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91.
Wei Wang Huange Xi Qirui Bi Ying Hu Yang Zhang Mengxiang Ni 《Microbiological research》2013,168(6):360-366
d-Aminoacylase catalyzes the conversion of N-acyl-d-amino acids to d-amino acids and fatty acids. The aim of this study was to identify the d-aminoacylase gene from Achromobacter xylosoxidans subsp. denitrificans ATCC 15173 and investigate the biochemical characterization of the enzyme. A previously uncharacterized d-aminoacylase gene (ADdan) from this organism was cloned and sequenced. The open reading frame (ORF) of ADdan was 1467 bp in size encoding a 488-amino acid polypeptide. ADdan, with a high amino acid similarity to N-acyl-d-aspartate amidohydrolase from Alcaligenes A6, showed relatively low sequence similarities to other characterized d-aminoacylases. The recombinant ADdan protein was expressed in Escherichia coli BL21 (DE3) using pET-28a with a T7 promoter. The enzyme was purified in a single chromatographic step using nickel affinity gel column. The molecular mass of the expressed protein, calculated by SDS–PAGE, was about 52 kDa. The purified ADdan showed optimal activity at pH 8.0 and 50 °C, and was stable at pH 6.0–8.0 and up to 45 °C. Its activity was inhibited by Cu2+, Fe2+, Ca2+, Mn2+, Ni2+, Zn2+ and Hg2+, whereas Mg2+ had no significant influence on this recombinant d-aminoacylase. This is the first report on the characterization of d-aminoacylase with activity towards both N-acyl derivatives of neutral d-amino acids and N-acyl-d-aspartate. The characteristics of ADdan could prove to be of interest in industrial production of d-amino acids. 相似文献
92.
Genome-wide identification and expression profiling of ankyrin-repeat gene family in maize 总被引:1,自引:0,他引:1
Haiyang Jiang Qingqing Wu Jing Jin Lei Sheng Hanwei Yan Beijiu Cheng Suwen Zhu 《Development genes and evolution》2013,223(5):303-318
Members of the ankyrin repeats (ANK) gene family encode ANK domain that are common in diverse organisms and play important roles in cell growth and development, such as cell-cell signal transduction and cell cycle regulation. Recently, genome-wide identification and evolutionary analyses of the ANK gene family have been carried out in Arabidopsis and rice. However, little is known regarding the ANK genes in the entire maize genome. In this study, we described the identification and structural characterization of 71 ANK genes in maize (ZmANK). Then, comprehensive bioinformatics analyses of ZmANK genes family were performed including phylogenetic, domain and motif analysis, chromosomal localization, intron/exon structural patterns, gene duplications and expression profiling. Domain composition analyses showed that ZmANK genes formed ten subfamilies. Five tandem duplications and 14 segmental duplications were identified in ZmANK genes. Furthermore, we took comparative analysis of the total ANK gene family in Arabidopsis, rice and maize, ZmANKs were more closely paired with OsANKs than with AtANKs. At last, expression profile analyses were performed. Forty-one members of ZmANK genes held EST sequences records. Semi-quantitative expression and microarray data analysis of these 41 ZmANK genes demonstrated that ZmANK genes exhibit a various expression pattern, suggesting that functional diversification of ZmANK genes family. The results will present significant insights to explore ANK genes expression and function in future studies in maize. 相似文献
93.
Özlem Biçen Ünlüer Arzu Ersöz Ridvan Say Özlem Tomsuk Hülya Sivas 《Biotechnology progress》2013,29(2):472-479
This study describes preparation and use of novel labeled and antibodious polymeric nanolabels (anti‐alpha fetoprotein cross‐linked nanolabels) as an immunogenic and semisynthetic nanolabel with potential prognostic and therapeutic roles for hepatoma cancer. Specificity, uptake, and binding efficiencies of the nanolabel have been examined in a human hepatosarcoma cell line HepG2, a human colorectal cell line DLD‐1, and a mouse myoblast cell line C2. Labeling of the cells has been performed by treating live and fixed cells with varying concentrations of the nanolabels and then, the cells have been examined under a fluorescence microscope. In addition, all cell lines have also been labeled using FITC‐conjugated nanotrastuzumab to compare the results obtained with those of the binding of the FITC‐nanoanti‐alpha fetoprotein nanolabels. Results show that FITC‐conjugated anti‐alpha fetoprotein cross‐linked nanolabels have been taken up by both live and fixed cells and have efficiently and specifically labeled HepG2 cells at a quite low concentration. Taken all together, the results indicate that the novel targeted nanoimaging tools and technique demonstrated their ability to detect the distribution of the nanolabels as probes in hepatoma cells. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 472–479, 2013 相似文献
94.
Na-Na Du Zong-Gen Peng Chong-Wen Bi Sheng Tang Ying-Hong Li Jian-Rui Li Yan-Ping Zhu Jing-Pu Zhang Yan-Xiang Wang Jian-Dong Jiang Dan-Qing Song 《PloS one》2013,8(3)
Heat-stress cognate 70 (Hsc70) is a host factor that helps hepatitis C virus (HCV) to complete its life cycle in infected hepatocytes. Using Hsc70 as a target for HCV inhibition, a series of novel N-substituted benzyl matrinic/sophoridinic acid derivatives was synthesized and evaluated for their anti-HCV activity in vitro. Among these analogues, compound 7c possessing N-p-methylbenzyl afforded an appealing ability to inhibit HCV replication with SI value over 53. Furthermore, it showed a good oral pharmacokinetic profile with area-under-curve (AUC) of 13.4 µM·h, and a considerably good safety in oral administration in mice (LD50>1000 mg/kg). As 7c suppresses HCV replication via an action mode distinctly different from that of the marketed anti-HCV drugs, it has been selected as a new mechanism anti-HCV candidate for further investigation, with an advantage of no or decreased chance to induce drug-resistant mutations. 相似文献
95.
Jie Zhang Yuhong Chen Yu Xu Mian Li Tiange Wang Baihui Xu Jichao Sun Min Xu Jieli Lu Yufang Bi 《PloS one》2013,8(6)
Background
Micro-albuminuria has been well established as one of the risk factors of metabolic syndrome (MetS). However, the association of MetS and its components with low-grade albuminuria among those with normal urinary albumin excretion has not been clearly elucidated in Chinese population.Methodology and Findings
A cross-sectional study was conducted among 9,579 participants with normal urinary albumin excretion, who were recruited from Jia Ding District, Shanghai, China. The single-void first morning urine sample was collected for urinary albumin and creatinine measurements, and urinary albumin-to-creatinine ratio (UACR) was calculated as urinary albumin divided by creatinine. Low-grade albuminuria was classified as sex-specific upper UACR quartile in this population. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. The prevalence of MetS and its components increased across the UACR quartiles (all P trend <0.01). A multivariable adjusted logistic regression analysis revealed that the prevalence of MetS was gradually elevated according to the UACR quartiles (adjusted odds ratios [ORs] were 1.14, 1.24 and 1.59 for UACR quartiles 2, 3 and 4, compared with the lowest quartile; P trend<0.0001). In the further stratified logistic regression analyses, the associations between low-grade albuminuria and MetS were significant in both sex strata (male and female), both age strata (<60 and ≥60 years), both body mass index strata (<24 and ≥24 kg/m2), and both diabetes strata (yes and no). Compared to the lowest UACR quartile, the participants in the highest quartile of UACR had the highest prevalence of central obesity (OR = 1.43; 95%CI = 1.25–1.63), high blood pressure (OR = 1.64; 95%CI = 1.43–1.87), hyperglycemia (OR = 1.52; 95%CI = 1.30–1.78) and high triglycerides (OR = 1.19; 95%CI = 1.04–1.37).Conclusions and Significance
Low-grade albuminuria was significantly associated with the increasing prevalence of MetS and its components in the middle-aged and elderly Chinese population with normal urinary albumin excretion. 相似文献96.
Penghong Song Wenfeng Song Xiaosun Liu Changhai Jin Haiyang Xie Lin Zhou Biguang Tuo Shusen Zheng 《PloS one》2013,8(4)
The secretion function of intestinal graft is one of the most important factors for successful intestinal transplantation. Cystic fibrosis transmembrane conductance regulator (CFTR) mediates HCO3
- and Cl- secretions in intestinal epithelial cells. In this study, we made investigation on the expression and function of CFTR in an experimental model of murine small intestinal transplantation. Heterotopic intestinal transplantations were performed in syngeneic mice. The mRNA and protein expressions of CFTR were analyzed by real time PCR and western blot. Murine intestinal mucosal HCO3
- and Cl- secretions were examined in vitro in Ussing chambers by the pH stat and short circuit current (Isc) techniques. The results showed that forskolin, an activator of CFTR, stimulated jejunal mucosal epithelial HCO3
- and Cl- secretions in mice, but forskolin-stimulated HCO3
- and Cl- secretions in donor and recipient jejunal mucosae of mice after heterotopic jejunal transplantation were markedly decreased, compared with controls (P<0.001). The mRNA and protein expression levels of CFTR in donor and recipient jejunal mucosae of mice were also markedly lower than those in controls (P<0.001), and the mRNA and protein expression levels of tumor necrosis factor α (TNFα) were markedly increased in donor jejunal mucosae of mice (P<0.001), compared with controls. Further experiments showed that TNFα down-regulated the expression of CFTR mRNA in murine jejunal mucosa. In conclusion, after intestinal transplantation, the function of CFTR was impaired, and its mRNA and protein expressions were down-regulated, which may be induced by TNFα. 相似文献
97.
Hongren Qu Limin Yang Shanshan Meng Lei Xu Yuhai Bi Xiaojuan Jia Jing Li Lei Sun Wenjun Liu 《PloS one》2013,8(3)
Chicken interferon α (ChIFN-α) and ChIFN-β are type I IFNs that are important antiviral cytokines in the innate immune system. In the present study, we identified the virus-induced expression of ChIFN-α and ChIFN-β in chicken fibroblast DF-1 cells and systematically evaluated the antiviral activities of recombinant ChIFN-α and ChIFN-β by cytopathic-effect (CPE) inhibition assays. We found that ChIFN-α exhibited stronger antiviral activity than ChIFN-β in terms of inhibiting the replication of vesicular stomatitis virus, Newcastle disease virus and avian influenza virus, respectively. To elucidate the mechanism of differential antiviral activities between the two ChIFNs, we measured the relative mRNA levels of IFN-stimulated genes (ISGs) in IFN-treated DF-1 cells by real-time PCR. ChIFN-α displayed greater induction potency than ChIFN-β on several ISGs encoding antiviral proteins and MHC-I, whereas ChIFN-α was less potent than ChIFN-β for inducing ISGs involved in signaling pathways. In conclusion, ChIFN-α and ChIFN-β presented differential induction potency on various sets of ISGs, and the stronger antiviral activity of ChIFN-α is likely attributed to the greater expression levels of downstream antiviral ISGs. 相似文献
98.
Erythropoietin (EPO) has multiple biological functions, including the modulation of glucose metabolism. However, the mechanisms underlying the action of EPO are still obscure. This study is aimed at investigating the potential mechanisms by which EPO improves glucose tolerance in an animal model of type 2 diabetes. Male C57BL/6 mice were fed with high-fat diet (HFD) for 12 weeks and then treated with EPO (HFD-EPO) or vehicle saline (HFD-Con) for two week. The levels of fasting blood glucose, serum insulin and glucose tolerance were measured and the relative levels of insulin-related phosphatidylinositol 3-kinase (PI3K)/Akt, insulin receptor (IR) and IR substrate 1 (IRS1) phosphorylation were determined. The levels of phosphoenolpyruvate carboxykinase (PEPCK), glucose-6- phosphatase (G6Pase), toll like receptor 4 (TLR4), tumor necrosis factor (TNF)-α and IL-6 expression and nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK), extracellular-signal-regulated kinase (ERK) and p38 MAPK activation in the liver were examined. EPO treatment significantly reduced the body weights and the levels of fasting blood glucose and serum insulin and improved the HFD-induced glucose intolerance in mice. EPO treatment significantly enhanced the levels of Akt, but not IR and IRS1, phosphorylation, accompanied by inhibiting the PEPCK and G6Pase expression in the liver. Furthermore, EPO treatment mitigated the HFD-induced inflammatory TNF-α and IL-6 production, TLR4 expression, NF-κB and JNK, but not ERK and p38 MAPK, phosphorylation in the liver. Therefore, our data indicated that EPO treatment improved glucose intolerance by inhibiting gluconeogenesis and inflammation in the livers of HFD-fed mice. 相似文献
99.
100.
End-to-end automated microfluidic platform for synthetic biology: from design to functional analysis
Gregory?LinshizEmail author Erik?Jensen Nina?Stawski Changhao?Bi Nick?Elsbree Hong?Jiao Jungkyu?Kim Richard?Mathies Jay?D.?Keasling Nathan?J.?HillsonEmail author 《Journal of biological engineering》2016,10(1):3