Docking of B-cell epitope antigen to specific hepatitis B antibody

The interaction of pres1 region of hepatitis B virus B-cell epitope antigen with specific hepatitis B neutralizing monoclonal antibody was examined by docking study. We modelled the 3D complex structure of B-cell epitope antigen residues CTTPAQGNSMFPSCCCTKPTDGNCY by homology modelling and docked it with the crystal structure of monoclonal antibody specific for the pres1 region of the hepatitis B virus. At the optimized docked conformation, the interactions between the amino acids of antigen and antibody were examined. It is found that the docked complex is stabilized by 59.3 kcal/mol. The stability of the docked antigen-antibody complex is due to hydrogen bonding and van der Waals interactions. The amino acids of the antigen and antibody responsible for the interaction were identified.     

Expression of Human Hepatitis B Virus Surface Antigen Gene in Transgenic Tobacco

Expression of Human hepatitis B virus surface antigen (HBsAg) gene in plant was reported for the first time. The recombinant plasmid pRoKⅡ-HBsAg was constructed by inserting HBsAg gene into the downstream of CaMV 35S promoter of binary vector pRoKⅡ and then introduced into Agrobacterium tumefaciens LBA4404. The kanamycin-resistant plants were obtained by Agrobacterium-mediated transformation system. It was shown that HBsAg gene was expressed in transgenic tobacco plants and their progenies by ELISA. The spherical particles of ψ 22 nm in the leaf extract of trangenic tobacco were observed by immunosorbent electron microscopy.     

In Silico Molecular Docking and Simulation Studies of Protein HBx Involved in the Pathogenesis of Hepatitis B Virus-HBV

Current drug discovery involves finding leading drug candidates for further development. New scientific approaches include molecular docking, ADMET studies, and molecular dynamic simulation to determine targets and lead compounds. Hepatitis B is a disease of concern that is a life-threatening liver infection. The protein considered for the study was HBx. The hepatitis B X-interacting protein crystal structure was obtained from the PDB database (PDB ID-3MSH). Twenty ligands were chosen from the PubChem database for further in silico studies. The present study focused on in silico molecular docking studies using iGEMDOCK. The triethylene glycol monoethyl ether derivative showed an optimum binding affinity with the molecular target HBx, with a high negative affinity binding energy of −59.02 kcal/mol. Lipinski’s rule of five, Veber, and Ghose were followed in subsequent ADMET studies. Molecular dynamic simulation was performed to confirm the docking studies and to analyze the stability of the structure. In these respects, the triethylene glycol monoethyl ether derivative may be a promising molecule to prepare future hepatitis B drug candidates. Substantial research effort to find a promising drug for hepatitis B is warranted in the future.     

高效液相色谱法同时测定妊娠合并乙型肝炎患者血浆中的吲哚与3-甲基吲哚

建立了一种高效液相色谱-荧光检测法用于同时测定血浆中的吲哚与3-甲基吲哚。样本经液液萃取法提取,采用Shim-Pack VP-ODS柱(150 mm×4.6 mm,4.6μm),以15 mmol/L磷酸二氢钠溶液-甲醇(40∶60,v/v)为流动相,甲奈酚为内标,荧光激发和发射波长分别为274 nm和340 nm。吲哚和3-甲基吲哚的线性范围分别为2.22~88.89μg/L和1.11~44.44μg/L;检出限分别为0.11μg/L(吲哚)和0.06μg/L(3-甲基吲哚);平均回收率为95.5%~112.3%,日内与日间相对标准偏差均小于6.8%。利用该方法对妊娠合并乙肝患者(n=29)和正常孕妇(n=46)的血浆进行了测定,结果表明妊娠合并乙肝患者血浆中吲哚和3-甲基吲哚水平均显著高于正常对照组,且与肝损伤指标转氨酶水平呈正相关。     

Size‐selective purification of hepatitis B virus‐like particle in flow‐through chromatography: Types of ion exchange adsorbent and grafted polymer architecture

Hepatitis B virus‐like particles expressed in Escherichia coli were purified using anion exchange adsorbents grafted with polymer poly(oligo(ethylene glycol) methacrylate) in flow‐through chromatography mode. The virus‐like particles were selectively excluded, while the relatively smaller sized host cell proteins were absorbed. The exclusion of virus‐like particles was governed by the accessibility of binding sites (the size of adsorbents and the charge of grafted dextran chains) as well as the architecture (branch‐chain length) of the grafted polymer. The branch‐chain length of grafted polymer was altered by changing the type of monomers used. The larger adsorbent (90 μm) had an approximately twofold increase in the flow‐through recovery, as compared to the smaller adsorbent (30 μm). Generally, polymer‐grafted adsorbents improved the exclusion of the virus‐like particles. Overall, the middle branch‐chain length polymer grafted on larger adsorbent showed optimal performance at 92% flow‐through recovery with a purification factor of 1.53. A comparative study between the adsorbent with dextran grafts and the polymer‐grafted adsorbent showed that a better exclusion of virus‐like particles was achieved with the absorbent grafted with inert polymer. The grafted polymer was also shown to reduce strong interaction between binding sites and virus‐like particles, which preserved the particles’ structure.