The Improvement of Stability, Activity, and Substrate Promiscuity of Glycerol Dehydrogenase Substituted by Divalent Metal Ions

Shizhen Wang,Jing Wang,Xiaofen Zhou,Yingxia Guo,Baishan Fang 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.4

The substitution of the catalytic zinc ion of glycerol dehydrogenase (GDH) from Klebsiella pneumonia sp. by divalent metal ions, Mn2+ and Mg2+, enabled improvements of activity, substrate promiscuity and stability. The activity of Mn-GDH and Mg-GDH improved several folds in comparison to the native GDH. The activity of substituted GDH towards non-natural substrates, 4-chloroacetoacetate,3-chloroacetylpyridine, p-chloroacetophenone, and acetophenone was 30 folds higher than native GDH. Manganese substitution increased the half-life of GDH by 6 folds at 60and 70oC. The two-fraction first order inactivation models fitted the nonlinear thermal inactivation curves well. Combined with the kinetic and thermodynamic analysis,further mechanistic insights to the metal ion roles in thermostability enhancements were studied. The thermodynamic parameters of inactivation, enthalpy, entropy and the Gibbs free energy indicated that Mn-GDH was stabilized entropically and elucidated the mechanisms of enzyme inactivation.

Genome-wide identification of microRNAs and phased siRNAs in soybean roots under long-term salt stress

Qian Wang,Yingxia Yang,Guoqing Lu,Xianjun Sun,Youren Feng,Shuangyong Yan,Huiyuan Zhang,Qiyan Jiang,Hui Zhang,Zheng Hu,Rui Chen 한국유전학회 2020 Genes & Genomics Vol.42 No.11

Background Salinity stress, as the key limiting factor for agricultural productivity, can activate a series of molecular responses and alter gene expression in plants. Endogenous regulatory small RNAs, such as microRNAs (miRNAs) and phased siRNAs (phasiRNAs), play crucial roles during stress adaptation and prevent the injury from environmental circumstances. Objective To identify long-term salt stress responsive miRNAs and phasiRNAs as well as their associated genes and pathways in soybean roots. Methods Small RNA and degradome sequencing strategies were applied to genome widely investigate miRNAs and phasiRNAs in soybean roots under control and long-term salt stress conditions. Results In this study, stringent bioinformatic analysis led to the identifcation of 253 conserved and 38 novel miRNA candidates. Results of expression profling, target and endogenous target mimics predictions provided valuable clues to their functional roles. Furthermore, 156 genes were identifed to be capable of generating 21 nt and 24 nt phasiRNAs, in which 37 candidates were confrmed by degradome data for miRNA-directed cleavage. Approximately 90% of these phasiRNA loci were protein coding genes. And GO enrichment analysis pointed to “signal transduction” and “ADP binding” entries and refected the functional roles of identifed phasiRNA genes. Conclusion Taken together, our fndings extended the knowledge of salt responsive miRNAs and phasiRNAs in soybean roots, and provided valuable information for a better understanding of the regulatory events caused by small RNAs underlying plant adaptations to long-term salt stress.

Seasonal Variation and Sources of Heavy Metals in Urban Street Dusts and River Sediments of Dongluo River Watershed in Ji’nan City, China

Tingting Duan,Shanjun Liu,Dongying Wang,Jiashen Feng,Ningning Song,Yanxin Yu,Yingxia Li 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.5

Due to intense human activities, urban street dusts and river sediments are usually polluted by heavy metals. This study investigated the seasonal variations (summer and winter) of pollution level, spatial distribution and potential sources of heavy metals in street dusts (SD) and river sediments (RS) of Dongluo River watershed, Ji’nan, China. Results showed cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) contents were 3.5 (8.6), 3.0 (1.4), 4.9 (2.6), 4.1 (1.1) and 3.9 (4.0)-fold of their geochemical soil background values (BGV) of Shandong Province, China in summer (winter). Mercury (Hg) and arsenic (As) contents were lower than their background values in both summer and winter. The differences of Cd, Cr, Cu, Pb, Zn, Mn and As contents in river sediments between winter and summer were not statistically significant. The correlation coefficients between metal contents and the distance between sampling sites and the east-west boundary of study area were higher in summer than those in winter. Based on principal component analysis (PCA) and multivariate linear regression (MLR), coal combustion and traffic-related sources were the main sources in winter, and agricultural activities and traffic-related sources were the main sources in summer.

Modification of Wool via Grafting β-cyclodextrin Oxidized by Sodium Periodate

Chaoqian Lou,Yuanyuan Yin,Xiuzhi Tian,Haibo Deng,Yingxia Wang,Xue Jiang 한국섬유공학회 2020 Fibers and polymers Vol.21 No.8

The modification of wool fabrics is significant in preparation of functional textiles. Sodium periodate oxidized β-cyclodextrin was grafted onto wool fabric through Schiff base reaction to obtain fabric with controlled release property. β-cyclodextrin was oxidized to aldehyde-β-cyclodextrin, and the results show that the inclusion constant and aldehyde contentof aldehyde-β-cyclodextrin are varied with the reaction parameters such as molar ratio of reaction agents and the reactiontemperature. The degree of oxidation was confirmed by ion chromatography. The drug loading test shows that the oxidizedcyclodextrin still had inclusion ability towards phenolphthalein, while the inclusion constant was only 50 % of the original β-CD. The ATR-FTIR spectra proved the occurrence of grafting reaction between the aldehyde groups of aldehyde-β-cyclodextrin and the amino groups on wool fiber. The aldehyde-β-cyclodextrin grafted wool fabric show great washingdurability even after 5 washing cycles. Compared with the aldehyde-β-cyclodextrin power, the inclusion ability of aldehyde-β-cyclodextrin fixed on the wool fiber decreased by 60 %.

Hydrophilic Finishing of PET Fabrics by Applying Chitosan and the Periodate Oxidized β-cyclodextrin for Wash Resistance Improvement

Chaoqian Lou,Yuanyuan Yin,Xiuzhi Tian,Haibo Deng,Yingxia Wang,Xue Jiang 한국섬유공학회 2020 Fibers and polymers Vol.21 No.1

β-cyclodextrin (β-CD) was oxidized by sodium periodate to yield a mixture of dialdehyde oligosaccharides. Theperiodate-oxidized β-CD (O-β-CD) together with chitosan (CTS) was firstly used to finish poly(ethylene terephthalate)(PET) fabrics by immersion-padding method, in which O-β-CD acted as a hydrophilic finishing agent plus a cross-linker. Theprocesses including the periodate oxidization of β-CD and the CTS/O-β-CD hydrophilic finishing of PET fabrics were ecofriendly. The results from the hydroxylamine hydrochloride titration showed that the aldehyde content in O-β-CD was3.0 mmol/g. With increasing the CTS/O-β-CD mass ratio, the finished fabric had better hydrophilic properties. When theCTS/O-β-CD mass ratio was 1:1, the moisture regain and water drops wetting time of the finished fabric reached 1.85 % and5.06 s, respectively. They became 1.50 % and 5.70 s, respectively after 25 times of laundering cycle. The occurrence of crosslinkingbetween O-β-CD and CTS was confirmed by the gel test and FT-IR characterization. The cross-linking networkdeposited on the fiber surface brought on excellent wash resistance of the CTS/O-β-CD finished PET fabrics.

Host Langerin (CD207) is a receptor for <i>Yersinia pestis</i> phagocytosis and promotes dissemination

Yang, Kun,Park, Chae G,Cheong, Cheolho,Bulgheresi, Silvia,Zhang, Shusheng,Zhang, Pei,He, Yingxia,Jiang, Lingyu,Huang, Hongping,Ding, Honghui,Wu, Yiping,Wang, Shaogang,Zhang, Lin,Li, Anyi,Xia, Lianxu,B Nature Publishing Group 2015 Immunology and Cell Biology Vol. No.

<P><I>Yersinia pestis</I> is a Gram‐negative bacterium that causes plague. After <I>Y. pestis</I> overcomes the skin barrier, it encounters antigen‐presenting cells (APCs), such as Langerhans and dendritic cells. They transport the bacteria from the skin to the lymph nodes. However, the molecular mechanisms involved in bacterial transmission are unclear. Langerhans cells (LCs) express Langerin (CD207), a calcium‐dependent (C‐type) lectin. Furthermore, <I>Y. pestis</I> possesses exposed core oligosaccharides. In this study, we show that <I>Y. pestis</I> invades LCs and Langerin‐expressing transfectants. However, when the bacterial core oligosaccharides are shielded or truncated, <I>Y. pestis</I> propensity to invade Langerhans and Langerin‐expressing cells decreases. Moreover, the interaction of <I>Y. pestis</I> with Langerin‐expressing transfectants is inhibited by purified Langerin, a DC‐SIGN (DC‐specific intercellular adhesion molecule 3 grabbing nonintegrin)‐like molecule, an anti‐CD207 antibody, purified core oligosaccharides and several oligosaccharides. Furthermore, covering core oligosaccharides reduces the mortality associated with murine infection by adversely affecting the transmission of <I>Y. pestis</I> to lymph nodes. These results demonstrate that direct interaction of core oligosaccharides with Langerin facilitates the invasion of LCs by <I>Y. pestis</I>. Therefore, Langerin‐mediated binding of <I>Y. pestis</I> to APCs may promote its dissemination and infection.</P>

Integration Method of Multi-grid Evacuation Model in 3D Virtual Indoor Environment

Ying Xia,Ke Wang 보안공학연구지원센터 2013 International Journal of Multimedia and Ubiquitous Vol.8 No.3