The complex impact of cancer-related missense mutations on the stability and on the biophysical and biochemical properties of MAPK1 and MAPK3 somatic variants

Table 6 Kinetic parameters and effect of temperature on kinase activity of MAPK3 wild type and variants^a

	K_m (μM)	kcat (s⁻¹)	[enzyme] (nM)	kcat/K_m (s⁻¹ μM⁻¹)	V_max (μM/sec)	T_max (°C)	Ea (kcal/mol)
Wild type	3.17 ± 0.59	2.05	8.0	0.65	1.638 × 10^–2	37.0	4.28 ± 0.28
GROUP I and II
E98K	2.46 ± 0.43	2.65	10.0	1.08	2.65 × 10^–2	25.0	5.88 ± 1.12
R152W	11.14 ± 1.8	1.80	15.5	0.16	2.79 × 10^–2	40.0	5.57 ± 0.28
P336Q	3.52 ± 0.49	0.80	25.0	0.23	2.00 × 10^–2	37.0	6.26 ± 0.81
E339V	2.91 ± 0.59	1.07	10.0	0.37	1.07 × 10^–2	30.0	4.81 ± 0.71
GROUP III
I73M	5.30 ± 0.80	1.71	15.0	0.32	2.56 × 10^–2	40.0	4.83 ± 0.38
Q79H	3.31 ± 0.44	0.16	122	0.05	2.01 × 10^–2	25.0	8.61 ± 1.82
A160T	3.41 ± 0.72	2.06	8.00	0.60	1.65 × 10^–2	25.0	9.32 ± 1.74
T198I	3.27 ± 0.45	10.74	40.0	3.28	4.30 × 10^–1	25.0	8.16 ± 1.87
E214D	8.51 ± 1.20	0.49	90.0	0.06	4.40 × 10^–2	37.0	8.75 ± 0.83
L281I	2.23 ± 0.37	0.93	10.0	0.42	9.27 × 10^–3	30.0	10.2 ± 0.59
V290A	14.49 ± 1.60	1.27	50.0	0.09	6.34 × 10^–2	20.0	12.7 ± 1.95
R359W	3.17 ± 0.48	1.47	10.0	0.46	1.47 × 10^–2	35.0	6.37 ± 0.68
E362K	6.55 ± 0.52	1.14	20.0	0.17	2.28 × 10^–2	25.0	11.1 ± 0.52

^aThe catalytic activity of the P-MAPK3 wild type and variants was determined at the desired temperature with the substrate peptide AQT0490. Kinetic parameters were determined at 30 °C by using at least at 10 different concentrations of AQT0490. Ea was determined by Eq. (1) in the temperature range between 10 °C and the temperature of maximal activity (T_max) for each protein. Data are reported as the mean ± SE of the fit

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