FIGURE 7.

Binding of gp4 to ATP determined by surface plasmon resonance. Biotinylated ATP (300 RU) was immobilized on the surface of the chip via biotin-streptavidin interaction. The wild-type gp4, gp4-W97Y, gp4-W147Y, and gp4-W147A (0.7 μm) in 60 μl of flow buffer were injected at a flow rate of 50 μl/min. Binding of gp4 to ATP is represented by the difference in binding signal obtained by flowing gp4 over the lane with either biotinylated ATP or biotin, as shown in response units on the y axis. The arrows indicate the start and end of injection of protein in each panel.