chromatography (SEC). The results showed that the enzymes limited the interaction between tannins and cell walls, especially cellulase, pectinase and xylanase, an effect associated with the cell wall structural modifications caused by the enzymes, which reduced their capacity to bind tannins. With regards to the tannin desorption process, enzymes did not play a significant role in liberating bound tannins. Those enzymes that showed the highest effect in limiting the adsorption of tannins and in disorganizing the cell wall structure, cellulase and pectinase, did not lead to a desorption of bound tannins, although they still showed a capacity of affecting cell wall structure. The results indicate that enzymes are not able to access those polysaccharides where tannins are bound, thus, they are not a useful tool for desorbing tannins from cell walls. The practical importance implications of these findings are discussed in the manuscript.

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25

Li, Weiqiang, Liai Xu, Rui Xia, Ying Shen, Zhujun Zhu, Youjian Yu, and Yunxiang Zang. "Cloning and Functional Identification of SlPG49 in Solanum lycopersicum." Applied Sciences 11, no. 23 (December 3, 2021): 11450. http://dx.doi.org/10.3390/app112311450.

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The modification and degradation of pectin in cell walls are necessary for the fruit softening process, which involves a series of pectin-modifying enzymes. Polygalacturonases (PGs) are a major group of pectin-hydrolyzing enzymes, which participate in fruit maturation, organ shedding, pollen development, and other processes by catalyzing the degradation of polygalacturonic acid. However, their function in plants has not yet been fully elucidated. In this paper, a full-length cDNA encoding SlPG49 was cloned from a tomato. Sequence alignment and phylogenetic analysis demonstrated that SlPG49 contains four typical conserved domains and belongs to clade E in PG classification. Quantitative real-time PCR analysis showed that SlPG49 was highly expressed in fruits during the softening stage, indicating that SlPG49 may be involved in fruit softening. Subcellular localization results revealed that SlPG49 was located in the cell membrane and the cell wall. In addition, an in vitro enzymatic activity assay confirmed that SlPG49 does have the ability to catalyze the hydrolysis of polygalacturonic acid. These results indicate that SlPG49 is a newly discovered PG gene involved in tomato fruit softening, and provide an experimental basis for elucidating the biological functions of plant PGs during fruit softening.

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26

Cruz-Valderrama, José Erik, Judith Jazmin Bernal-Gallardo, Humberto Herrera-Ubaldo, and Stefan de Folter. "Building a Flower: The Influence of Cell Wall Composition on Flower Development and Reproduction." Genes 12, no. 7 (June 26, 2021): 978. http://dx.doi.org/10.3390/genes12070978.

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Floral patterning is a complex task. Various organs and tissues must be formed to fulfill reproductive functions. Flower development has been studied, mainly looking for master regulators. However, downstream changes such as the cell wall composition are relevant since they allow cells to divide, differentiate, and grow. In this review, we focus on the main components of the primary cell wall—cellulose, hemicellulose, and pectins—to describe how enzymes involved in the biosynthesis, modifications, and degradation of cell wall components are related to the formation of the floral organs. Additionally, internal and external stimuli participate in the genetic regulation that modulates the activity of cell wall remodeling proteins.

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27

Rakitzis, E. T., and T. B. Malliopoulou. "Kinetics of protein-modification reactions. Stoichiometry of modification-produced enzyme inactivation: modification of rhodanese by 2,4,6-trinitrobenzenesulphonic acid." Biochemical Journal 230, no. 1 (August 15, 1985): 89–93. http://dx.doi.org/10.1042/bj2300089.

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A mathematical treatment is presented for the dependence of enzyme activity loss on the numbers and reactivities of the groups essential for catalytic function, when enzyme protein modification is carried out by the use of concentrations of protein reactive groups well in excess of that of modifying agent. Experimentally obtained data on the modification of rhodanese (thiosulphate sulphurtransferase, EC 2.8.1.1) by 2,4,6-trinitrobenzenesulphonic acid are presented, and it is shown that, at pH9.00, the fractional concentration of rhodanese groups, or of rhodanese group reactivities, essential for enzyme catalytic function is 0.88; this value is found to decrease with decreasing pH of the reaction medium. The possibility that rhodanese inactivation by 2,4,6-trinitrobenzenesulphonic acid is brought about by modification of groups other than amino groups is ruled out by a comparison of the enzyme-inactivation and protein-modification stoichiometries, for putative reaction models for enzyme and modifying agent.

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28

DAY, D. F. "Bacterial Alginate Control of Enzyme Modification." Annals of the New York Academy of Sciences 542, no. 1 Enzyme Engine (December 1988): 107–10. http://dx.doi.org/10.1111/j.1749-6632.1988.tb25813.x.

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29

Sakiyama, Fumio. "Modification of enzyme structure and function." Kobunshi 35, no. 10 (1986): 950–53. http://dx.doi.org/10.1295/kobunshi.35.950.

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30

Sala, Ana, Martin Ehrbar, Diana Trentin, Ronald G. Schoenmakers, Janos Vörös, and Franz E. Weber. "Enzyme Mediated Site-Specific Surface Modification." Langmuir 26, no. 13 (July 6, 2010): 11127–34. http://dx.doi.org/10.1021/la1008895.

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31

Poudyal, Raghav R., Phuong D. M. Nguyen, Melissa P. Lokugamage, Mackenzie K. Callaway, Jesse V. Gavette, Ramanarayanan Krishnamurthy, and Donald H. Burke. "Nucleobase modification by an RNA enzyme." Nucleic Acids Research 45, no. 3 (December 6, 2016): 1345–54. http://dx.doi.org/10.1093/nar/gkw1199.

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32

Jarvie, Ann W. P., Nigel Overton, and Christopher B. St Pourçain. "Enzyme catalysed modification of synthetic polymers." Journal of the Chemical Society, Perkin Transactions 1, no. 15 (1999): 2171–76. http://dx.doi.org/10.1039/a902165e.

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33

Tanaka, Tsutomu, Takayuki Sakamoto, Kanako Wakamura, Ryosuke Takase, Takuya Matsumoto, Shiori Sawamoto, and Akihiko Kondo. "Enzyme-mediated site-specific protein modification." Journal of Bioscience and Bioengineering 108 (November 2009): S96—S97. http://dx.doi.org/10.1016/j.jbiosc.2009.08.282.

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34

Dominiak, Malgorzata, Karen M. Søndergaard, Jesper Wichmann, Silvia Vidal-Melgosa, William G. T. Willats, Anne S. Meyer, and Jørn D. Mikkelsen. "Application of enzymes for efficient extraction, modification, and development of functional properties of lime pectin." Food Hydrocolloids 40 (October 2014): 273–82. http://dx.doi.org/10.1016/j.foodhyd.2014.03.009.

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35

Yoo, Sang-Dong, Zhifang Gao, Claudio Cantini, Wayne H. Loescher, and Steven van Nocker. "Fruit Ripening in Sour Cherry: Changes in Expression of Genes Encoding Expansins and other Cell-wall-modifying Enzymes." Journal of the American Society for Horticultural Science 128, no. 1 (January 2003): 16–22. http://dx.doi.org/10.21273/jashs.128.1.0016.

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A preliminary understanding of developmental processes among divergent species is essential to evaluate the applicability of information from model species to plants of agricultural importance. In tomato (Lycopersicon esculentum Mill.), where the molecular biology associated with fruit ripening has been studied most extensively, tissue softening is due at least in part to the activity of proteins called expansins, in concert with enzymatic activities that modify the pectin and xyloglucan components of the cell wall. We evaluated the potential for the concerted action of expansins and other cell wall-modifying enzymes during ripening in a highly divergent fruit species, sour cherry (Prunus cerasus L.). We identified a family of four expansin genes that was strongly upregulated at the advent of ripening. Activation of these genes was accompanied by strong upregulation of gene(s) encoding potential pectin methylesterases, pectate lyase(s), and xyloglucan endotransglycosylase(s). Initiation of ripening and gene induction were also associated with a rapid decrease in cell wall weight. These results suggest that expansin and several other distinct activities could be involved in ripening-associated cell wall modification in cherries.

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36

Koksharov, Sergey A., Olga V. Lepilova, and Svetlana V. Aleeva. "Technology for Preparation of Hybrid Sorbents Based on Plant Raw Materials and Montmorillonite." Solid State Phenomena 316 (April 2021): 142–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.316.142.

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The possibility of preparation of hybrid nanocomposites, based on Burdock Arctium Lappa L biomass, modified with enzymes and montmorillonite, was substantiated. It was founded that bio-modification allowing releasing pectin into the biomass Burdock structure that allow fixing clay mineral particles onto biomass. It was found that the increase of pore spaces occurs at the expense of increasing mesopore spaces to 93 %. It allows increasing the adsorption capacity of hybrid nanocomposites to zinc ions and methylene blue to 52.2 and 166.9 mg g-1 respectively; that is 3.5 and 9 times more than adsorption capacityfor initial plant Burdock

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37

Khan, Mudassar Nawaz, Iftikhar Ahmed, Israr Ud Din, Ahmed Noureldeen, Hadeer Darwish, and Majid Khan. "Proteomic insight into soybean response to flooding stress reveals changes in energy metabolism and cell wall modifications." PLOS ONE 17, no. 5 (May 5, 2022): e0264453. http://dx.doi.org/10.1371/journal.pone.0264453.

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Soybean is a legume crop enriched with proteins and oil. It is frequently exposed to anthropogenic and natural flooding that limits its growth and yield. Current study applied gel-free proteomic techniques to unravel soybean response mechanism to flooding stress. Two-days-old soybeans were flooded for 4 days continuously and root samples were collected at days 2 to 6 for proteomic and enzymatic analyses. Age-matched untreated soybeans were collected as control. After protein extraction, purification and tryptic digestion, the peptides were analyzed on nano-liquid chromatography-mass spectrometry. A total of 539 and 472 proteins with matched peptides 2 or more were identified in control and flooded seedlings, respectively. Among these 364 proteins were commonly identified in both control and flooded soybeans. Fourty-two protein’s abundances were changed 4-fold after 2-days of flooding stress as compared to starting point. The cluster analysis showed that highly increased proteins included cupin family proteins, enolase, pectin methylesterase inhibitor, glyoxalase II, alcohol dehydrogenase and aldolase. The enzyme assay of enolase and pectin methylesterase inhibitor confirmed protein abundance changes. These findings suggest that soybean adopts the less energy consuming strategies and brings biochemical and structural changes in the cell wall to effectively respond to flooding stress and for the survival.

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38

Chakraborty, Soma, Bishwabhusan Sahoo, Iwao Teraoka, Lisa M. Miller, and Richard A. Gross. "Enzyme-Catalyzed Regioselective Modification of Starch Nanoparticles." Macromolecules 38, no. 1 (January 2005): 61–68. http://dx.doi.org/10.1021/ma048842w.

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39

Baran, Erkan Türker, Nazmi Özer, and Vasif Hasirci. "Solid-phase enzyme modification via affinity chromatography." Journal of Chromatography B 794, no. 2 (September 2003): 311–22. http://dx.doi.org/10.1016/s1570-0232(03)00487-2.

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40

KEYES, M. H., D. E. ALBERT, and S. SARASWATHI. "Enzyme Semisynthesis by Conformational Modification of Proteins." Annals of the New York Academy of Sciences 501, no. 1 Enzyme Engine (June 1987): 201–4. http://dx.doi.org/10.1111/j.1749-6632.1987.tb45709.x.

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41

Ringel, Michael T., Gerald Dräger, and Thomas Brüser. "PvdN Enzyme Catalyzes a Periplasmic Pyoverdine Modification." Journal of Biological Chemistry 291, no. 46 (October 4, 2016): 23929–38. http://dx.doi.org/10.1074/jbc.m116.755611.

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42

Osa, Tetsuo. "Enzyme modification of LB membrane-deposited ISFET." Applied Biochemistry and Biotechnology 41, no. 1-2 (April 1993): 41–49. http://dx.doi.org/10.1007/bf02918527.

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43

Rakitzis, Emmanuel T. "Interpretation of Biphasic Protein Modification and Modification-Induced Enzyme Inactivation Reaction Plots." Journal of Enzyme Inhibition 4, no. 1 (January 1990): 57–62. http://dx.doi.org/10.3109/14756369009030389.

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44

Yang, S. H., C. H. Wu, and W. Y. Lin. "Chemical modification of aminopeptidase isolated from Pronase." Biochemical Journal 302, no. 2 (September 1, 1994): 595–600. http://dx.doi.org/10.1042/bj3020595.

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Chemical modification of aminopeptidase from pronase has revealed two important histidines in enzyme catalysis. In the absence of metal ions, modification of the readily-modified histidine (pKa 6.9 +/- 0.5) results in a drastic loss of activity, indicating that this residue is indispensible for enzyme activity. In the presence of CaCl2, the modified enzyme still retains approx. 60% of the activity, whereas modification of another histidine (pKa 7.7 +/- 0.2) leads to a dramatic loss of activity. In fact, the enzyme with the first histidine being modified is active only in the presence of metal ions. Moreover, modification of the second histidine is prevented by the presence of Ca(II). These results indicate that the second histidine is serving as a ligand for Ca(II) and the bound Ca(II) is directly involved in enzyme catalysis. The c.d. spectra of the modified and unmodified enzymes in the absence or presence of CaCl2 are all very similar, indicating that no gross conformational changes in protein occur upon modification or by the presence of Ca(II). Modification of both histidines is prevented by the presence of a competitive inhibitor, suggesting that they are located in the active centre. Modification of 11 amino groups, two tyrosines, or four arginines causes no appreciable inactivation of the enzyme, indicating that these residues are not directly involved in enzyme catalysis.

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45

Du, Min, Xin Ping Li, and Wu Guang Li. "Modification of Bleached Softwood Pulp with Xylanase." Advanced Materials Research 393-395 (November 2011): 855–58. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.855.

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Xylanse named as Pulpzyme HC was used to modify bleached softwood pulp before refining. The efficiency of modification by different enzyme dosage was invested in this paper. The result showed that enzymatic treatment decreased the dissolved charge and absolute Zeta potential of the slurry and increased the fiber surface wettability. Appropriate Pulpzyme HC (0.4u/g) could improve the refining efficiency by 9.5°SR. The brightness and bulk of hand sheets increased with the increasing of the enzyme. Tensile index and tear index of hand sheets reached the maximum at the enzyme dosage of 0.2u/g. In this dosage, fiber length, knot index and curl index of fiber increased. But excessive enzyme decreased the tear index and had no effect on the tensile index.

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46

Heiss, Elke, and Verena Dirsch. "Regulation of eNOS Enzyme Activity by Posttranslational Modification." Current Pharmaceutical Design 20, no. 22 (June 2014): 3503–13. http://dx.doi.org/10.2174/13816128113196660745.

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47

D’Arrigo, Paola, Ezio Fasoli, Giuseppe Pedrocchi-Fantoni, Stefano Servi, and Davide Tessaro. "Membrane assisted coupled enzyme system for phospholipid modification." Enzyme and Microbial Technology 37, no. 4 (September 2005): 435–40. http://dx.doi.org/10.1016/j.enzmictec.2005.03.021.

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48

Tann, Cheng-Min, Dongfeng Qi, and Mark D. Distefano. "Enzyme design by chemical modification of protein scaffolds." Current Opinion in Chemical Biology 5, no. 6 (December 2001): 696–704. http://dx.doi.org/10.1016/s1367-5931(01)00268-x.

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49

Rakels, J. L. L., P. Caillat, A. J. J. Straathof, and J. J. Heijnen. "Modification of the Enzyme Enantioselectivity by Product Inhibition." Biotechnology Progress 10, no. 4 (July 1994): 403–9. http://dx.doi.org/10.1021/bp00028a010.

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50

Keffer-Wilkes, Laura Carole, Govardhan Reddy Veerareddygari, and Ute Kothe. "RNA modification enzyme TruB is a tRNA chaperone." Proceedings of the National Academy of Sciences 113, no. 50 (November 14, 2016): 14306–11. http://dx.doi.org/10.1073/pnas.1607512113.

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Cellular RNAs are chemically modified by many RNA modification enzymes; however, often the functions of modifications remain unclear, such as for pseudouridine formation in the tRNA TΨC arm by the bacterial tRNA pseudouridine synthase TruB. Here we test the hypothesis that RNA modification enzymes also act as RNA chaperones. Using TruB as a model, we demonstrate that TruB folds tRNA independent of its catalytic activity, thus increasing the fraction of tRNA that can be aminoacylated. By rapid kinetic stopped-flow analysis, we identified the molecular mechanism of TruB’s RNA chaperone activity: TruB binds and unfolds both misfolded and folded tRNAs thereby providing misfolded tRNAs a second chance at folding. Previously, it has been shown that a catalytically inactive TruB variant has no phenotype when expressed in an Escherichia coli truB KO strain [Gutgsell N, et al. (2000) RNA 6(12):1870–1881]. However, here we uncover that E. coli strains expressing a TruB variant impaired in tRNA binding and in in vitro tRNA folding cannot compete with WT E. coli. Consequently, the tRNA chaperone activity of TruB is critical for bacterial fitness. In conclusion, we prove the tRNA chaperone activity of the pseudouridine synthase TruB, reveal its molecular mechanism, and demonstrate its importance for cellular fitness. We discuss the likelihood that other RNA modification enzymes are also RNA chaperones.

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Journal articles on the topic 'Enzyme de modification des pectines'

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