检索结果-内蒙古大学图书馆

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

Using Modeling to Understand structure-function relationships in Proteins

Using Modeling to Understand Structure-Function Relationship...

引用

作者： Barnes, Jonathan E. University of Idaho

学位级别：Ph.D., Doctor of Philosophy

Proteins are critical to the function of cells and to life. It is well established that changes to the DNA sequence (genotype) of a protein can have a significant impact on how they function or interact within the cell. Understanding the mapping between changes in a protein genotype and how those changes modify an organism phenotype is a largely unsolved problem in biology. Solving this problem will require integration of experimental methods with computational and mathematical approaches. In this thesis, we utilize both computational and mathematical methodologies. We start by using statistical methods to investigate potential physical features that can explain epistasis in proteins. Here we find a number of intuitive features that play a role, but we can only explain ~30% of the observed epistasis in both protein binding and folding. Next, we use molecular dynamics to inform statistical models and predict the spectral sensitivity of opsin proteins with high accuracy. Following that, we investigate a suite of fast methods for predicting protein-protein binding affinity, finding their performance to be largely context dependent. Lastly, we explore using two different molecular modeling techniques to calculate free energies and build a watch list of antibody escape mutations for the current COVID-19 pandemic.

关键词： structure-function relationships Proteins DNA sequence Genotype COVID-19

来源：评论

学校读者我要写书评

暂无评论

Biophysics and structure-function relationships of LRRC8-Formed Volume-Regulated Anion Channels

引用

BIOPHYSICAL JOURNAL 2019年第7期116卷 1185-1193页

作者： Koenig, Benjamin Stauber, Tobias Free Univ Berlin Inst Chem & Biochem Berlin Germany

Volume-regulated anion channels (VRACs) are key players in regulatory volume decrease of vertebrate cells by mediating the extrusion of chloride and organic osmolytes. They play additional roles in various physiological processes beyond their role in osmotic volume regulation. VRACs are formed by heteromers of LRRC8 proteins;LRRC8A (also called SWELL1) is an essential subunit that combines with any of its paralogs, LRRC8B-E, to form hexameric VRAC complexes. The subunit composition of VRACs determines electrophysiological characteristics of their anion transport such as single-channel conductance, outward rectification, and depolarization-dependent inactivation kinetics. In addition, differently composed VRACs conduct diverse substrates, such as LRRC8D enhancing VRAC permeability to organic substances like taurine or cisplatin. Here, after a recapitulation of the biophysical properties of VRAC-mediated ion and osmolyte transport, we summarize the insights gathered since the molecular identification of VRACs. We describe the recently solved structures of LRRC8 complexes and discuss them in terms of their structure-function relationships. These studies open up many potential avenues for future research.

关键词： anions Physiological Processes Taurine Biophysics structure-function relationships Osmolytes

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

Recent insights into structure-function relationships of antimicrobial peptides

引用

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

来源：评论

学校读者我要写书评

暂无评论

A global view of structure-function relationships in the tautomerase superfamily

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2018年第7期293卷 2342-2357页

作者： Davidson, Rebecca Baas, Bert-Jan Akiva, Eyal Holliday, Gemma L. Polacco, Benjamin J. LeVieux, Jake A. Pullara, Collin R. Zhang, Yan Jessie Whitman, Christian P. Babbitt, Patricia C. Univ Calif San Francisco Dept Bioengn & Therapeut Sci San Francisco CA 94143 USA Univ Calif San Francisco Dept Pharmaceut Chem San Francisco CA 94143 USA Univ Calif San Francisco Quantitat Biosci Inst San Francisco CA 94143 USA Univ Texas Austin Div Chem Biol & Med Chem Coll Pharm Austin TX 78712 USA Univ Texas Austin Dept Mol Biosci Austin TX 78712 USA Univ Texas Austin Inst Cellular & Mol Biol Austin TX 78712 USA

The tautomerase superfamily (TSF) consists of more than 11,000 nonredundant sequences present throughout the biosphere. Characterized members have attracted much attention because of the unusual and key catalytic role of an N-terminal proline. These few characterized members catalyze a diverse range of chemical reactions, but the full scale of their chemical capabilities and biological functions remains unknown. To gain new insight into TSF structure-function relationships, we performed a global analysis of similarities across the entire superfamily and computed a sequence similarity network to guide classification into distinct subgroups. Our results indicate that TSF members are found in all domains of life, with most being present in bacteria. The eukaryotic members of the cis-3-chloroacrylic acid dehalogenase subgroup are limited to fungal species, whereas the macrophage migration inhibitory factor subgroup has wide eukaryotic representation (including mammals). Unexpectedly, we found that 346 TSF sequences lack Pro-1, of which 85% are present in the malonate semialdehyde decarboxylase subgroup. The computed network also enabled the identification of similarity paths, namely sequences that link functionally diverse subgroups and exhibit transitional structural features that may help explain reaction divergence. A structure-guided comparison of these linker proteins identified conserved transitions between them, and kinetic analysis paralleled these observations. Phylogenetic reconstruction of the linker set was consistent with these findings. Our results also suggest that contemporary TSF members may have evolved from a short 4-oxalocrotonate tautomerase-like ancestor followed by gene dupli-cation and fusion. Our new linker-guided strategy can be used to enrich the discovery of sequence/structure/function transitions in other enzyme superfamilies.

关键词： enzyme structure evolution protein evolution protein sequence protein structure structure-function enzyme superfamily structure-function relationships tautomerase superfamily

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：