Structure elucidation of DNA interstrand cross-link by a combination of nuclease P1 digestion with mass spectrometry.
DNA interstrand cross-link reagents are among the most powerful agents for cancer treatment. Here we report a combined nuclease P1 digestion/mass spectrometry method for the structure elucidation of duplex oligodeoxynucleotides (ODNs) containing an interstrand cross-link. Our results demonstrate that nuclease P1 digestion of a double-stranded ODN containing an interstrand cross-link (ICL) of 4,5',8-trimethylpsoralen or mitomycin C gives a tetranucleotide bearing the cross-linked nucleobase moiety. Product ion spectra of the deprotonated ions of the tetranucleotides provide information about the structure of the cross-link. Furthermore, product-ion spectra of tetranucleotides containing two orientation isomers of mitomycin C interstrand cross-link are distinctive. We believe that the method described in this paper can be generally applicable for investigating the structures of other DNA ICLs.
Wang
Yuesong
Y
Department of Chemistry-027, University of California at Riverside, Riverside, California 92521-0403, USA.
Wang
Yinsheng
Y
D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D007536:Isomerism; D013058:Mass Spectrometry; D016685:Mitomycin / Q000737:chemistry; D015394:Molecular Structure; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism*; D014307:Trioxsalen / Q000737:chemistry
D003432:Cross-Linking Reagents; D016685:Mitomycin; D004247:DNA; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014307:Trioxsalen