Table 1.

Summary of experimentally measured 1456 residue-specific wild-type pKa values collected from literature

Residue ID	No. of measurements	Average pKa	Lowest pKa	Highest pKa	Intrinsic pKa
ASP	450	3.56	0.5	9.9	3.9
GLU	455	4.13	2.1	7.2	6.5
HIS	264	6.61	2.5	9.19	4.3
LYS	168	10.69	6.5	12.12	9.8
TYR	50	10.50	9.14	>12.5	10.4
CYS	22	6.10	2.88	>14.9	8.6
N-term	22	7.64	6.91	9.14	8.0
C-term	25	3.15	2.4	4.03	3.7

^afootnoteA.

^bfootnote B.