胸腺淋巴细胞末端脱氧核苷酸转移酶和脱氧核糖核酸α-聚合酶活性的部分抑制

小牛胸腺末端脱氧核苷酰转移酶(TdT)和脱氧核糖核酸α-聚合酶(α-酶)的活性同时存在于淋巴细胞的提取液中,经35-50％硫酸铵沉淀和p-纤维素柱层析使该两种酶部分纯化。药物抑制试验观察到环磷酰胺等抗癌药物对TdT活性有轻微抑制作用;放线菌素D、正定霉素、溴乙啶等对α-酶有明显抑制作用。但溴乙啶和正定霉素对TdT活性无抑制作用,放线菌素D对TdT的抑制不如对α-酶的抑制强烈。

Partial Inhition of DNA Polymerase and Terminal Deoxyribonucleotide Transferase Activities from Bovine Thymus Lymphocytes

This is a report of the partial inhibition of the activities of DNA polymerase and terminal deoxyribonucleotide transferase isolated from bovine thymus lymphocytes. These two enzymes which co-exist in the extract of the lymphocytes, can be partially purified through 35-50% ammonium sulfate precipitation and p cellulose chromatography. In the inhibition experiments by some antitumor drugs, we have observed that the terminal transferase activity was slightly inhibited by cyelophosphamide and the activity of DNA polymerase was only inhibited by the drugs actinomycin D, zhengdinmycin, and ethidium bramide, which all were known to act on the DNA template. Of these three drugs only actinomycin D was inhibitory to the activity of terminal transferase, and the other two had no such effect.