CHARACTERIZATION OF THE PROTEINASE SPECIFIED BY VARICELLA-ZOSTER VIRUS GENE-33

Varicella-zoster virus (VZV) genes 33 and 33.5 are predicted to encode the VZV proteinase and its substrate (the assembly protein) respectiv ely. These genes were expressed in insect cells using recombinant bacu lovirus and it was confirmed that gene 33 encodes a proteinase capable of autoproteolytic processing at two positions. When VZV gene 33.5 wa s co-expressed with the VZV proteinase, processing of the VZV33.5 gene product was observed. A polyclonal antiserum to the VZV assembly prot ein domain highlighted a set of proteins in VZV infected HEL cells ide ntical to those identified in insect cells expressing VZV genes 33 and 33.5. To facilitate further characterization of the VZV proteinase th e enzyme was purified by affinity chromatography from an E. coil expre ssion system and in vitro activity was observed.