Table 3.

Classification of phenotypic consequences due to NQO1 mutations based on experimental data. The experimental scores (ES) are calculated as the average from individual scores determined for each phenotypic trait as follows: Expression: +++, 50–100% of WT levels; ++, 20–50% of WT levels; +, <20% of WT levels; Thermal stability: +++, within 2 °C of WT T_m; ++, within 2–5 °C of WT T_m; +, >5 °C lower than WT T_m; Proteolysis: +++, rate constant within three-fold vs. WT (0.65 kcal·mol⁻¹); ++, within 3 to 30-fold vs. WT (2 kcal·mol⁻¹); ++ >30-fold faster than WT (over 2 kcal·mol⁻¹); FAD binding: +++, within three-fold of WT K_d; ++, within 3–10 fold higher than WT K_d; +, >10-fold higher than WT K_d; Dic binding: +++, within three-fold of WT K_d; ++, within 3–10 fold higher than WT K_d; +, >10-fold higher than WT K_d.

Variant	Expression	Thermal Stability	Proteolysis	FAD Binding	Dic Binding	ES
G3S	+++	+++	+++	+++	+++	3
G3D	+++	+++	+++	+++	+++	3
L7P	+					1
L7R	+					1
V9I	+++	+++	+++	+++	+++	3
T16M	+++	++	++	+	+++	2.2
Y20N	+++	++	+++	++	+++	2.6
A29T	+++	+++	+++	++	+++	2.8
P187S	+++	+	+	+	+	1.4
P187E	+					1
P187R	+					1
P187L	+					1
P187A	+++	++	+	++	++	2
P187G	++	+	++	+++	++	2
P187T	+++	++	+	++	+	1.8
K240Q	+++	+++	++	++	++	2.4
K240I	+++	+++	++	+++	+++	2.8
K240E	+++	+++	+	++	++	2.2
K240T	+++	+++	+++	++	+++	2.8
K240H	+++	+++	++	++	+++	2.6
K240A	+++	+++	+	+++	+++	2.6
K240G	+++	+++	+	++	++	2.2