SRCD spectra of six FGFs and their complexes. SRCD spectra were recorded on beamline B-23 at Diamond Synchrotron between 180 and 260 nm of the FGFs (FGF-1, FGF-2, FGF-7, FGF-9, FGF-18, and FGF-21), in the absence or presence of heparin (molar ratio 1:5). A heparin control spectrum (1.4 mg/ml) was also recorded. A, FGF-1 and heparin spectra. B, FGF-2. C, FGF-7. D, FGF-9. E, FGF-18. F, FGF-21.