Yoshida S, Tamiya-Koizumi K, Kojima K
Laboratory of Cancer Cell Biology, Nagoya University School of Medicine, Japan.
Biochim Biophys Acta. 1989 Jan 23;1007(1):61-6. doi: 10.1016/0167-4781(89)90130-9.
Effects of various phospholipids on the in vitro reactions of eukaryotic DNA polymerases alpha, beta and gamma were tested systematically. When phospholipids were added directly to the reaction mixture, neither stimulation nor inhibition was produced. However, when phospholipids were preincubated with enzymes in the absence of template-primer, some of them showed strong inhibition. Cardiolipin strongly inhibited the reactions of all three DNA polymerases and also of terminal deoxynucleotidyl transferase. Phosphatidylinositol selectively inhibited the reaction of DNA polymerase gamma. Phosphatidic acid moderately inhibited DNA polymerase alpha and strongly inhibited DNA polymerase gamma. The inhibition of DNA polymerase gamma by cardiolipin was nearly competitive with template-primer. Since the inhibition was reversed by the addition of 0.05% Triton-X 100 during preincubation, the phospholipid might interact with enzyme protein at the hydrophobic region in competition with template-primer. These results suggest a possible involvement of phospholipids in DNA replication in mitochondria and in nucleus through interaction with DNA polymerase.
系统测试了各种磷脂对真核生物DNA聚合酶α、β和γ体外反应的影响。当将磷脂直接添加到反应混合物中时，既没有产生刺激作用也没有抑制作用。然而，当在没有模板引物的情况下将磷脂与酶预孵育时，其中一些显示出强烈的抑制作用。心磷脂强烈抑制所有三种DNA聚合酶以及末端脱氧核苷酸转移酶的反应。磷脂酰肌醇选择性抑制DNA聚合酶γ的反应。磷脂酸适度抑制DNA聚合酶α并强烈抑制DNA聚合酶γ。心磷脂对DNA聚合酶γ的抑制作用几乎与模板引物存在竞争关系。由于在预孵育期间添加0.05%的 Triton-X 100可逆转这种抑制作用，因此磷脂可能在疏水区域与酶蛋白相互作用，与模板引物形成竞争。这些结果表明，磷脂可能通过与DNA聚合酶相互作用参与线粒体和细胞核中的DNA复制。
