3D-QSAR studies on thiazole derivatives as potent inhibitors of dihydroorotate dehydrogenase / 药物评价研究

Objective The three-dimensional quantitative structure activity relationship (3D-QSAR) method was applied to study thiazole derivatives as potent inhibitors ofdihydroorotate dehydrogenase,which provided useful guidance for more discovery of potent inhibitors of dihydroorotate dehydrogenase.Methods Molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were applied to systematicly investigate 3D-QSAR of 38 hiazole derivatives as potent inhibitors of dihydroorotate dehydrogenase.Established models of CoMFA and CoMSIA and the predictive ability of models were validated.Three dimensional map was applied to analyzing the relationship between structure and activity of thiazole derivatives.Results The coefficients of cross validation q2 and non-cross validation r2 for CoMFA model were 0.796 and 0.978,and for CoMSIA model were 0.721 and 0.976 respectively.The prediction of activity of compound was close to the actual value of the two models.Effect of compound structure on its activity could be analyzed comprehensively and intuitively by three dimensional map.Conclusion The model reveals the relationship between the structure characteristics and the inhibitory activity,and has good predictive capability and stability to lay a good foundation for further development and research.

Immunogenicity of the immunodominant cytotoxic T lymphocyte epitope E749-57 in HPV16 oncoprotein E7 chaperoned by HSP110 / 中华皮肤科杂志

Objective To investigate the immunogenicity of immunodominant cytotoxic T lymphocyte epitope E749-57 of human papilloma virus (HPV) 16 oncoprotein E7 chaperoned by heat shock protein (HSP)110. Methods Mouse HSP110 gene was cloned into prokaryotic expression vector pQE-80L for the expression of HSP110 protein, which was purified using Ni-NTA column. SDS-PAGE and Western-blot were conducted to confirm the purified mHSP110 protein, which was subsequently incubated with E749-57 peptide under heat shock condition, and high-performance liquid chromatography (HPLC) was used to evaluate the binding efficiency of the recombinant protein and E749-57 peptide. Twenty mice were divided into 4 groups to be immunized with mHSP110 protein, E749-57 peptide, mHSP110-E749-57 complex and phosphate buffered saline (PBS),respectively. Two weeks after the last immunization, spleen cells were collected from the immunized mice and divided into 2 parts: one were stimulated by E749-57 peptide followed by the detection of CD8+ INF-γ+ T cells with flow cytometry; the other one were subjected to MTT analysis for the estimation of cell proliferation. The mHSP110-E749-57 complex was also used to immunize TC-1 tumor bearing mice to observe its anti-tumor effect.Results The full-length 2577 bp-sized mHSP110 gene was amplified from mouse liver cDNA and cloned into pQE-80L vector. Direct sequencing confirmed the correctness of the cloning. SDS-PAGE and Western-blot demonstrated the successful purification of mHSP110. HPLC assay showed that the purified mHSP110 protein could bind with E749-57 to form a relatively stable protein complex. The percentage of IFN-γ+ CD8+ T cells in and proliferation index of spleen cells from the complex-immunized mice were statistically higher than those from the other 3 groups of mice. Moreover, the complex could obviously inhibit the growth of TC-1 tumor in mice. Conclusion The mHSP110-E749-57 complex could enhance the generation of specific cytotoxic T lymphocytes and exert anti-tumor effects in mice.

Construction of prokaryotic expression vector of HPV16E6 gene and its expression / 生物医学工程学杂志

Prokaryotic expression vector of mouse HPV16E6 gene was constructed. A pair of primers were designed according to the digestion sites in plasmid pGEX-KG and the HPV16E6 gene sequence published by GenBank. The DNA fragment of 321bp was amplified by PCR from the HPV recombinant plasmid with HPV16E6 gene, then cloned into pGEX-KG and transformed into the host E. coli strain JM109. The fragment was conformed to the original sequence, which indicated that fusion expression vector pGEX-KG-HPV16E6 was constructed. The pGEX-KG-HPV16E6 plasmid was taken and transformed into BL21(DE3) for expression. Induced by IPTG at 37 degrees C, the expression product of HPV16E6 gene was identified by SDS-PAGE and Western blot. HPV16E6 fusion protein had been expressed successfully in the form of inclusion bodies, the molecular weight of fusion protein being 38 kD. Meanwhile, the optimum condition of HPV16E6 fusion protein expression was induced with 1.0 mmol/L IPTG for 4h. The fusion protein reacted specifically with the antibodies against HPV16E6. HPV16E6 gene was successfully expressed in E. coli, which could be used as a basis for preparing HPV16E6 vaccine in human.

Cloning and Expression of HPV18 E6 Gene / 天津医药

Objective: To express the protein of HPV18E6 based on pET-32a(+) at high level and study the expression and significance of HPV18E6 proteins in laryngeal carcinoma. Methods: The HPV18E6 gene was amplified by PCR and cloned into pET-32a(+). The amplified fragment was inserted into the plasmid pET32a (+) that was digested with BamHⅠand Hind Ⅲ. The recombinant plasmid pET32/E6 was transformed into E.coli JM109 which was selected with ampicillin. The recombinant plasmids were successfully introduced into E.coli BL21(DE 3) and were induced by IPTG. SDS-PAGE and Western blot analysis were used to detect the confusion protein. Finally, the optimization of expression conditions, such as temperature, concentration of IPTG, was studied. Results: The recombinant plasmids were identified and confirmed with enzyme digestion and sequencing. The BL21(DE3) transformed recombinant plasmid pET32/E6 had expressed HPV18E6 recombinant protein effectively. The optimum conditions of expression were 37 ℃, 1 mmol/L IPTG. Conclusion:Prokaryotic expression vector pET-32a(+)-HPV18E6 was successfully constructed. The high-level expression of HPV18E6 was achieved in E.coli BL21(DE3).

Toward the quantitative prediction of T-cell epitopes: QSAR studies on peptides having affinity with the class I MHC molecular HLA-A*0201.

It would be useful for vaccine development to develop a method of rapidly identifying peptide epitopes. In this paper, the empirical three-dimensional quantitative structure-affinity relationship (3D-QSAR) methods were used to study the relationship between the three dimensional structural parameters (the isotropic surface area, ISA, and the electronic charge index, ECI) of the HLA-A*0201 binding peptide and the HLA-A*0201/peptide binding affinities. A set of 102 peptides having affinity with the class I MHC HLA-A*0201 molecule was used as training set. A test set of 40 peptides was used to determine the predictive value of the models. The 3D-QSAR models yielded a q2 = 0.5724 and a high rpred2 = 0.6955. The standard regression coefficients indicated that the hydrophobic interactions played an important role in peptide-MHC molecule binding and predicted the specific amino acid residue essential at a certain position of the peptide. The approach tested in the current paper is highly complementary to many of the methods described in references and possesses good predictability. It is a rapid and convenient method to detect high affinity peptide epitopes.

Identification a HLA-A2-restricted CTL epitope of breast cancer differentiation antigen NY-BR-1 / 中国免疫学杂志

Objective:To identify HLA-A2-restricted CTL epitope of breast cancer differentiation antigen NY-BR-1.Methods:The HLA-A2-restricted CTL epitope of breast cancer differentiation antigen NY-BR-1 is predicted by combination quantitative motif method and the molecular dynamics.The three epitope were assayed their affinity to HLA-A2.Results:The affinity to HLA-A2 of NY-BR-1_ 1043-1051 is a best.Conclusion:NY-BR-1_ 1043-1051 is a HLA-A2 restricted epitope.

Modification and identification of tyrosinase related protein-2(180-188) epitope / 第三军医大学学报

Objective To modify HLA-A2.1 restricted epitope of tyrosinase related protein-2 (TRP-2) (180-188) of human melanoma differentiation antigen and enhance HLA-A2.1 molecule its affinity to. Methods The TRP-2 (180-188) nave epitope was altered with the predominant amino acid for the primary anchor residues and auxiliary anchor residues. Altered peptide ligands (APLs) were scanned by polynomial method, the quantitative motif method and OSAR methods. The analogues their affinity to HLA-A2.1 molecule were assayed. Results Compared with the nave peptide, APLs had stronger affinity to HLA-A2 molecules. Conclusion Our results suggest that altered nave epitope with P1 (Y) and/or P2(L, M) can enhance affinity to HLA-A2 molecule. However, the immunogical efficacy of APLs needs to be identified in studies in vitro and in vivo.