Inhibition of purified human and herpes simplex virus-induced DNA polymerases by 9-(2-hydroxyethoxymethyl)guanine triphosphate. Effects on primer-template function.

摘要: Abstract The inhibition of highly purified herpes simplex virus (HSV)-induced and host cell DNA polymerases by the triphosphate form 9-(2-hydroxyethoxymethyl)guanine (acyclovir; acycloguanosine) was examined. Acyclovir (acyclo-GTP) competitively inhibited incorporation dGMP into DNA, catalyzed HSV polymerase; apparent Km Ki values dGTP acyclo-GTP were 0.15 microM 0.003 microM, respectively. HeLa polymerase alpha also inhibited; 1.2 0.18 In contrast, beta insensitive to analogue. "limited" synthesis observed when omitted from or reactions in a concentration-dependent manner. Prior incubation activated acyclo-GTP, (alpha resulted marked decrease utilization primer-template subsequent reactions. This decreased ability preincubated primer-templates support dependent on enzyme concentration, time prior incubation. Acyclo-GMP-terminated found inhibit polymerase-catalyzed synthesis. Kinetic experiments with variable concentrations fixed acyclo-GMP-terminated revealed noncompetitive HSV-1 polymerase. 3'-hydroxyl termini 1.1 X 10(-7) M, Kii Kis acyclo-GMP 8.8 10(-8) M 2.1 10(-9) Finally, 14C-labeled residues incorporated could not be excised polymerase-associated 3',5'-exonuclease activity.