Passadore M, Bianchi N, Feriotto G, Mischiati C, Giacomini P, Piva R, Gambari R
Department of Biochemistry and Molecular Biology, Ferrara University, Italy.
Biochem J. 1995 Jun 1;308 ( Pt 2)(Pt 2):513-9. doi: 10.1042/bj3080513.
In this report we analyse the effects of distamycin and five distamycin analogues on amplification by polymerase-chain reaction (PCR) of two gene sequences displaying a different A+T/G+C content. The first was a 5' region of the human oestrogen receptor (ER) gene, containing a (TA)26 stretch; the second was a CG-rich sequence of the human Ha-ras oncogene. The results obtained unequivocally demonstrate that the addition of one pyrrole ring significantly improves the ability of distamycin derivatives to interfere with PCR-mediated amplification of the human ER genomic region carrying a (TA)26 stretch. The distamycin analogues analysed differ in the number of pyrrole rings and in the presence of an N-formyl, an N-formimidoyl or a retroamide group at position X1. Among compounds carrying the same number of pyrrole rings, those carrying an N-formyl or an N-formimidoyl group retain a similar inhibitory activity. The retroamide analogues, on the contrary, are much less efficient in inhibiting PCR-mediated amplification of the 5'ER region. With respect to sequence selectivity both distamycin and distamycin analogues exhibit a sequence preference, since they do not inhibit PCR amplification of Ha-ras CG-rich gene regions, with the exception of a distamycin analogue carrying four pyrrole rings.
在本报告中，我们分析了偏端霉素及其五种类似物对两个具有不同A+T/G+C含量的基因序列进行聚合酶链反应（PCR）扩增的影响。第一个序列是人类雌激素受体（ER）基因的5'区域，包含一段（TA）26重复序列；第二个序列是人类Ha-ras癌基因的富含CG的序列。所获得的结果明确表明，添加一个吡咯环可显著提高偏端霉素衍生物干扰携带（TA）26重复序列的人类ER基因组区域的PCR介导扩增的能力。所分析的偏端霉素类似物在吡咯环数量以及X1位置是否存在N-甲酰基、N-甲脒基或反向酰胺基团方面存在差异。在携带相同数量吡咯环的化合物中，那些携带N-甲酰基或N-甲脒基的化合物具有相似的抑制活性。相反，反向酰胺类似物在抑制5'ER区域的PCR介导扩增方面效率要低得多。关于序列选择性，偏端霉素及其类似物都表现出序列偏好性，因为它们不抑制Ha-ras富含CG的基因区域的PCR扩增，但携带四个吡咯环的偏端霉素类似物除外。
