Tolwińska-Stańczyk Z, Wilmańska D, Studzian K, Gniazdowski M
Department of General Chemistry, Medical University of Lódź, Poland.
Mutat Res. 1997 Mar 4;374(1):139-43. doi: 10.1016/s0027-5107(96)00186-8.
The transcriptional template activity of covalent modified DNA is compared. 8-Methoxypsoralen (MOP), 3,4'dimethyl-8-methoxypsoralen (DMMOP) and benzopsoralen (BP) forming with DNA covalent complexes upon UV irradiation and exhibiting preference to pyrimidines, mostly thymines, differ in their cross-linking potency. MOP and DMMOP form both monoadducts and diadducts while no cross-links are formed by BP. Nitracrine (NC) forms covalent complexes with DNA upon reductive activation with dithiothreitol exhibiting a preference to purines and low cross-linking potency. Semilogarithmic plots of the relative template activity against the number of the drugs molecules covalently bound per 10(3) DNA nucleotides fit to regression lines corresponding to one-hit inactivation characteristics. The number of drug molecules decreasing RNA synthesis to 37% differ from 0.25 to 1.26 depending on the template used and the base preference but no dependence on the cross-linking potency was found.
比较了共价修饰DNA的转录模板活性。8-甲氧基补骨脂素（MOP）、3,4'-二甲基-8-甲氧基补骨脂素（DMMOP）和苯并补骨脂素（BP）在紫外线照射下与DNA形成共价复合物，且对嘧啶（主要是胸腺嘧啶）具有偏好性，它们的交联能力有所不同。MOP和DMMOP既形成单加合物也形成双加合物，而BP不形成交联。硝唑尼特（NC）在用二硫苏糖醇进行还原活化后与DNA形成共价复合物，对嘌呤具有偏好性且交联能力较低。相对模板活性相对于每10³个DNA核苷酸共价结合的药物分子数的半对数图符合对应于单次打击失活特征的回归线。使RNA合成降低至37%的药物分子数在0.25至1.26之间，这取决于所使用的模板和碱基偏好，但未发现与交联能力有关。
