Table III.

The dependence of the calculated pK_a of the V66D mutant of SNase on the method used ^(a)

	ΔGnp→crg	ΔΔGw→p	$\mathrm{\Delta }\mathrm{\Delta }{G}_{\mathit{sol},LW}^{w\to p(AH,MW)}$	pKa (4.0+ ΔΔGw→p/1.37)
In water (ΔGw)	−81.0	---
In protein (ΔGp) (procedure A)	−46.0	35.0		29.5
In protein (ΔGp) (procedure B)	−72.6	8.4	0.0	10.1

^(a)Energy values are reported in kcal/mol. A weak constraint of 0.3 kcal/mol was used to keep the LRA/MC generated water molecules in place. Procedure A corresponds to using standard solvation approach while including water molecules resolved by X-ray, whereas Procedure B corresponds to using our water flooding LRA/MC screening approach. All of these molecular dynamics simulations are performed using the polarizable ENZYMIX force field [36].