Bando Toshikazu, Minoshima Masafumi, Kashiwazaki Gengo, Shinohara Ken-Ichi, Sasaki Shunta, Fujimoto Jun, Ohtsuki Akimichi, Murakami Masataka, Nakazono Satomi, Sugiyama Hiroshi
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
Bioorg Med Chem. 2008 Mar 1;16(5):2286-91. doi: 10.1016/j.bmc.2007.11.064. Epub 2007 Nov 29.
To investigate the effect of incorporation of beta-alanine in alkylating N-methylpyrrole (Py)-N-methylimidazole (Im) polyamide, seco-CBI conjugates 2-8 were synthesized by an Fmoc solid-phase method and subsequent coupling with an alkylating moiety. DNA-alkylating activities of conjugates 2-8 were evaluated by high-resolution denaturing gel electrophoresis with 202-base pair (bp) DNA fragments. Alkylation by conjugates 2 and 3, which have antiparallel pairings of beta-alanine (beta) opposite beta (beta/beta) and Py/beta, occurred mainly at the adenine (A) of the matching sequences, 5'-AGCTCCA-3' (site 1) and 5'-AGCACCA-3' (site 3). However, conjugate 4, with beta/Py, did not show any DNA-alkylating activities. Similarly, conjugate 5, which possessed a Py/Py pair, weakly alkylated the matching sites at micromolar concentrations. Conjugates 6 and 7, which possessed beta/beta and Py/beta pairs, respectively, alkylated at the A of the matching sequences, 5'-ACTACCA-3' (site 2) and 5'-ACAACCA-3' (site 4). In contrast, conjugated 8, with a Py/Py pair, showed lower activity and less alkylated DNA at sites 2 and 4 with mismatched alkylation at site 1 at a higher concentration than that of 6 and 7. These results demonstrate that incorporation of beta-alanine is required for the sequence-specific alkylation by seco-CBI Py-Im conjugates with a seven-base pair sequence.
为了研究将β-丙氨酸引入烷基化的N-甲基吡咯（Py）-N-甲基咪唑（Im）聚酰胺中的效果，通过Fmoc固相法并随后与烷基化部分偶联合成了开环喜树碱（seco-CBI）缀合物2-8。通过使用202碱基对（bp）DNA片段的高分辨率变性凝胶电泳评估缀合物2-8的DNA烷基化活性。具有β-丙氨酸（β）与β（β/β）和Py/β反平行配对的缀合物2和3的烷基化主要发生在匹配序列5'-AGCTCCA-3'（位点1）和5'-AGCACCA-3'（位点3）的腺嘌呤（A）处。然而，具有β/Py的缀合物4没有显示出任何DNA烷基化活性。同样，具有Py/Py对的缀合物5在微摩尔浓度下对匹配位点的烷基化作用较弱。分别具有β/β和Py/β对的缀合物6和7在匹配序列5'-ACTACCA-3'（位点2）和5'-ACAACCA-3'（位点4）的A处发生烷基化。相比之下，具有Py/Py对的缀合物8活性较低，在位点2和4处的DNA烷基化较少，在较高浓度下在位点1处存在错配烷基化，其烷基化程度低于缀合物6和7。这些结果表明，对于具有七个碱基对序列的seco-CBI Py-Im缀合物进行序列特异性烷基化，需要引入β-丙氨酸。
