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本文从腹水型肝癌细胞部分纯化了依赖于ＤＮＡ的ＤＮＡ聚合酶。，以热变性的小牛胸腺ＤＮＡ为模板，观察了ＨＰＤ的光敏效应对这－ＤＮＡ合成体系的影响。结果表明，单独的ＨＰＤ或光照对无细胞体系ＤＮＡ合成无影响；而既用ＨＰＤ处理，又经光照后的ＤＮＡ合成系统表现出明显的抑制作用。此抑制作用呈显著的剂量和时间的依赖效应关系．ＨＰＤ的光敏反应与ＤＮＡ模板非竞争性地作用于酶。增加模板量不能使抑制作用逆转：而增加酶量可使抑制作用部分逆转。四种脱氧核苷三磷酸与ＨＰＤ预保温未见抑制作用；酶与ＨＰＤ预保温后抑制率比对照组增加两倍；而酶和ＤＮＡ一起与之预保温后抑制率则增加近４倍。捉示ＨＰＡ的光敏效应是既抑制了酶活性又破坏了ＤＮＡ模板的结构和功能，从而发挥最大的抑制作用。
Herein, DNA-dependent DNA polymerases were partially purified from ascites-type hepatoma cells. The heat-denatured calf thymus DNA was used as a template to observe the effect of the photosensitive effect of HPD on this DNA synthesis system. The results showed that HPD alone or light had no effect on DNA synthesis in cell-free systems; both HPD-treated and light-exposed DNA synthesis systems showed significant inhibitory effects. This inhibition is a significant dose-and time-dependent effect. The photosensitive reaction of HPD and the DNA template act on the enzyme non-competitively. Increasing the amount of template does not reverse the inhibition: increasing the amount of enzyme can reverse some of the inhibition. Pre-incubation of four deoxynucleoside triphosphates with HPD showed no inhibitory effect; the inhibition rate after pre-incubation of the enzyme with HPD was twice as high as that of the control group; and the inhibition rate of the enzyme and DNA pre-incubated with it was increased by nearly 4 times. The photosensitizing effect of HPA is to both inhibit the enzyme activity and destroy the structure and function of the DNA template, thereby exerting the greatest inhibitory effect.