Table 4.

pKa values for methylated nucleobases and m⁷G

Nucleobase/nucleoside	pKa*
m7G	7.5†
m1Ade	7.5†
m3Ade	6.3
m1Cyt	6.3
m3Cyt	7.3†

^*Standard deviations between 0.3 and 0.5. 

^†pKa values of 7.5, 7.2, and 7.4 have previously been reported for m⁷G (8), m¹Ade, and m³Cyt (19), respectively.