FIGURE 6.

BMP-7 PD interacts with itself. A, dialysis of BMP-7 complex into 0.25–4 m urea reveals the presence of PD dimers monitored by velocity sedimentation experiments using 5–20% sucrose gradients. Each gradient was collected in 28 fractions (fraction 1 at 5% and fraction 28 at 20% sucrose) and subjected to Western blotting analysis for BMP-7 complex components. Western blots were incubated with anti-BMP-7 PD antibody first, stripped, and subsequently re-incubated with anti-BMP-7 GF antibody. B, SPR sensorgrams of self-interaction studies with BMP-7 full-length PD, 48–292, and 55–292, respectively, of immobilized full-length PD and PD variants representing the C-terminal end. C, BMP-7 complex reconstitution is affected by 30% upon deletion of the N-terminal PD self-interaction site. Error bars, mean ± S.D. from three independent experiments.