Nucleic Acids Research, 2003, Vol. 31, No. 18 5413-5424
© 2003 Oxford University Press
Identification and characterization of a novel cross-link lesion in d(CpC) upon 365-nm irradiation in the presence of 2-methyl-1,4-naphthoquinone
Department of Chemistry-027, University of California at Riverside, Riverside, CA 92521-0403, USA
*To whom correspondence should be addressed. Tel: +1 909 787 2700; Fax: +1 909 787 4713; Email: yinsheng.wang{at}ucr.edu
We report the isolation and characterization for the first time of a cross-link lesion between two adjacent cytosines from the 2-methyl-1,4-naphthoquinone (menadione)-sensitized 365-nm irradiation of d(CpC). Electrospray ionization mass spectrometry (ESI-MS), tandem MS and 1H NMR results indicate that the cross-link occurs between the C5 carbon atom of one cytosine and the N4 nitrogen atom of the other cytosine. Furthermore, we synthesized d(CpC) with a 15N being incorporated on the amino group of either of the two cytosines. We then irradiated the two 15N-labeled dinucleoside monophosphates, isolated the cross-link products and characterized them by MS and multi-stage tandem MS. The latter results established unambiguously that the N4 nitrogen atom of the 3'-nucleobase is involved in the covalent bond formation between the two cytosines. This, in combination with two-dimensional nuclear Overhauser effect spectroscopy (NOESY) results, demonstrates that the cross-link arises from the formation of a covalent bond between the C5 carbon atom of the 5' cytosine and the N4 nitrogen atom of the 3' cytosine. We also show that the solution pH has a significant effect on the formation of the cross-link lesion, which supports that the deprotonation at the exocyclic amino group of cytosine cation radical is essential for the formation of the cross-link lesion.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
Y. Zeng and Y. Wang Sequence-dependent formation of intrastrand crosslink products from the UVB irradiation of duplex DNA containing a 5-bromo-2'-deoxyuridine or 5-bromo-2'-deoxycytidine Nucleic Acids Res., December 2, 2006; 34(22): 6521 - 6529. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Zhang and Y. Wang Generation of 5-(2'-deoxycytidyl)methyl radical and the formation of intrastrand cross-link lesions in oligodeoxyribonucleotides Nucleic Acids Res., March 14, 2005; 33(5): 1593 - 1603. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Bergeron, D. Houde, D. J. Hunting, and J. R. Wagner Electron transfer in DNA duplexes containing 2-methyl-1,4-naphthoquinone Nucleic Acids Res., December 7, 2004; 32(21): 6154 - 6163. [Abstract] [Full Text] [PDF] |
||||
