Table 4.

Comparison of some data from Table 3 to pK_a correlations.^[a]

Base pair	Melting temp. (°C)	ΔpKa	pKa 3pH for each base pH was conducted at 7.9
3 H-bonds:
isoG :isoC	61.5, 63.3	~4.8	1 (isoG), 3.7 (isoC)
G :C	58.5, 59.5	~5.1	1.8 (G), 3.5 (C)
Dap : T	56.9, 58.4	~4.6	2.4 (Dap), 1.9 (T)
Dap : Psi	56.7	~4.5	2.4 (Dap), 1.8 (Psi)
Xan :Dpy[b]	47.5	~2	~1 (Xan), ~1.6 (Dpy)
2 H-bonds:
A :T	52.9, 55.9	~6.1	4.2 (A), 1.8 (T)
A :Psi	54.4	~6	4.2 (A), 1.8 (Psi)
Hyp : C	52.8, 54.6	~4.5	~1 (Hyp), 3.5 (C)
Hyp : Dpy	47.5	~1.8	1 (Hyp), 1.6 (Dpy)

^[a]Calculations were made using model presented in reference [63].

^[b]The pH in this experiment was measured at 5.4.