Publications by authors named "Juankun Zhang"

Influenza B virus is one of the causes for seasonal influenza, which can account for serious illness or even death in some cases. We tested the expression of extracellular domain of hemagglutinin (HA-ecto) of influenza B viruses in mammalian cells, and then determined the immunogenicity of HA-ecto in mice. The gene sequence encoding influenza B virus HA-ecto, foldon sequence, and HIS tag was optimized and inserted into pCAGGS vector.

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Ginsenoside Rh2, a rare protopanaxadiol (PPD)-type triterpene saponin isolated from Panax ginseng, exhibits notable anticancer and immune-system-enhancing activities. Glycosylation catalyzed by uridine diphosphate-dependent glucosyltransferase (UGT) is the final biosynthetic step of ginsenoside Rh2. In this study, UGT73C5 isolated from Arabidopsis thaliana was demonstrated to selectively transfer a glucosyl moiety to the C3 hydroxyl group of PPD to synthesize ginsenoside Rh2.

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There are excessive by-products in the biocatalysis process of this whole-cell biocatalytic production of melibiose from raffinose with current Saccharomyces cerevisiae strains. To solve this problem, we constructed engineered strains based on a liquor yeast (S. cerevisiae) via gene deletion (mel1 gene), heterologous integration (fsy1 or/and ffzi1 gene from Candida magnoliae), and gene overexpression (gcr1 gene).

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Melibiose is widely used as a functional carbohydrate. Whole-cell biocatalytic production of melibiose from raffinose could reduce its cost. However, characteristics of strains for whole-cell biocatalysis and mechanism of such process are unclear.

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Xylanase, which catalyzes the random hydrolysis of internal xylosidic linkages, is a critical enzyme participating in xylan decomposition and has been widely applied in industrial utilizations. Xylanase isolated from the extremophilic Streptomyces sp. S9 (XynAS9) possesses broad adaptability to temperature and pH and thus is an attractive candidate in industrial applications.

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Developing reagents with high affinity and specificity are critical to detect the environmental hormones or toxicants. Ribosome display technology has been widely used in functional protein or peptide screening and in directed evolution of protein molecules in vitro. In this study, single-chain variable fragments (scFvs) against bisphenol A (BPA) were selected from a library constructed from splenocytes of non-immunized mice.

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In the present study, we aimed to develop a nucleic acid lateral-flow method for the rapid and sensitive detection of multiple bacteria that contaminate platelet concentrations (PCs). Polymerase chain reaction (PCR) amplicons were produced by a set of board-range primers that recognize the conserved region of bacteria 16S rDNA, followed by hybridization with both an FITC (fluorescein isothiocyanate)-labelled probe and biotin-labelled probe, and then a nucleic acid lateral-flow dipstick (LFD) assay. The LFD accurately identified 7 species of bacteria, but had no cross-reactivity with human genomic DNA.

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A novel aptamer biosensor for fast tetracyclines determination was established and illustrated in this paper. The tetracyclines aptamer as a specific affinity molecule was immobilized on the surface of the glassy carbon (GC) electrodes. It can specifically bind tetracyclines quickly in milk and other samples without sample treatment.

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A fermentation medium for avilamycin production by Streptomyces viridochromogenes Tü57-1 has been optimized. Important components and their concentrations were investigated using fractional factorial design and Box-Behnken Design. The results showed that soybean flour, soluble starch, MgSO4.

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An antibody-based rapid, quantitative, and qualitative tube enzyme-linked immunosorbent assay (tube-ELISA) was developed and used to determine carbaryl (1-naphthyl methylcarbamate) residues in agricultural products (apple, Chinese cabbage, rice, and barley). The tube-ELISA is a competitive immunoassay in which the antibody is coated in the polystyrene tube, with a dynamic range between 0.7 and 46.

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We immobilized his-tag alkaline phosphatase (ALP) randomly and with the desirable orientation (site directed) to compare the effects of the enzyme activity on the beads. The chemiluminescence was employed to increase the sensitivity of enzyme labelled assays. Flow injection was also carried out for the detection of chemical and biological molecules in flow solutions.

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The ability of epithelial cells to polarize requires cell-cell adhesion mediated by cadherin receptors. During cell-cell contact, the mechanism via which a flat, spread cell shape is changed into a tall, cuboidal epithelial morphology is not known. We found that cadherin-dependent adhesion modulates actin dynamics by triggering changes in actin organization both locally at junctions and within the rest of the cell.

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Cadherins are transmembrane receptors that mediate cell-cell adhesion. They play an essential role in embryonic development and maintenance of tissue architecture. The Rho family small GTPases regulate actin cytoskeletal dynamics in different cell types.

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