Correction: Shokeer et al. Mutational Analysis of the Binding of Alternative Substrates and Inhibitors to the Active Site of Human Glutathione Transferase P1–1. Processes 2020, 8, 1232

The changes below represent the corrections the authors wish to make to the original paper [1].

Errors in Tables

The authors wish to make changes to Tables 2–4. In the original publication, one of the values in Table 2 was not consistent with the text. For Tables 3 and 4, several values were missing a decimal point. The new

Table 2. Steady-state kinetic parameters of wild-type human GST P1–1 and mutants.

Parameter	Varied Substrate		GST P1–1 Variant
		Wild-Type	Q52K	Q52A	K45A
kcat/Km (s−1 mM−1) kcat/Km (s−1 mM−1)	CDNB Glutathione	83 ± 2 345 ± 9	4.9 ± 0.5 5.0 ± 0.5	25.6 ± 0.9 17.3 ± 0.8	46 ± 22 21.6 ± 0.4
Km (mM) Km (mM)	CDNB Glutathione	2.6 ± 0.2 0.5 ± 0.1	7.0 ± 2 4.7 ± 0.6	6.2 ± 0.8 2.8 ± 0.3	3.8 ± 0.4 0.8 ± 0.1
Vmax (µmol min−1 mg−1)		570 ± 30	70 ± 20	340 ± 30	440 ± 30

One substrate concentration was varied, whereas the concentration of the other substrate was kept constant. Constant CDNB was kept at 2 mM, and constant glutathione was kept at 6 mM in order to maintain approximately saturating conditions.

,

Table 3. Saturation kinetics in three dimensions.

Vmax (µmol min−1 mg−1)
[CDNB] (mM)	Wild-Type GSH	Q52K GSH	Wild-Type	Q52K
0.2	63	1.1	7.0	<0.1
0.5	110	2.9	9.9	0.6
1	162	5.9	11.6	4.3
“Saturated”	278	No value	13.8	No value

V_max values as obtained for three different concentrations of CDNB with variable concentrations of glutathione or γ-glutamylcysteine.

and

Table 4. Catalytic efficiency (k_cat/K_m) of GST P1–1 variants with alternative thiol substrates.

Substrate	GST P1–1 Variant
	Wild-TYPE kcat/Km (mM−1 s−1)	Q52K kcat/Km (mM−1 s−1)
GSH	380 ± 40	5.9 ± 0.6
γE-C	70 ± 1.3	3.6 ± 1.4

are attached below.

Changes to Figure and Figure Legend

The authors wish to make changes to Figure 3 and the Figure legend. In the original publication, some values were miscalculated, and a minor typographical error was detected in the Figure legend. The new Figure 3 with the Figure legend has been updated below.

Correction to Equation

The equation present in the original publication had a typographical error in it. The adjusted equation is attached below.

ΔΔG = −RT ln (Ki/Ki*)

(1)

Correction to Text

The authors wish to make changes to errors found in the main text.

3.3. Steady-State Kinetics

Paragraph 1: Original text: Mutant Q52K is most strongly affected with a nine-fold increase of K_M^CDNB, an eight-fold decrease of k_cat, and a resulting 70-fold decrease of k_cat/K_M^GSH (Table 2).

New text: Mutant Q52K is most strongly affected with a nine-fold increase in K_M^GSH, an eight-fold decrease in k_cat, and a resulting seventy-fold decrease in k_cat/K_M^GSH (Table 2).

Paragraph 3: Original text: However, the catalytic efficiency could be determined and showed that mutant Q52K was 50% more efficient than the wild-type enzyme with GSH as the varied thiol substrate.

New text: However, the catalytic efficiency could be determined and showed that the mutant Q52K only displayed a fraction (1.5%) of the efficiency of the wild-type enzyme with GSH as the varied thiol substrate.

3.4. Inhibition Studies

Paragraph 8: Original text: a potent ligand.

New text: a potent inhibitor.

The authors apologize for any inconvenience caused and state that the scientific conclusion of the paper is unaffected. The original publication has also been updated.