. Author manuscript; available in PMC: 2008 Sep 21.

Published in final edited form as: Biochemistry. 2006 Oct 3;45(39):11867–11878. doi: 10.1021/bi060930g

Table 2.

Predicted pKa values of key residues in the active site of wild type and H103W mutant SmNACE and human CD38

Residue	SmNACE				Human CD38

	pKa (WT )		pKa (H103W)		pKa

Glu (signature)^d	0.96^a	0.00^b	5.22^a	1.45^b	5.78^a	1.55^b
Glu (catalytic)^e	6.83^a	4.25^b	7.18^a	6.25^b	7.16^a	4.75^b
His¹⁰³	7.16^a	6.35^b	n.a.^c	n.a.^c	n.a.^c	n.a.^c

Empirical calculation using PROPKA.

Calculation based on electrostatic continuum model using dielectric constant values ranging from 2 for the catalytic Glu to 6 for His¹⁰³ and the ‘signature’ Glu.

Not applicable.

Glu¹²⁴ and Glu¹⁴⁶ in SmNACE and human CD38, respectively, are part of the ‘signature region’ of the ADP-ribosyl cyclases.

Glu²⁰² and Glu²²⁶ in SmNACE and human CD38, respectively.