Table 2.

Binding affinity (nM) of FGF19,A¹⁹⁴ analog relative to native FGFs at human FGFR1c/KLB and human FGFR4/KLB receptor complexes.

	FGFR1c/KLB	hFGFR4/KLB
FGF21	122.8 ± 8.7	1224.3 ± 177.9
FGF19	269.6 ± 15.0	10.6 ± 0.3
FGF19,A194	35.7 ± 1.2	9.1 ± 0.0

The affinity of FGF21, FGF19, and FGF19,A¹⁹⁴ for FGFR1c/KLB or FGFR4/KLB-receptor complexes was analyzed using the AlphaScreen technology. Purified ectodomains of human FGFR1c and FGFR4 were coupled to acceptor beads and biotinylated FGF21 was coupled to donor beads while adding human soluble KLB generated a signal. The binding affinities of the protein analogs were estimated by their ability to displace the biotinylated FGF21 from the pre-formed FGF21/FGFR-KLB ternary complex; values presented in nM, mean ± SEM, n = 3.