Weidner M F, Sigurdsson S T, Hopkins P B
Department of Chemistry, University of Washington, Seattle 98195.
Biochemistry. 1990 Oct 2;29(39):9225-33. doi: 10.1021/bi00491a017.
The nucleotide sequence preferences of the DNA interstrand cross-linking agents dehydroretronecine diacetate (DHRA), 2,3-bis(acetoxymethyl)-1-methylpyrrole (BAMP), dehydromonocrotaline, and dehydroretrorsine were studied by using synthetic DNA duplex fragments and polyacrylamide gel electrophoresis (PAGE). These agents have structural features in common with the reductively activated aziridinomitosene of mitomycin C (MC). Like MC, they preferentially cross-linked DNA duplexes containing the duplex sequence 5'-CG. For DHRA and BAMP interstrand cross-linked DNA duplexes, PAGE analysis of iron(II)-EDTA fragmentation reactions revealed the interstrand cross-links to be deoxyguanosine to deoxyguanosine (dG-to-dG), again analogous to DNA cross-links caused by MC. Unlike MC, DHRA could be shown to dG-to-dG cross-link a 5'-GC sequence. Furthermore, the impact of flanking sequence on the efficiency of interstrand cross-linking at 5'-CG was reduced for BAMP, with 5'-TCGA and 5'-GCGC being equally efficiently cross-linked. Possible origins of the 5'-CG sequence recognition common to all of the agents are discussed. A model is presented in which the transition state for the conversion of monoadducts to cross-links more closely resembles ground-state DNA at 5'-CG sequences.
通过使用合成DNA双链片段和聚丙烯酰胺凝胶电泳（PAGE），研究了DNA链间交联剂二乙酸脱氢雷托品（DHRA）、2,3-双（乙酰氧基甲基）-1-甲基吡咯（BAMP）、脱氢野百合碱和脱氢倒千里光碱的核苷酸序列偏好性。这些试剂与丝裂霉素C（MC）的还原活化氮丙啶丝裂霉素具有共同的结构特征。与MC一样，它们优先交联含有双链序列5'-CG的DNA双链体。对于DHRA和BAMP链间交联的DNA双链体，铁（II）-EDTA断裂反应的PAGE分析表明，链间交联是脱氧鸟苷与脱氧鸟苷（dG-to-dG），这再次类似于MC引起的DNA交联。与MC不同，DHRA可以被证明能使5'-GC序列发生dG-to-dG交联。此外，对于BAMP，侧翼序列对5'-CG处链间交联效率的影响降低，5'-TCGA和5'-GCGC被同等有效地交联。讨论了所有试剂共有的5'-CG序列识别的可能起源。提出了一个模型，其中单加合物转化为交联的过渡态在5'-CG序列处更类似于基态DNA。
