85819-69-8Relevant articles and documents
Synthesis, miscoding specificity, and thermodynamic stability of oligodeoxynucleotide containing 8-methyl-2'-deoxyguanosine
Kohda, Kohfuku,Tsunomoto, Hirotaka,Minoura, Yasushi,Tanabe, Kazushi,Shibutani, Shinya
, p. 1278 - 1284 (1996)
8-Methyl-2'-deoxyguanosine (8-MedG) was synthesized by reacting dG under the methyl radical generating system and incorporated into oligodeoxynucleotides using phosphoramidite techniques. The site-specifically modified oligodeoxynucleotide containing a single 8-MedG was then used as a template for primer extension reactions catalyzed by the 3'-5' exonuclease- free (exo-) Klenow fragment of Escherichia coli DNA polymerase I and mammalian DNA polymerase α. Primer extension catalyzed by the exo- Klenow fragment readily passed the 8-MedG lesion in the template while that catalyzed by pol α was retarded opposite the lesion. The fully extended products formed during DNA synthesis were analyzed to quantify the miscoding specificities of 8-MedG. Both DNA polymerases incorporated primarily dCMP, the correct base opposite the lesion, along with small amounts of incorporation of dGMP and dAMP. In addition, two-base deletion was observed only when the exo- Klenow fragment was used. The thermodynamic stability of 8-MedG in the duplex was also studied. The duplex containing 8-MedG:dG was more thermally and thermodynamically stable than that of dG:dG. The duplex containing 8-MedG:dA was more thermodynamically stable than that of dG:dA. We conclude that 8-MedG is a miscoding lesion and capable of generating G → C and G → T transversions and deletion in cells.
