1.Advance in Herpesvirus US10 gene and its encoded protein
Daixi ZHANG ; Anchun CHENG ; Mingshu WANG
Chinese Journal of Zoonoses 2017;33(1):61-66
US10 gene of Herpesvirus is located in the short unique region of its genome and not essential for virus replication.US10 gene encodes a phosphorylated tegument-capsid associated protein or type Ⅰ transmembrane glycoprotein which selectively targets the cytoplasmic tail of HLA-G,a kind of nonclassical class Ⅰ MHC molecular,to reduce and block the host NK cell cytotoxicity in immune evasion.US10 can also interact with host proteins to play a pathogenic role and regulate the expression of other viral proteins such as glycoprotein E (gE).Through further research,the role of US10 in virulence and its ability to combine with RNA and regulate transcription can be judged in the future.
2.Investigation on bioactive protective function of amino acids to insulin by molecular simulation.
Daixi LI ; Zhen ZHAI ; Baisong GUO ; Baolin LIU ; Yan ZHANG ; Huaxing YU ; Li LIU ; Chunsheng YANG
Journal of Biomedical Engineering 2014;31(4):822-826
Heat sensitive protein medicines are increasingly exhibiting their critical importance on treatment of various diseases at present. But their popularization and application meet a great challenge because of their heat instability. In the present study, insulin was taken as a heat sensitive protein medicine and amino acid as bio-protective agent in order to investigate if these amino acids can protect the insulin from losing its bioactivity due to desiccation. The experiment was performed by using replica exchange molecular simulation (REMD) method and Gromacs software with Gromos96 (53a6) force field. The REMD results indicated that these amino acids could protect the bioactive structure of insulin during desiccation. The configurations of the protected insulin were preserved very well. Those results proved that amino acid is a kind of good bioactive protective agent for the heat sensitive protein medicines.
Amino Acids
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chemistry
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Desiccation
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Drug Stability
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Insulin
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chemistry
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Molecular Dynamics Simulation
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Software
3.Investigation on bioactive protection of LEA protein for insulin by molecular simulation in the low-temperature drying process.
Daixi LI ; Yan ZHANG ; Baisong GUO ; Baolin LIU ; Chunsheng YANG ; Yaru LIU ; Zhen ZHAI
Journal of Biomedical Engineering 2013;30(4):854-859
Nowadays various protein medicines are increasingly playing significant roles in the treatment of many diseases, but the bioactive structures of such kinds of protein medicines are unstable because they are heat sensitive. Therefore, it is very important to explore a protective method and to explain the protective mechanism of protein medicines. In the present research, insulin was chosen as a heat-sensitive protein medicine, and a Group 3 late embryogenesis abundant (LEA) protein was chosen as its bioactive protectant during desiccation. The results of replica exchange molecular dynamics simulation suggest that comparing with insulin without any protection, the bioactive 3D structure and secondary structure of the insulin protected by LEA protein were preserved very well. All analyzing results proved that the LEA protein was a good bioactive protectant for heat sensitive protein medicines.
Animals
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Cold Temperature
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Drug Stability
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Freeze Drying
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Helminth Proteins
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chemistry
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Insulin
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chemistry
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Nematoda
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Plant Proteins
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pharmacology
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Protein Interaction Domains and Motifs
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Protein Structure, Secondary
4.Overexpression of Wnt3 inhibits apoptosis of hepatic progenitor cells in vitro.
Xifeng ZHANG ; Daixi HU ; Chao ZHANG ; Qin ZHONG ; Tao FENG ; Jiayi HUANG
Journal of Southern Medical University 2014;34(1):46-50
OBJECTIVETo investigate the effects of adenoviral vector-mediated over-expression of Wnt3 on the apoptosis of hepatic progenitor cells in vitro.
METHODSHepatic progenitor cells transfected with Ad-GFP-Wnt3 vector or the control vector Ad-GFP were examined for cell apoptosis under fluorescence microscopy with Hoechst 33342 staining, and the proportion of apoptotic cells were determined by flow cytometric analysis with Annexin-PE/7-ADD staining. The mRNA and protein expressions of Bax, Bcl-2 and Bcl-xl in the cells were detected by real-time PCR and Western blotting, respectively.
RESULTSReal-time PCR and Western blotting showed a high expression of Wnt3 in Ad-GFP-Wnt3-transfected hepatic progenitor cells, which exhibited significantly decreased cell apoptosis as compared with the control group. The expressions of Bcl-2 and Bcl-xl mRNA and proteins increased significantly while Bax expression decreased obviously in Ad-GFP-Wnt3-transfected cells (P<0.05).
CONCLUSIONSAdenoviral vector-mediated over-expression of Wnt3 can suppress apoptosis of hepatic progenitor cells possibly through the Bcl-2 pathway.
Apoptosis ; Cells, Cultured ; Genetic Vectors ; Hepatocytes ; cytology ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Stem Cells ; cytology ; Transfection ; Wnt3 Protein ; metabolism ; bcl-X Protein ; metabolism
5.Molecular simulation research on aggregation of insulin.
Daixi LI ; Baolin LIU ; Baisong GUO ; Yaru LIU ; Zhen ZHAI ; Yan ZHANG ; Chenglung CHEN ; Shanlin LIU
Journal of Biomedical Engineering 2013;30(5):936-941
In the present research, molecular simulation and quantum chemistry calculations were combined to investigate the thermal stability of three kinds of insulin aggregations and the effect of Zn (II) ion coordination on these aggregations. The results of molecular simulation indicated that the three insulin dimers in the same sphere closed hexamer had synergistic stability. It is the synergistic stability that enhances the structural and thermal stability of insulin, preserves its bioactivity during production, storage, and delivery of insulin formulations, and prolongs its halflife in human bodies. According to the results of quantum chemistry calculations, each Zn (II)-N (Im-insulin) bond energy can reach 73.610 kJ/mol for insulin hexamer and 79.907 kJ/mol for insulin tetramer. However, the results of Gibbs free energy changes still indicats that the coordination of zinc (II) ions is unfavorable for the formation of insulin hexamer, because the standard Gibbs free energy change of the coordinate reaction of zinc (II) ions associated with the formatting insulin hexamer is positive and increased.
Insulin
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chemistry
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metabolism
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Molecular Dynamics Simulation
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Protein Stability
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Zinc
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chemistry