Objective To explore the application of ROC curve analysis in evaluating the virtual screening of ?-secretase (BACE-1) inhibitors.Methods Virtual screening were performed for BACE-1 inhibitors using different scoring functions (Surflex-score,D-score,G-score,PMF-score,ChemScore),the screening library was composed of 50 BACE-1 inhibitors and 9 950 inactive compounds.Five scoring functions were used for ranking,and application of ROC curve analysis in evaluating the results of ranking.Results Using D-score to rank the database,the area under the curve (AUC) was 0.935.If specificity was considered primarily,more active compound were obtained by Surflex-score;if sensitivity was considered primarily,more active compounds were obtained by D-score.Conclusions ROC curve consists of sensitivity and specificity together,it can be used to set the right threshold after virtual screening to obtain active compounds as many as possible.

Objective · To investigate the effects of a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580 on biological function changes of human extravillous trophoblast cells induced by hypoxia/re-oxygenation (H/R). Methods · In-vitro cultured early pregnancy villus explants and human extravillous trophoblast cell line HTR8/SVneo were assigned to 4 groups according to different interventions, i.e. control group, SB203580 group (p38 MAPK inhibition), H/R group (simulation of preeclampsia by the oxidative stress model), and SB203580+H/R group. The effects of SB203580 on biological functions of human extravillous trophoblast cells under oxidative stress in early pregnancy villus explants were observed. Protein expression and phosphorylation of p38 MAPK in HTR8/SVneo cells were measured with Western blotting. Cell migration and invasion were observed with Transwell migration and Matrigel invasion assay, respectively. Gelatin zymography was used to measure the activity of matrix metalloproteinase (MMP) -2/9 in supernatant. ELISA was used to detect the levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng). Results · SB203580 could promote the exogenous migration of human extravillous trophoblast cells in early pregnancy villus explants under oxidative stress. H/R could decrease the migration and invasion of HTR8/SVneo cells , and increase the phosphorylation level of p38 MAPK in HTR8/SVneo cells and the secretion of sFlt-1 and sEng. SB203580 could increase the activity of MMP2/9 in supernatant and cell migration and invasion, decrease the phosphorylation level of p38 MAPK in HTR8/SVneo cells under oxidative stress and the secretion of sFlt-1 and sEng. Conclusion · SB203580 can protect biological functions of human extravillous trophobalst cells under oxidative stress.

Objective · To investigate the effects of growth arrest and DNA damage 45 alpha (Gadd45α) on the migration and invasion function of human extravillous trophoblast cells under hypoxia/re-oxygenation (H/R). Methods · Human extravillous trophoblast cells were infected by shRNA lentivirus targeting Gadd45α gene, to knock down Gadd45α gene expression. Then the oxidative stress model of preeclampsia was used in vitro to observe the changes of cell biological functions. The experiments were divided into 4 groups, nontreated group, hypoxia/re-oxygenation group, shRNA Gadd45α+H/R group and shRNA negative control+H/R group. Human villous explant experiments were used to determine the effects of silencing Gadd45α on human extravillous trophoblast cell under oxidative stress. Protein expression of Gadd45α was identified by Western blotting. Changes of cell migration and invasion were detected by transwell migration and Matrigel invasion assay. Gelatin zymography was used to detect the expression of matrix metalloproteinase (MMP) -2/9 in culture medium. Results · Hypoxia/re-oxygenation can increase the expression of Gadd45α in HTR8/SVneo cells and damage the trophoblast cell migration and invasion. Knocking down Gadd45α can increase the activities of MMP2/9, which can increase the cell migration and invasion. Conclusion · Knockdown of Gadd45α gene has promoted cell migration and invasion function of human extravillous trophobalst cells under oxidative stress.

Degenerate PCR primers were designed by multiple alignment of the protein sequences of known structural genes encoding the catalytic subunits of NiFe-hydrogenases obtained from Swiss-Prot Protein Sequence Database through CLUSTAL-W software and compared for conserved sequence motifs. An amplified PCR product 1 kb in size was obtained from the genomic DNA of Klebsiella pneumoniae using a set of degenerate primers, and then inverse PCR technique was used to obtain the full hydrogenase coding region. A predicted secondary structure and 3D structural model were constructed by homology modeling and docking. On the basis of these results, it was inferred that NiFe-hydrogenase from Klebsiella pneumoniae belongs to the membrane-bound H2 evolving hydrogenase group (Ech hydrogenase group).
Bacterial Proteins ; chemistry ; genetics ; Cloning, Molecular ; Codon ; genetics ; DNA, Bacterial ; chemistry ; genetics ; Databases, Protein ; Hydrogen Bonding ; Hydrogenase ; chemistry ; genetics ; Klebsiella pneumoniae ; enzymology ; genetics ; Models, Molecular ; Molecular Sequence Data ; Protein Conformation ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Sequence Analysis, DNA

Objective To investigate the biomechanical properties of human calcaneus by finite element method. Methods Through CT scanning, Mimics, Geomagic and other software, the finite element model of calcaneus was established. The stress distribution and displacement tendency of calcaneus under normal standing and external force were analyzed. Results Under normal standing, the calcaneal stress was uniformly distributed and small. Under external force, the entire calcaneus stress increased significantly, and the stress on calcaneocuboid articular surface also obviously increased. Conclusions The analysis of the stress and strain distribution on calcaneus in neutral position under different loading, and the investigation on biomechanical properties of calcaneus and mechanism of calcaneal fracture will provide theoretical basis for clinical treatment of calcaneal fractures.

The development of biotechnology and the in-depth research on disease mechanisms have led to increased application of enzymes in the treatment of diseases. In addition, enzymes have shown great potential in drug manufacturing, particularly in production of non-natural organic compounds, due to the advantages of mild reaction conditions, high catalytic efficiency, high specificity, high selectivity and few side reactions. Moreover, the application of genetic engineering, chemical modification of enzymes and immobilization technologies have further improved the function of enzymes. This review summarized the advances of using enzymes as drugs for disease treatment or as catalysts for drug manufacturing, followed by discussing challenges, potential solutions and future perspectives on the application of enzymes in the medical and pharmaceutical field.
Biocatalysis ; Biotechnology ; Catalysis ; Drug Compounding ; Enzymes/metabolism*

Eight phenolic compounds (1-7) were isolated from the methanol extract of the root of Rhodiola dumulosa. Their structures were identified as kaemperol (1), Quercetin (2), Gallic acid (3), (+) -Isolariciresinol-3alpha-O-beta-D-glucopyranoside (4), (-)-Isolariciresinol-3alpha-O-beta-D-glucopyra-noside (5), kaemperol-3-O-beta-D-glucopyranoside-7-alpha-O-L-rhamnoside (6), rutin (7) respectively on the basis of chemical and spectroscopic evidence. The compounds 3-7 were isolated from R. dumulosa for the first time.
Kaempferols ; chemistry ; isolation & purification ; Phenols ; chemistry ; isolation & purification ; Quercetin ; chemistry ; isolation & purification ; Rhodiola ; chemistry ; Rutin ; chemistry ; isolation & purification

Seven steroids and two cumarins were isolated from the petroleum ether extract of the specie Cacalia tangutica of the family Compositae which were collected in Minhe county, Qinhai province of China. The structures were identified as Stigmast4-en-3beta, 6beta-diol (1), 24-ethyl-5alpha-cholestane-3beta, 5, 6beta-triol (2), 7beta- methoxy-stigmast-5-en-3beta-ol (3), Schleicherastatin 1 (4), Stigmast-5-en-3beta, 7alpha-diol (5), umbelliferone (6) and hydrangetin (7) by the means of chemical and modern spectroscopic analysis (MS, 1H-NMR, 13C-NMR, DEPT). The compounds 1-5 were isolated from Cacalia tangutica for the first time.
Asteraceae ; chemistry ; Drugs, Chinese Herbal ; chemistry ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Molecular Structure ; Plants, Medicinal ; chemistry ; Steroids ; chemistry

Despite recent advances in conventional therapeutic approaches for cancer, the efficacy of chemotherapy for cancer is limited due to the drug resistance and toxic side effects during treatment. To overcome drug resistance, higher doses of the toxic chemotherapy drugs are frequently administered, thus leading to even severe adverse side effects, which have limited their clinical application. Cationic liposome as a novel non-viral carrier for co-delivery of gene and chemotherapy drugs in cancer gene therapy has already attracted more and more attention in recent years. Most importantly, this combined strategy can generate a significant synergistic effect, which can silence the related gene expression and increase the concentration of the intracellular chemotherapy drugs. This approach allows the use of a much lower dose of the chemotherapy drugs to achieve same therapeutic effect, which may have the potential for overcoming some major limitations of the conventional chemotherapy. In conclusion, co-delivery of gene and chemotherapy drugs with cationic liposome delivery system will play a vital role in the future and especially could be a promising clinical treatment for drug-resistant tumors.
Animals ; Antineoplastic Combined Chemotherapy Protocols ; administration & dosage ; therapeutic use ; Cations ; Cell Line, Tumor ; DNA ; administration & dosage ; genetics ; Drug Carriers ; Drug Delivery Systems ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Humans ; Liposomes ; administration & dosage ; chemistry ; Neoplasms ; therapy ; RNA, Small Interfering ; administration & dosage ; genetics

Kallistatin (Kal) is a negative acute phase endogenous protein which can inhibit tumor angiogenesis, growth and metastasis effectively. To express and purify recombinant human kallistatin (rHKal), and characterize its biological activity, P. pastoris was transformed with pPIC9-Kal/GS115 (His4) to express rHKal. The fermentation was carried out in a 7.5 L bioreactor with high density cell culture. 1%-2% methanol was added to the medium to induce the expression of rHKal. The secretion was purified with phenyl sepharose, G-25 sepharose, heparin sepharose and Sephacryl S-100 chromatography. The biological activity of purified bulk rHKal on HUVEC was evaluated with MTT and tube formation assays. The final expression of rHKal in the supernatant reached 50 mg x L(-1), the purity of bulk rHKal after purification was above 98%. A dose-dependent inhibition of rHKal on HUVEC proliferation was observed, however, a U-shaped dose-response curve of rHKal on capillary formation of HUVEC was revealed. The described protocol provides an effective means for preparing rHKal that could be used for anti-angiogenesis therapy in the future.
Bioreactors ; Capillaries ; drug effects ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Electrophoresis, Polyacrylamide Gel ; Fermentation ; Human Umbilical Vein Endothelial Cells ; Humans ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; Serpins ; biosynthesis ; genetics ; pharmacology