Table 1.

WT and mutant KIT: kinase activity of activated proteins and affinity of sunitinib for unactivated proteins

Protein	Kinase activity of activated proteins				Unactivated proteins
	ATP Km, μM	kcat, s−1	kcat/Km, s−1M−1	SU IC50, μM	SU Kd*, nM
WT	42.5	1.67	39,294	21	20 ± 13
D816H	22.0	1.29	58,636	>30	22 ± 15
D816V	17.0	0.55	32,559	>30	13 ± 6
V560D	35.0	1.47	41,857	25	4.4 ± 0.6
V654A	13.5	1.26	93,333	8.6	ND
V560D + T670I	12.8	0.96	75,156	>30	14 ± 9

cat, catalytic; SU, sunitinib; ND, not determined.

*Determined by using the Trp fluorescence quench assay.