2′-Deoxyguanosine (2′-dG), 2′-deoxyguanosine 3′-monophosphate (3′-dGMP), 2′-deoxyguanosine 5′-monophosphate (5′-dGMP) and lithium chloride (99% anhydrous, SigmaUltra) were obtained from Sigma Chemical Company (St Louis). Potassium persulfate (crystal) was purchased from Mallinckrodt, Inc. (Paris, KY). 3′-D-2′-deoxyguanosine (3′-D-2′-dG) and 5′,5′-D,D-2′-deoxyguanosine (5′-D,D-2′-dG) were obtained from Omicron Biochemicals, Inc. (South Bend, IN). All chemicals were used without further purification. Deuteration at C-8 in the guanine moiety of 2′-dG, 5′-D,D-2′-dG, 3′-dGMP and 5′-dGMP was performed according to Huang et al. (34 (link)) using triethylamine (TEA) from Fischer Scientific, NJ; the degree of deuteration (≥96%) was determined by 1D NMR signal integration using a Bruker 200 MHz NMR.
To prepare glassy samples, ∼3 mg of nucleoside or nucleotide were dissolved in 1 ml of 7 M LiCl in D2O in the presence of 5 mg K2S2O8. If required, the pH was adjusted by adding appropriate amounts of 1 M NaOH in D2O or concentrated HCl under ice-cooled conditions. All pHs were measured using pH paper; because of this and because of the high ionic strength of the glasses, the pHs reported here are approximations. The solutions were then thoroughly bubbled with nitrogen. Using these solutions, the glassy samples were then prepared by cooling to 77 K as reported earlier (15 (link)). All samples are stored at 77 K.
To prepare glassy samples, ∼3 mg of nucleoside or nucleotide were dissolved in 1 ml of 7 M LiCl in D2O in the presence of 5 mg K2S2O8. If required, the pH was adjusted by adding appropriate amounts of 1 M NaOH in D2O or concentrated HCl under ice-cooled conditions. All pHs were measured using pH paper; because of this and because of the high ionic strength of the glasses, the pHs reported here are approximations. The solutions were then thoroughly bubbled with nitrogen. Using these solutions, the glassy samples were then prepared by cooling to 77 K as reported earlier (15 (link)). All samples are stored at 77 K.
