Table 1.

Inhibition of protein kinases by imatinib

EnzymeSubstrate phosphorylation IC50 [μM]Cellular tyrosine phosphorylation IC50 [μM]
c-ABL 0.2; 0.025* ND
ν-ABL 0.038 0.1-0.3
P210BCR-ABL 0.025* 0.25
P185BCR-ABL 0.025* 0.25
TEL-ABL ND 0.35
PDGF-R α and β 0.38 (PDGF-Rβ) 0.1
Tel-PDGF-R ND 0.15
c-KIT 0.41 0.1
FLT-3 > 10 > 10
Btk > 10 ND
c-FMS and v-FMS ND > 10
c-SRC > 100 ND
v-SRC ND > 10
c-LYN > 100 ND
c-FGR > 100 ND
LCK 9.0 ND
SYK (TPK-IIB) > 100 ND
JAK-2 > 100* > 100
EGF-R > 100 > 100
Insulin receptor > 10 > 100
IGF-IR > 10 > 100
FGF-R1 31.2 ND
VEGF-R2 (KDR) 10.7 ND
VEGF-R1 (FLT-1) 19.5 ND
VEGF-R3 (FLT-4) 5.7 ND
TIE-2 (TEK) > 50 ND
c-MET > 100 ND
PKA > 500 ND
PPK > 500 ND
PKCα, β1, β2, γ, δ, ϵ, ζ, or η > 100 ND
Protein kinase CK-1, CK-2 > 100 ND
PKB > 10 ND
P38 > 10 ND
PDK1 > 10 ND
c-Raf-1 0.97 ND
CDC2/cyclin B > 100 ND
  • Imatinib concentrations causing a 50% reduction in kinase activity (IC50) are given.

    PDGF-R indicates platelet-derived growth-factor receptor; ND, not done; Btk, Bruton tyrosine kinase; TPK, tyrosine-protein kinase; EGF-R, epidermal growth-factor receptor; IGF-IR, insulin-like growth factor receptor I, FGF-R1, fibroblast growth factor receptor 1; VEGF-R, vascular endothelial growth factor receptor; PKA, cAMP-dependent protein kinase; PPK, phosphorylase kinase; PKC, protein kinase C; CK, casein kinase; PKB, protein kinase B (also known as Akt); and PKD1, 3-phosphoinoside-dependent protein kinase 1.

  • * IC50 was determined in immunocomplex assays.