INTERMOLECULAR CLEAVAGE OF HEPATITIS-A VIRUS (HAV) PRECURSOR PROTEIN P1-P2 BY RECOMBINANT HAV PROTEINASE-3C

Active proteinase 3C of hepatitis A virus (HAV) was expressed in bacteria either as a mature enzyme or as a protein fused to the entire polymerase 3D or to a part of it, and their identities were shown by immunoblot analysis. Intermolecular cleavage activity was demonstrated by incubating in vitro-translated and radiolabeled HAV precursor protein P1-P2 with extracts of bacteria transformed with plasmids containing recombinant HAV 3C. Identification of cleavage products P1, VPI, and VP0-VP3 by immunoprecipitation clearly demonstrates that HAV 3C can cleave between Pl and P2 as well as within P1 and thus shows an activity profile similar to that of cardiovirus 3C.