Matrix-assisted laser desorption/ionization mass spectrometry of deoxynucleotides labeled with an IMI dye.
The four major deoxynucleotides of DNA, and adduct mixtures resulting from separate reactions of 5'-dAMP and 5'-dGMP with benzo[a]pyrene diolepoxide (BPDE), were analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) after labeling of their phosphate group with an IMI dye. The latter reagent comprises an imidazole functional group attached to a BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene+ ++) fluorophore. Good sensitivity was observed in the detection of the IMI-labeled products by MALDI-MS: 300-500 fmol in the laser spot (1% of the 30-50 pmol sample on the target) gave a signal-to-noise (S/N) of >/=30 from 20-30 superimposed laser shots. The BPDE reaction products, after the IMI labeling, were also subjected to capillary electrophoresis with laser-induced fluorescence detection, which revealed a complex mixture of products. Overall the results encourage the further development of this 'IMI-postlabeling' methodology as an alternative to (32)P-postlabeling for the detection of DNA adducts.
Department of Pharmaceutical Sciences in the Bouvé College of Pharmacy and Health Professions, Barnett Institute, and Chemistry Department, Northeastern University, Boston, MA 02115, USA.
Z H
ZH
Lan
P
P
Wang
R W
RW
Giese
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D018736:DNA Adducts / Q000737:chemistry; D003854:Deoxyribonucleotides / Q000737:chemistry*; D005456:Fluorescent Dyes; D013058:Mass Spectrometry / Q000379:methods*
D018736:DNA Adducts; D003854:Deoxyribonucleotides; D005456:Fluorescent Dyes; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide