Immunochemical characterization of pyrimidine kinase induced by varicella-zoster virus

Thymidine kinase (TK) induced by varicella-zoster virus (VZV) was precipitated with ammonium sulphate and purified by Sephadex G-150, QAE-Sephadex and Blue Sepharose column chromatographies. The purified TK fraction also contained deoxycytidine kinase (dCK) activity and a 35000 mol. wt. (35K) polypeptide as a major component. The TK and dCK activities were both neutralized by anti-VZV serum. Antiserum to an extract of cells infected with a bromodeoxyuridine (BUdR)-resistant mutant virus contained no antibody to the viral TK and dCK activities or to the 35K polypeptide. Antiserum to the purified viral TK fraction was prepared and absorbed with a lysate of BUdR-resistant mutant virus-infected cells. The resulting absorbed antiserum (anti-vTK serum) neutralized the viral activities of both TK and dCK, and specifically immunoprecipitated a 35K polypeptide from the lysate of parental virus-infected cells, but did not immunoprecipitate any detectable polypeptide from cells infected with BUdR-resistant mutant virus. Anti-vTK serum stained mainly the nuclei of cells infected with the parental virus strain, but did not stain those infected with BUdR-resistant mutant virus by an indirect fluorescent antibody test. These results suggest that the 35K polypeptide produced in VZV-infected cells is responsible for the viral TK and dCK activities, and that the TK and dCK are mainly localized in the nuclei of infected cells.