679 research outputs found
Construction and Characterization of a Novel Fusion Protein MG7-scFv/SEB against Gastric Cancer
Antibody-targeted superantigen has been developed into a new strategy to treat many malignant tumors. In this study, for specific targeting to gastric cancer cell, superantigen SEB (Staphylococcal Enterotoxin B) was genetically fused to the single-chain variable fragment of gastric carcinoma-associated antibody MG7(MG7-scFv) that recognizes the MG7 antigen frequently expressed in gastric cancer cell. The recombinant MG7-scFv/SEB fusion proteins are expressed in E. coli as inclusion bodies, and the purified MG7-scFv/SEB retains high binding affinity with gastric cancer cell SGC-7901 (positive MG7 antigen expression). When incubated with effector cell—peripheral blood mononuclear cells (PBMCs), MG7-scFv/SEB could effectively inhibit the proliferation and induce apoptosis of SGC-7901. After being treated with MG7-scFv/SEB, PBMCs remarkably increased the production of Th1 cytokines (IFN-gamma, IL-2), and slightly increased the production of Th2 cytokines (IL-4, IL-10) in vitro. It was observed that gastric-tumor-bearing rats administrated with MG7-scFv/SEB showed more inflammatory cell infiltration, more significant tumor inhibition, and longer survival time than those of rats treated with SEB or NS (Normal Saline). The data indicated that MG7-scFv/SEB fusion protein could specifically target gastric cancer cell, enhance the activity of T cells and induce tumor cell apoptosis to exert the antitumor effect on gastric cancer
Bis[tris(ethylenediamine-κ2 N,N′)cobalt(III)] octakis-μ-3-oxido-hexadeca-μ2-oxido-tetradecaoxido-μ12-tetraoxosilicato-octamolybdenum(VI)hexavanadium(IV,V) hexahydrate
The title compound, [Co(C2H8N2)3]2[SiMo8V4O40(VO)2]·6H2O, was prepared under hydrothermal conditions. The asymmetric unit consists of a transition metal complex [Co(en)3]3+ cation (en is ethylenediamine), one half of an [SiMo8V4O40(VO)2]6− heteropolyanion, two solvent water molecules in general positions and two half-molecules of water located on a mirror plane. In the complex cation, the Co3+ ion is in a distorted octahedral coordination environment formed by six N atoms of the three chelating en ligands. One of the en ligands exhibits disorder of its aliphatic chain over two sets of sites of equal occupancy. The [SiMo8V4O40(VO)2]6− heteropolyanion is a four-electron reduced bivanadyl-capped α-Keggin-type molybdenum–vanadium–oxide cluster. In the crystal, it is located on a mirror plane, which results in disorder of the central tetrahedral SiO4 group: the O atoms of this group occupy two sets of sites related by a mirror plane. Furthermore, all of the eight μ2-oxide groups are also disordered over two sets of sites with equal occupancy. There are extensive intermolecular N—H⋯O hydrogen bonds between the complex cations and inorganic polyoxidoanions, leading to a three-dimensional supramolecular network
Characterization of Chemical Composition of Pericarpium Citri Reticulatae Volatile Oil by Comprehensive Two-Dimensional Gas Chromatography with High-Resolution Time-of-Flight Mass Spectrometry
Pericarpium Citri Reticulatae (Chenpi in Chinese) has been widely used as an herbal medicine in Korea, China, and Japan. Chenpi extracts are used to treat indigestion and inflammatory syndromes of the respiratory tract such as bronchitis and asthma. This thesis will analyze chemical compositions of Chenpi volatile oil, which was performed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HR-TOFMS). One hundred and sixty-seven components were tentatively identified, and terpene compounds are the main components of Chenpi volatile oil, a significant larger number than in previous studies. The majority of the eluted compounds, which were identified, were well separated as a result of high-resolution capability of the GC × GC method, which significantly reduces, the coelution. β-Elemene is tentatively qualified by means of GC × GC in tandem with high-resolution TOFMS detection, which plays an important role in enhancing the effects of many anticancer drugs and in reducing the side effects of chemotherapy. This study suggests that GC × GC-HR-TOFMS is suitable for routine characterization of chemical composition of volatile oil in herbal medicines
-wave Superconductivity, Pseudogap, and the Phase Diagram of -- Model at Finite Temperature
Recently, a robust -wave superconductivity has been unveiled in the ground
state of the 2D -- model -- with both nearest-neighbor () and
next-nearest-neighbor () hoppings -- through the density matrix
renormalization group calculations in the ground state. In this study, we
exploit the state-of-the-art thermal tensor network approach to accurately
simulate the finite-temperature electron states of the -- model on
cylinders with widths up to . Our analysis suggests that in the dome-like
superconducting phase, the -wave pairing susceptibility exhibits a divergent
behavior with below the onset temperature
. Near the optimal doping, reaches its highest value of about
(). Above yet below a higher crossover
temperature , the magnetic susceptibility is suppressed, and the Fermi
surface also exhibits node-antinode structure, resembling the pseudogap
behaviors observed in cuprates. Our unbiased and accurate thermal tensor
network calculations obtain the phase diagram of the -- model with
, shedding light on the -wave superconducting and pseudogap phases
in the enigmatic cuprate phase diagram.Comment: 7+5 pages, 4+8 figure
Isolation and open reading frame 5 gene analysis of porcine reproductive and respiratory syndrome virus in Yunnan Province, China
Two porcine reproductive and respiratory syndrome virus (PRRSV), respectively named YN-1 and YN-2 strains, were isolated by inoculation into Marc-145 cell. The two isolated strains induce Marc-145 cell stack together, pull net, form plaque and other typical lesions after 4 blind passages. With extracted viral RNA of fourth generation, reverse transcriptase (RT)-PCR based on open reading frame 5 (ORF5) gene showed that there was porcine reproductive and respiratory syndrome virus in Marc-145 cell of fourth generation. TCID50 of isolate measured by Reed-Muench method was 10-3.6/0.1 ml. Genetic evolution of ORF5 indicated that the two isolated strains were in a small branch with high identity of 99.5%. They were in a branch with Shandong strain JN-HS, Hennan-1 and Vietnam 347-T-KSA strain with identity of 99.2 to 99.8%. The two isolated strains were in a different branch with Ch-1a and VR-2332 strains having identity of 94.4 to 94.5%.Key words: Porcine reproductive and respiratory syndrome virus (PRRSV), isolation, ORF5 gene, genetic evolution
Investigation and identification of protein γ-glutamyl carboxylation sites
<p>Abstract</p> <p>Background</p> <p>Carboxylation is a modification of glutamate (Glu) residues which occurs post-translation that is catalyzed by γ-glutamyl carboxylase in the lumen of the endoplasmic reticulum. Vitamin K is a critical co-factor in the post-translational conversion of Glu residues to γ-carboxyglutamate (Gla) residues. It has been shown that the process of carboxylation is involved in the blood clotting cascade, bone growth, and extraosseous calcification. However, studies in this field have been limited by the difficulty of experimentally studying substrate site specificity in γ-glutamyl carboxylation. <it>In silico</it> investigations have the potential for characterizing carboxylated sites before experiments are carried out.</p> <p>Results</p> <p>Because of the importance of γ-glutamyl carboxylation in biological mechanisms, this study investigates the substrate site specificity in carboxylation sites. It considers not only the composition of amino acids that surround carboxylation sites, but also the structural characteristics of these sites, including secondary structure and solvent-accessible surface area (ASA). The explored features are used to establish a predictive model for differentiating between carboxylation sites and non-carboxylation sites. A support vector machine (SVM) is employed to establish a predictive model with various features. A five-fold cross-validation evaluation reveals that the SVM model, trained with the combined features of positional weighted matrix (PWM), amino acid composition (AAC), and ASA, yields the highest accuracy (0.892). Furthermore, an independent testing set is constructed to evaluate whether the predictive model is over-fitted to the training set.</p> <p>Conclusions</p> <p>Independent testing data that did not undergo the cross-validation process shows that the proposed model can differentiate between carboxylation sites and non-carboxylation sites. This investigation is the first to study carboxylation sites and to develop a system for identifying them. The proposed method is a practical means of preliminary analysis and greatly diminishes the total number of potential carboxylation sites requiring further experimental confirmation.</p
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