BIOTECHNOLOGY LETTERS
·
2017
·Vol. 39
·期 8
·1229-1235
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IF 1.73
Wang Qianqian,Xu Yixiang,Xu Jiaqi,Wang Xudong,Shen Chen,Zhang Yan,Liu Xiufeng,Yu Boyang,Zhang Jian
Objectives To characterize glycosyltransferases from Bacillus subtilis ATCC 6633 and investigate their substrate specificity towards plant polyphenols. Results Among the cloned and expressed six UDP-glycosyltransferases (BsGT1-6), BsGT-1 showed activity with a wide range of polyphenols: morin, quercetin, alizarin, rehin, curcumin and aloe emodin. The gene of BsGT-1 has an ORF of 1206 bp encoding 402 amino acids. The recombinant enzyme was purified to homogeneity by Ni–NTA affinity chromatograph, and its biochemical characteristics were identified by HPLC–UV/MS, 1 H-NMR and 13 C-NMR. BsGT-1 has an MW of approx. 46 kDa as indicated by SDS-PAGE; its activity was optimal at 40 °C and pH 8.5. The Km value of BsGT-1 towards morin was 110 μM. Conclusions BsGT-1 from B. subtilis was cloned. It had high catalytic capabilities towards polyphenols which would make it feasible for the structural modification of polyphenols.
研究领域:
生物化学
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分子生物学
·
酶学
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Lishan Xu,Yaojie Zhang,Lizhi Wang
Dragon fruit is a tropical fruit with good taste. It can bring health benefits to human body. As one of the major bioactive components in this fruit, the polysaccharides might contribute to the health benefits. However, the precise structure information remains unknown. A leading polysaccharide of dragon fruit pulp, DFPP, was purified and identified by NMR and GC–MS. →4-β- d -Glc p A-1→, →6-β- d -Gal p -1→ and →4-α- l -Rha p -1→ constituted the backbone and α- l -Ara f -1 → 5-α- l -Ara f -1→ formed the branch chain. The precise structure was putatively identified as below. The molecular weight was 2.2 × 10 3 kDa. The structure information of polysaccharides will be helpful to understand this fruit. Download : Download high-res image (88KB) Download : Download full-size image
研究领域:
食品科学
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植物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2024
·
IF 5.9
Yinhai Pan,Du Wei,Shuo Yao,Haijun Zhang,Quanzhi Tian
Coal gasification slag (CGS) is rich in Li and Ga. However, few studies have focused on the extraction of Li and Ga from CGS. In the present study, the leaching of Li and Ga from CGS calcined with the alkali reagents including NaOH, KOH, Na 2 O 2 , Na 2 CO 3 and K 2 CO 3 were studied through water leaching and solid characterizations including XRD, TG-DSC and NMR. The best leaching percentages of Li and Ga from NaOH-, KOH-, Na 2 O 2 -, Na 2 CO 3 - and K 2 CO 3 -roasted products were 40.81% and 47.89%, 41.19% and 31.60%, 28.04% and 52.40%, 28.21% and 48.58%, and 34.29% and 38.61%, respectively, showing Li and Ga are difficult to be leached out. It has been proven that the formation of insoluble crystal substances (such as NaAlSiO 4 ) in alkali fusion products inhibits the leaching of Li and Ga. In addition, Li and Ga can be released from the insoluble crystal substances due to Na 2 SiO 3 in alkali fusion products can promote the dissolution of insoluble crystal substances into SiO 4 and AlO 4 species, which can improve the leaching of Li and Ga. However, part of the released Li and Ga are stabled in the structure of amorphous substances generated by SiO 4 and AlO 4 species in the form of isomorphism, reducing the leaching of Li and Ga. Thus, this work would provide guidance for the leaching of Li and Ga from CGS.
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
Biomolecules
·
2020
·Vol. 10
·期 2
·231
·
IF 4.082
Rabia Durrani,Faez Iqbal Khan,Shahid Ali,Yonghua Wang,Bo Yang
Phospholipase B (EC 3.1.1.5) are a distinctive group of enzymes that catalyzes the hydrolysis of fatty acids esterified at thesn-1andsn-2positions forming free fatty acids and lysophospholipids. The structural information and catalytic mechanism of phospholipase B are still not clear. Herein, we reported a putative phospholipase B (TmPLB1) fromTalaromyces marneffeiGD-0079 synthesized by genome mining library. The gene (TmPlb1) was expressed and the TmPLB1 was purified usingE. colishuffle T7 expression system. The putative TmPLB1 was purified by affinity chromatography with a yield of 13.5%. The TmPLB1 showed optimum activity at 35 °C and pH 7.0. The TmPLB1 showed enzymatic activity using Lecithin (soybean > 98% pure), and the hydrolysis of TmPLB1 by31P NMR showed phosphatidylcholine (PC) as a major phospholipid along with lyso-phospholipids (1-LPC and 2-LPC) and some minor phospholipids. The molecular modeling studies indicate that its active site pocket contains Ser125, Asp183 and His215 as the catalytic triad. The structure dynamics and simulations results explained the conformational changes associated with different environmental conditions. This is the first report on biochemical characterization and structure dynamics of TmPLB1 enzyme. The present study could be helpful to utilize TmPLB1 in food industry for the determination of food components containing phosphorus. Additionally, such enzyme could also be useful in Industry for the modifications of phospholipids.Keywords:free fatty acids (FFAs);NMR (nuclear magnetic resonance);phospholipase B;Talaromyces marneffei;affinity chromatography
研究领域:
生物化学
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分子生物学
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食品科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
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2017
·
IF 1.071
Xing-Peng Hu,Hua Zhou,Yang-Min Du,Shi-Yi Ou,Rian Yan,Yong Wang
The isolation and structure elucidation of two new flavonoids, chrysanthumones A and B from the extracts of Allium chrysanthum were reported. Seven known phenolic constituents were also isolated. Their structures were determined on the basis of NMR and MS techniques.
研究领域:
植物化学
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天然产物研究
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药物化学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Xubao Jiang,Xiaoli Zhu,Alexandre A. Arnold,Xiang Zheng Kong,Jerome P. Claverie
Owing to the presence of abundant interchain interactions such as hydrogen bonds, polyureas (PU) are only swellable or soluble in a limited number of highly protonic solvents, and the viscosity of the solutions obtained is very high, making their chemical structure characterization hard or even impossible by standard NMR. Accurate structure analysis is also hard by solid-state NMR due to low spectral resolution. The presence of a side reaction in their synthesis generating biuret cross-links is often invoked to explain their insolubility. Here we demonstrate that High Resolution Magic Angle Spinning (HR-MAS) NMR is an efficient tool for the chemical structure analysis even for cross-linked PU. With 1H, 13C, and 1H–15N HSQC combined, a variety of linear and cross-linked PU is analyzed by HR-MAS NMR, and conclusive information on their chemical structure is obtained, which reveals for the first time that the biuret group is absent in all PU.
研究领域:
材料科学
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分析化学
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产品关联
DOI
高影响因子
Frontiers in Endocrinology
·
2022
·
IF 6.055
Yang Yanwu,Glidden Michael D.,Dhayalan Balamurugan,Zaykov Alexander N.,Chen Yen-Shan,Wickramasinghe Nalinda P.,DiMarchi Richard D.,Weiss Michael A.
Toxic misfolding of proinsulin variants in β-cells defines a monogenic diabetes syndrome, designated mutant INS-gene induced diabetes of the young (MIDY). In our first study (previous article in this issue), we described a one-disulfide peptide model of a proinsulin folding intermediate and its use to study such variants. The mutations (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser) probe residues conserved among vertebrate insulins. In this companion study, we describe 1H and 1H-13C NMR studies of the peptides; key NMR resonance assignments were verified by synthetic 13C-labeling. Parent spectra retain nativelike features in the neighborhood of the single disulfide bridge (cystine B19-A20), including secondary NMR chemical shifts and nonlocal nuclear Overhauser effects. This partial fold engages wild-type side chains LeuB15, LeuA16 and PheB24 at the nexus of nativelike α-helices α1 and α3 (as defined in native proinsulin) and flanking β-strand (residues B24-B26). The variant peptides exhibit successive structural perturbations in order: parent (most organized) > SerB24 >> ProA16 > ProB15 (least organized). The same order pertains to (a) overall α-helix content as probed by circular dichroism, (b) synthetic yields of corresponding three-disulfide insulin analogs, and (c) ER stress induced in cell culture by corresponding mutant proinsulins. These findings suggest that this and related peptide models will provide a general platform for classification of MIDY mutations based on molecular mechanisms by which nascent disulfide pairing is impaired. We propose that the syndrome’s variable phenotypic spectrum—onsets ranging from the neonatal period to later in childhood or adolescence—reflects structural features of respective folding intermediates.
研究领域:
生物化学
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分子生物学
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医学遗传学
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DOI
高影响因子
ENERGY & FUELS
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2018
·
IF 3.024
Yuning Meng,Xindian Wang,Feng Zhang,Zhibing Zhang,Youting Wu
Dual amino functionalized ionic liquid tetramethylammonium lysinate ([N1111][Lys]) was synthesized and mixed with 2-[2-(dimethylamino)ethoxy]ethanol (DMEE) to obtain a series of nonwater absorbents for CO2 capture. The density and viscosity of the IL hybrids were measured. Using dual-vessel absorption system, CO2 absorption capacity and rate were investigated over a wide range of IL mass fractions (5–100%) to evaluate the influence of DMEE content, and 20% was chosen for further studies including influences of temperature and regeneration performances. Mass transfer coefficients with constant absorption area were calculated from apparent absorption rate constant. Fourier transform infrared (FT-IR) and 13C NMR spectra were applied to indicate the absorption process and mechanism. This new nonwater mixed system was proved to have high absorption capacities and prominent regeneration efficiency under mild conditions (80 °C).
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
PLoS One
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2013
·Vol. 8
·期 6
·e64722
·
IF 3.73
Fei Wang,Naimin Shao,Yiyun Cheng
In this study, the host-guest behavior of poly(amidoamine) (PAMAM) dendrimers bearing amine, hydroxyl, or carboxylate surface functionalities were investigated by paramagnetic NMR studies. 2,2,6,6-Tetramethylpiperidinyloxy (TEMPO) derivatives were used as paramagnetic guest molecules. The results showed that TEMPO-COOH significantly broaden the 1 H NMR peaks of amine- and hydroxyl-terminated PAMAM dendrimers. In comparison, no paramagnetic relaxation enhancement (PRE) was observed between TEMPO-NH 2 , TEMPO-OH and the three types of PAMAM dendrimers. The PRE phenomenon observed is correlated with the encapsulation of TEMPO-COOH within dendrimer pockets. Protonation of the tertiary amine groups within PAMAM dendrimers plays an important role during this process. Interestingly, the absence of TEMPO-COOH encapsulation within carboxylate-terminated PAMAM dendrimer is observed due to the repulsion of TEMPO-COO- anion and anionic dendrimer surface. The combination of paramagnetic probes and 1 H NMR linewidth analysis can be used as a powerful tool in the analysis of dendrimer-based host-guest systems.
研究领域:
化学
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材料科学
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生物物理学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2018
·Vol. 36
·期 10
·1150-1156
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IF 2.016
Qiu Wei-Guang,Zhang Fei-Long,Jiang Xu-Bao,Kong Xiang-Zheng
Polyureas (PU) are well known as a class of high impact engineering materials, and widely used also in emerging advanced applications. As a general observation, most of them are only soluble in a very limited number of highly protonic solvents, which makes their chemical structure analysis a great challenge. Besides the presence of abundant hydrogen bonding, the poor solubility of PU in common organic solvents is often ascribed to the formation of biuret crosslinking in their molecular chains. To clarify the presence of biuret groups in PU has been of great interest. To this end, two samples, based on hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI) respectively, were synthesized by precipitation polymerization of each of these diisocyanates in water-acetone at 30 °C. Their chemical structures were analyzed by high resolution magic angle spinning (HR-MAS) NMR, and through comparison of their NMR spectra with those of specially prepared biuret-containing polyurea oligomers, it was concluded that biuret group was absent in all the PU prepared at 30 °C. In addition, this NMR analysis was also applied to a PU obtained by copolymerization of TDI with ethylene diamine (EDA) and water at 65 °C in EDA aqueous solution. It was confirmed that biuret unit was also absent in this PU and that EDA was more active than water towards TDI. The presence of EDA was crucial to the formation of uniform PU microspheres. This study provides therefore a reliable method for the analysis of PU chemical structure.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 19
·4929-4935
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IF 3.286
Cheng Kai,Wu Qiong,Jiang Ling,Liu Maili,Li Conggang
Ionic liquids have been extensively used as environmentally friendly solvents for enzymatic reactions and other biological systems. Understanding the mechanism of how ionic liquids affect protein stability is crucial for the biological reaction processes and protein storage using ionic liquids as solvents. Although effects of ionic liquids on protein stability have been studied, equilibrium thermodynamics of protein stability in ionic liquids has not been quantitatively measured. Herein, we utilized 19 F NMR to measure the equilibrium thermodynamics of protein stability in ionic liquid [C 4 -mim]Br. Our results show that proteins are significantly destabilized in [C 4 -mim]Br ionic liquids. Our results suggest that 19 F NMR provides a simple and effective way to study the thermodynamics of protein stability in ionic liquids. 19 F NMR will be applicable to facilitate the protein–protein interaction study in ionic liquids.
Graphical abstract
研究领域:
生物化学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Current Analytical Chemistry
·
2024
·Vol. 20
·期 9
·686-696
·
IF 1.7
Xin Ye,Zhenyu Xu,Da Xu,Jibao Cai,Shuiping Dai,Yuting Luo,Lei Guo,Ying Wang,Jiakun Su,Jun Yang
Background: As one of the most important economic crops, tobacco products have a long history and dominate the development of the world economy. Pectin, as a complex colloidal substance widely present in plant cell walls, its content is an important factor affecting the safety of tobacco smoking. Objective: This study aimed to analyze the content and structure of pectin in tobacco samples. Methods: In this study, tobacco pectin was extracted by ultrasonic-assisted ionic liquid extraction, and the 13C MultiCP/MAS NMR spectral analysis of pectin was conducted. Results: The type of extractant, duration of ultrasonication, extraction temperature, and solid-liquid ratio were optimized. Under the conditions of using 1-Butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) as the extractant, the solid-liquid ratio of 1:20 g/mL, and the ultrasonic power of 600 w for 30 min at 30°C, the yield of 23.7% of tobacco stem pectin and the purity of 54.2% could be obtained. The optimized MultiCP sequence parameters, with 10 CP cycles of 1.0 ms and the repolarization time of 50 ms could obtain high-resolution spectra within a time of 1.0 h. The C-6 peaks of the pectin in spectra were fitted using the spectral deconvolution technique and calculated the methylesterification (DM) of the tobacco pectin, which was generally less than 50% and belonged to the low methyl esterification pectin. The pectin content of the tobacco sample was calculated using the standard curve method with the addition of dimethyl sulfone (DMS) as an internal reference. The results of this method were consistent with the colorimetric method. Conclusion: The 13C MultiCP/MAS NMR method has the advantages of being green, fast, and accurate and provides a new technical tool for quantitative and qualitative studies of cell wall substances in tobacco samples.
研究领域:
植物化学
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分析化学
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烟草科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）