Table 4.

Averaged ΔE values calculated using SQM methods between VA (neutral and cation radical) and the wild-type and mutated regions (REG and MREG, respectively) constituted by amino acids located at <5.5 Å from LiPH8 Trp171, which was included in its non-radical (Trp171), radical cation (Trp171^•+) and neutral radical (Trp171^•) forms. Averaged SASA values for Trp171 are also shown.

LiP regionsa	Average interaction energy (ΔE in kcal·mol−1)			Residual Activityb (%)	Trp171 SASAc (Å2)
	Trp•/VA	TrpH•+/VA	Trp/VA•+
REG(wild type)	−10.4 ± 0.4	−29.6 ± 0.4	−161.9 ± 0.2	100 ± 0.9	399 ± 0.3
MREG(D165N)	−5.5 ± 0.3	−15.3 ± 0.3	−124.3 ± 0.3	59.0 ± 0.4	385 ± 0.4
MREG(E168Q)	−8.1 ± 0.2	−24.4 ± 0.2	−138.4 ± 0.3	68.2 ± 1.3	394 ± 0.3
MREG(E250Q)	−4.1 ± 0.2	−5.1 ± 0.3	−109.1 ± 0.2	24.0 ± 0.4	379 ± 0.2
MREG(D264N)	−9.8 ± 0.4	−22.7 ± 0.2	−145.8 ± 0.4	92.3 ± 1.8	404 ± 0.4
MREG(F267I)	−6.5 ± 0.2	−18.1 ± 0.4	−135.9 ± 0.5	71.0 ± 1.7	390 ± 0.3

^aRegions located at <5.5 Å from Trp171.

^bThe residual activity was evaluated in 0.1 M sodium tartrate buffer pH 3.0 using 0.31 mM VA (saturated concentration), 0.25 mM H₂O₂ and 0.01 μM of enzyme. Residual activity (%) was calculated as the quotient between enzyme activity of each mutant and wild type LiP, and then multiplied by 100.

^cAveraged SASA of Trp171 considering the steric hindrance at the different (wild-type and mutated) LiP regions.