Mizushina Yoshiyuki, Kamisuki Shinji, Kasai Nobuyuki, Ishidoh Tomomi, Shimazaki Noriko, Takemura Masaharu, Asahara Hitomi, Linn Stuart, Yoshida Shonen, Koiwai Osamu, Sugawara Fumio, Yoshida Hiromi, Sakaguchi Kengo
Laboratory of Food and Nutritional Sciences, Department of Nutritional Science, and High Technology Research Center, Kobe-Gakuin University, Nishi-ku, Kobe, Hyogo 651-2180, Japan.
Biochemistry. 2002 Dec 10;41(49):14463-71. doi: 10.1021/bi020476q.
Petasiphenol, a bio-antimutagen isolated from a Japanese vegetable, Petasites japonicus, selectively inhibits the activities of mammalian DNA polymerase lambda (pol lambda) in vitro. The compound did not influence the activities of replicative DNA polymerases such as alpha, delta, and epsilon but also showed no effect even on the pol beta activity, the three-dimensional structure of which is thought to be highly similar to pol lambda. The inhibitory effect of petasiphenol on intact pol lambda including the BRCA1 C-terminus (BRCT) domain was dose-dependent, and 50% inhibition was observed at a concentration of 7.8 microM. The petasiphenol-induced inhibition of the pol lambda activity was noncompetitive with respect to both the DNA template-primer and the dNTP substrate. Petasiphenol did not only inhibit the activity of the truncated pol lambda including the pol beta-like core, in which the BRCT motif was deleted in its N-terminal region. BIAcore analysis demonstrated that petasiphenol bound selectively to the N-terminal domain of pol lambda but did not bind to the C-terminal region. On the basis of these results, the pol lambda inhibitory mechanism of petasiphenol is discussed.
蜂斗酚是从日本蔬菜蜂斗菜中分离出的一种生物抗诱变剂，它在体外能选择性抑制哺乳动物DNA聚合酶λ（pol λ）的活性。该化合物不影响诸如α、δ和ε等复制性DNA聚合酶的活性，对pol β的活性也没有影响，而pol β的三维结构被认为与pol λ高度相似。蜂斗酚对包含BRCA1 C末端（BRCT）结构域的完整pol λ的抑制作用呈剂量依赖性，在浓度为7.8 microM时观察到50%的抑制率。蜂斗酚对pol λ活性的抑制作用在DNA模板引物和dNTP底物方面均为非竞争性。蜂斗酚不仅抑制包含类pol β核心的截短型pol λ的活性，其中BRCT基序在其N端区域被删除。BIAcore分析表明，蜂斗酚选择性地与pol λ的N端结构域结合，但不与C端区域结合。基于这些结果，对蜂斗酚的pol λ抑制机制进行了讨论。
