Figure 1

Analysis of phosphoprotein profiles by SELDI-TOF MS. Lysate from A549 cells was purified by IMAC resins and subsequently analyzed by SELDI-TOF MS as described in Methods. Two regions of SELDI-TOF MS spectra were shown (A and B). The eluate from the IMAC resin was treated without (A-a, B-a) or with (A-b, B-b) λ-PPase for 1 hr at 30°C, and then was applied onto the Q10 chips. The mass spectrum of the sole λ-PPase protein was also analyzed by SELDI-TOF MS (B-c). The A549 cells pre-treated with 0.5 μM (B-d) and 1.5 μM (A-c, B-e) of ZSTK474 for 30 min were lysed and processed for analysis by SELDI-TOF MS. The intensity of the 12.9 kDa protein peak decreased by ZSTK474 treatment in a dose dependent manner (B-a, d, and e). The left-right arrow indicates a mass difference of 80 Da that accounts for the MW of a phosphate group.