Tandem mass spectrometry for the determination of the sites of DNA interstrand cross-link.
Formation of DNA interstrand cross-link is implicated in the mechanism of anticancer activity of some drugs. Here we examined the fragmentation of deprotonated ions of double-stranded oligodeoxynucleotides (ODNs) that are covalently held together with either a mitomycin C or a 4,5',8-trimethylpsoralen. Our results showed that, upon collisional activation, the covalently-bound duplex ODNs cleaved to give a series of wn and [an-base] ions; the sites of interstrand cross-linking could be determined from the mass shifts of some product ions. In addition, compared with the product-ion spectra acquired on an ion trap, those obtained from sustained off-resonance irradiation-collisionally activated dissociation (SORI-CAD) on a Fourier transform mass spectrometer offered high mass-resolving power, which facilitated unambiguous assignment of product ions and made it an effective method for locating the cross-linking sites.
Wang
Yuesong
Y
Department of Chemistry, University of California at Riverside, Riverside, California 92521-0403, USA.
Zhang
Qingchun
Q
Wang
Yinsheng
Y
D000903:Antibiotics, Antineoplastic / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D016685:Mitomycin / Q000737:chemistry*; D017319:Photosensitizing Agents / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D014307:Trioxsalen / Q000737:chemistry*
D000903:Antibiotics, Antineoplastic; D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D016685:Mitomycin; D004247:DNA; D014307:Trioxsalen