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structure-function relationships of pectic polysaccharides from broccoli by-products with in vitro B lymphocyte stimulatory activity

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CARBOHYDRATE POLYMERS 2023年 303卷 120432页

作者： Ferreira, Sonia S. Correia, Alexandra Silva, Artur M. S. Wessel, Dulcineia Ferreira Cardoso, Susana M. Vilanova, Manuel Coimbra, Manuel A. Univ Aveiro Dept Chem LAQV REQUIMTE P-3810193 Aveiro Portugal Univ Aveiro Aveiro Inst Materials Dept Chem CICECO P-3810193 Aveiro Portugal Univ Porto I3S Inst Invest & Inovacao Saude P-4200135 Porto Portugal Univ Porto IBMC Inst Biol Mol & Celular P-4150180 Porto Portugal Univ Porto Fac Ciencias DGAOT Rua Campo Alegre P-4169007 Porto Portugal Polytechn Inst Viseu Sch Agr P-3500606 Viseu Portugal Univ Tros Os Montes & Alto Douro CITAB P-5001801 Vila Real Portugal Univ Porto ICBAS Inst Ciencias Biomed Abel Salazar P-4050313 Porto Portugal

To study structure-function relationships of pectic polysaccharides with their immunostimulatory activity, broccoli by-products were used. Pectic polysaccharides composed by 64 mol% uronic acids, 18 mol% Ara, and 10 mol% Gal, obtained by hot water extraction, activated B lymphocytes in vitro (25???250 ??g/mL). To disclose active structural features, combinations of ethanol and chromatographic fractionation and modification of the polysaccharides were performed. Polysaccharides insoluble in 80 % ethanol (Et80) showed higher immunostimulatory activity than the pristine mixture, which was independent of molecular weight range (12???400 kDa) and removal of terminal or short Ara side chains. Chemical sulfation did not promote B lymphocyte activation. However, the action of pectin methylesterase and endo-polygalacturonase on hot water extracted polysaccharides produced an acidic fraction with a high immunostimulatory activity. The de-esterified homogalacturonan region seem to be an important core to confer pectic polysaccharides immunostimulatory activity. Therefore, agri-food by-products are a source of pectic polysaccharide functional food ingredients.

关键词： Brassica by-products Sulfated pectic polysaccharides Arabinogalactans NMR Methylation analysis Enzyme modified pectin structure-function relationships

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functional carbon nanodots enhance tomato tolerance to zinc deficient soils: Mechanisms and structure-function relationships

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SCIENCE OF THE TOTAL ENVIRONMENT 2024年 953卷 176113页

作者： Chen, Qiong Xing, Guling Cao, Xiufeng Liang, Taibo Chen, Lijuan Dai, Linna Ci, Lijie Yan, Mei Univ Jinan Sch Chem & Chem Engn Jinan 250022 Peoples R China Harbin Inst Technol Shenzhen Sch Mat Sci & Engn Shenzhen 518055 Peoples R China Shandong Jianzhu Univ Sch Municipal & Environm Engn Jinan 250101 Peoples R China Zhengzhou Tobacco Res Inst CNTC Zhengzhou 450001 Peoples R China Zhengzhou Univ Light Ind Coll Tobacco Sci & Engn Zhengzhou 450001 Peoples R China Hubei Univ Technol Sch Sci Wuhan 430068 Peoples R China

Zinc (Zn) deficiency is a global problem disorder affecting both crops and humans. Herein, modified functional carbon nanodots (MFCNs) with various structures and characteristics were developed to regulate tomato yields and Zn migration in plant-soil systems affected by Zn deficiency through structure-function relationships. Sulfur-doped FCNs (S-FCNs), nitrogen-doped FCNs (N-FCNs), and nitrogen-sulfur co-doped FCNs (N,S-FCNs) were hydrothermally modified using FCNs as precursors. Their regulatory effects on tomatoes growing in Zn-deficient alkaline soils were studied in pot culture experiments. Specifically, 8 mg kg(-1) of FCNs and S-FCNs improved tomato yields by 132 % and 108 %, respectively, compared with the control. However, N-FCNs and N,S-FCNs showed no significant effect on yield compared with the control (P < 0.05). Moreover, the application of FCNs or S-FCNs significantly improved fruit quality and nutritional value, including Zn content (by 26.3 % and 22.0 %, respectively) and naturally occurring antioxidants (by 3.37- and 2.08-fold for lycopene, 1.31- and 1.18-fold for flavonoids, and 2.28- and 1.89-fold for phenolics, respectively;P < 0.05). Although N-FCNs and N,S-FCNs increased Zn contents, they inhibited the synthesis of naturally occurring antioxidants in fruits. Zn bioaccessibility, uptake, and transportation in plant-soil systems were regulated by MFCNs through both direct and indirect mechanisms, including ionic reactions, plant physiology, and environmental effects. MFCNs regulated plant tolerance to Zn deficiency not only by affecting root activity, redox homeostasis, micronutrient balance, chelator synthesis, genetic expression, and plant photosynthesis but also by influencing rhizosphere soil properties and the microbial environment. Based on their dual role as "plant growth regulators" and "soil conditioners", MFCNs may have general applicability in agriculture. This study highlights the behavior of MFCNs in plant-soil systems, providing inno

关键词： Nanomaterial Zn deficiency Yield structure-function relationships Nutrient uptake

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Unraveling microbial community structure-function relationships in the horizontal and vertical spatial dimensions in extreme environments

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ECOGRAPHY 2024年第6期2024卷 e07118-e07118页

作者： Jing, Xin Classen, Aimee T. Li, Daijiang Lin, Litao Lu, Mingzhen Sanders, Nathan J. Wang, Yugang Feng, Wenting Lanzhou Univ Coll Pastoral Agr Sci & Technol State Key Lab Herbage Improvement & Grassland Agr Lanzhou Gansu Peoples R China Univ Michigan Dept Ecol & Evolutionary Biol Ann Arbor MI USA Louisiana State Univ Dept Biol Sci Baton Rouge LA USA Louisiana State Univ Ctr Computat & Technol Baton Rouge LA USA Chinese Res Inst Environm Sci Beijing Peoples R China Santa Fe Inst Santa Fe NM USA NYU Dept Environm Studies New York NY USA Chinese Acad Sci Xinjiang Inst Ecol & Geog State Key Lab Desert & Oasis Ecol Urumqi Xinjiang Peoples R China Chinese Acad Sci Fukang Stn Desert Ecol Fukang Xinjiang Peoples R China Univ Chinese Acad Sci Beijing Peoples R China Beijing Forestry Univ Sch Grassland Sci Beijing Peoples R China

A fundamental challenge in soil macroecology is to understand how microbial community structure shapes ecosystem function along environmental gradients of the land surface at broad spatial scales (i.e. the horizontal dimension). However, little is known about microbial community structure-function relationships in extreme environments along environmental gradients of soil depth at finer spatial scales (i.e. the vertical dimension). Here, we propose a general spatial dimension partitioning approach for assessing the patterns and drivers of soil microbial community structure-function relationships across horizontal and vertical spatial gradients simultaneously. We leveraged a 200-km desert soil salinity gradient created by a 12-year saline-water irrigation in the Tarim basin of Taklamakan Desert. Specifically, using a general linear model, hierarchical variance partitioning, and a path model, we assessed the patterns and key ecological processes controlling spatial turnover in microbial community structure (i.e. beta-diversity) and enzymatic activity relevant to carbon, nitrogen, and phosphorus cycling along soil salinity gradients across study sites (horizontal dimension) and soil depths (vertical dimension). We found a decoupled relationship between soil microbial beta-diversity and enzymatic activity. Differences in soil depth (on the scale of meters) were as important as geographic distance (on the scale of kilometers) in shaping bacterial and fungal beta-diversity. However, the vertical and horizontal turnover in enzymatic activity was largely attributed to an increase in the heterogeneity of soil properties, such as soil texture, water content, and pH. Our findings suggest that dispersal limitation controls microbial community beta-diversity and that environmental heterogeneity, rather than soil salinization, controls enzymatic activity. Taken together, this work highlights that in the face of ongoing environmental alterations, soil depth is an under-explored sp

关键词： ecosystem function extreme environments microbial beta-biodiversity soil macroecology structure-function relationships Taklamakan desert

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Unveiling structure-function relationships in deep eutectic solvents based biomimetic catalysis for aerobic oxidative desulfurization

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FUEL 2022年 308卷 122070-122070页

作者： Zhu, Zhiguo Lin, Haoyi Chi, Mingyue Gao, Xiongjie Feng, Yongmei Yang, Kaixuan Lu, Hongying Yantai Univ Coll Chem & Chem Engn 30 Qingquan Rd Yantai 264005 Shandong Peoples R China

Organic sulfides in fuel oil result in the formation of environmentally hazardous sulfur oxide through the combustion in vehicle engine. Oxidative desulfurization is considered to be an effective technique to eliminate sulfides in fuel oil, whose core is the construction of efficient catalytic systems under mild conditions. Herein, a biomimetic catalytic system was designed for aerobic oxidative desulfurization via coupling ammonium molybdate polyoxometalate with four different deep eutectic solvents (DESs), obeying multi-step electron transfer mechanism. It was found that the desulfurization efficiency was not directly associated with conductivity, viscosity and hydrogen-bonding strength. In combination with density functional theory (DFT) calculation, the difference in desulfurization efficiency was ascribed to the distinguished intrinsic oxidation ability of organic acid in DES. The optimal catalytic system not only could resist the adverse effect of naphthaline and indole within suitable concentration scope, but also did not show obvious decrease in desulfurization performance after ten runs. More importantly, deep desulfurization was still afforded for actual diesels using this catalytic system, indicating its enormously potential applications on an industrial level under mild conditions.

关键词： Deep eutectic solvents Biomimetic catalysis system Fuel oil Oxidative desulfurization structure-function relationships

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Bioactive polysaccharides and oligosaccharides from garlic (Allium sativum L.): Production, physicochemical and biological properties, and structure-function relationships

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COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY 2022年第4期21卷 3033-3095页

作者： Qiu, Zhichang Qiao, Yiteng Zhang, Bin Sun-Waterhouse, Dongxiao Zheng, Zhenjia Shandong Agr Univ Coll Food Sci & Engn Shandong Higher Educ Inst Key Lab Food Proc Technol & Qual Control 61Daizong Rd Tai An 271018 Shandong Peoples R China Jiangnan Univ Sch Food Sci & Technol Wuxi Jiangsu Peoples R China Univ Auckland Sch Chem Sci Auckland New Zealand

Garlic is a common food, and many of its biological functions are attributed to its components including functional carbohydrates. Garlic polysaccharides and oligosaccharides as main components are understudied but have future value due to the growing demand for bioactive polysaccharides/oligosaccharides from natural sources. Garlic polysaccharides have molecular weights of 1 x 10(3) to 2 x 10(6) Da, containing small amounts of pectins and fructooligosaccharides and large amounts of inulin-type fructans ((2 -> 1)-linked beta-d-Fruf backbones alone or with attached (2 -> 6)-linked beta-d-Fruf branched chains). This article provides a detailed review of research progress and identifies knowledge gaps in extraction, production, composition, molecular characteristics, structural features, physicochemical properties, bioactivities, and structure-function relationships of garlic polysaccharides/oligosaccharides. Whether the extraction processes, synthesis approaches, and modification methods established for other non-garlic polysaccharides are also effective for garlic polysaccharides/oligosaccharides (to preserve their desired molecular structures and bioactivities) requires verification. The metabolic processes of ingested garlic polysaccharides/oligosaccharides (as food ingredients/dietary supplements), their modes of action in healthy humans or populations with chronic conditions, and molecular/chain organization-bioactivity relationships remain unclear. Future research directions related to garlic polysaccharides/oligosaccharides are discussed.

关键词： garlic polysaccharides and oligosaccharides production physicochemical properties biological activities structure-function relationships

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Insight into the structure-function relationships of deep eutectic solvents during rice straw pretreatment

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BIORESOURCE TECHNOLOGY 2018年 249卷 261-267页

作者： Hou, Xue-Dan Li, Ao-Lin Lin, Kai-Peng Wang, Yuan-Yuan Kuang, Zhi-Yin Cao, Shi-Lin Guangdong Univ Technol Sch Chem Engn & Light Ind Guangzhou 510006 Guangdong Peoples R China Foshan Univ Dept Food Sci Foshan 528231 Peoples R China

Rice straw pretreatment mediated by choline chloride (ChCl) or lactic acid (Lac) sequences deep eutectic solvents (DESs) was investigated in this work. Hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) proved to be both important for DESs pretreatment efficiency. DESs containing lots of hydroxyl or amino groups with a high intermolecular hydrogen-bond (H-bond) strength exhibited weak biomass deconstruction abilities. The presence of strong electron-withdrawing groups in DESs was benefit for xylan removal, thus furnishing higher cellulose digestibility. The relationships between the properties of DESs, xylan removal and cellulose digestibility of pretreated biomass were established. It was found that xylan removal was negatively correlated with the pKa values of HBDs, and the enzymatic cellulose digestibility of the residues was linearly and positively related to xylan removal instead of delignification. These results provide a preliminary reference for rational design of novel DESs for biomass pretreatment.

关键词： Deep eutectic solvents Rice straw pretreatment Cellulose digestibility Xylan removal structure-function relationships

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Recent insights into structure-function relationships of antimicrobial peptides

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JOURNAL OF FOOD BIOCHEMISTRY 2019年第1期43卷 e12546页

作者： Ahmed, Tamer A. E. Hammami, Riadh Univ Ottawa Dept Cellular & Mol Med Fac Med Ottawa ON Canada City Sci Res & Technol Applicat SRTA City Genet Engn & Biotechnol Res Inst Med Biotechnol Dept Alexandria Egypt Univ Ottawa Sch Nutr Sci Fac Hlth Sci Ottawa ON Canada

The application of antimicrobial peptides (AMPs) in food preservation presents a promising alternative and offers many benefits, such as reducing the use of chemical preservatives, reducing food losses due to spoilage, and development of health-promoting food supplements. The biological activity of AMPs largely dependent on several physicochemical features including charge, the degree of helicity, hydrophobicity, and sequence. The present review provides an overview of the structural classification of AMPs emphasizing the importance of their structural features for biological activity, followed by the description of some antimicrobial mechanism of action. Despite the several hurdles that must be overcome for the exploitation of food-derived AMPs in drug discovery and food systems, the developments discussed in this review offer a taste of future trends in food and pharmaceutical applications of these intriguing molecules.

关键词： antimicrobial peptides foodborne inhibition food protein mechanism of action structure-function relationships

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structure-function relationships for the selective inhibition of human 3β-hydroxysteroid dehydrogenase type 1 by a novel androgen analog

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JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017年 174卷 257-264页

作者： Pham, Jenny H. Will, Catherine M. Mack, Vance L. Halbert, Matthew Conner, Edward Alexander Bucholtz, Kevin M. Thomas, James L. Dept Biomed Sci Macon GA 31207 USA Mercer Univ Dept Ob Gyn Sch Med Macon GA 31207 USA Mercer Univ Dept Chem Macon GA 31207 USA

3 beta-Hydroxysteroid dehydrogenase type 1 (3 beta-HSD1) is selectively expressed in human placenta, mammary glands and breast tumors in women. Human 3 beta-HSD2 is selectively expressed in adrenal glands and ovaries. Based on AutoDock 3 and 4 results, we have exploited key differences in the amino acid sequences of 3 beta-HSD1 (Ser 194, Arg195) and 3 beta-HSD2 (Gly194, Pro195) by designing a selective inhibitor of 3 beta-HSD1. 2,16-Dicyano-4,5-epoxy-androstane-3,17-dione (16-cyano-17-keto-trilostane or DiCN-AND) was synthesized in a 4-step procedure from androstenedione. In purified 3 beta-HSD inhibition studies, DiCN-AND competitively inhibited 3 beta-HSD1 with K-i = 4.7 mu M and noncompetitively inhibited 3 beta-HSD2 with a 6.5-fold higher K-i = 30.7 mu M. We previously reported similar isoenzyme-specific inhibition profiles for trilostane. Based on our docking results, we created, expressed and purified the chimeric S194G-1 mutant of 3 beta-HSD1. Trilostane inhibited S194G-1 (K-i = 0.67 mu M) with a noncompetitive mode compared to its 6.7-fold higher affinity, competitive inhibition of 3 beta-HSD1 (K-i = 0.10 mu M). DiCN-AND inhibited S194G-1 with a 6.3-fold higher K-i (29.5 mu M) than measured for 3 beta-HSD1 (K-i = 4.7 mu M) but with the same competitive mode for both enzyme species. Since DiCN-AND noncompetitively inhibits 3 beta-HSD2, which has the Gly194 and Pro195 of 3 beta-HSD2 in place of the Ser194 and Arg195 in 3 beta-HSD1, this suggests that Arg195 alone in 3 beta-HSD1 or S194G-1 is required to bind DiCN-AND in the substrate binding site (competitive inhibition). However, both Ser194 and Arg195 are required to bind trilostane in the 3 beta-HSD1 substrate site based on its noncompetitive inhibition of S194G-1 and 3 beta-HSD2. In support of this hypothesis, DiCN-AND inhibited our chimeric R195P-1 mutant noncompetitively with a K-i = 41.3 mu M (similar to the 3 beta-HSD2 inhibition profile). Since DiCN-AND competitively inhibited S194G-1 that still conta

关键词： 3 beta-Hydroxysteroid dehydrogenase Short-chain dehydrogenase/reductase Mutagenesis structure-function relationships

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Effect of formulation on structure-function relationships of concentrated emulsions: Rheological, tribological, and microstructural characterization

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FOOD HYDROCOLLOIDS 2017年 72卷 11-26页

作者： Anvari, Mohammad Joyner (Melito), Helen S. Univ Idaho Sch Food Sci 875 Perimeter DrMS 2312 Moscow ID 83844 USA

Since concentrated emulsions are the basis for many commercial products, conducting comprehensive studies on structureefunction relationships of emulsion systems is necessary for targeted product design. Hence, the objectives of this study were to 1) characterize the effects of fish gelatin concentration and oil phase volume fraction on the rheological, tribological and microstructural properties of concentrated emulsions and 2) determine structureefunction relationships based on the measured parameters. Emulsions were prepared using different amounts of oil and fish gelatin, and characterized by rheometry and microscopy. Emulsions containing higher oil or fish gelatin concentrations had greater stability to creaming, larger critical strains, and lower friction profiles. However, they exhibited increased nonlinear behavior under large amplitude oscillatory shear. These results were ascribed to increased homogeneity, higher network extension, and smaller oil droplets in emulsions with higher protein or oil concentrations. These results can be used to incorporate concentrated emulsions in emulsion-based formulations. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Concentrated emulsion Rheology structure-function relationships Tribology

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An observation that illustrates most T cell receptor structure-function relationships

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IMMUNOLOGIC RESEARCH 2017年第6期65卷 1095-1098页

作者： Cohn, Melvin Salk Inst Biol Studies Conceptual Immunol Grp 10010 N Torrey Pines Rd La Jolla CA 92037 USA

The Standard model of the T cell receptor (TCR) structure-function relationships is based on an analogy with the B cell receptor. Here a single observation is analyzed to show why this appears to be untenable. The Standard model cannot account for allele-specific recognition of theMHC-encoded presenter of peptide (R) by the TCR nor can it adequately explain alloreactivity. The competing framework is based on the assumptions that (1) single V-domains recognize the alleles of R, (2) restrictive reactivity is peptide specific, whereas alloreactivity is peptide unspecific, and (3) the TCR is born in two conformations, which display reciprocal behaviors (see text). In any case, whatever position one takes regarding these two models, competing conceptualizations are of crucial value in guiding experimentation, not to mention creative thinking.

关键词： TCR Restrictive recognition of peptide Alloreactivity Signaling structure-function relationships

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