[Mutual interaction between hepatitis B virus antigen and metallothionein].
OBJECTIVE
To screen and identify the protein interacting with HBV antigen in hepatocytes. Then investigate the biological functions of hepatitis B virus antigen in the pathogenesis of hepatitis B and seek effective methods to prevent and treat it.


METHODS
The yeast two-hybrid system-3 technique was used to construct HBV PreS2, HBeAg, HBcAg, HBxAg bait plasmids. The bait plasmids transformed the yeast AH109 and expressed themselves in it. After being identified by SDS-PAGE and Western blot, the AH109 yeast was mated with yeast Y187 containing liver cDNA library plasmid in 2 x YPDA medium to form diploid yeast and was then plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-alpha-gal for screening. Plasmids of blue colonies were extracted and transformed into Escherichia coli, then analyzed by DNA sequencing and bioinformatics. To further prove the interaction between HBV antigen and metallothionein, translation was performed by using reticulocyte lysate and coimmunoprecipitation was displayed in vitro.


RESULTS
Genes coding for HBV antigen binding protein were successfully cloned and metallothionein was found in that protein. The interaction between HBeAg, HBcAg and HBxAg and metallothionein were further proved by coimmunoprecipitation in vitro.


CONCLUSIONS
The interaction between HBV antigen and metallothionein indicates that metallothionein may participate in the pathogenesis of hepatitis B
Lu
Yin-Ying
YY
Gene Therapy Research Center, Institute of Infectious Diseases, 302 Hospital of People's Liberation Army, Beijing 100039, China.
Liang
Yao-Dong
YD
Cheng
Jun
J
Chen
Tian-Yan
TY
Wang
Lin
L
Liu
Yan
Y
Li
Ke
K
Zhang
Ling-Xia
LX
Yang
Yong-Ping
YP
D006509:Hepatitis B / Q000378:metabolism*; D006511:Hepatitis B Antigens / Q000737:chemistry*; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D008668:Metallothionein / Q000737:chemistry*; D025941:Protein Interaction Mapping; D020798:Two-Hybrid System Techniques
D006511:Hepatitis B Antigens; D008668:Metallothionein