Synthesis and Characterization of Fapy•dG-containing Oligonucleotides

[γ-³²P]-ATP was from Perkin Elmer Health Sciences Inc. (Shelton, CT). dNTPs were purchased from New England Biolabs (Beverly, MA). Oligonucleotides were either synthesized on an ABI 394 oligonucleotide synthesizer at JHU or obtained from Integrated DNA Technologies (Coralville, IA). Fapy•dG-containing oligonucleotides were synthesized as described previously (21 (link)), purified by 20% denaturing polyacrylamide gel electrophoresis and characterized by MALDI-TOF MS (Supplementary Figures S2 and S3). PC Spacer phosphoramidite for 5′-phosphorylation, 5′-cyanoethyl phosphoramidites for thymidine (T), N,N-dimethylformamidine-2′-deoxyguanosine (dG^dmf), as well as other reagents required for oligonucleotide synthesis were purchased from GLEN Research (Sterling, VA). N-Acetyl 2′-deoxycytidine 5′-cyanoethyl phosphoramidite (dC^Ac) and Universal UnyLinker™ Support were purchased from Chemgenes (Wilmington, MA). 5′-cyanoethyl phosphoramidite of N-Pac-2′-deoxyadenosine was prepared as previously described (22 (link)). Disodium 2-carbamoyl-2-cyanoethylene-1,1-dithiolate trihydrate for methyl deprotection was prepared as previously described (38 (link)).