Identification of an attachment site for human liver plasma membranes on hepatitis B virus particles

The surface antigen of hepatitis B virus (HBsAg) exposes three protein domains: preS1, preS2, and S. In a previous study we have shown that preS1 sequences expressed in transfected yeast cells bind specifically to plasma membranes of human liver. In this study we show that purified virus particles from a virus carrier bind also specifically to such membranes. Subviral HBsAg filaments which are rich in preS1 bind well too, while HBsAg 20-nm particles which contain small amounts of preS1 bind to a much lesser degree. The binding can be inhibited by a monoclonal antibody which recognizes a sequential epitope between amino acids 27 and 49 of the preS1 domain.