scholarly journals Phosphorylation of hepatitis B virus Cp at Ser87 facilitates core assembly

2006 ◽  
Vol 398 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Hee Yong Kang ◽  
Seungkeun Lee ◽  
Sung Gyoo Park ◽  
Jaehoon Yu ◽  
Youngsoo Kim ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Protein Kinase ◽  
Hepatitis B ◽  
Protein Interactions ◽  
Present Report ◽  
Protein Protein Interactions ◽  
B Virus ◽  
Dimeric Form ◽  
Genome Encapsidation

Protein–protein interactions can be regulated by protein modifications such as phosphorylation. Some of the phosphorylation sites (Ser155, Ser162 and Ser170) of HBV (hepatitis B virus) Cp have been discovered and these sites are implicated in the regulation of viral genome encapsidation, capsid localization and nucleocapsid maturation. In the present report, the dimeric form of HBV Cp was phosphorylated by PKA (protein kinase A), but not by protein kinase C in vitro, and the phosphorylation of dimeric Cp facilitated HBV core assembly. Matrix-assisted laser-desorption ionization–time-of-flight analysis revealed that the HBV Cp was phosphorylated at Ser87 by PKA. This was further confirmed using a mutant HBV Cp with S87G mutation. The S87G mutation inhibited the phosphorylation and, as a result, the in vitro HBV core assembly was not facilitated by PKA. In addition, when either pCMV/FLAG–Core(WT) or pCMV/FLAG–Core(S87G) was transfected into HepG2 cells, few mutant Cps (S87G) assembled into capsids compared with the wild-type (WT) Cps, although the same level of total Cps was expressed in both cases. In conclusion, PKA facilitates HBV core assembly through phosphorylation of the HBV Cp at Ser87.

scholarly journals Identification of Compounds Targeting Hepatitis B Virus Core Protein Dimerization through a Split Luciferase Complementation Assay

2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Xia-Fei Wei ◽  
Chun-Yang Gan ◽  
Jing Cui ◽  
Ying-Ying Luo ◽  
Xue-Fei Cai ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Protein Interactions ◽  
Core Protein ◽  
Cell Model ◽  
Protein Protein Interactions ◽  
B Virus ◽  
Split Luciferase Complementation ◽  
Split Luciferase

ABSTRACTThe capsid of the hepatitis B virus is an attractive antiviral target for developing therapies against chronic hepatitis B infection. Currently available core protein allosteric modulators (CpAMs) mainly affect one of the two major types of protein-protein interactions involved in the process of capsid assembly, namely, the interaction between the core dimers. Compounds targeting the interaction between two core monomers have not been rigorously screened due to the lack of screening models. We report here a cell-based assay in which the formation of core dimers is indicated by split luciferase complementation (SLC). Making use of this model, 2 compounds, Arbidol (umifenovir) and 20-deoxyingenol, were identified from a library containing 672 compounds as core dimerization regulators. Arbidol and 20-deoxyingenol inhibit the hepatitis B virus (HBV) DNA replicationin vitroby decreasing and increasing the formation of core dimer and capsid, respectively. Our results provided a proof of concept for the cell model to be used to screen new agents targeting the step of core dimer and capsid formation.

Green tea extract and its major component epigallocatechin gallate inhibits hepatitis B virus in vitro

2008 ◽  
Vol 78 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Jun Xu ◽  
Jue Wang ◽  
Fei Deng ◽  
Zhihong Hu ◽  
Hualin Wang
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Green Tea Extract ◽  
B Virus ◽  
Tea Extract

scholarly journals Epitope–Paratope Interaction of a Neutralizing Human Anti-Hepatitis B Virus PreS1 Antibody That Recognizes the Receptor-Binding Motif

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 754
Author(s):  
Jisu Hong ◽  
Youngjin Choi ◽  
Yoonjoo Choi ◽  
Jiwoo Lee ◽  
Hyo Jeong Hong
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Hbv Infection ◽  
Binding Motif ◽  
Alanine Scanning Mutagenesis ◽  
B Virus ◽  
Complementarity Determining Regions

Hepatitis B virus (HBV) is a global health burden that causes acute and chronic hepatitis. To develop an HBV-neutralizing antibody that effectively prevents HBV infection, we previously generated a human anti-preS1 monoclonal antibody (1A8) that binds to genotypes A–D and validated its HBV-neutralizing activity in vitro. In the present study, we aimed to determine the fine epitope and paratope of 1A8 to understand the mechanism of HBV neutralization. We performed alanine-scanning mutagenesis on the preS1 (aa 19–34, genotype C) and the heavy (HCDR) and light (LCDR) chain complementarity-determining regions. The 1A8 recognized the three residues (Leu22, Gly23, and Phe25) within the highly conserved receptor-binding motif (NPLGFFP) of the preS1, while four CDR residues of 1A8 were critical in antigen binding. Structural analysis of the epitope–paratope interaction by molecular modeling revealed that Leu100 in the HCDR3, Ala50 in the HCDR2, and Tyr96 in the LCDR3 closely interacted with Leu22, Gly23, and Phe25 of the preS1. Additionally, we found that 1A8 also binds to the receptor-binding motif (NPLGFLP) of infrequently occurring HBV. The results suggest that 1A8 may broadly and effectively block HBV entry and thus have potential as a promising candidate for the prevention and treatment of HBV infection.

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