Effect of Polymethylene and Phenylene Linking Groups on the DNA Cleavage Specificity of Distamycin-Linked Hydroxamic Acid-Vanadyl Complexes.
作者:Shigeki HASHIMOTO、Takahiro INUI、Yushin NAKAMURA
DOI:10.1248/cpb.48.603
日期:——
Two types of distamycin-linked hydroxamic acids (DHA), which contain various lengths of polymethylene chains (PM-DHA) and relatively rigid phenylene ones (Ph-DHA), have been synthesized for the first time. Their DNA cleavage specificities were investigated by an end-labeled fragment cleavage experiment in the presence of vanadyl ion and hydrogen peroxide. The DNA cleavage by the PM-DHA·VO(II) complexes was shown to be very dependent on the length of the chain and the AT sequences. The tetramethylene DHA (1b) complex exhibited highly specific cleavage patterns flanking the 8 and 10 AT sites. Interestingly, the Ph-DHA complexes selectively cleaved the 5' end-labeled strand at the AT sites, but did not cleave the 3' end-labeled strand. The vanadyl complexing moieties and the local sequence conformation of the AT tract are suggested to contribute significantly to the DNA recognition of the PM-DHA·VO(II) complexes.
我们首次合成了两种与地霉素相连的羟肟酸(DHA),它们分别含有不同长度的聚亚甲基链(PM-DHA)和相对刚性的亚苯基链(Ph-DHA)。在香草醛离子和过氧化氢存在下,通过末端标记片段裂解实验研究了它们的 DNA 裂解特异性。结果表明,PM-DHA-VO(II)复合物对 DNA 的裂解作用与链的长度和 AT 序列有很大关系。四亚甲基 DHA(1b)复合物在 8 AT 位点和 10 AT 位点两侧表现出高度特异性的裂解模式。有趣的是,Ph-DHA 复合物可选择性地裂解 AT 位点上的 5'末端标记链,但不会裂解 3'末端标记链。这表明香草酰复合物分子和 AT 道的局部序列构象对 PM-DHA-VO(II) 复合物的 DNA 识别起了重要作用。