Comparative study of herpes group virus-induced DNA polymerases

A comparative biochemical study of virus-induced DNA polymerases was made among the herpes group viruses: namely, herpes simplex virus (HSV) type 1 and type 2, human cytomegalovirus (HCMV) and varicella-zoster virus (VZV). Although these virus-induced enzymes shared some biochemical properties, they differed in several important aspects. All these virus-induced DNA polymerases could efficiently use poly(dC) . oligo(dG)12--18 and poly(dA) . oligo(dT)12--18 as template-primers. However, in phosphocellulose chromatography, HSV-1- and HSV-2-induced enzymes were eluted at the low concentration of 0.18--0.20 M NaCl and the counterparts of HCMV and VZV were eluted at 0.30--0.32 M. The former two enzymes were more sensitive to lower concentrations of phosphonoacetate and ethyl phosphonoacetate than the latter two enzymes. Moreover, the activity of HSV-1- and HSV-2-specified DNA polymerases was 5 times greater in the presence of 60 mM ammonium sulfate if poly(dA) . oligo(dT)12--18 was used as template-primer, while HCMV- and VZV-induced enzyme activities were only about twice as great under the same conditions. Futhermore, DNase activity was conspicuous in both HSV-1- and HSV-2-infected WI-38 cells, but was not detectable in HCMV- and VZV-infected cells. After storage for 1 year at 4 degrees, the HSV-1-induced DNA polymerase was the most thermostable of the four viral enzymes.