FIGURE 6.

Binding and complex formation among KLB, FGFR4, FGF19, and FGF1. A, differential binding of ¹²⁵I-labeled FGF1 and FGF19. 293 cells expressing cKLB, iFGFR4, or their combination after Tet induction for 24 h were incubated with labeled FGF1 (white bar) or FGF19 (black bar). Cell surface bound radioactivity was determined by γ-counter. The data are the means ± S.D. of three independent experiments. B, covalent affinity cross-linked complexes. After binding with 10 ng/ml labeled FGF, the covalent affinity cross-linker disuccinimidyl suberate was used to cross-link the formed complex as described (37).