Figure 4: High-throughput profiling of intracellular protein kinase activities by using a peptide microarray system. (a) Comparative data obtained by probing with HRP–SA only (left), with the complex of BTL-111 and HRP–SA (center), or with the complex of BTL-104 and HRP–SA (right). The locations of control spots of phosphopeptides (spots #M22 and #O2) are shown in the center panel. (b) Profiling of Tyr kinase activities involved in the EGF-signaling pathway of A431 cells. The images of detections using the lysates before (control, –) and after (+) EGF stimulation are shown in the left and center panels, respectively. These two images were superimposed (right panel). (c) Profiling of Tyr kinase activities involved in the treatment of EGF-stimulated A431 cells with Src kinase inhibitor I. The images from lysate samples before (control, –) and after (+) treatment with the inhibitor are shown in the left and center panels, respectively. These two images were superimposed (right panel). All the ECL images were obtained by using the Lumigen TMA-6 and LAS 3000 image analyzer. [Reprinted with permission from Ref. 28 ©(2012) Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim].