Abstract:Aquaporin belongs to a highly conserved group of membrane proteins called major intrinsic proteins (MIPs) that facilitate water transport across biological membranes. Aquaporins are membrane water channels that play critical roles in controlling the water content of cells and tissues. We focused on GhPIP1;2 which belongs to the PIP subfamily and GhgTIP1 which belongs to the gTIP group of the TIP subfamily. Northern blot analysis with gene-specific probes and real-time PCR demonstrated that GhPIP1;2 and GhgTIP1 are predominantly expressed during cotton fiber elongation, with the highest expression levels at 5 days post anthesis. The high and preferential expression of GhPIP1;2 and GhgTIP1 suggests that they may play important roles in supporting the rapid influx of water into vacuoles during cotton fiber cell expansion. Also, the effects of Ca2+ on aquaporins in salinity-stressed plants were studied. Researchers treated the protoplasts and plasma membrane with NaCl or CaCl2, alone or in combination. Under saline conditions, osmotic water permeability (Pf) values decreased in protoplasts and plasma membrane vesicles, and the same reduction was observed in the PIP1 aquaporin abundance, indicating inhibitory effects of NaCl on aquaporin functionality and protein abundance. Two different actions of Ca2+ were observed. Increase in free cytosolic calcium concentrations associated with stress perception may lead to aquaporin closure, however, the extra-calcium would lead to an upregulation of aquaporins. Meanwhile, experiments have demonstrated HvPIP2;1, one of barley aquaporins, has a higher water and CO2 transport activity. The goal of our plant aquaporin research is to determine the key aquaporin species responsible for water and CO2 transport, and to improve plant water relations, stress tolerance, CO2 uptake or assimilation, and plant productivity.

Abstract:Two oligonucleotide probes are permitted to anneal to the nucleic acid target of interest so that the ends of two probes immediately become adjacent to each other. The ligase can then efficiently join the two juxtaposed oligonucleotide probes by the formation of a phosphodiester bond if and only if perfectly matched base-pairs at the nick are present. During past 20 years, many ligase-mediated techniques have been developed for analyzing various bio-molecules, such as known/unknown point mutations, small-scale insertions and deletions, CpG islands methylation, large sets of single nucleotide polymorphisms (SNPs), specific proteins and DNA regions with which some other proteins can interact. Since the ligation reaction can be easily integrated into other techniques, certain advances have been already achieved. These novel approaches retain high accuracy through multiple hybridization and enzymatic processing events, and provide inherent quality control checking. In this article, we provide a comprehensive review of the ligase-mediated techniques for bio-molecular analysis.

Abstract:To construct the recombinant vector Pact-EGFP, the Act-1 core promoter region was amplified from the pUCm-T/Act-1 and subcloned into pEGFP-4.1 vector (derived from pEGFP-N1 with the removal of human cytomegalovirus immediate early promoter), by restriction enzymes Bgl II and Hind III. Transfection of Pact-EGFP vector into Vero cell by liposome indicated that Act-1 core promoter regulated the expression of EGFP gene in lower level in Vero cells. After Pact-EGFP microinjection into the gonad of Caenorhabditis elegans with pRF4 as a gene marker, green fluorescence was detected in the cortex, vice cortex and the pharyngeal of C. elegans. According to the locations, two different transgene lines were separated. The expression level of EGFP expressed in C. elegans was more than that in Vero cell. Some unique motifs might exist in Act-1 core promoter region of C. elegans, which was closely related to the expression level of EGFP. These results lay the foundation for the further research on gene function of parasitic nematodes using C. elegans.

Abstract:Salmonella choleraesuis C500 strain is an attenuated vaccine preventing piglet from paratyphoid and can also be used as a live vector of other DNA vaccines. Through mucosal immunization, immune response to specific antigens carried by it can be induced. To enhance the immune efficiency of DNA vaccine it carried, promoter Ptrc was inserted into the down stream of the CMV immediate early promoter of eukaryotic expression plasmid pEGFP-C1. Then transcription terminator rrnbT1T2 was inserted into down stream of the multiple clone sites of pEGFP-C1, and the dual-promoter expression vector pEGFPPtrcR was constructed. Using 1×TSS method, the recombinant plasmid was transformed into C500, C500/pEGFPPtrcR was obtained. SDS-PAGE and Western blotting was used to detect the expression of report gene EGFP. Strong green fluorescence can be observed under fluorescent microscope. The stable passages of this recombinant bacterium were at least 20 generations in vitro. The plasmid pEGFPPtrcR was transfected into vero cell using liposome. After 24 h, green fluorescent was observed, showing the expression of EGFP in nuclei and endochylema. The result manifested that the construction of dual-promoter expression vector pEGFPPtrcR was successful. It also indicated that the foreign gene was expressed in salmonella strain C500 and somatocytes, resulting in increased antigen expression. This research provided a foundation for the research of new DNA vaccines using salmonella C500 as carrier.

Abstract:Binding sites of five monoclonal antibodies were obtained by reinforceable method of overlapping recombinant prion protein and synthetic peptide. Overlapping peptides of PrP core were expressed in Escherichia coli by insertion of serial PCR amplicons of ovine PrP gene fragments into pET32a. The expressed fusion peptides were then tested for the binding activity to PrP monoclonal antibodies in Western blotting. The binding sites of 5 monoclonal antibodies of ovine PrP were located respectively as follows: 2H3 in 199 aa-213 aa, 4C6, 5F11 and 7F11 in 139 aa-168 aa and 7F1 in 214 aa-227 aa. There oligo peptides were synthesized and used in ELISA test for more accurate localization of the binding sites. The binding sites of 4C6, 5F11 and 7F11 were further confirmed to be in 149 aa~158 aa. This conclusion may contribute to the research for pathogenesis and diagnostic method of scrapie and bovine transmissible spongiform encephalopathy.

Abstract:In order to examine the role of astacene on mice body development and the expression of energy metabolism related genes in mice, we treated mice (Kunming white) and primary culture of mouse muscle cells with astacene of higher and lower concentration. Then the total mRNA was extracted from the muscle tissue and cells respectively, and the mRNA levels of UCP3 and LXRα were detected by RT-PCR in all the samples. Compared with the control group, the body weight of mice in high concentrations of astacene group grown slowly, and the expressions of UCP3 genes decreased significantly in muscle tissue of the 10th day and the 30th day as well as the cells of treated for 24 h (P<0.05). The expression of LXRα gene increased significantly in all samples (P<0.05) and reached its peak at 72 h (P<0.01). With the treatment of lower concentration of astacene, the expressions of UCP3 and LXRα gene mRNA in muscle tissue did not alter much, but in muscle cells treated for 24 h, the mRNA level of UCP3 gene decreased significantly (P<0.05), and LXRα gene increased significantly (P<0.05). The results suggest that astacene has a role in regulating the energy use in mice muscle.

Abstract:To improve spinosyn-producing strain and enhance spinosyns yield, we studied the effects of glycin concentration and the operational time, temperature and lysozyme concentration on protoplast preparation of Saccharopolyspora spinosa SP06081. We also studied different regeneration media and osmotic stabilizing agents. In addition, we compared the change of morphology and spinosyns yield of the regenerated strains. The results showed that the Saccharopolyspora spinosa SP06081 protoplast yield was the highest under these conditions: the collected mycelium from SP06081 grown in Tryptic Soy Broth (TSB) medium with 0.2% glycin for 48 h was treated by 0.1 mg/mL lysozyme at 28oC for 20 min, then plated on the R2YE medium with sucrose as osmotic stabilizer, the number of regeneration protoplast was up to 108/mL. The protoplast-regenerated strains exhibited changes in morphology and antibiotic production, 29.3% protoplast-regenerated strains was characterized by loose mycelium and abundant broken branches as did their parent. Among them, 58.2% strains presented the trend to positive variation in spinosad yield, with the highest spinosad yield of up to 582.0 mg/L, 85.6% higher than that of their parent. There is significant correlation between the morphological differentiation and antibiotic yield of the protoplast-regenerated strains from spinosyn-producing strain.

Abstract:We isolated three secondary metabolites by silica gel column chromatography from endophytic fungus 12.3.2 that was isolated from Taxus yunnanensis and could produce taxanes. They were identified as cembrene (3,7,11-trimethyl-14-(1-methylethyl)-1,3,6,10-cyclotetradecatetraene), diisooctyl phthalate (1,2-benzenedicarboxylic acid diisooctylester) and ethyl oleate (9-octadecenoic acid-ethyl ester) by infrared spectra (IR), mass spectra (MS) and 1H-nuclear magnetic resonance (NMR). Their antibacterial activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans were examined. Results show that all of the three compounds could inhibit the growth of those pathogenic bacteria. Especially, cembrene showed stronger inhibition to S. aureus, B. subtilis and C. albicans. This is the first report on cembrene produced by plant endophytic fungus.

Abstract:Bacillus licheniformis a-amylase (BLA) is one of the most important enzymes involved in starch hydrolysis and many biotechnological processes. To improve the BLA productivity, an integrative plasmid pBL-amyL carrying amyL gene encoding a thermophilic a-amylase of B. licheniformis was constructed and transformed into B. licheniformis B0204, an industrial α-amylase producer. The transformants harboring different copies of amyL were developed on kanamycin by using homolog-mediated chromosomal amplification of a-amylase gene. The recombinants with different multiple copies of amyL integrated in the chromosome were identified by real-time PCR and evaluated by shake-flask fermentation. Recombinants harboring 2?5 multiple copies of amyL produced more a-amylase comparison to the parental strain B0204.

Abstract:Aspergillus niger lipases are important biocatalysis widely used in industries for food processing and pharmaceutical preparation. High-level expression recombinants can lead to cost effective lipase large scale production. Full length gene synthesis is an efficient measure to enhance the expression level of the gene. In order to reduce the non-specific binding between oligonucleotides and bases mutation caused by the complicate secondary structure of DNA and excessive PCR amplification, a frequently phenomenon in one-step gene synthesis, we used a two-step method including assembly PCR (A-PCR) and digestion-ligation step to synthesis Aspergillus niger lipase gene lipA. Assisted by DNA2.0 and Gene2Oliga software, we optimized the codon usage and secondary structure of RNA and induced enzyme sites Cla I (237 site) and Pst I (475 site) into the gene. In the first step, fragments F1 (237 bp), F2 (238 bp) and F3 (422 bp) were separately synthesized by assembly PCR. In the second step, fragments F1, F2 and F3 were separately digested by Cla I and Pst I, and then ligated into a full length lipA gene. Two-step method efficiently enhanced successful ratio for full-length gene synthesis and dispersed the risk for gene redesign. The synthesized gene was cloned into pPIC9K vector and transferred into Pichia pastoris. After methanol inducement, the expression level of the codon optimized lipA-syn gene reached 176.0 U/mL, 10.8-fold of the original lipA gene (16.3 U/mL) in Pichia pastoris GS115. The recombinant offers the possibility for lipase large-scale production.

Abstract:Keeping an enzyme in its native form with high catalytic activity is of great significance. In the present study, thermal stabilizers of horseradish peroxidase (HRP) were screened. The results indicated that thermal stability of HRP was enhanced by magnesium sulphate and gelatin. A synergic effect of magnesium sulphate and gelatin was observed. In the presence of the stabilizer, the enzymatic activity of HRP remained 89% after kept for 80 h at 50oC and 57% for 90 days at room temperature. Thermal alterations of HRP structure in the absence and presence of the stabilizers were explored by using UV absorption spectra at 402 nm (Soret band), intrinsic fluorescence and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence. The results suggested that magnesium sulphate and gelatin attenuated the extent of unfolding of HRP and therefore the native enzyme structure was stabilized.

Abstract:We constructed inducible and constitutive heterotrophic expression vectors of Dunaliella salina (D. salina) and identified heterotrophic transformants. A gene encoding a glucose transporter (Glut1) was cloned from human placenta tissues by RT-PCR and sequenced. Inducible heterotrophic expression vector pMDDGN-Bar of D. salina, which included a duplicated carbonic anhydrase (DCA) promotor and a Bar selectable marker that could drive expression of the Glut1 gene in D. salina, was constructed by molecular biology methods. In addition, we constructed another vector G5Glut1-Bar that contained a constitutive ubiquitin promotor, Glut1 and Bar box. The two expression vectors were introduced into D. salina by electroporation method, and then screened the transformants with phosphinothricin (PPT). Total RNA of the transformants extracted was used to analyze the integration of the target gene (Glut1) by RT-PCR. The cloned Glut1 sequence was 1479 bp and encoded 493 amino acids. The results of all enzymes digesting showed that two expression vectors were successfully constructed. After screening by PPT for several weeks, the transfomants grew well whereas wild-type cells died completely. The result of RT-PCR indicated that two transformants both had an about 250 bp specific band and the sequence homology was 100% compared with the human Glut1 sequence by Blast analysis. Taken altogether, inducible and constitutive heterotrophic expression vectors of D. salina was constructed successfully and the Glut1 gene was integrated into the genome of D. salina. Expression vectors above-mentioned may be used for the expression of the foreign Glut1 gene in D. salina.

Abstract:By constructing the genomic DNA library of Meiothermus ruber CBS-01, the genes of trehalose phosphate synthase (TPS) and trehalose phosphate phosphatase (TPP) involved in trehalose synthesis were cloned. The genes were cloned into the plasmid pET21a, and expressed in Escherichia coli Rosetta gami (DE3). The activities of these two purified enzymes were confirmed by thin layer chromatography (TLC). Meanwhile, we tested the cellular compatible solutes of M. ruber CBS-01 under different environmental pressure, and found that under hyperosmotic pressure, this strain can accumulate trhalose-6-phosphate, but not trehalose. These results can give more insight to future research in the roles of TPS/TPP and TreS pathway.

Abstract:Start-up and process control of a pilot-scale anaerobic ammonium-oxidizing (Anammox) bioreactor were studied at ambient temperature. Inoculated with a mixture of nitrification-denitrification sludge, nitritation sludge, anaerobic floc sludge and anaerobic granular sludge, the pilot-scale Anammox bioreactor was successfully started up within 255 days at 5oC ?27oC. The nitrogen removal rate reached 1.30 kg/(m3·d). Three facets were taken into account to facilitate the process initiation. First, in terms of alkalization in Anammox, influent pH was kept at about 6.8. Besides, nitrite concentration was kept as low as 13?36 mg/L. Finally, 2% (volumetric ratio) of Anammox sludge from lab-scale bioreactors was supplemented to the pilot-scale one.

Abstract:In this study, peaT1 gene was subcloned into the Pichia pastoris expression vector pPIC9K, which contained both the methanol-inducible promoter and the transcription terminator of the AOX1 gene, resulting the plasmid pPIC9K-peaT1. The recombinant plasmid was linearized by Sal I or Bgl II and transformed into P. pastoris GS115 by electroporation method. Recombinant strain was screened by Minimal Dextrose Medium and further confirmed by PCR. The gene was in frame integrated into the Pichia genome through homologous recombination, resulting the recombinant strain. Regulated by the α-Factor, promoter of AOX1 gene and termination signal of yeast genomic, the recombinant protein was expressed and secreted into the supernatant. The SDS-PAGE analysis indicated that the apparent molecular weight of target protein was about 35 kD. Bioassay results showed that the inhibition rate of the expressed protein against TMV was 30.37%. The supernatant was collected and then purified by anion exchange chromatography. This protein can promote seedling growth of wheat obviously.

Abstract:Sorghum (Sorghum bicolor L.) was one of the most important crops in the world next to wheat, rice, maize, soybean and barley. Using the callus derived from immature inflorescence as the recipients, we efficiently transformed sorghum varieties 115, ICS21B and 5-27 with the insecticidal Bacillus thuringiensis (Bt) cry1Ab gene carried in the T-DNA of binary vectors which contained hygromycin resistance gene and gus gene via Agrobacterium tumefaciens. After gradient selection with hygromycin, a total of 21 independent transgenic plant lines, 52 transgenic plants were regenerated, and the average stably transformation efficiency was 1.9%. The integration and transcription of cry1Ab gene in transgenic sorghum was confirmed by PCR analysis, Southern blotting and RT-PCR analysis. The Bt proteins were expressed in most transgenic plants with different level from plant to plant by Western blotting and ELISA assay. According to insect bioassay in laboratory, the transgenic plants with a relatively high level of Bt gene expression displayed insect-resistance to pink rice borer (Sesamina inferens).

Abstract:With Jingkang No.5 (PiA), calli of the PiA induced for 10?15 days were transferred into amino acid liquid culture medium, to establish excellent rice suspension cell lines successfully in a relative short time. The growth characteristics and differentiation conditions of suspension cells were measured at different phases. Results revealed that the optimal subculture time was 7?10 days, and the cells cultured for 30?120 days had the best differentiation ability (57.1%) and regeneration ability (20%). This study is promising in further using the suspension cell for genetic transformation and protoplasm isolation.

Abstract:One pair of primers were designed and synthesized based on the cDNA sequence encoding Homo sapiens poly (ADP-ribose) polymerase family, member 10 (PARP10) reported on the GenBank. The cDNA sequence encoding PARP10 was cloned from 293FT cell by RT-PCR. Then the RT-PCR product was cloned into pCMV-Myc and pEGFP-C1 plasmids. The interaction between PARP10 and β-actin was identified through immuno-precipitation and laser confocal microscopy. Extensive expression of PARP10 in mouse tissues was confirmed by RT-PCR. Besides, Western blotting analysis indicated that cell injury caused by UV treatment could promote the expression of PARP10. The results in this paper would benefit further study of PARP10.

Abstract:The artificial 5-helix can inhibit the formation of trimer-of-hairpins structure during the course of HIV-directed membrane fusion and then inhibit human immunodeficiency virus (HIV) infecting target cells. But 5-helix was apt to form inclusion body when expressed directly in prokaryotic cell and was difficult to renature, which causes inconvenience to future study. We found a proper expression vector by simulating protein structure. We simulated its proper conformation in two vectors pGEX-6P-1 and pET44b by homology modeling. The contrast of conformations showed that the energy of salvation of its fusion protein with NusA in vector pET44b was higher than its fusion protein with glutathione-S-transferase (GST) in pGEX-6P-1 and its restriction site lay on the surface of its fusion protein in vector pET44b. 5-helix gene was amplified from pGEX-6P-1-5H by PCR, and was ligated to pET44b to construct recombinant vector pET44b-PSP-5Helix after tested correctly by enzymes digestion. The recombinant vector was transformed into Escherichia coil BL21 (DE3) to express 5-helix protein at different temperatures. Aim protein was purified with Ni column and GST column, and was determined by SDS-PAGE. Then the purified 5 -Helix was used to test the inhibitive activity of pseudo HIV virus infecting GHOST-CXCR4. Results show that its fusion protein with NusA can be effectively soluble expressed and easier to be cleaved, and that the purified 5-helix can efficiently inhibit pseudo HIV virus infecting GHOST-CXCR4 and its IC50 value is (22.77±5.64) nmol/L, which lay the foundation to further discuss the application in HIV-1 infection.

Abstract:Fungi immunoregulatory proteins family is effective in immunological regulation and anti-tumor. We used Pichia pastoris expression system for recombinant expression of Lz-8, an immunomodulatory protein isolated from fruiting body of Ganoderma lucidum. The Gs115 (mut+) strains of P. pastoris was used as host cells. PCR and sequencing of DNA showed that Lz-8 cDNA was successfully integrated into the P. pastoris genome. Electrophoresis(SDS-PAGE), matrix assisted laser desorption ionisation time-of-flight mass spectrometry(MALDI-TOF-MS) and immunological techniques were used to identify recombinant Lz-8 (rLz-8). Lz-8 expressed in Escherichia coli, the Pichia system requires further optimization to obtain more active fungi immunomodulatory protein. Lz-8 was expressed in P. pastoris successfully, and polyacrylamide gel electrophoresis in the presence of SDS-PAGE gave a single band with an apparent Mr=14 000 D. MALDI-TOF-MS also showed that molecular weight of rLz-8 was 12 722 D. Aggregation was observed from sheep red blood cells in the presence of purified rLz-8 within the concentration range of 12.5–50 mg/mL. However, no aggregation was seen at concentration greater than 50 mg/mL for any type of human red blood cell. The dose at 0.5 mg/kg of rLz-8 induced macrophage cytophagocytesis, and set interferon as control at 0.5 mg/kg. These results suggested that active and stable rLz-8 was obtained in P. pastoris expression system.

Abstract:To explore the influence of calculus bovis on the function of primary cultured mice oral fibroblasts, we determined the effects of calculus bovis on the fibroblast proliferation, collagen production, matrix metalloproteinases-2, -9 activities and tissue inhibitor of metalloproteinase-1 production by MTT assay, chloramine T method, gelatin zymography and enzyme-linked immunosorbent assays respectively. The results showed that calculus bovis could significantly inhibit the proliferation of fibroblasts and collagen synthesis in a concentration dependent manner, could significantly (P<0.05) suppress matrix metalloproteinases-2 activity and very significantly (P<0.01) inhibit the production of tissue inhibitor of metalloproteinase-1. In conclusion, the major function of calculus bovis in the process of ulcer healing is not to promote tissue regeneration, the mechanism that calculus bovis inhibits collagen synthesis may be partly due to its ability to very significantly (P<0.01) suppress the production of tissue inhibitor of metalloproteinase-1.

Abstract:To establish a green fluorescent protein (GFP)-based cellular model for screening proteasome inhibitors from compounds including extracts from Traditional Chinese Medicinal herbs, we transfected A549 cells with lentivirus expression vector pGC-E1-ZU1-GFP, and selected clones stably expressing ZU1-GFP. The A549-ZU1-GFP cells were treated with PS-341 for 24 h, and the accumulation of GFP was analyzed by fluorescence microscope. We found that the fluorescence intensity of A549-ZU1-GFP cells treated with PS-341 was significantly increased as compared to the control. We screened for proteasome inhibitors from compounds including some from Traditional Chinese Medicinal herbs, and the data suggested a few compounds could be novel proteasome inhibitors.

Abstract:To identify metabotropic glutamate receptor 4 (mGluR4) modulators by Ca2+ influx assay, we developed the functional cell-based high throughput-screening (HTS) assay. The human mGluR4 cDNA was transfected into HEK-293 stably expressing promiscuous G-protein (Ga15) cells. Recombinant stable mGluR4 cell line was selected under Zeocin and validated by Ca2+ influx assay. The assay was optimized on loading time of Fluo Calcium Indicator, Dimethyl sulfoxide (DMSO) tolerance and sodium hydroxide (NaOH) tolerance using agonist (L-Glutamic acid (L-Glu)) of mGluR4. The rank order of the agonist potency for the stable human mGluR4 cell line was L-(+)-2-Amino-4-phosphonobutyric acid (L-AP4)>L-Serine-O-phosphate (L-SOP)>L-Glu, and of the antagonist potency was (RS)-a-Methylserine-O-phosphate (MSOP)>(RS)-a-Methyl-4-phosphonophenylglycine (MPPG). Z’ factor value of the cell line in 96- and 384-well plate format was 0.80 and 0.65. Our data indicate a successful development of functional human mGluR4 recombinant stable cell line that was suitable for high throughput screening to identify mGluR4 agonist/antagonist.

Abstract:The complete gene sequences of eight capripoxvirus strains in GenBank were aligned and analyzed with DNAStar software. We selected a size of 64 bp gene fragment that was located in gp064 region of goat pox virus (GPV) genome, and designed a pair of primers and a TaqMan-MGB probe against the gene fragment with Primer Express 2.0 software. Then, the fluorescence quantitative PCR (FQ-PCR) assay was developed and the standard curve of different dilution series was described. We extracted the DNA samples from clinical skin pox, scab and GPV infected materials of artificial challenge animals. The FQ-PCR assay has been performed for all kinds of DNA samples. The results showed that the FQ-PCR assay was sensitive, specific, stable and could be used for clinical diagnosis. This method provided an important tool for rapid diagnosis of goat pox clinically, and for study GPV pathogenesis in the course of disease occurrence, development and convalescence.