PF-573228 is a potent and selective FAK inhibitor with IC50 of 4 nM for inhibiton of purified recombinant catalytic fragment of FAK; inhibits FAK phosphorylation on Tyr(397) with an IC(50) of 30-100 nM.

inhibited purified recombinant catalytic fragment of FAK with an IC(50) of 4 nM. In cultured cells, PF-573,228 inhibited FAK phosphorylation on Tyr(397) with an IC(50) of 30-100 nM. Treatment of cells with concentrations of PF-573,228 that significantly decreased FAK Tyr(397) phosphorylation failed to inhibit cell growth or induce apoptosis. Treatment with either FAK Inhibitor 14 or PF-573,228 resulted in reduced HUVEC viability, migration and tube formation in response to vascular endothelial growth factor (VEGF). Furthermore, we found that PF-573,228 had the added ability to induce apoptosis of endothelial cells within 36 h post-drug administration even in the continued presence of VEGF stimulation. In whole-cell experiments, PF573228 reversibly increased the amplitude of Ca(2+)-activated K(+) currents (I(K(Ca))) in GH(3) cells. In inside-out recordings, this compound added to the bath did not modify single-channel conductance but stimulated large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels with an EC(50) value of 3.2 μM.