- Cooperative dimerization of fibroblast growth factor 1 (FGF1) upon a single heparin saccharide may drive the formation of 2:2:1 FGF1.FGFR2c.heparin ternary complexes. Robinson, C.J., Harmer, N.J., Goodger, S.J., Blundell, T.L., Gallagher, J.T. J. Biol. Chem. (2005)