Table 1.

The two pK _a values and their ∆pK _a difference for each peptide: KK, KAK, KAK2, KAK3, KAK4, KAK5, in water, at 298.1 K obtained by fitting of the equilibrium model of dissociation to the potentiometric titration curves

	KK	KAK	KAK2	KAK3	KAK4	KAK5
pK a1	5.95 (0.12)a	8.73 (0.23)	9.36 (0.09)	8.20 (0.12)	9.67 (0.10)	9.93 (0.14)
pK a2	8.66 (0.13)	8.91 (0.14)	9.93 (0.17)	11.41 (0.29)	11.92 (0.27)	10.99 (0.19)
ΔpK ba	2.71	0.18	0.57	3.41	2.25	1.06

^aNumbers in parentheses are the standard deviations

^bpK _a2−pK _a1