Polymerase-related polypeptides associated with woodchuck hepatitis core antigen (WHcAg) particles

The woodchuck hepatitis virus (WHV) polymerase (pol)-encoded polypeptide(s), obtained from purified virus nucleocapsid particles, have been characterized by Western blotting. Peptide antibodies to amino-terminal (residues 32-45, WHV pol-6) and carboxy-terminal (residues 861-879, WHV pol-1) sequences were used, in addition to monoclonal antibodies made from purified woodchuck hepatitis core antigen (WHcAg) particles. One of the monoclonal antibodies, WC pol-11, specifically bound WHV pol-1. Both peptide and monoclonal anti-WHV pol-1 also bound a recombinant DNA-produced WHV polymerase polypeptide. These antibodies specifically detected WHcAg-associated polymerase polypeptides at 65,000 (p65) and 31,000 (p31) Da by Western blotting. These results support the conclusion that WHV pol-11 has anti-pol reactivity and that it binds the carboxyl-terminal sequences of the WHV polymerase. The finding that these reagents also specifically bind to corresponding sequences from the carboxy terminus of the hepatitis B virus polymerase suggests that these viral polymerases are cross reactive. Finally, anti-WHV pol-6 did not bind either WHcAg p65 or p31, suggesting that both of these polypeptides have different amino-terminal but the same carboxy-terminal sequences.