Mass spectrometric sequencing of site-specific carcinogen-modified oligodeoxyribonucleotides containing bulky benzo[a]pyrene diol epoxide-deoxyguanosyl adducts.
Site-specific carcinogen-modified oligonucleotides are often used in site-directed mutagenesis and other biological and biochemical studies of structure-function relationships. Postsynthetic analysis and confirmation of the sites of carcinogen binding in such oligonucleotides is an important step in the characterization of these site-specific carcinogen-DNA adducts. It is shown here that negative ion mode electrospray tandem mass spectrometry methods and collision-induced dissociation offer a rapid and convenient approach for the sequencing of products derived from the reaction of the carcinogenic and mutagenic metabolite of benzo[a]pyrene, the diol epoxide r7,t8-dihydroxy-t9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE), with the 11-mer oligonucleotide d(CATGCGGCCTAC). The site of reaction of anti-BPDE with either one of the three dG residues in this oligonucleotide can be accurately established by comparing the mass/charge ratios of the observed collision-induced dissociation fragments with calculated values.
Ni
J
J
American Health Foundation, Valhalla, New York 10595, USA.
Liu
T
T
Kolbanovskiy
A
A
Krzeminski
J
J
Amin
S
S
Geacintov
N E
NE
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000032:analysis* / Q000138:chemical synthesis; D000838:Anions; D002851:Chromatography, High Pressure Liquid; D018736:DNA Adducts / Q000032:analysis* / Q000138:chemical synthesis; D013058:Mass Spectrometry / Q000379:methods*; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000235:genetics*; D011849:Radioactive Tracers; D017422:Sequence Analysis, DNA / Q000379:methods*
D000838:Anions; D018736:DNA Adducts; D009838:Oligodeoxyribonucleotides; D011849:Radioactive Tracers; C043931:benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide-DNA; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide