Table 1.

Differentially protonated residues in catB and pK_a values

		Average values during 40ns MD
Residue	predicted crystal	pH 5,5	pH 8
C29	2,14	3.7 ± 1.5	7.3 +1.6
E36	5,9	5.4 ± 0.5	3.4 ± 1.2
H97	6,9	7.1 ± 0.2	7.3 ± 0.4
H110	6,6	6.6 ± 0.8	8.1 ± 0.7
E171	7,7	7.4 ± 0.2	6.5 ± 0.4
H190	7,2	7.1 ± 0.2	7.4 ± 0.7
H199	7,8	8.1 ± 2	4.5 ± 1.7

pK_a values predicted by PROPKA and the state of ionizable groups under different pH conditions are indicated. The protonation state of C29 at pH 8 were obtained taking into account deprotonation of H199 as previously proposed for papain. The protonation states of the catalytic residues (C29 and H199) are highlighted.