Iiyama Takamasa, Chikira Makoto, Oyoshi Takanori, Sugiyama Hiroshi
J Biol Inorg Chem. 2003 Jan;8(1-2):135-40. doi: 10.1007/s00775-002-0398-3. Epub 2002 Sep 11.
Binding structures of metal complexes of deglyco-peplomycin (dPEP) on DNA were investigated by comparing dPEP complexes with those of bleomycin (BLM) using DNA fiber EPR spectroscopy. A low spin species of Fe(III)dPEP observed in the DNA pellet changed irreversibly to several high spin species after the fabrication of the DNA fibers. The g values of the high spin species were different from those of Fe(III)BLM. The high spin species could not be nitrosylated reductively to ON-Fe(II)dPEP, suggesting that some nitrogen atoms coordinated to the Fe(III) were displaced on the DNA fibers. On the other hand, O(2)-Co(II)dPEP remained intact on the fibers similarly to O(2)-Co(II)BLM but with an increased randomness in the orientation on the DNA. In contrast to Cu(II)BLM, a considerable amount of Cu(II)dPEP bound almost randomly on B-form DNA fibers. These results indicated that the sugar moiety in peplomycin or bleomycin is playing an important role in enhancing the stability of the metal-binding domain and in the stereospecificity of the binding on DNA.
通过使用DNA纤维电子顺磁共振光谱法比较去糖肽博来霉素（dPEP）与博来霉素（BLM）的配合物，研究了dPEP金属配合物在DNA上的结合结构。在DNA沉淀中观察到的低自旋态Fe(III)dPEP在制造DNA纤维后不可逆地转变为几种高自旋态。高自旋态的g值与Fe(III)BLM的不同。高自旋态不能被还原亚硝化形成ON-Fe(II)dPEP，这表明与Fe(III)配位的一些氮原子在DNA纤维上发生了位移。另一方面，O(2)-Co(II)dPEP在纤维上保持完整，类似于O(2)-Co(II)BLM，但在DNA上的取向随机性增加。与Cu(II)BLM不同，相当数量的Cu(II)dPEP几乎随机地结合在B型DNA纤维上。这些结果表明，肽博来霉素或博来霉素中的糖部分在增强金属结合域的稳定性以及在DNA上结合的立体特异性方面起着重要作用。
