. Author manuscript; available in PMC: 2011 Dec 17.

Published in final edited form as: J Mol Biol. 2010 Oct 13;404(5):902–916. doi: 10.1016/j.jmb.2010.09.027

Table 3.

Calculated pKa values for different types of titratable residues.

	Reference	Exposed (average value + SD)	N (exposed)	Buried (average value + SD)	N (buried)
CYS	9	7.49 ± 1.38	1857	9.51 ± 2.11	3925
TYR	10	10.55 ± 1.01	7227	11.56 ± 1.61	6646
HIS	6.5	6.61 ± 0.35	4837	4.12 ± 2.23	3358
ARG	12.5	12.18 ± 0.24	16091	11.64 ± 1.57	2950
LYS	10.5	10.33 ± 0.25	15083	9.85 ± 1.84	3746
GLU	4.5	4.18 ± 0.60	15636	4.6 ± 2.07	3263
ASP	3.8	3.45 ± 0. 58	10398	3.84 ± 2.20	7246

Each titratable residue in the analyzed set of 1,000 protein structures was divided in exposed and buried. In the case of Cys, only free and reduced Cys were analyzed (i.e., disulfide and metal-binding Cys, as defined in the text, were filtered out).