Murugesan N, Ehrenfeld G M, Hecht S M
J Biol Chem. 1982 Aug 10;257(15):8600-3.
Both Fe(III) and Cu(II) complexes of bleomycin (BLM), but not N-acetyl BLM . Fe(III), mediated the transfer of oxygen from iodosobenzene to organic substrates. In analogy with results obtained using certain cytochrome P-450 analogs, cis-stilbene was converted cleanly to the respective oxide, while no more than traces of trans-stilbene oxide were formed from trans-stilbene under identical conditions. The possible relevance of these observations to the degradation of DNA by bleomycin was also studied. In both the presence and absence of O2, BLM . Cu(II) . C6H5IO effected DNA degradation, as judged by the release of [3H]thymine from radiolabeled Escherichia coli DNA. These findings provide a valuable new assay system for the study of bleomycin analogs and suggest the possibility that bleomycin may function as an "oxygen transferase" in its degradation of DNA in situ.
博来霉素（BLM）的铁（III）和铜（II）配合物能介导氧从亚碘酰苯转移至有机底物，但N - 乙酰博来霉素·铁（III）则不能。与使用某些细胞色素P - 450类似物得到的结果相似，顺式芪能被顺利转化为相应的氧化物，而在相同条件下，反式芪生成的反式芪氧化物不超过痕量。还研究了这些观察结果与博来霉素降解DNA的可能相关性。无论有无O₂，通过放射性标记的大肠杆菌DNA中[³H]胸腺嘧啶的释放判断，博来霉素·铜（II）·碘苯均能导致DNA降解。这些发现为博来霉素类似物的研究提供了一个有价值的新检测系统，并提示博来霉素在原位降解DNA时可能作为一种“氧转移酶”发挥作用。
