Usuki T, Inoue M, Akiyama K, Hirama M. ESR studies on DNA cleavage induced by enediyne C-1027 chromophore.
Bioorg Med Chem 2005;
13:5218-24. [PMID:
15979878 DOI:
10.1016/j.bmc.2005.05.049]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Revised: 05/26/2005] [Accepted: 05/26/2005] [Indexed: 11/23/2022]
Abstract
C-1027 belongs to the family of chromoprotein antitumor antibiotics, which contain a carrier apoprotein and a highly unstable enediyne chromophore. The enediyne spontaneously aromatizes to generate p-benzyne biradical, and subsequently abstracts hydrogens from the DNA sugar backbone, resulting in cleavage of the double strand. Using spin-trapping methods, we obtained direct proof of radical intermediates during an DNA cleavage, and found intriguing difference in behavior between the trapping agents 2-methyl-2-nitrosopropane (MNP) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO): MNP added to the sugar radicals of the DNA, whereas DMPO directly trapped a phenyl radical or p-benzyne biradical derived from the C-1027 chromophore.
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