Inhibition of α-glucosidase by 2-thiobarbituric acid: Molecular dynamics simulation integrating parabolic noncompetitive inhibition kinetics

Qin, Xiu-Yuan,Lee, Jinhyuk,Zheng, Li,Yang, Jun-Mo,Gong, Yan,Park, Yong-Doo Elsevier 2018 Process biochemistry Vol.65 No.-

<P><B>Abstract</B></P> <P>The phenomenon of α-glucosidase inhibition has attracted the attention of researchers due to its association with type 2 diabetes treatment in humans. In this study, we found that 2-thiobarbituric acid (TBA) induces complex inhibition of α-glucosidase using kinetics tests and molecular dynamics (MD) simulations. Computational MD and docking simulations demonstrate that TBA interacts with three residues on active sites of α-glucosidase such as Met69, Arg212, and His348. These biochemical tests indicate that TBA reversibly inhibits α-glucosidase in a parabolic noncompetitive manner (<I>IC</I> <SUB>50</SUB> =17.13±1.14mM; <I>K</I> <SUB>i</SUB> =13.25±0.56mM) and that this inhibition is accompanied by a biphasic kinetic process. The tertiary conformational changes were not synchronized with TBA inhibition but we observed hydrophobic disruption after inactivation at higher concentrations of TBA. Our results provide insight into the functional roles of residues located at the active sites of α-glucosidase, and we suggest that compounds similar to TBA (heterocyclic compounds) targeting the key residues of active sites are potential α-glucosidase inhibitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 2-Thiobarbituric acid (TBA) induces complex inhibition of α-glucosidase. </LI> <LI> Computational MD simulations demonstrate that TBA interacts with Met69, Arg212, and His348. </LI> <LI> TBA reversibly inhibits α-glucosidase in a parabolic noncompetitive manner (<I>IC</I> <SUB>50</SUB> =17.13±1.14mM; <I>K</I> <SUB>i</SUB> =13.25±0.56mM). </LI> <LI> The high dose of TBA induces hydrophobic disruption after inactivation. </LI> <LI> Heterocyclic compounds targeting the key residues of active sites are potential α-glucosidase inhibitors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Novel 3D Polypseudo-rotaxane Metal-organic Framework Based on a Flexible Bis-pyridyl-bis-amide Ligand

Xiu-Li Wang,Na Han, Hong-Yan Lin,Chuang Xu,Jian Luan,Guo-Cheng Liu 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

A novel 3D compound {[Cu(L)(H2O)4][Cu2(SIP)2(L)2]}·2H2O (1) (L = N,N-bis(4-pyridinecarboxamide)-1,4- butane, SIP = 5-sulfoisophthalate) is hydrothermally synthesized. X-ray diffraction analysis reveals that compound 1 is composed of 2D anionic [Cu2(SIP)2(L)2]n 2n− double-layers and discrete 1D cationic [CuL(H2O)4]n 2n+ polymeric chains, which represents a rare 3D polypseudo-rotaxane MOF from intercalation of 1D and 2D framework. In addition, the luminescent property and electrochemical behavior of compound 1 have been investigated.

Differentiation and identification of ginsenoside structural isomers by two-dimensional mass spectrometry combined with statistical analysis

Xiu, Yang,Ma, Li,Zhao, Huanxi,Sun, Xiuli,Li, Xue,Liu, Shuying The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.3

Background: In the current phytochemical research on ginseng, the differentiation and structural identification of ginsenosides isomers remain challenging. In this paper, a two-dimensional mass spectrometry (2D-MS) method was developed and combined with statistical analysis for the direct differentiation, identification, and relative quantification of protopanaxadiol (PPD)-type ginsenoside isomers. Methods: Collision-induced dissociation was performed at successive collision energy values to produce distinct profiles of the intensity fraction (IF) and ratio of intensity (RI) of the fragment ions. To amplify the differences in tandem mass spectra between isomers, IF and RI were plotted against collision energy. The resulting data distributions were then used to obtain the parameters of the fitted curves, which were used to evaluate the statistical significance of the differences between these distributions via the unpaired t test. Results: A triplet and two pairs of PPD-type ginsenoside isomers were differentiated and identified by their distinct IF and RI distributions. In addition, the fragmentation preference of PPD-type ginsenosides was determined on the basis of the activation energy. The developed 2D-MS method was also extended to quantitatively determine the molar composition of ginsenoside isomers in mixtures of biotransformation products. Conclusion: In comparison with conventional mass spectrometry methods, 2D-MS provides more direct insights into the subtle structural differences between isomers and can be used as an alternative approach for the differentiation of isomeric ginsenosides and natural products.

H∞ Control for Networked Systems with Random Delays and Packet Dro-pouts

Xiu-Ying Li,Shu-Li Sun 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.5

This paper is concerned with the control problem for a class of systems with random delays and packet dropouts which unavoidably occur during the data transmission in the network. A novel model is developed to describe the random one-step delays and multiple packet dropouts from sensors to controllers and from controllers to actuators by applying four Bernoulli distributed stochastic variables. An observer-based feedback controller is designed via a linear matrix inequality (LMI) approach which guarantees the closed-loop networked system to be exponentially stable in the sense of mean square and also achieves the prescribed H∞ disturbance-rejection-attenuation level. A simulation example shows the effectiveness of the proposed algorithm.

H∞ Control with Multiple Packets Compensation Scheme for T-S Fuzzy Systems Subject to Cyber Attacks

Xiu-Ying Li,Bao-Jun Wang,Lei Zhang,Xiang-Hua Ma 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.1

This paper is concerned with the H∞ controller design problem for a class of network-based nonlinearsystems (NCSs) represented by the Takagi-Sugeno (T-S) fuzzy model. A multiple packets compensation schemeis developed which uses all the data stored in a finite memory buffer to compensate the negative effects of packetdropouts. This model contains the medium access constraint problem as a special case. The time-multiplexingmechanism may be used for such a case so that there are multiple packets arrive at the receiver side. By taking thestochastic cyber attacks into account, the desired controller in terms of linear matrix inequalities (LMIs) is designedby using fuzzy-rule-dependent Lyapunov method. The sufficient condition is obtained which makes the closed-loopsystem be asymptotically mean-square stable and achieve the prescribed H∞ disturbance-rejection-attenuation level. Finally, a mass-spring-damping system is given to show the effectiveness of the algorithm.

H<SUB>∞</SUB> Filtering for T-S Fuzzy Systems with Random Multiple Delays and Packet Dropouts Subject to Sensor Saturations

Xiu-Ying Li,Yue Xu,Shu-Li Sun 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

This paper focuses on the problem of H∞ filter design for a class of Takagi-Sugeno (T-S) fuzzy network-based systems where the measurement output is subject to the sensor saturations described by sectornonlinearity. The investigated issues caused typically in the wireless communication include the multiple and bounded transmission delays as well as the consecutive packet dropouts whose random nature is governed by Bernoulli distributed random variables. A full-order H∞ filter is designed such that, in the simultaneous presence of the multiple delays and packet dropouts as well as sensor saturations, the filtering error system is asymptotically mean-square stable and satisfies the prescribed H∞ performance index. A sufficient condition for the existence of such a filter is established in terms of solutions to a set of linear matrix inequalities (LMIs). Finally, a numerical example is presented to illustrate the effectiveness and the feasibility of the proposed filtering design method.

Microporous Zn(II)-MOF for Selective C₂H₂ Adsorption and Anti-cancer Activity on Liver Cancer Combined with LL-37

Xiu-Qin Wei,Shuan-Yuan Yang,Xiao-Xia Li,Mei-Li Xu 한국고분자학회 2021 폴리머 Vol.45 No.6

By employment of a semi-rigid carboxylic acid ligand 5,5" -((5-carboxy-1,3-phenylene)bis(azanediyl))diiso- phthalic acid (H5L) with the -NH- joints, a new porous metal-organic framework (MOF) based on Zn(II) ions as nodes has been generated in success, and its chemical formula is {[Zn₃(μ₃-OH)(L)(H₂O₃)]·3DEF·H₂O}n (1). Owing to its Lewis basic -NH- joints and the π-electron-rich benzene rings on the skeleton, the activated complex 1 offers a favourable pore environment for binding C₂H₂ in preference to CO₂ and CH₄. The inhibitory activity of compound on the liver cancer viability was determined through exploiting the Cell Counting Kit-8 kit. Afterwards, the invasion and migration ability for the liver cancer cells was measured after indicated treatment. Multiple binding interactions are identified by performing the molecular docking simulation, indicating the stabilization effect of the Zn complex towards the target protein, and therefore, the proposed drug molecule exhibits good anticancer activities.

Properties of an AlGaN/AlN Distributed-Bragg-reflector Structure

Li-Li Zhang,Zhan-Hui Liu,Xiao-Gu Huang,Qing-Fang Li,Rong Zhang,Zi-Li Xie,Xiang-Qian Xiu 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.7

An AlGaN/AlN distributed-Bragg-reflector (DBR) structure with a high Al content was grown byusing plasma-assisted molecular beam epitaxy (PA-MBE). The properties of the sample were characterizedby using the transmission electron microscopy, high-resolution X-ray diffraction, atomicforce microscopy, and reflectivity spectrum measurements. The reciprocal space mapping analysisindicated that the strain in the AlGaN layers was partially relaxed. The morphology of the DBRexhibited a surface covered by grains (average size of about 130 nm), and the surface roughness wasabout 2 nm. The spectral measurements showed that the DBR structure presented a peak reflectivityof 68.8% at the center wavelength of 247 nm, which indicated that this DBR structure couldwork in the deep solar-blind UV region with acceptable reflectivity. However, the optical propertiesof the DBR structure were deteriorated by the fluctuation of the Al composition, non-uniformity ofthe layer thickness, the blurry, rough interface in the DBR structure, and so on.

Correlation between fat accumulation and fecal microbiota in crossbred pigs

Li Xin,Li Mengyu,Han Jinyi,Liu Chuang,Han Xuelei,Wang Kejun,Qiao Ruimin,Li Xiu-Ling,Li Xin-Jian 한국미생물학회 2022 The journal of microbiology Vol.60 No.11

Backfat thickness (BF) is an important indicator of fat deposition capacity and lean meat rate in pigs and is very important in porcine genetics and breeding. Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on fat deposition of livestock animals. To investigate the relationship between the pig gut microbiome and BF, 20 low-BF (L-BF) and 20 high-BF (H-BF) pigs were selected as two groups from Yunong Black pigs in the present study. Fecal samples from pigs were analyzed for microbial diversity, composition, and predicted functionality using 16S rRNA gene sequencing. The results showed that there were significant differences in microbial β diversity between the two groups. LEfSe analysis revealed a number of bacterial features being differentially enriched in either L-BF or H-BF pigs. Spearman correlation analysis identified the abundance of Oscillospira, Peptococcus, and Bulleidia were significantly positive correlations with BF (P < 0.05), while Sutterella and Bifidobacterium were significantly negatively correlated with BF (P < 0.05). Importantly, the bacteria significantly positively correlated with BF mainly belong to Clostridium, which can ferment host-indigestible plant polysaccharides into shortchain fatty acid (SCFA) and promote fat synthesis and deposition. Predictive functional analysis indicated that the pathway abundance of cell motility and glycan biosynthesis were significantly widespread in the microbiota of the H-BF group. The results of this study will be useful for the development of microbial biomarkers for predicting and improving porcine BF, as well as for the investigation of targets for dietary strategies.

Genome of Betaproteobacterium Caenimonas sp. Strain SL110 Contains a Coenzyme F420 Biosynthesis Gene Cluster

( Xiu Ling Li ),( Fu Ying Feng ),( Yong Hui Zeng ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.11

To probe the genomic properties of microbes thriving in desert lakes, we sequenced the full genome of a betaproteobacterial strain (SL110) belonging to the understudied genus Caenimonas of the family Comamonadaceae. This strain was isolated from a freshwater lake in the western Gobi Desert, Northern China. Its genome contains genes encoding carbon monoxide dehydrogenase, nitrate reductase, nitrite reductase, nitric oxide reductase, and sulfur oxidation enzymes, highlighting the potentially important contribution of this group of bacteria to the cycling of inorganic elements in nature. Unexpectedly, a coenzyme F420 biosynthesis gene cluster was identified. A further search for F420 biosynthesis gene homologs in genomic databases suggests the possible widespread presence of F420 biosynthesis gene clusters in proteobacterial genomes.